Science.gov

Sample records for cricket-inspired biomimetic artificial

  1. Swimming like algae: biomimetic soft artificial cilia.

    PubMed

    Sareh, Sina; Rossiter, Jonathan; Conn, Andrew; Drescher, Knut; Goldstein, Raymond

    2013-01-06

    Cilia are used effectively in a wide variety of biological systems from fluid transport to thrust generation. Here, we present the design and implementation of artificial cilia, based on a biomimetic planar actuator using soft-smart materials. This actuator is modelled on the cilia movement of the alga Volvox, and represents the cilium as a piecewise constant-curvature robotic actuator that enables the subsequent direct translation of natural articulation into a multi-segment ionic polymer metal composite actuator. It is demonstrated how the combination of optimal segmentation pattern and biologically derived per-segment driving signals reproduce natural ciliary motion. The amenability of the artificial cilia to scaling is also demonstrated through the comparison of the Reynolds number achieved with that of natural cilia.

  2. Biomimetic artificial sphincter muscles: status and challenges

    NASA Astrophysics Data System (ADS)

    Leung, Vanessa; Fattorini, Elisa; Karapetkova, Maria; Osmani, Bekim; Töpper, Tino; Weiss, Florian; Müller, Bert

    2016-04-01

    Fecal incontinence is the involuntary loss of bowel content and affects more than 12% of the adult population, including 45% of retirement home residents. Severe fecal incontinence is often treated by implanting an artificial sphincter. Currently available implants, however, have long-term reoperation rates of 95% and definitive explantation rates of 40%. These statistics show that the implants fail to reproduce the capabilities of the natural sphincter and that the development of an adaptive, biologically inspired implant is required. Dielectric elastomer actuators (DEA) are being developed as artificial muscles for a biomimetic sphincter, due to their suitable response time, reaction forces, and energy consumption. However, at present the operation voltage of DEAs is too high for artificial muscles implanted in the human body. To reduce the operating voltage to tens of volts, we are using microfabrication to reduce the thickness of the elastomer layer to the nanometer level. Two microfabrication methods are being investigated: molecular beam deposition and electrospray deposition. This communication covers the current status and a perspective on the way forward, including the long-term prospects of constructing a smart sphincter from low-voltage sensors and actuators based on nanometer-thin dielectric elastomer films. As DEA can also provide sensory feedback, a biomimetic sphincter can be designed in accordance with the geometrical and mechanical parameters of its natural counterpart. The availability of such technology will enable fast pressure adaption comparable to the natural feedback mechanism, so that tissue atrophy and erosion can be avoided while maintaining continence du ring daily activities.

  3. Progress of Biomimetic Artificial Nose and Tongue

    NASA Astrophysics Data System (ADS)

    Wang, Ping; Liu, Qingjun

    2009-05-01

    As two of the basic senses of human beings, olfaction and gustation play a very important role in daily life. These two types of chemical sensors are important for recognizing environmental conditions. Electronic nose and electronic tongue, which mimics animals' olfaction and gustation to detect odors and chemical components, have been carried out due to their potential commercial applications for biomedicine, food industry and environmental protection. In this report, the biomimetic artificial nose and tongue is presented. Firstly, the smell and taste sensors mimicking the mammalian olfaction and gustation was described, and then, some mimetic design of electronic nose and tongue for odorants and tastants detection are developed. Finally, olfactory and gustatory biosensors are presented as the developing trends of this field.

  4. Biomimetic actuators using electroactive polymers (EAP) as artificial muscles

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph

    2006-01-01

    Evolution has resolved many of nature's challenges leading to lasting solutions with maximal performance and effective use of resources. Nature's inventions have always inspired human achievements leading to effective materials, structures, tools, mechanisms, processes, algorithms, methods, systems and many other benefits. The field of mimicking nature is known as Biomimetics and one of its topics includes electroactive polymers that gain the moniker artificial muscles. Integrating EAP with embedded sensors, self-repair and many other capabilities that are used in composite materials can add greatly to the capability of smart biomimetic systems. Such development would enable fascinating possibilities potentially turning science fiction ideas into engineering reality.

  5. From natural to bioassisted and biomimetic artificial water channel systems.

    PubMed

    Barboiu, Mihail; Gilles, Arnaud

    2013-12-17

    Within biological systems, natural channels and pores transport metabolites across the cell membranes. Researchers have explored artificial ion-channel architectures as potential mimics of natural ionic conduction. All these synthetic systems have produced an impressive collection of alternative artificial ion-channels. Amazingly, researchers have made far less progress in the area of synthetic water channels. The development of synthetic biomimetic water channels and pores could contribute to a better understanding of the natural function of protein channels and could offer new strategies to generate highly selective, advanced water purification systems. Despite the imaginative work by synthetic chemists to produce sophisticated architectures that confine water clusters, most synthetic water channels have used natural proteins channels as the selectivity components, embedded in the diverse arrays of bioassisted artificial systems. These systems combine natural proteins that present high water conductance states under natural conditions with artificial lipidic or polymeric matrixes. Experimental results have demonstrated that natural biomolecules can be used as bioassisted building blocks for the construction of highly selective water transport through artificial membranes. A next step to further the potential of these systems was the design and construction of simpler compounds that maintain the high conduction activity obtained with natural compounds leading to fully synthetic artificial biomimetic systems. Such studies aim to use constitutional selective artificial superstructures for water/proton transport to select functions similar to the natural structures. Moving to simpler water channel systems offers a chance to better understand mechanistic and structural behaviors and to uncover novel interactive water-channels that might parallel those in biomolecular systems. This Account discusses the incipient development of the first artificial water channels

  6. An Experimental Biomimetic Platform for Artificial Olfaction

    PubMed Central

    Di Natale, Corrado; Martinelli, Eugenio; Paolesse, Roberto; D'Amico, Arnaldo; Filippini, Daniel; Lundström, Ingemar

    2008-01-01

    Artificial olfactory systems have been studied for the last two decades mainly from the point of view of the features of olfactory neuron receptor fields. Other fundamental olfaction properties have only been episodically considered in artificial systems. As a result, current artificial olfactory systems are mostly intended as instruments and are of poor benefit for biologists who may need tools to model and test olfactory models. Herewith, we show how a simple experimental approach can be used to account for several phenomena observed in olfaction. An artificial epithelium is formed as a disordered distributed layer of broadly selective color indicators dispersed in a transparent polymer layer. The whole epithelium is probed with colored light, imaged with a digital camera and the olfactory response upon exposure to an odor is the change of the multispectral image. The pixels are treated as olfactory receptor neurons, whose optical properties are used to build a convergence classifier into a number of mathematically defined artificial glomeruli. A non-homogenous exposure of the test structure to the odours gives rise to a time and spatial dependence of the response of the different glomeruli strikingly similar to patterns observed in the olfactory bulb. The model seems to mimick both the formation of glomeruli, the zonal nature of olfactory epithelium, and the spatio-temporal signal patterns at the glomeruli level. This platform is able to provide a readily available test vehicle for chemists developing optical indicators for chemical sensing purposes and for biologists to test models of olfactory system organization. PMID:18769554

  7. Biomimetic robots using EAP as artificial muscles - progress and challenges

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph

    2004-01-01

    Biology offers a great model for emulation in areas ranging from tools, computational algorithms, materials science, mechanisms and information technology. In recent years, the field of biomimetics, namely mimicking biology, has blossomed with significant advances enabling the reverse engineering of many animals' functions and implementation of some of these capabilities.

  8. In vitro evaluation and in vivo demonstration of a biomimetic, hemocompatible, microfluidic artificial lung.

    PubMed

    Kovach, K M; LaBarbera, M A; Moyer, M C; Cmolik, B L; van Lunteren, E; Sen Gupta, A; Capadona, J R; Potkay, J A

    2015-03-07

    Despite the promising potential of microfluidic artificial lungs, current designs suffer from short functional lifetimes due to surface chemistry and blood flow patterns that act to reduce hemocompatibility. Here, we present the first microfluidic artificial lung featuring a hemocompatible surface coating and a biomimetic blood path. The polyethylene-glycol (PEG) coated microfluidic lung exhibited a significantly improved in vitro lifetime compared to uncoated controls as well as consistent and significantly improved gas exchange over the entire testing period. Enabled by our hemocompatible PEG coating, we additionally describe the first extended (3 h) in vivo demonstration of a microfluidic artificial lung.

  9. Remineralization of artificial dentinal caries lesions by biomimetically modified Mineral Trioxide Aggregate

    PubMed Central

    Qi, Yi-pin; Li, Nan; Niu, Li-na; Primus, Carolyn M.; Ling, Jun-Qi; Pashley, David H.; Tay, Franklin R.

    2011-01-01

    Fluoride-releasing restorative materials are available for remineralization of enamel and root caries. However, dentin remineralization is more difficult than enamel remineralization due to the paucity of apatite seed crystallites along the lesion surface for heterogeneous crystal growth. Extracellular matrix proteins play critical roles in controlling apatite nucleation/growth in collagenous tissues. This study examined the remineralization efficacy of mineral trioxide aggregate (MTA) in phosphate-containing simulated body fluid (SBF) by incorporating polyacrylic acid and sodium tripolyphosphate as biomimetic analogs of matrix proteins for remineralizing caries-like dentin. Artificial caries-like dentin lesions incubated in SBF were remineralized over a 6-week period using MTA or MTA containing biomimetic analogs in the absence or presence of dentin adhesive application. Lesion depths and integrated mineral loss were monitored with micro-computed tomography. Ultrastructure of baseline and remineralized lesions were examined by transmission electron microscopy. Dentin remineralization was best achieved using MTA containing biomimetic analogs regardless of whether an adhesive was applied; dentinal tubules within the remineralized dentin were occluded by apatite. It is concluded that the MTA version employed in the study may be doped with biomimetic analogs for remineralization of unbonded and bonded artificial caries-like lesions in the presence of SBF. PMID:22085925

  10. Hybrid artificial photosynthetic systems comprising semiconductors as light harvesters and biomimetic complexes as molecular cocatalysts.

    PubMed

    Wen, Fuyu; Li, Can

    2013-11-19

    Solar fuel production through artificial photosynthesis may be a key to generating abundant and clean energy, thus addressing the high energy needs of the world's expanding population. As the crucial components of photosynthesis, the artificial photosynthetic system should be composed of a light harvester (e.g., semiconductor or molecular dye), a reduction cocatalyst (e.g., hydrogenase mimic, noble metal), and an oxidation cocatalyst (e.g., photosystem II mimic for oxygen evolution from water oxidation). Solar fuel production catalyzed by an artificial photosynthetic system starts from the absorption of sunlight by the light harvester, where charge separation takes place, followed by a charge transfer to the reduction and oxidation cocatalysts, where redox reaction processes occur. One of the most challenging problems is to develop an artificial photosynthetic solar fuel production system that is both highly efficient and stable. The assembly of cocatalysts on the semiconductor (light harvester) not only can facilitate the charge separation, but also can lower the activation energy or overpotential for the reactions. An efficient light harvester loaded with suitable reduction and oxidation cocatalysts is the key for high efficiency of artificial photosynthetic systems. In this Account, we describe our strategy of hybrid photocatalysts using semiconductors as light harvesters with biomimetic complexes as molecular cocatalysts to construct efficient and stable artificial photosynthetic systems. We chose semiconductor nanoparticles as light harvesters because of their broad spectral absorption and relatively robust properties compared with a natural photosynthesis system. Using biomimetic complexes as cocatalysts can significantly facilitate charge separation via fast charge transfer from the semiconductor to the molecular cocatalysts and also catalyze the chemical reactions of solar fuel production. The hybrid photocatalysts supply us with a platform to study the

  11. Artificial hydrogenase: biomimetic approaches controlling active molecular catalysts.

    PubMed

    Onoda, Akira; Hayashi, Takashi

    2015-04-01

    Hydrogenase catalyses reversible transformation of H2 to H(+) using an active site which includes an iron or nickel atom. Synthetic model complexes and molecular catalysts inspired by nature have unveiled the structural and functional basis of the active site with remarkable accuracy and this has led to the discovery of active synthetic catalysts. To further improve the activity of such molecular catalysts, both the first and outer coordination spheres should be well-organized and harmonized for an efficient shuttling of H(+), electrons, and H2. This article reviews recent advances in the design and catalytic properties of artificial enzymes that mimic the hydrogenase active site and the outer coordination sphere in combination with a peptide or protein scaffold.

  12. Artificial photosynthesis: biomimetic approaches to solar energy conversion and storage.

    PubMed

    Kalyanasundaram, K; Graetzel, M

    2010-06-01

    Using sun as the energy source, natural photosynthesis carries out a number of useful reactions such as oxidation of water to molecular oxygen and fixation of CO(2) in the form of sugars. These are achieved through a series of light-induced multi-electron-transfer reactions involving chlorophylls in a special arrangement and several other species including specific enzymes. Artificial photosynthesis attempts to reconstruct these key processes in simpler model systems such that solar energy and abundant natural resources can be used to generate high energy fuels and restrict the amount of CO(2) in the atmosphere. Details of few model catalytic systems that lead to clean oxidation of water to H(2) and O(2), photoelectrochemical solar cells for the direct conversion of sunlight to electricity, solar cells for total decomposition of water and catalytic systems for fixation of CO(2) to fuels such as methanol and methane are reviewed here.

  13. Roughness encoding in human and biomimetic artificial touch: spatiotemporal frequency modulation and structural anisotropy of fingerprints.

    PubMed

    Oddo, Calogero Maria; Beccai, Lucia; Wessberg, Johan; Wasling, Helena Backlund; Mattioli, Fabio; Carrozza, Maria Chiara

    2011-01-01

    The influence of fingerprints and their curvature in tactile sensing performance is investigated by comparative analysis of different design parameters in a biomimetic artificial fingertip, having straight or curved fingerprints. The strength in the encoding of the principal spatial period of ridged tactile stimuli (gratings) is evaluated by indenting and sliding the surfaces at controlled normal contact force and tangential sliding velocity, as a function of fingertip rotation along the indentation axis. Curved fingerprints guaranteed higher directional isotropy than straight fingerprints in the encoding of the principal frequency resulting from the ratio between the sliding velocity and the spatial periodicity of the grating. In parallel, human microneurography experiments were performed and a selection of results is included in this work in order to support the significance of the biorobotic study with the artificial tactile system.

  14. Artificial Muscles Based on Electroactive Polymers as an Enabling Tool in Biomimetics

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Y.

    2007-01-01

    Evolution has resolved many of nature's challenges leading to working and lasting solutions that employ principles of physics, chemistry, mechanical engineering, materials science, and many other fields of science and engineering. Nature's inventions have always inspired human achievements leading to effective materials, structures, tools, mechanisms, processes, algorithms, methods, systems, and many other benefits. Some of the technologies that have emerged include artificial intelligence, artificial vision, and artificial muscles, where the latter is the moniker for electroactive polymers (EAPs). To take advantage of these materials and make them practical actuators, efforts are made worldwide to develop capabilities that are critical to the field infrastructure. Researchers are developing analytical model and comprehensive understanding of EAP materials response mechanism as well as effective processing and characterization techniques. The field is still in its emerging state and robust materials are still not readily available; however, in recent years, significant progress has been made and commercial products have already started to appear. In the current paper, the state-of-the-art and challenges to artificial muscles as well as their potential application to biomimetic mechanisms and devices are described and discussed.

  15. Biomimetic biodegradable artificial antigen presenting cells synergize with PD-1 blockade to treat melanoma.

    PubMed

    Kosmides, A K; Meyer, R A; Hickey, J W; Aje, K; Cheung, K N; Green, J J; Schneck, J P

    2017-02-01

    Biomimetic materials that target the immune system and generate an anti-tumor responses hold promise in augmenting cancer immunotherapy. These synthetic materials can be engineered and optimized for their biodegradability, physical parameters such as shape and size, and controlled release of immune-modulators. As these new platforms enter the playing field, it is imperative to understand their interaction with existing immunotherapies since single-targeted approaches have limited efficacy. Here, we investigate the synergy between a PLGA-based artificial antigen presenting cell (aAPC) and a checkpoint blockade molecule, anti-PD1 monoclonal antibody (mAb). The combination of antigen-specific aAPC-based activation and anti-PD-1 mAb checkpoint blockade induced the greatest IFN-γ secretion by CD8+ T cells in vitro. Combination treatment also acted synergistically in an in vivo murine melanoma model to result in delayed tumor growth and extended survival, while either treatment alone had no effect. This was shown mechanistically to be due to decreased PD-1 expression and increased antigen-specific proliferation of CD8+ T cells within the tumor microenvironment and spleen. Thus, biomaterial-based therapy can synergize with other immunotherapies and motivates the translation of biomimetic combinatorial treatments.

  16. Silk fibroin based biomimetic artificial extracellular matrix for hepatic tissue engineering applications.

    PubMed

    Kasoju, Naresh; Bora, Utpal

    2012-08-01

    Hepatic tissue engineering, which aims to construct artificial liver tissues, requires a suitable extracellular matrix (ECM) for growth and proliferation of metabolically active hepatocytes. The current paper describes the development of a biomimetic artificial ECM, for hepatic tissue engineering applications, by mimicking the architectural features and biochemical composition of native ECM. Electrospinning was chosen as the fabrication technique of choice, while regenerated silk fibroin (RSF) and galactosylated chitosan (GalCS) were chosen as materials of choice. Poly(ethylene oxide) was used as a processing aid. Methodical optimization studies were performed to obtain smooth and continuous nanofibers with homogenous size distribution. Extensive characterization studies were performed to determine its morphological, physical, chemical/structural, thermal and cytotoxicity properties. Subsequently, detailed in vitro hepatocyte compatibility studies were performed using HepG2 cell line. Remarkably, the studies revealed that the growth, viability, metabolic activity and proliferation of hepatocytes were relatively superior on RSF-GalCS scaffold than on pure RSF and pure GalCS. In summary, the electrospun nanofibrous RSF-GalCS scaffold tries to mimic both architectural and biochemical features of native ECM, and hence could be an appropriate scaffold for in vitro engineering of hepatic tissue. However, additional experiments are needed to confirm the superiority in characteristic functionality of hepatocytes growing on RSF-GalCS scaffold in relation to RSF and GalCS scaffolds, and to test its behavior in vivo.

  17. The use of sodium trimetaphosphate as a biomimetic analog of matrix phosphoproteins for remineralization of artificial caries-like dentin

    PubMed Central

    Liu, Yan; Li, Nan; Qi, Yipin; Niu, Li-na; Elshafiy, Sally; Mao, Jing; Breschi, Lorenzo; Pashley, David H.; Tay, Franklin R.

    2011-01-01

    Objectives This study examined the use of sodium trimetaphosphate (STMP) as a biomimetic analog of matrix phosphoproteins for remineralization of artificial carious-affected dentin. Methods Artificial carious lesions with lesion depths of 300±30 µm were created by pH-cycling. 2.5% hydrolyzed STMP was applied to the artificial carious lesions to phosphorylate the partially-demineralized collagen matrix. Half of the STMP-treated specimens were bonded with One-Step. The adhesive and non-adhesive infiltrated specimens were remineralized in a Portland cement-simulated body fluid system containing polyacrylic acid (PAA) to stabilize amorphous calcium phosphate as nanoprecursors. Micro-computed tomography (micro-CT) and transmission electron microscopy (TEM) were used to evaluate the results of remineralization after a 4-month period. Results In absence of PAA and STMP as biomimetic analogs (control groups), there was no remineralization irrespective of whether the lesions were infiltrated with adhesive. For the STMP-treated experimental groups immersed in PAA-containing simulated body fluid, specimens without adhesive infiltration were more heavily remineralized than those infiltrated with adhesive. Statistical analysis of the 4-month micro-CT data revealed significant differences in the lesion depth, relative mineral content along the lesion surface and changes in ΔZ between the non-adhesive and adhesive experimental groups (p<0.05 for all the three parameters). TEM examination indicated that collagen degradation occurred in both the non-adhesive and adhesive control and experimental groups after 4 months of remineralization. Significance Biomimetic remineralization using STMP is a promising method to remineralize artificial carious lesions particularly in areas devoid of seed crystallites. Future studies should consider the incorporation of MMP-inhibitors within the partially-demineralized collagen matrix to prevent collagen degradation during remineralization. PMID

  18. Preparation and in vitro evaluation of a biomimetic nanoscale calcium phosphate coating on a polyethylene terephthalate artificial ligament

    PubMed Central

    CHEN, CHEN; LI, HONG; GUO, CHANGAN; CHEN, SHIYI

    2016-01-01

    In the present study, a polyethylene terephthalate (PET) artificial ligament was coated with an organic layer-by-layer (LBL) self-assembled template of chitosan and hyaluronic acid, and then incubated in a calcium phosphate (CaP) solution to prepare a biomimetic CaP coating. The surface characterization of the ligament was examined using scanning electron microscopy, atomic force microscopy and energy-dispersive X-ray spectroscopy. The effects of CaP coatings on the osteogenic activity of MC3T3 E1 mouse osteoblastic cells were investigated by evaluating their attachment, proliferation and the relative expression levels of alkaline phosphatase. The results revealed that the organic LBL template on the PET artificial ligament was effective for CaP apatite formation. Following incubation for 72 h, numerous nanoscale CaP apatites were deposited on the PET ligament fibers. In addition, the results of the in vitro culture of MC3T3-E1 mouse osteoblastic cells demonstrated that the CaP coating had a good biocompatibility for cell proliferation and adhesion, and the CaP-coated group had a significantly higher alkaline phosphatase activity compared with the uncoated control group after seven days of cell culture. Collectively, these results demonstrated that the biomimetic nanoscale CaP-coated PET artificial ligaments have potential in bone-tissue engineering. PMID:27347053

  19. Selected papers from the 7th International Conference on Biomimetics, Artificial Muscles and Nano-bio (BAMN2013)

    NASA Astrophysics Data System (ADS)

    Shahinpoor, Mohsen; Oh, Ilkwon

    2014-07-01

    The 7th International Congress on Biomimetics, Artificial Muscles and Nano-Bio was held on the magnificent and beautiful Jeju Island in Korea on 26-30 August 2013. In June 2007, the volcanic island and lava tube cave systems were designated as UNESCO World Natural Heritage Sites for their natural beauty and unique geographical values. The aim of the congress was to offer high-level lectures, extensive discussions and communications covering the state-of-the-art on biomimetics, artificial muscles, and nano-bio technologies providing an overview of their potential applications in the industrial, biomedical, scientific and robotic fields. This conference provided a necessary platform for an ongoing dialogue between researchers from different areas (chemistry, physics, biology, medicine, engineering, robotics, etc) within biomimetics, artificial muscle and nano-bio technologies. This special issue of Smart Materials and Structures is devoted to a selected number of research papers that were presented at BAMN2013. Of the 400 or so papers and over 220 posters presented at this international congress, 15 papers were finally received, reviewed and accepted for this special issue, following the regular peer review procedures of the journal. The special issue covers polymeric artificial muscles, electroactive polymers, multifunctional nanocomposites, and their applications. In particular, electromechanical performance and other characteristics of ionic polymer-metal composites (IPMCs) fabricated with various commercially available ion exchange membranes are discussed. Additionally, the control of free-edge interlaminar stresses in composite laminates using piezoelectric actuators is elaborated on. Further, the electrode effects of a cellulose-based electroactive paper energy harvester are described. Next, a flexible tactile-feedback touch screen using transparent ferroelectric polymer film vibrators is discussed. A broad coverage of bio-applications of IPMC transducers is

  20. Biomimetic artificial inorganic enzyme-free self-propelled microfish robot for selective detection of Pb(2+) in water.

    PubMed

    Moo, James Guo Sheng; Wang, Hong; Zhao, Guanjia; Pumera, Martin

    2014-04-07

    The availability of drinking water is of utmost importance for the world population. Anthropogenic pollutants of water, such as heavy-metal ions, are major problems in water contamination. The toxicity assays used range from cell assays to animal tests. Herein, we replace biological toxicity assays, which use higher organisms, with artificial inorganic self-propelled microtubular robots. The viability and activity of these robots are negatively influenced by heavy metals, such as Pb(2+) , in a similar manner to that of live fish models. This allows the establishment of a lethal dose (LD50 ) of heavy metal for artificial inorganic microfish robots. The self-propelled microfish robots show specific response to Pb(2+) compared to other heavy metals, such as Cd(2+) , and can be used for selective determination of Pb(2+) in water. It is a first step towards replacing the biological toxicity assays with biomimetic inorganic autonomous robotic systems.

  1. PREFACE: Biomimetics, Artificial Muscles & Nano-Bio 2007: Scientists Meet Doctors

    NASA Astrophysics Data System (ADS)

    Fernández Otero, Toribio

    2008-02-01

    invaded by a new virus. A very expensive trial and error (still pseudo-alchemic) procedure has to be initiated to try to enable ill people to get better. Nowadays models from chemical kinetics do not include any quantification of either changes to the molecular interactions inside the system during reaction or structural information about the conformational changes brought about by enzymes or reactive proteins. From our point of view this is one the most important scientific challenges for the 21st century, involving responses to questions related to life, health and illness. Those responses, due to the magnitude of the challenge, can only be obtained by cooperative work involving chemists, physicist, engineers, biologists and clinicians. Figure Figure showing the full distance inside the universe. Small and large systems are submitted as `constant physical' interactions affording quite predictive models. Life is based on chemistry giving rise to simultaneous changes on all the molecular interactions included in the system: their interpretation is outside current chemical or physical models. Most technological advances developed by human beings are inspired by biological systems, organs, or mechanisms present in living creatures. The main difference between human technology and natural organs is the changes in chemical composition occurring inside the wet natural organ during actuation: they are reactive, soft and wet materials. Our artificial machines are constructed of dry materials that maintain a constant composition under actuation. This is the context proposed for the consecutive World Congresses on Biomimetics, Artificial Muscles & Nano-Bio and more specifically for the IVth Congress held in Torre Pacheco, Spain, 6-9 November 2007. The papers selected for this volume of Journal of Physics: Conference Series includes: dry and wet materials, chemically reactive or physically reactive materials, organic and inorganic materials, macroscopic films and nanoparticles

  2. Hairy polyelectrolyte brushes-grafted thermosensitive microgels as artificial synovial fluid for simultaneous biomimetic lubrication and arthritis treatment.

    PubMed

    Liu, Guoqiang; Liu, Zhilu; Li, Na; Wang, Xiaolong; Zhou, Feng; Liu, Weimin

    2014-11-26

    We report the fabrication of poly(3-sulfopropyl methacrylate potassium salt) (PSPMK) brushes grafted poly(N-isopropylacrylamide) (PNIPAAm) microgels and their potential as artificial synovial fluid for biomimetic aqueous lubrication and arthritis treatment. The negatively charged PSPMK brushes and thermosensitive PNIPAAm microgels play water-based hydration lubrication and temperature-triggered drug release, respectively. Under soft friction pairs, an ultralow coefficient of friction was achieved, while the hairy thermosensitive microgels showed a desirable temperature-triggered drugs release performance. Such a soft charged hairy microgel offers great possibility for designing intelligent synovial fluid. What is more, the combination of lubrication and drug loading capabilities enables the large clinical potential of novel soft hairy nanoparticles as synthetic joint lubricant fluid in arthritis treatment.

  3. Artificial Niches for Stromal Stem Cells as a Potential Instrument for the Design of the Surface of Biomimetic Osteogenic Materials

    NASA Astrophysics Data System (ADS)

    Khlusov, I. A.; Khlusova, M. Yu.; Pichugin, V. F.; Sharkeev, Yu. P.; Legostaeva, E. V.

    2014-02-01

    A relationship between the topography of rough calcium phosphate surfaces having osteogenic niche-reliefs and the electrostatic potential of these surfaces as a possible instrument to control stromal stem cells has been investigated. The in vitro culture of human lung prenatal stromal cells on nanostructured/ultrafine-grained VT1.0 titanium alloy plates with bilateral rough calcium phosphate (CaP) microarc coating was used. It was established that the amplitude of the electret CaP surface potential linearly increased with increasing area of valleys (sockets), and the negative charge is formed on the socket surface. The area of alkaline phosphatase staining (the marker of osteoblast maturation and differentiation) of adherent CD34- CD44+ cells increases linearly with increasing area of artificial microterritory (socket) of the CaP surface occupied with each cell. The negative electret potential in valleys (sockets) of microarc CaP coatings can be the physical mechanism mediating the influence of the surface topography on osteogenic maturation and differentiation of cells in vitro. This mechanism can be called "niche-potential" and can be used as an instrument for biomimetic modification of smooth CaP surfaces to strengthen their integration with the bone tissue.

  4. A bio-mimetic zinc/tau protein as an artificial catalase.

    PubMed

    Asadollahi, Kazem; Jasemi, Neda Sadat Kazemein; Riazi, Gholam Hossein; Katuli, Fatemeh Hedayati; Yazdani, Fahimeh; Sartipnia, Nasrin; Moosavi, Mohammad Amin; Rahimi, Arash; Falahati, Mojtaba

    2016-11-01

    In this study, the catalase-like activity of monomeric tau protein was reported in the presence of of zinc (Zn(II)) ions at low pH value. Monomeric tau protein contains two SH groups that are a target of disulfide bond formation. However these SH groups are able to interact with Zn(II) ion at pH 7.2 which creates a thiol bond as a mimetic model of chloroperoxidase active site which performs catalase like activity at low pH. Zn(II)/tau protein complex decomposed H2O2 with a high rate (Vm) as well as an efficient turn oven number (kcat) at pH 3. This remarkable catalase like activity is may be attributed to the conformational reorientation of protein at low pH. Circular dichroism (CD) studies did not demonstrate any secondary structural changes of tau protein after addition of Zn(II) ions at pH 7.2. In addition, tau protein shows identical CD bands at pH 7.2 and 3. Moreover, fluorescence quenching of tau by Zn(II) at pH 7.2 was initiated by complex formation rather than by dynamic collision. A significant red shift (6nm) was observed in the emission maximum of the fluorescence spectra when the protein was dissolved at pH 3 compared to pH 7.2. This conformational change can provide information regarding the rearrangements of the protein structure and exposure of Cys-Zn(II) group to the solvent which induces easy access of active site to H2O2 molecules and corresponding enhanced catalytic activity of Zn(II)/tau protein complex. This study introduces tau protein as a bio-inspired high performing scaffold for transition metal encapsulation and introducing an engineered apoprotein-induced biomimetic enzyme.

  5. Biomimetic approaches to the design of materials for artificial tactile perception

    NASA Astrophysics Data System (ADS)

    de Rossi, Danilo

    While the computational and materials-synthesis aspects of artificial tactile perception remain rather abstract, three fields of investigation have been identified as promising: thermotactile interactions for sensory fusion, strain dilatation sensing for low-level computation, and strain-rate-to-impulse frequency information coding. Attention is also given to the possibilities of a 'pseudoepidermal layer' capable of resolving individual stress tensor components, and a 'pseudodermal pad' that can serve as a rheological skin-analog.

  6. From Biological Cilia to Artificial Flow Sensors: Biomimetic Soft Polymer Nanosensors with High Sensing Performance

    PubMed Central

    Asadnia, Mohsen; Kottapalli, Ajay Giri Prakash; Karavitaki, K. Domenica; Warkiani, Majid Ebrahimi; Miao, Jianmin; Corey, David P.; Triantafyllou, Michael

    2016-01-01

    We report the development of a new class of miniature all-polymer flow sensors that closely mimic the intricate morphology of the mechanosensory ciliary bundles in biological hair cells. An artificial ciliary bundle is achieved by fabricating bundled polydimethylsiloxane (PDMS) micro-pillars with graded heights and electrospinning polyvinylidenefluoride (PVDF) piezoelectric nanofiber tip links. The piezoelectric nature of a single nanofiber tip link is confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Rheology and nanoindentation experiments are used to ensure that the viscous properties of the hyaluronic acid (HA)-based hydrogel are close to the biological cupula. A dome-shaped HA hydrogel cupula that encapsulates the artificial hair cell bundle is formed through precision drop-casting and swelling processes. Fluid drag force actuates the hydrogel cupula and deflects the micro-pillar bundle, stretching the nanofibers and generating electric charges. Functioning with principles analogous to the hair bundles, the sensors achieve a sensitivity and threshold detection limit of 300 mV/(m/s) and 8 μm/s, respectively. These self-powered, sensitive, flexible, biocompatibale and miniaturized sensors can find extensive applications in navigation and maneuvering of underwater robots, artificial hearing systems, biomedical and microfluidic devices. PMID:27622466

  7. From Biological Cilia to Artificial Flow Sensors: Biomimetic Soft Polymer Nanosensors with High Sensing Performance.

    PubMed

    Asadnia, Mohsen; Kottapalli, Ajay Giri Prakash; Karavitaki, K Domenica; Warkiani, Majid Ebrahimi; Miao, Jianmin; Corey, David P; Triantafyllou, Michael

    2016-09-13

    We report the development of a new class of miniature all-polymer flow sensors that closely mimic the intricate morphology of the mechanosensory ciliary bundles in biological hair cells. An artificial ciliary bundle is achieved by fabricating bundled polydimethylsiloxane (PDMS) micro-pillars with graded heights and electrospinning polyvinylidenefluoride (PVDF) piezoelectric nanofiber tip links. The piezoelectric nature of a single nanofiber tip link is confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Rheology and nanoindentation experiments are used to ensure that the viscous properties of the hyaluronic acid (HA)-based hydrogel are close to the biological cupula. A dome-shaped HA hydrogel cupula that encapsulates the artificial hair cell bundle is formed through precision drop-casting and swelling processes. Fluid drag force actuates the hydrogel cupula and deflects the micro-pillar bundle, stretching the nanofibers and generating electric charges. Functioning with principles analogous to the hair bundles, the sensors achieve a sensitivity and threshold detection limit of 300 mV/(m/s) and 8 μm/s, respectively. These self-powered, sensitive, flexible, biocompatibale and miniaturized sensors can find extensive applications in navigation and maneuvering of underwater robots, artificial hearing systems, biomedical and microfluidic devices.

  8. From Biological Cilia to Artificial Flow Sensors: Biomimetic Soft Polymer Nanosensors with High Sensing Performance

    NASA Astrophysics Data System (ADS)

    Asadnia, Mohsen; Kottapalli, Ajay Giri Prakash; Karavitaki, K. Domenica; Warkiani, Majid Ebrahimi; Miao, Jianmin; Corey, David P.; Triantafyllou, Michael

    2016-09-01

    We report the development of a new class of miniature all-polymer flow sensors that closely mimic the intricate morphology of the mechanosensory ciliary bundles in biological hair cells. An artificial ciliary bundle is achieved by fabricating bundled polydimethylsiloxane (PDMS) micro-pillars with graded heights and electrospinning polyvinylidenefluoride (PVDF) piezoelectric nanofiber tip links. The piezoelectric nature of a single nanofiber tip link is confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Rheology and nanoindentation experiments are used to ensure that the viscous properties of the hyaluronic acid (HA)-based hydrogel are close to the biological cupula. A dome-shaped HA hydrogel cupula that encapsulates the artificial hair cell bundle is formed through precision drop-casting and swelling processes. Fluid drag force actuates the hydrogel cupula and deflects the micro-pillar bundle, stretching the nanofibers and generating electric charges. Functioning with principles analogous to the hair bundles, the sensors achieve a sensitivity and threshold detection limit of 300 mV/(m/s) and 8 μm/s, respectively. These self-powered, sensitive, flexible, biocompatibale and miniaturized sensors can find extensive applications in navigation and maneuvering of underwater robots, artificial hearing systems, biomedical and microfluidic devices.

  9. Ionic Polymer-Metal Composites (IPMCs) as Biomimetic Sensors, Actuators and Artificial Muscles: A Review

    NASA Technical Reports Server (NTRS)

    Shahinpoor, M.; Bar-Cohen, Y.; Simpson, J. O.; Smith, J.

    1998-01-01

    This paper presents an introduction to ionic polymer-metal composites and some mathematical modeling pertaining to them. It further discusses a number of recent findings in connection with ion-exchange polymer-metal composites (IPMCS) as biomimetic sensors and actuators. Strips of these composites can undergo large bending and flapping displacement if an electric field is imposed across their thickness. Thus, in this sense they are large motion actuators. Conversely by bending the composite strip, either quasi-statically or dynamically, a voltage is produced across the thickness of the strip. Thus, they are also large motion sensors. The output voltage can be calibrated for a standard size sensor and correlated to the applied loads or stresses. They can be manufactured and cut in any size and shape. In this paper first the sensing capability of these materials is reported. The preliminary results show the existence of a linear relationship between the output voltage and the imposed displacement for almost all cases. Furthermore, the ability of these IPMCs as large motion actuators and robotic manipulators is presented. Several muscle configurations are constructed to demonstrate the capabilities of these IPMC actuators. This paper further identifies key parameters involving the vibrational and resonance characteristics of sensors and actuators made with IPMCS. When the applied signal frequency varies, so does the displacement up to a critical frequency called the resonant frequency where maximum deformation is observed, beyond which the actuator response is diminished. A data acquisition system was used to measure the parameters involved and record the results in real time basis. Also the load characterizations of the IPMCs were measured and it was shown that these actuators exhibit good force to weight characteristics in the presence of low applied voltages. Finally reported are the cryogenic properties of these muscles for potential utilization in an outer space

  10. Biomimetic Particles as Therapeutics

    PubMed Central

    Green, Jordan J.

    2015-01-01

    In recent years, there have been major advances in the development of novel nanoparticle and microparticle-based therapeutics. An emerging paradigm is the incorporation of biomimetic features into these synthetic therapeutic constructs to enable them to better interface with biological systems. Through the control of size, shape, and material consistency, particle cores have been generated that better mimic natural cells and viruses. In addition, there have been significant advances in biomimetic surface functionalization of particles through the integration of bio-inspired artificial cell membranes and naturally derived cell membranes. Biomimetic technologies enable therapeutic particles to have increased potency to benefit human health. PMID:26277289

  11. Biomimetic particles as therapeutics.

    PubMed

    Meyer, Randall A; Sunshine, Joel C; Green, Jordan J

    2015-09-01

    In recent years, there have been major advances in the development of novel nanoparticle- and microparticle-based therapeutics. An emerging paradigm is the incorporation of biomimetic features into these synthetic therapeutic constructs to enable them to better interface with biological systems. Through the control of size, shape, and material consistency, particle cores have been generated that better mimic natural cells and viruses. In addition, there have been significant advances in biomimetic surface functionalization of particles through the integration of bio-inspired artificial cell membranes and naturally derived cell membranes. Biomimetic technologies enable therapeutic particles to have increased potency to benefit human health.

  12. EDITORIAL: Artificial Muscles: Selected papers from the 5th World Congress on Biomimetics, Artificial Muscles and Nano-Bio (Osaka, Japan, 25-27 November 2009) Artificial Muscles: Selected papers from the 5th World Congress on Biomimetics, Artificial Muscles and Nano-Bio (Osaka, Japan, 25-27 November 2009)

    NASA Astrophysics Data System (ADS)

    Shahinpoor, Mohsen

    2011-12-01

    The 5th World Congress on Biomimetics, Artificial Muscles and Nano-Bio and the 4th International Conference on Artificial Muscles were held in Osaka, Japan, 23-27 November 2009. This special section of Smart Materials and Structures is devoted to a selected number of research papers presented at this international conference and congress. Of the 76 or so papers presented at the conference, only 10 papers were finally selected, reviewed and accepted for this special section, following the regular reviewing procedures of the journal. This special section is focused on polymeric artificial muscles, electroactive polymers, multifunctional nanocomposites and their applications. In particular, an electromechanical model for self-sensing ionic polymer-metal composite actuating devices with patterned surface electrodes is presented which discusses the concept of creating self-sensing ionic polymer-metal composite (IPMC) actuating devices with patterned surface electrodes where actuator and sensor elements are separated by a grounded shielding electrode. Eventually, an electromechanical model of the device is also proposed and validated. Following that, there is broad coverage of polytetrahydrofurane-polyethylene oxide-PEDOT conducting interpenetrating polymer networks (IPNs) for high speed actuators. The conducting polymer (poly(3,4-ethylenedioxythiophene)) is incorporated within the IPNs, which are synthesized from polyethylene oxide (PEO)/polytetrahydrofurane (PTHF) networks. PEO/PTHF IPNs are prepared using poly(ethylene glycol) methacrylate and dimethacrylate and hydroxythelechelic PTHF as starting materials. The conducting IPN actuators are prepared by oxidative polymerization of 3,4-ethylenedioxithiophene (EDOT) using FeCl3 as an oxidizing agent within the PEO/PTHF IPN host matrix. Subsequently, giant and reversible magnetorheology of carrageenan/iron oxide magnetic gels are discussed and the effect of magnetic fields on the viscoelastic properties

  13. Biomimetic artificial Si compound eye surface structures with broadband and wide-angle antireflection properties for Si-based optoelectronic applications

    NASA Astrophysics Data System (ADS)

    Leem, Jung Woo; Song, Young Min; Yu, Jae Su

    2013-10-01

    We report the biomimetic artificial silicon (Si) compound eye structures for broadband and wide-angle antireflection by integrating nanostructures (NSs) into periodically patterned microstructures (p-MSs) via thermal dewetting of gold and subsequent dry etching. The truncated cone microstructures with a two-dimensional hexagonal symmetry pattern were fabricated by photolithography and dry etching processes. The desirable shape and density of the nanostructures were obtained by controlled dewetting. The incorporation of p-MSs into the NS/Si surface further reduced the surface total reflectance over a wide wavelength range of 300-1030 nm at near normal incidence, indicating the average reflectance (Ravg) and solar weighted reflectance (RSWR) values of ~2.5% and 2%, respectively, compared to the only NSs on the flat Si surface (i.e., Ravg ~ 4.9% and RSWR ~ 4.5%). Additionally, the resulting structure improved the angle-dependent antireflection property due to its relatively omnidirectional shape, which exhibited the Ravg < 4.3% and RSWR < 3.7% in the wavelength region of 300-1100 nm even at a high incident light angle of 70° in the specular reflectance.We report the biomimetic artificial silicon (Si) compound eye structures for broadband and wide-angle antireflection by integrating nanostructures (NSs) into periodically patterned microstructures (p-MSs) via thermal dewetting of gold and subsequent dry etching. The truncated cone microstructures with a two-dimensional hexagonal symmetry pattern were fabricated by photolithography and dry etching processes. The desirable shape and density of the nanostructures were obtained by controlled dewetting. The incorporation of p-MSs into the NS/Si surface further reduced the surface total reflectance over a wide wavelength range of 300-1030 nm at near normal incidence, indicating the average reflectance (Ravg) and solar weighted reflectance (RSWR) values of ~2.5% and 2%, respectively, compared to the only NSs on the flat Si

  14. Nano-sized layered Mn oxides as promising and biomimetic water oxidizing catalysts for water splitting in artificial photosynthetic systems.

    PubMed

    Najafpour, Mohammad Mahdi; Heidari, Sima; Amini, Emad; Khatamian, Masoumeh; Carpentier, Robert; Allakhverdiev, Suleyman I

    2014-04-05

    One challenge in artificial photosynthetic systems is the development of artificial model compounds to oxidize water. The water-oxidizing complex of Photosystem II which is responsible for biological water oxidation contains a cluster of four Mn ions bridged by five oxygen atoms. Layered Mn oxides as efficient, stable, low cost, environmentally friendly and easy to use, synthesize, and manufacture compounds could be considered as functional and structural models for the site. Because of the related structure of these Mn oxides and the catalytic centre of the active site of the water oxidizing complex of Photosystem II, the study of layered Mn oxides may also help to understand more about the mechanism of water oxidation by the natural site. This review provides an overview of the current status of layered Mn oxides in artificial photosynthesis and discuss the sophisticated design strategies for Mn oxides as water oxidizing catalysts.

  15. Biomimetic remineralization of dentin

    PubMed Central

    Niu, Li-na; Zhang, Wei; Pashley, David H.; Breschi, Lorenzo; Mao, Jing; Chen, Ji-hua; Tay, Franklin R.

    2013-01-01

    Objectives Remineralization of demineralized dentin is important for improving dentin bonding stability and controlling primary and secondary caries. Nevertheless, conventional dentin remineralization strategy is not suitable for remineralizing completely-demineralized dentin within hybrid layers created by etch-and-rinse and moderately aggressive self-etch adhesive systems, or the superficial part of a caries-affected dentin lesion left behind after minimally invasive caries removal. Biomimetic remineralization represents a different approach to this problem by attempting to backfill the demineralized dentin collagen with liquid-like amorphous calcium phosphate nanoprecursor particles that are stabilized by biomimetic analogs of noncollagenous proteins. Methods This paper reviewed the changing concepts in calcium phosphate mineralization of fibrillar collagen, including the recently discovered, non-classical particle-based crystallization concept, formation of polymer-induced liquid- precursors (PILP), experimental collagen models for mineralization, and the need for using phosphate-containing biomimetic analogs for biomimetic mineralization of collagen. Published work on the remineralization of resin-dentin bonds and artificial caries-like lesions by various research groups was then reviewed. Finally, the problems and progress associated with the translation of a scientifically-sound concept into a clinically-applicable approach are discussed. Results and Significance The particle-based biomimetic remineralization strategy based on the PILP process demonstrates great potential in remineralizing faulty hybrid layers or caries-like dentin. Based on this concept, research in the development of more clinically feasible dentin remineralization strategy, such as incorporating poly(anionic) acid-stabilized amorphous calcium phosphate nanoprecursor-containing mesoporous silica nanofillers in dentin adhesives, may provide a promising strategy for increasing of the

  16. Biomimetic modelling.

    PubMed Central

    Vincent, Julian F V

    2003-01-01

    Biomimetics is seen as a path from biology to engineering. The only path from engineering to biology in current use is the application of engineering concepts and models to biological systems. However, there is another pathway: the verification of biological mechanisms by manufacture, leading to an iterative process between biology and engineering in which the new understanding that the engineering implementation of a biological system can bring is fed back into biology, allowing a more complete and certain understanding and the possibility of further revelations for application in engineering. This is a pathway as yet unformalized, and one that offers the possibility that engineers can also be scientists. PMID:14561351

  17. Development of a Molecularly Imprinted Biomimetic Electrode

    PubMed Central

    Kindschy, Lisa M.; Alocilja, Evangelyn C.

    2007-01-01

    The technique of molecular imprinting produces artificial receptor sites in a polymer that can be used in a biomimetic sensor. This research extends previous studies of a molecularly imprinted polymer (MIP) biomimetic sensor for the small drug theophylline. The presence of theophylline in the biomimetic sensor was monitored by analyzing the peak currents from cyclic voltammetry experiments. The functional working range of the MIP modified electrode was 2 - 4 mM theophylline. The concentration of theophylline that resulted in the best signal was 3 mM. The MIP sensor showed no response to the structurally related molecule caffeine, and therefore was selective to the target analyte theophylline. This research will provide the foundation for future studies that will result in durable biomimetic sensors that can offer a viable alternative to current sensors.

  18. Calcifying tissue regeneration via biomimetic materials chemistry

    PubMed Central

    Green, David W.; Goto, Tazuko K.; Kim, Kye-Seong; Jung, Han-Sung

    2014-01-01

    Materials chemistry is making a fundamental impact in regenerative sciences providing many platforms for tissue development. However, there is a surprising paucity of replacements that accurately mimic the structure and function of the structural fabric of tissues or promote faithful tissue reconstruction. Methodologies in biomimetic materials chemistry have shown promise in replicating morphologies, architectures and functional building blocks of acellular mineralized tissues dentine, enamel and bone or that can be used to fully regenerate them with integrated cell populations. Biomimetic materials chemistry encompasses the two processes of crystal formation and mineralization of crystals into inorganic formations on organic templates. This review will revisit the successes of biomimetics materials chemistry in regenerative medicine, including coccolithophore simulants able to promote in vivo bone formation. In-depth knowledge of biomineralization throughout evolution informs the biomimetic materials chemist of the most effective techniques for regenerative framework construction exemplified via exploitation of liquid crystals (LCs) and complex self-organizing media. Therefore, a new innovative direction would be to create chemical environments that perform reaction–diffusion exchanges as the basis for building complex biomimetic inorganic structures. This has evolved widely in biology, as have LCs, serving as self-organizing templates in pattern formation of structural biomaterials. For instance, a study is highlighted in which artificially fabricated chiral LCs, made from bacteriophages are transformed into a faithful copy of enamel. While chemical-based strategies are highly promising at creating new biomimetic structures there are limits to the degree of complexity that can be generated. Thus, there may be good reason to implement living or artificial cells in ‘morphosynthesis’ of complex inorganic constructs. In the future, cellular construction is

  19. Calcifying tissue regeneration via biomimetic materials chemistry.

    PubMed

    Green, David W; Goto, Tazuko K; Kim, Kye-Seong; Jung, Han-Sung

    2014-12-06

    Materials chemistry is making a fundamental impact in regenerative sciences providing many platforms for tissue development. However, there is a surprising paucity of replacements that accurately mimic the structure and function of the structural fabric of tissues or promote faithful tissue reconstruction. Methodologies in biomimetic materials chemistry have shown promise in replicating morphologies, architectures and functional building blocks of acellular mineralized tissues dentine, enamel and bone or that can be used to fully regenerate them with integrated cell populations. Biomimetic materials chemistry encompasses the two processes of crystal formation and mineralization of crystals into inorganic formations on organic templates. This review will revisit the successes of biomimetics materials chemistry in regenerative medicine, including coccolithophore simulants able to promote in vivo bone formation. In-depth knowledge of biomineralization throughout evolution informs the biomimetic materials chemist of the most effective techniques for regenerative framework construction exemplified via exploitation of liquid crystals (LCs) and complex self-organizing media. Therefore, a new innovative direction would be to create chemical environments that perform reaction-diffusion exchanges as the basis for building complex biomimetic inorganic structures. This has evolved widely in biology, as have LCs, serving as self-organizing templates in pattern formation of structural biomaterials. For instance, a study is highlighted in which artificially fabricated chiral LCs, made from bacteriophages are transformed into a faithful copy of enamel. While chemical-based strategies are highly promising at creating new biomimetic structures there are limits to the degree of complexity that can be generated. Thus, there may be good reason to implement living or artificial cells in 'morphosynthesis' of complex inorganic constructs. In the future, cellular construction is probably

  20. Biomimetic Production of Hydrogen

    NASA Astrophysics Data System (ADS)

    Gust, Devens

    2004-03-01

    The basic reaction for hydrogen generation is formation of molecular hydrogen from two electrons and two protons. Although there are many possible sources for the protons and electrons, and a variety of mechanisms for providing the requisite energy for hydrogen synthesis, the most abundant and readily available source of protons and electrons is water, and the most attractive source of energy for powering the process is sunlight. Not surprisingly, living systems have evolved to take advantage of these sources for materials and energy. Thus, biology provides paradigms for carrying out the reactions necessary for hydrogen production. Photosynthesis in green plants uses sunlight as the source of energy for the oxidation of water to give molecular oxygen, protons, and reduction potential. Some photosynthetic organisms are capable of using this reduction potential, in the form of the reduced redox protein ferredoxin, to reduce protons and produce molecular hydrogen via the action of an hydrogenase enzyme. A variety of other organisms metabolize the reduced carbon compounds that are ultimately the major products of photosynthesis to produce molecular hydrogen. These facts suggest that it might be possible to use light energy to make molecular hydrogen via biomimetic constructs that employ principles similar to those used by natural organisms, or perhaps with hybrid "bionic" systems that combine biomimetic materials with natural enzymes. It is now possible to construct artificial photosynthetic systems that mimic some of the major steps in the natural process.(1) Artificial antennas based on porphyrins, carotenoids and other chromophores absorb light at various wavelengths in the solar spectrum and transfer the harvested excitation energy to artificial photosynthetic reaction centers.(2) In these centers, photoinduced electron transfer uses the energy from light to move an electron from a donor to an acceptor moiety, generating a high-energy charge-separated state

  1. Neurotechnology for Biomimetic Robots

    DTIC Science & Technology

    2007-11-02

    This award funded in part, the travel of three investigators to the international conference on Neurotechnology for Biomimetic Robots. The three...investigators participated in a conference held at Northeastern University May 14-16 on the subject of ’ Neurotechnology for Biomimetic Robots’. Each

  2. Biomimetic thin film synthesis

    SciTech Connect

    Graff, G.L.; Campbell, A.A.; Gordon, N.R.

    1995-05-01

    The purpose of this program is to develop a new process for forming thin film coatings and to demonstrate that the biomimetic thin film technology developed at PNL is useful for industrial applications. In the biomimetic process, mineral deposition from aqueous solution is controlled by organic functional groups attached to the underlying substrate surface. The coatings process is simple, benign, inexpensive, energy efficient, and particularly suited for temperature sensitive substrate materials (such as polymers). In addition, biomimetic thin films can be deposited uniformly on complex shaped and porous substrates providing a unique capability over more traditional line-of-sight methods.

  3. Biomimetics for next generation materials.

    PubMed

    Barthelat, Francois

    2007-12-15

    Billions of years of evolution have produced extremely efficient natural materials, which are increasingly becoming a source of inspiration for engineers. Biomimetics-the science of imitating nature-is a growing multidisciplinary field which is now leading to the fabrication of novel materials with remarkable mechanical properties. This article discusses the mechanics of hard biological materials, and more specifically of nacre and bone. These high-performance natural composites are made up of relatively weak components (brittle minerals and soft proteins) arranged in intricate ways to achieve specific combinations of stiffness, strength and toughness (resistance to cracking). Determining which features control the performance of these materials is the first step in biomimetics. These 'key features' can then be implemented into artificial bio-inspired synthetic materials, using innovative techniques such as layer-by-layer assembly or ice-templated crystallization. The most promising approaches, however, are self-assembly and biomineralization because they will enable tight control of structures at the nanoscale. In this 'bottom-up' fabrication, also inspired from nature, molecular structures and crystals are assembled with a little or no external intervention. The resulting materials will offer new combinations of low weight, stiffness and toughness, with added functionalities such as self-healing. Only tight collaborations between engineers, chemists, materials scientists and biologists will make these 'next-generation' materials a reality.

  4. Biomimetics--a review.

    PubMed

    Vincent, J F V

    2009-11-01

    Biology can inform technology at all levels (materials, structures, mechanisms, machines, and control) but there is still a gap between biology and technology. This review itemizes examples of biomimetic products and concludes that the Russian system for inventive problem solving (teoriya resheniya izobreatatelskikh zadatch (TRIZ)) is the best system to underpin the technology transfer. Biomimetics also challenges the current paradigm of technology and suggests more sustainable ways to manipulate the world.

  5. Kirigami design and fabrication for biomimetic robotics

    NASA Astrophysics Data System (ADS)

    Rossiter, Jonathan; Sareh, Sina

    2014-03-01

    Biomimetics faces a continual challenge of how to bridge the gap between what Nature has so effectively evolved and the current tools and materials that engineers and scientists can exploit. Kirigami, from the Japanese `cut' and `paper', is a method of design where laminar materials are cut and then forced out-of-plane to yield 3D structures. Kirimimetic design provides a convenient and relatively closed design space within which to replicate some of the most interesting niche biological mechanisms. These include complex flexing organelles such as cilia in algae, energy storage and buckled structures in plants, and organic appendages that actuate out-of-plane such as the myoneme of the Vorticella protozoa. Where traditional kirigami employs passive materials which must be forced to transition to higher dimensions, we can exploit planar smart actuators and artificial muscles to create self-actuating kirigami structures. Here we review biomimetics with respect to the kirigami design and fabrication methods and examine how smart materials, including electroactive polymers and shape memory polymers, can be used to realise effective biomimetic components for robotic, deployable structures and engineering systems. One-way actuation, for example using shape memory polymers, can yield complete self-deploying structures. Bi-directional actuation, in contrast, can be exploited to mimic fundamental biological mechanisms such as thrust generation and fluid control. We present recent examples of kirigami robotic mechanisms and actuators and discuss planar fabrication methods, including rapid prototyping and 3D printing, and how current technologies, and their limitations, affect Kirigami robotics.

  6. Biomimetics: process, tools and practice.

    PubMed

    Fayemi, P E; Wanieck, K; Zollfrank, C; Maranzana, N; Aoussat, A

    2017-01-23

    Biomimetics applies principles and strategies abstracted from biological systems to engineering and technological design. With a huge potential for innovation, biomimetics could evolve into a key process in businesses. Yet challenges remain within the process of biomimetics, especially from the perspective of potential users. We work to clarify the understanding of the process of biomimetics. Therefore, we briefly summarize the terminology of biomimetics and bioinspiration. The implementation of biomimetics requires a stated process. Therefore, we present a model of the problem-driven process of biomimetics that can be used for problem-solving activity. The process of biomimetics can be facilitated by existing tools and creative methods. We mapped a set of tools to the biomimetic process model and set up assessment sheets to evaluate the theoretical and practical value of these tools. We analyzed the tools in interdisciplinary research workshops and present the characteristics of the tools. We also present the attempt of a utility tree which, once finalized, could be used to guide users through the process by choosing appropriate tools respective to their own expertize. The aim of this paper is to foster the dialogue and facilitate a closer collaboration within the field of biomimetics.

  7. A future of living machines?: International trends and prospects in biomimetic and biohybrid systems

    NASA Astrophysics Data System (ADS)

    Prescott, Tony J.; Lepora, Nathan; Vershure, Paul F. M. J.

    2014-03-01

    Research in the fields of biomimetic and biohybrid systems is developing at an accelerating rate. Biomimetics can be understood as the development of new technologies using principles abstracted from the study of biological systems, however, biomimetics can also be viewed from an alternate perspective as an important methodology for improving our understanding of the world we live in and of ourselves as biological organisms. A biohybrid entity comprises at least one artificial (engineered) component combined with a biological one. With technologies such as microscale mobile computing, prosthetics and implants, humankind is moving towards a more biohybrid future in which biomimetics helps us to engineer biocompatible technologies. This paper reviews recent progress in the development of biomimetic and biohybrid systems focusing particularly on technologies that emulate living organisms—living machines. Based on our recent bibliographic analysis [1] we examine how biomimetics is already creating life-like robots and identify some key unresolved challenges that constitute bottlenecks for the field. Drawing on our recent research in biomimetic mammalian robots, including humanoids, we review the future prospects for such machines and consider some of their likely impacts on society, including the existential risk of creating artifacts with significant autonomy that could come to match or exceed humankind in intelligence. We conclude that living machines are more likely to be a benefit than a threat but that we should also ensure that progress in biomimetics and biohybrid systems is made with broad societal consent.

  8. Biomimetic Strategies for Sensing Biological Species

    PubMed Central

    Hussain, Munawar; Wackerlig, Judith; Lieberzeit, Peter A.

    2013-01-01

    The starting point of modern biosensing was the application of actual biological species for recognition. Increasing understanding of the principles underlying such recognition (and biofunctionality in general), however, has triggered a dynamic field in chemistry and materials sciences that aims at joining the best of two worlds by combining concepts derived from nature with the processability of manmade materials, e.g., sensitivity and ruggedness. This review covers different biomimetic strategies leading to highly selective (bio)chemical sensors: the first section covers molecularly imprinted polymers (MIP) that attempt to generate a fully artificial, macromolecular mold of a species in order to detect it selectively. A different strategy comprises of devising polymer coatings to change the biocompatibility of surfaces that can also be used to immobilized natural receptors/ligands and thus stabilize them. Rationally speaking, this leads to self-assembled monolayers closely resembling cell membranes, sometimes also including bioreceptors. Finally, this review will highlight some approaches to generate artificial analogs of natural recognition materials and biomimetic approaches in nanotechnology. It mainly focuses on the literature published since 2005. PMID:25587400

  9. Amelogenin and Enamel Biomimetics

    PubMed Central

    Ruan, Qichao; Moradian-Oldak, Janet

    2015-01-01

    Mature tooth enamel is acellular and does not regenerate itself. Developing technologies that rebuild tooth enamel and preserve tooth structure is therefore of great interest. Considering the importance of amelogenin protein in dental enamel formation, its ability to control apatite mineralization in vitro, and its potential to be applied in fabrication of future bio-inspired dental material this review focuses on two major subjects: amelogenin and enamel biomimetics. We review the most recent findings on amelogenin secondary and tertiary structural properties with a focus on its interactions with different targets including other enamel proteins, apatite mineral, and phospholipids. Following a brief overview of enamel hierarchical structure and its mechanical properties we will present the state-of-the-art strategies in the biomimetic reconstruction of human enamel. PMID:26251723

  10. Biomimetic sensor design

    NASA Astrophysics Data System (ADS)

    Lee, Ju Hun; Jin, Hyo-Eon; Desai, Malav S.; Ren, Shuo; Kim, Soyoun; Lee, Seung-Wuk

    2015-11-01

    Detection of desired target chemicals in a sensitive and selective manner is critically important to protect human health, environment and national security. Nature has been a great source of inspiration for the design of sensitive and selective sensors. In this mini-review, we overview the recent developments in bio-inspired sensor development. There are four major components of sensor design: design of receptors for specific targets; coating materials to integrate receptors to transducing machinery; sensitive transducing of signals; and decision making based on the sensing results. We discuss the biomimetic methods to discover specific receptors followed by a discussion about bio-inspired nanocoating material design. We then review the recent developments in phage-based bioinspired transducing systems followed by a discussion of biomimetic pattern recognition-based decision making systems. Our review will be helpful to understand recent approaches to reverse-engineer natural systems to design specific and sensitive sensors.

  11. Designing biomimetic antifouling surfaces.

    PubMed

    Salta, Maria; Wharton, Julian A; Stoodley, Paul; Dennington, Simon P; Goodes, Liam R; Werwinski, Stéphane; Mart, Ugar; Wood, Robert J K; Stokes, Keith R

    2010-10-28

    Marine biofouling is the accumulation of biological material on underwater surfaces, which has plagued both commercial and naval fleets. Biomimetic approaches may well provide new insights into designing and developing alternative, non-toxic, surface-active antifouling (AF) technologies. In the marine environment, all submerged surfaces are affected by the attachment of fouling organisms, such as bacteria, diatoms, algae and invertebrates, causing increased hydrodynamic drag, resulting in increased fuel consumption, and decreased speed and operational range. There are also additional expenses of dry-docking, together with increased fuel costs and corrosion, which are all important economic factors that demand the prevention of biofouling. Past solutions to AF have generally used toxic paints or coatings that have had a detrimental effect on marine life worldwide. The prohibited use of these antifoulants has led to the search for biologically inspired AF strategies. This review will explore the natural and biomimetic AF surface strategies for marine systems.

  12. Biomimetic Hydrogel Materials

    DOEpatents

    Bertozzi, Carolyn , Mukkamala, Ravindranath , Chen, Oing , Hu, Hopin , Baude, Dominique

    2003-04-22

    Novel biomimetic hydrogel materials and methods for their preparation. Hydrogels containing acrylamide-functionalized carbohydrate, sulfoxide, sulfide or sulfone copolymerized with a hydrophilic or hydrophobic copolymerizing material selected from the group consisting of an acrylamide, methacrylamide, acrylate, methacrylate, vinyl and a derivative thereof present in concentration from about 1 to about 99 wt %. and methods for their preparation. The method of use of the new hydrogels for fabrication of soft contact lenses and biomedical implants.

  13. Biomimetic hydrogel materials

    SciTech Connect

    Bertozzi, Carolyn; Mukkamala, Ravindranath; Chen, Qing; Hu, Hopin; Baude, Dominique

    2000-01-01

    Novel biomimetic hydrogel materials and methods for their preparation. Hydrogels containing acrylamide-functionalized carbohydrate, sulfoxide, sulfide or sulfone copolymerized with a hydrophilic or hydrophobic copolymerizing material selected from the group consisting of an acrylamide, methacrylamide, acrylate, methacrylate, vinyl and a derivative thereof present in concentration from about 1 to about 99 wt %. and methods for their preparation. The method of use of the new hydrogels for fabrication of soft contact lenses and biomedical implants.

  14. Templated biomimetic multifunctional coatings

    NASA Astrophysics Data System (ADS)

    Sun, Chih-Hung; Gonzalez, Adriel; Linn, Nicholas C.; Jiang, Peng; Jiang, Bin

    2008-02-01

    We report a bioinspired templating technique for fabricating multifunctional optical coatings that mimic both unique functionalities of antireflective moth eyes and superhydrophobic cicada wings. Subwavelength-structured fluoropolymer nipple arrays are created by a soft-lithography-like process. The utilization of fluoropolymers simultaneously enhances the antireflective performance and the hydrophobicity of the replicated films. The specular reflectivity matches the optical simulation using a thin-film multilayer model. The dependence of the size and the crystalline ordering of the replicated nipples on the resulting antireflective properties have also been investigated by experiment and modeling. These biomimetic materials may find important technological application in self-cleaning antireflection coatings.

  15. Biomimetic Receptors and Sensors

    PubMed Central

    Dickert, Franz L.

    2014-01-01

    In biomimetics, living systems are imitated to develop receptors for ions, molecules and bioparticles. The most pertinent idea is self-organization in analogy to evolution in nature, which created the key-lock principle. Today, modern science has been developing host-guest chemistry, a strategy of supramolecular chemistry for designing interactions of analytes with synthetic receptors. This can be realized, e.g., by self-assembled monolayers (SAMs) or molecular imprinting. The strategies are used for solid phase extraction (SPE), but preferably in developing recognition layers of chemical sensors. PMID:25436653

  16. Biomimetic materials processing

    NASA Astrophysics Data System (ADS)

    Ishizaki, Takahiro; Hieda, Junko; Bratescu, Maria A.; Saito, Nagahiro; Takai, Osamu

    2009-08-01

    A biomimetic super-hydrophobic/super-hydrophilic micro-patterned surface was successfully fabricated by microwave plasma enhanced chemical vapor deposition (MPECVD) and vacuum ultraviolet (VUV) light lithography. On the micropatterned surface, various site-selective immobilizations were carried out. The fluorescent polystyrene spheres and copper were deposited site-selectively on super-hydrophobic regions using electrostatic interactions. The micropatterned surface brought the discrete adhesions of E. coli and B. subtilis specifically on super-hydrophobic regions. On the other hand, NIH 3T3 fibroblast cells attached to the super-hydrophilic regions in a highly selective manner.

  17. Biomimetic receptors and sensors.

    PubMed

    Dickert, Franz L

    2014-11-27

    In biomimetics, living systems are imitated to develop receptors for ions, molecules and bioparticles. The most pertinent idea is self-organization in analogy to evolution in nature, which created the key-lock principle. Today, modern science has been developing host-guest chemistry, a strategy of supramolecular chemistry for designing interactions of analytes with synthetic receptors. This can be realized, e.g., by self-assembled monolayers (SAMs) or molecular imprinting. The strategies are used for solid phase extraction (SPE), but preferably in developing recognition layers of chemical sensors.

  18. Biomimetics in Tribology

    NASA Astrophysics Data System (ADS)

    Gebeshuber, I. C.; Majlis, B. Y.; Stachelberger, H.

    Science currently goes through a major change. Biology is evolving as new Leitwissenschaft, with more and more causation and natural laws being uncovered. The term `technoscience' denotes the field where science and technology are inseparably interconnected, the trend goes from papers to patents, and the scientific `search for truth' is increasingly replaced by search for applications with a potential economic value. Biomimetics, i.e. knowledge transfer from biology to technology, is a field that has the potential to drive major technical advances. The biomimetic approach might change the research landscape and the engineering culture dramatically, by the blending of disciplines. It might substantially support successful mastering of current tribological challenges: friction, adhesion, lubrication and wear in devices and systems from the meter to the nanometer scale. A highly successful method in biomimectics, the biomimicry innovation method, is applied in this chapter to identify nature's best practices regarding two key issues in tribology: maintenance of the physical integrity of a system, and permanent as well as temporary attachment. The best practices identified comprise highly diverse organisms and processes and are presented in a number of tables with detailed references.

  19. Bio-Mimetic Sensors Based on Molecularly Imprinted Membranes

    PubMed Central

    Algieri, Catia; Drioli, Enrico; Guzzo, Laura; Donato, Laura

    2014-01-01

    An important challenge for scientific research is the production of artificial systems able to mimic the recognition mechanisms occurring at the molecular level in living systems. A valid contribution in this direction resulted from the development of molecular imprinting. By means of this technology, selective molecular recognition sites are introduced in a polymer, thus conferring it bio-mimetic properties. The potential applications of these systems include affinity separations, medical diagnostics, drug delivery, catalysis, etc. Recently, bio-sensing systems using molecularly imprinted membranes, a special form of imprinted polymers, have received the attention of scientists in various fields. In these systems imprinted membranes are used as bio-mimetic recognition elements which are integrated with a transducer component. The direct and rapid determination of an interaction between the recognition element and the target analyte (template) was an encouraging factor for the development of such systems as alternatives to traditional bio-assay methods. Due to their high stability, sensitivity and specificity, bio-mimetic sensors-based membranes are used for environmental, food, and clinical uses. This review deals with the development of molecularly imprinted polymers and their different preparation methods. Referring to the last decades, the application of these membranes as bio-mimetic sensor devices will be also reported. PMID:25196110

  20. Bio-mimetic sensors based on molecularly imprinted membranes.

    PubMed

    Algieri, Catia; Drioli, Enrico; Guzzo, Laura; Donato, Laura

    2014-07-30

    An important challenge for scientific research is the production of artificial systems able to mimic the recognition mechanisms occurring at the molecular level in living systems. A valid contribution in this direction resulted from the development of molecular imprinting. By means of this technology, selective molecular recognition sites are introduced in a polymer, thus conferring it bio-mimetic properties. The potential applications of these systems include affinity separations, medical diagnostics, drug delivery, catalysis, etc. Recently, bio-sensing systems using molecularly imprinted membranes, a special form of imprinted polymers, have received the attention of scientists in various fields. In these systems imprinted membranes are used as bio-mimetic recognition elements which are integrated with a transducer component. The direct and rapid determination of an interaction between the recognition element and the target analyte (template) was an encouraging factor for the development of such systems as alternatives to traditional bio-assay methods. Due to their high stability, sensitivity and specificity, bio-mimetic sensors-based membranes are used for environmental, food, and clinical uses. This review deals with the development of molecularly imprinted polymers and their different preparation methods. Referring to the last decades, the application of these membranes as bio-mimetic sensor devices will be also reported.

  1. A pigeon-inspired design for a biomimetic flapping wing

    NASA Astrophysics Data System (ADS)

    Mahardika, Nanang; Nguyen, Quoc Viet; Park, Hoon Cheol

    2010-04-01

    As an effort to explore the potential implementation of wing feather separation and lead-lagging motion to a flapping wing, a biomimetic flapper with separable outer wings has been designed and demonstrated. The artificial wing feather separation is implemented to the biomimetic wing by dividing the wing into inner and outer wings. The features of flapping, lead-lagging and feather separation of the flapper are captured by a high-speed camera for evaluation. The performance of the biomimetic flapper with separable outer wings is compared with that of a flapper with inseparable outer wings in terms of lift and thrust production. For low flapping frequency ranging from 2.47 Hz to 3.90 Hz, the biomimetic flapper shows higher thrust and lift generation capability, which is demonstrated from a series of experiments. The experiments show that the outer parts of the separable wing are able to deform largely resulting smaller amount of drag production during upstroke, while still producing relatively larger lift and thrust during downstroke.

  2. Biomimetic mushroom-shaped fibrillar adhesive microstructure.

    PubMed

    Gorb, S; Varenberg, M; Peressadko, A; Tuma, J

    2007-04-22

    To improve the adhesive properties of artificial fibrillar contact structures, the attachment systems of beetles from the family Chrysomelidae were chosen to serve as a model. Biomimetic mushroom-shaped fibrillar adhesive microstructure inspired by these systems was characterized using a variety of measurement techniques and compared with a control flat surface made of the same material. Results revealed that pull-off force and peel strength of the structured specimens are more than twice those of the flat specimens. In contrast to the control system, the structured one is found to be very tolerant to contamination and able to recover its adhesive properties after being washed in a soap solution. Based on the combination of several geometrical principles found in biological attachment devices, the presented microstructure exhibits a considerable step towards the development of an industrial dry adhesive.

  3. Clues for biomimetics from natural composite materials

    PubMed Central

    Lapidot, Shaul; Meirovitch, Sigal; Sharon, Sigal; Heyman, Arnon; Kaplan, David L; Shoseyov, Oded

    2013-01-01

    Bio-inspired material systems are derived from different living organisms such as plants, arthropods, mammals and marine organisms. These biomaterial systems from nature are always present in the form of composites, with molecular-scale interactions optimized to direct functional features. With interest in replacing synthetic materials with natural materials due to biocompatibility, sustainability and green chemistry issues, it is important to understand the molecular structure and chemistry of the raw component materials to also learn from their natural engineering, interfaces and interactions leading to durable and highly functional material architectures. This review will focus on applications of biomaterials in single material forms, as well as biomimetic composites inspired by natural organizational features. Examples of different natural composite systems will be described, followed by implementation of the principles underlying their composite organization into artificial bio-inspired systems for materials with new functional features for future medicine. PMID:22994958

  4. Biomimetic gyroid nanostructures exceeding their natural origins

    PubMed Central

    Gan, Zongsong; Turner, Mark D.; Gu, Min

    2016-01-01

    Using optical two-beam lithography with improved resolution and enhanced mechanical strength, we demonstrate the replication of gyroid photonic nanostructures found in the butterfly Callophrys rubi. These artificial structures are shown to have size, controllability, and uniformity that are superior to those of their biological counterparts. In particular, the elastic Young’s modulus of fabricated nanowires is enhanced by up to 20%. As such, the circular dichroism enabled by the gyroid nanostructures can operate in the near-ultraviolet wavelength region, shorter than that supported by the natural butterfly wings of C. rubi. This fabrication technique provides a unique tool for extracting three-dimensional photonic designs from nature and will aid the investigation of biomimetic nanostructures. PMID:27386542

  5. Biomimetic Peptides for the Treatment of Cancer.

    PubMed

    Mine, Yuichi; Munir, Hafsa; Nakanishi, Yoichi; Sugiyama, Daisuke

    2016-07-01

    Cancer remains one of the leading causes of death worldwide, indicating that current cancer therapies are ineffective. Therefore, new treatments with high specificity and low toxicity are needed. Cancerous cells can be distinguished from normal cells based on expression of key proteins, namely surface proteins, scaffold proteins and signaling molecules. Moreover, cancer cells communicate with the tumor microenvironment consisting of a heterogenous population of cells, extracellular matrix components and soluble factors such as cytokines/chemokines and growth factors. Most therapeutic interventions have been designed to specifically target these proteins of interest. Biomimetic peptides (BPs) are artificially designed peptides that imitate the action of parent proteins or peptides. BPs can be classified into at least three types based on their target molecule: BPs that target (i) cell-surface molecules, (ii) intracellular molecules, and (iii) cancer cell-tumor microenvironment interactions. In this review, we analyze/discuss the current strategies for targeting tumors using BPs.

  6. Biologically inspired technologies using artificial muscles

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph

    2005-01-01

    One of the newest fields of biomimetics is the electroactive polymers (EAP) that are also known as artificial muscles. To take advantage of these materials, efforts are made worldwide to establish a strong infrastructure addressing the need for comprehensive analytical modeling of their response mechanism and develop effective processing and characterization techniques. The field is still in its emerging state and robust materials are still not readily available however in recent years significant progress has been made and commercial products have already started to appear. This paper covers the current state of- the-art and challenges to making artificial muscles and their potential biomimetic applications.

  7. External-integrated biomimetic micropump for microfluidic system

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Liu, Chong; Li, Jingmin; Xu, Zheng; Gan, Lu; Li, Tao; Zhou, Lijie; Ma, Yahui; Zhang, Hao; Zhang, Kaiping

    2014-07-01

    An external-integrated biomimetic micropump for a microfluidic system is demonstrated. An "artificial leaf" is constituted, which mimics the stomatal transpiration process in plants and utilizes the negative pressure generated to drive the fluid flow. The biomimetic micropump integrated an SU-8 film with a micropore array, agarose gel, a flow rate control unit, and additional necessary operating auxiliaries. SU-8 film with micropores and agarose gel is used to mimic the stomata and the mesophyll cells in a leaf, respectively. The flow rate control unit can change the flow rate of the micropump by adjusting the number of micropores that participate in transpiration. Additional necessary operating auxiliaries can fix a microchip, provide a continuous fluid supply, and speed up the fluid flow rate. Experiments on a microchip are conducted to evaluate the performance of the micropump platform. Results have shown that the flow rate of the micropump can be increased by accelerating the wind speed or raising the temperature.

  8. Bioimprinting strategies: from soft lithography to biomimetic sensors and beyond.

    PubMed

    Mujahid, Adnan; Iqbal, Naseer; Afzal, Adeel

    2013-12-01

    Imprinting is a straightforward, yet a reliable technique to develop dynamic artificial recognition materials-so called as synthetic antibodies. Surface imprinting strategies such as soft lithography allow biological stereotyping of polymers and sol-gel phases to prepare extremely selective receptor layers, which can be combined with suitable transducer systems to develop high performance biomimetic sensors. This article presents an overview of the remarkable technical advancements in the field of surface bioimprinting with particular emphasis on surface imprinted bioanalyte detection systems and their applications in rapid bioanalysis and biotechnology. Herein, we discuss a variety of surface imprinting strategies including soft lithography, template immobilization, grafting, emulsion polymerization, and others along with their biomimetic sensor applications, merits and demerits. The pioneering research works on surface patterned biosensors are described with selected examples of detecting biological agents ranging from small biomolecules and proteins to living cells and microorganisms.

  9. Photoluminescence of annealed biomimetic apatites.

    PubMed

    Zollfrank, Cordt; Müller, Lenka; Greil, Peter; Müller, Frank A

    2005-11-01

    Biomimetic apatite coatings are widely used in orthopaedic applications to provide bioinert material surfaces with bioactive behaviour by means of initiating bone growth at the implant surface. In this study we manufactured biomimetic calcium phosphate coatings consisting of a calcium deficient carbonated apatite by immersing activated titanium platelets into simulated body fluid. The development of the crystal phases was monitored by X-ray diffractometry in addition to Fourier-transform infrared spectroscopy. The microstructure of the biomimetic apatites and phase composition was analysed using scanning and transmission electron microscopy as well as attached energy dispersive X-ray spectrometry. The samples were annealed in air yielding in an inherent luminescence of the biomimetic apatite up to temperatures of 600 degrees C. The photo-induced emission spectra were recorded in the range from 400 to 750 nm at excitation wavelengths ranging 310-450 nm. A blue (437 nm) and a green (561 nm) emission were found between 200 and 600 degrees C visually appearing white. Photoluminescence of annealed biomimetic apatites might be of interest for histological probing and monitoring of bone re-modelling. The results are discussed in terms of chemical and crystallographic changes in the calcium phosphate layer during heat treatment.

  10. [Biomimetic nanosystems and novel composite nanobiomaterials].

    PubMed

    Khomutov, G B

    2011-01-01

    Biophysicochemical approaches to the solution of nanotechnology problems associated with the design of functional biomimetic nanosystems, hybrid and composite nanobiomaterials and study of their structure-function relationships. The results of studies concerned with physicochemical mechanisms of the formation of organized biomimetic nanostructures and bioinorganic nanomaterials in systems involving a bulky liquid phase and the interface (gas-liquid, solid-liquid, liquid-liquid) during the synthesis and structure formation with the participation of the components of colloid systems, inorganic nanoparticles of various composition and clusters of metals, surfactants, polyelectrolytes and their complexes are discussed. In the development of the methods for the formation of composite bioinorganic nanosystems containing inorganic nanocomponents, two major approaches were used: adsorption and incorporation into the biomolecular matrix or colloid system of presynthesized inorganic nanoparticles, as well as the synthesis of the inorganic nanophase immediately in the biomolecular system. The methods of obtaining biomaterials and nanosystems are based on the principles of biomimetics, biomineralization, self-assembly and self-organization, combination and integration of a number of synthetic and physicochemical methods (physical and chemical adsorption, Langmuir technique, the formation of polycomplexes, chemical linking, competitive interactions, and substitution of ligands in supramolecular and coordination complexes) and nanocomponents of different nature. In particular, a novel approach to the preparation of highly organized nanofilm materials was developed, which is based on the effect of self-assembly and self-organization of colloid nanoparticles during the formation of their complexes with polyfunctional biogenic ligands in the volume of the liquid phase in the absence of any surfaces and interfaces. The physical and chemical factors responsible for the formation of

  11. Repairable, nanostructured biomimetic hydrogels

    NASA Astrophysics Data System (ADS)

    Firestone, M.; Brombosz, S.; Grubjesic, S.

    2013-03-01

    Proteins facilitate many key cellular processes, including signal recognition and energy transduction. The ability to harness this evolutionarily-optimized functionality could lead to the development of protein-based systems useful for advancing alternative energy storage and conversion. The future of protein-based, however, requires the development of materials that will stabilize, order and control the activity of the proteins. Recently we have developed a synthetic approach for the preparation of a durable biomimetic chemical hydrogel that can be reversibly swollen in water. The matrix has proven ideal for the stable encapsulation of both water- and membrane-soluble proteins. The material is composed of an aqueous dispersion of a diacrylate end-derivatized PEO-PPO-PEO macromer, a saturated phospholipid and a zwitterionic co-surfactant that self-assembles into a nanostructured physical gel at room temperature as determined by X-ray scattering. The addition of a water soluble PEGDA co-monomer and photoinitator does not alter the self-assembled structure and UV irradiation serves to crosslink the acrylate end groups on the macromer with the PEGDA forming a network within the aqueous domains as determined by FT-IR. More recently we have begun to incorporate reversible crosslinks employing Diels-Alder chemistry, allowing for the extraction and replacement of inactive proteins. The ability to replenish the materials with active, non-denatured forms of protein is an important step in advancing these materials for use in nanostructured devices This work was supported by the Office of Basic Energy Sciences, Division of Materials Sciences, USDoE under Contract No. DE-AC02-06CH11357.

  12. Direct laser writing: biomimetic photonics and superresolution nanolithography

    NASA Astrophysics Data System (ADS)

    Gu, Min

    2014-03-01

    Biomimetic photonics is inspired by nature's ability to self-assemble complex nanostructured materials with superior properties to that of conventional materials. Biomimetic engineering of novel nanophotonic devices has led to optical nano-fountains, artificial compound eyes and optical gas sensors. Direct laser writing (DLW) is a powerful tool toward the development of ultimate three-dimensional (3D) biomimetic photonic devices. Here we demonstrate the fabrication (DWL) of a novel class of 3D photonic microstructures inspired by a recent finding in butterfly wing-scales and show that these nano-engineered 3D gyroid structures have the ability to redirect circularly polarized light as a chiral beamsplitter. Because of the increasing demand for realising nanogeometries, the diffraction-limited resolution associated with DLW, should be overcomed to access to the nanoscale. We will report on our recent progress on optical beam nanolithography by using the superresolution photoinduction-inhibited nanolithography (SPIN) technique. The smallest feature size of 9 nm for free-standing lines has been demonstrated.

  13. Inorganic biomimetic nanostructures.

    PubMed

    Levine, Lauren A; Williams, Mary Elizabeth

    2009-12-01

    Supramolecular structures modeled after biological systems (DNA and enzymes) are being developed to simultaneously mimic natural biological functions including catalysis, information storage, and self-assembly and to engineer novel electronic and magnetic properties. Structural mimics of nucleic acids containing multiple metal-coordinating ligands, and comprising natural and artificial bases or completely synthetic systems, create stable double-stranded structures with new electronic, spectroscopic, and magnetic properties. Supramolecular inorganic mimics of enzymatic function, including metallonucleases and metalloproteases, have begun to be constructed. Alternatively, metal-organic-frameworks have potential as artificial catalysts with substrate-specificity and size-selectivity analogous to biological processes. This review describes some of the recent themes in inorganic supramolecular systems that aim to mimic and exploit nature's ability to self-assemble polyfunctional architectures for new materials and biological applications.

  14. Bio-mimetic Flow Control

    NASA Astrophysics Data System (ADS)

    Choi, Haecheon

    2009-11-01

    Bio-mimetic engineering or bio-mimetics is the application of biological methods and systems found in nature to the study and design of engineering systems and modern technology (from Wikipedia). The concept itself is old, but successful developments have been made recently, especially in the research field of flow control. The objective of flow control based on the bio-mimetic approach is to develop novel concepts for reducing drag, increasing lift and enhancing aerodynamic performance. For skin friction reduction, a few ideas have been suggested such as the riblet from shark, compliant surface from dolphin, microbubble injection and multiple front-body curvature from penguin, and V-shaped protrusion from sailfish. For form drag reduction, several new attempts have been also made recently. Examples include the V-shaped spanwise grooves from saguaro cactus, overall shape of box fish, longitudinal grooves on scallop shell, bill of swordfish, hooked comb on owl wing, trailing-edge protrusion on dragonfly wing, and fillet. For the enhancement of aerodynamic performance, focuses have been made on the birds, fish and insects: e.g., double layered feather of landing bird, leading-edge serration of humpback-whale flipper, pectoral fin of flying fish, long tail on swallowtail-butterfly wing, wing flapping motion of dragonfly, and alula in birds. Living animals adapt their bodies to better performance in multi purposes, but engineering requires single purpose in most cases. Therefore, bio-mimetic approaches often produce excellent results more than expected. However, they are sometimes based on people's wrong understanding of nature and produce unwanted results. Successes and failures from bio-mimetic approaches in flow control will be discussed in the presentation.

  15. Tubular inverse opal scaffolds for biomimetic vessels

    NASA Astrophysics Data System (ADS)

    Zhao, Ze; Wang, Jie; Lu, Jie; Yu, Yunru; Fu, Fanfan; Wang, Huan; Liu, Yuxiao; Zhao, Yuanjin; Gu, Zhongze

    2016-07-01

    There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially oriented elliptical pattern microstructures on their surfaces. It is demonstrated that these tailored tubular scaffolds can effectively make endothelial cells to form an integrated hollow tubular structure on their inner surface and induce smooth muscle cells to form a circumferential orientation on their outer surface. These features of our tubular scaffolds make them highly promising for the construction of biomimetic blood vessels.There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially

  16. PREFACE: Symposium 13: Ceramics for Medicine, Biotechnology and Biomimetics

    NASA Astrophysics Data System (ADS)

    Ohtsuki, Chikara

    2011-10-01

    Preface to Symposium 13 (Ceramics for Medicine, Biotechnology and Biomimetics) of the International Congress on Ceramics III, 14-18 November 2010, Osaka, Japan Ceramic materials are now widely used in biomedical fields, such as applications of artificial bones, joints and teeth. The high potential of ceramics to exhibit biological functionality is expected to produce novel materials supporting biotechnology. These applications are governed by the interactions of materials and biological molecules. So far, 'bioceramics' is a type of biomaterial used for repairing damaged tissues. The orthopaedic application of bioceramics has advanced rapidly since the invention of Bioglass® that was found to encourage direct bonding with living bone. Hydroxyapatite and calcium phosphate ceramics are now popular bioceramics for use in artificial bones. While the bone-bonding behavior of materials was understood phenomenologically, very little has been known about the mechanism of either hard or soft tissue attachment or tissue growth on ceramic-based materials, such as glasses, glass-ceramics, ceramic composites and organic-inorganic hybrids. This symposium discussed the scientific understanding of the interface between biomedical materials and soft/hard tissues, and the design and construction of nanoscopic interfaces. It also involved establishment of biomimetic structures, characterization of natural life-related hard and soft tissues, and their formation mechanisms for a wide range of applications in biotechnology through 45 oral presentations including 5 invited lectures and 45 posters. I wish to express my sincere appreciation to the organizers of this symposium in the ICC3 conference. I am also grateful to the invited speakers, all the participants and organizing committee of the ICC3. It is my great pleasure that this proceedings could be published as the fruit of this symposium's achievement, which includes the contributions in all aspect of scientific understanding and

  17. Biomimetic membranes and methods of making biomimetic membranes

    DOEpatents

    Rempe, Susan; Brinker, Jeffrey C.; Rogers, David Michael; Jiang, Ying-Bing; Yang, Shaorong

    2016-11-08

    The present disclosure is directed to biomimetic membranes and methods of manufacturing such membranes that include structural features that mimic the structures of cellular membrane channels and produce membrane designs capable of high selectivity and high permeability or adsorptivity. The membrane structure, material and chemistry can be selected to perform liquid separations, gas separation and capture, ion transport and adsorption for a variety of applications.

  18. Hydrogen photoproduction by use of photosynthetic organisms and biomimetic systems.

    PubMed

    Allakhverdiev, Suleyman I; Kreslavski, Vladimir D; Thavasi, Velmurugan; Zharmukhamedov, Sergei K; Klimov, Vyacheslav V; Nagata, Toshi; Nishihara, Hiroshi; Ramakrishna, Seeram

    2009-02-01

    Hydrogen can be important clean fuel for future. Among different technologies for hydrogen production, oxygenic natural and artificial photosyntheses using direct photochemistry in synthetic complexes have a great potential to produce hydrogen, since both use clean and cheap sources: water and solar energy. Artificial photosynthesis is one way to produce hydrogen from water using sunlight by employing biomimetic complexes. However, splitting of water into protons and oxygen is energetically demanding and chemically difficult. In oxygenic photosynthetic microorganisms such as algae and cyanobacteria, water is split into electrons and protons, which during primary photosynthetic process are redirected by photosynthetic electron transport chain, and ferredoxin, to the hydrogen-producing enzymes hydrogenase or nitrogenase. By these enzymes, e- and H+ recombine and form gaseous hydrogen. Biohydrogen activity of hydrogenase can be very high but it is extremely sensitive to photosynthetic O2. In contrast, nitrogenase is insensitive to O2, but has lower activity. At the moment, the efficiency of biohydrogen production is low. However, theoretical expectations suggest that the rates of photon conversion efficiency for H2 bioproduction can be high enough (>10%). Our review examines the main pathways of H2 photoproduction by using of photosynthetic organisms and biomimetic photosynthetic systems.

  19. Nanotechnology Biomimetic Cartilage Regenerative Scaffolds

    PubMed Central

    Sardinha, Jose Paulo; Myers, Simon

    2014-01-01

    Cartilage has a limited regenerative capacity. Faced with the clinical challenge of reconstruction of cartilage defects, the field of cartilage engineering has evolved. This article reviews current concepts and strategies in cartilage engineering with an emphasis on the application of nanotechnology in the production of biomimetic cartilage regenerative scaffolds. The structural architecture and composition of the cartilage extracellular matrix and the evolution of tissue engineering concepts and scaffold technology over the last two decades are outlined. Current advances in biomimetic techniques to produce nanoscaled fibrous scaffolds, together with innovative methods to improve scaffold biofunctionality with bioactive cues are highlighted. To date, the majority of research into cartilage regeneration has been focused on articular cartilage due to the high prevalence of large joint osteoarthritis in an increasingly aging population. Nevertheless, the principles and advances are applicable to cartilage engineering for plastic and reconstructive surgery. PMID:24883273

  20. Biomimetic Materials for Tissue Engineering

    PubMed Central

    Ma, Peter X

    2008-01-01

    Tissue engineering and regenerative medicine is an exciting research area that aims at regenerative alternatives to harvested tissues for transplantation. Biomaterials play a pivotal role as scaffolds to provide three-dimensional templates and synthetic extracellular-matrix environments for tissue regeneration. It is often beneficial for the scaffolds to mimic certain advantageous characteristics of the natural extracellular matrix, or developmental or would healing programs. This article reviews current biomimetic materials approaches in tissue engineering. These include synthesis to achieve certain compositions or properties similar to those of the extracellular matrix, novel processing technologies to achieve structural features mimicking the extracellular matrix on various levels, approaches to emulate cell-extracellular matrix interactions, and biologic delivery strategies to recapitulate a signaling cascade or developmental/would-healing program. The article also provides examples of enhanced cellular/tissue functions and regenerative outcomes, demonstrating the excitement and significance of the biomimetic materials for tissue engineering and regeneration. PMID:18045729

  1. From biomimetic apatites to biologically inspired composites.

    PubMed

    Tampieri, A; Celotti, G; Landi, E

    2005-02-01

    Hydroxyapatite is an elective material for bone substitution. In this outline of our recent activity the crucial role of nanostructured ceramics in the design and preparation of ceramic scaffolds will be described, focussing on our more recent interest in biomimetic apatites, in particular apatites containing HPO42- CO32- and Mg2+ which are similar to the mineral component of bone. The paper describes such nanostructured products and, in particular, innovative synthetic techniques capable of yielding powders with higher reactivity and bioactivity. However, so far the characteristics of artificial bone tissues have been shown to be very different from those of natural bone, mainly because of the absence of the peculiar self-organizing interaction between apatites and the protein component. This causes modification of the structure of apatites and of the features of the overall composite forming human bone tissue. Therefore, attempts to mimic the features and structure of natural bone tissue, leading toward so-called bio-inspired materials, will be speculated upon. New techniques used to reproduce a composite in which a nanosize blade-like crystal of hydroxyapatite (HA) grows in contact with self-assembling fibres of natural polymer will be presented. In this specific case, the amazing ability of biological systems to store and process information at the molecular level, nucleating nanosize apatites (bio-inspired material), is exploited.

  2. Biomimetic Microelectronics for Regenerative Neuronal Cuff Implants.

    PubMed

    Karnaushenko, Daniil; Münzenrieder, Niko; Karnaushenko, Dmitriy D; Koch, Britta; Meyer, Anne K; Baunack, Stefan; Petti, Luisa; Tröster, Gerhard; Makarov, Denys; Schmidt, Oliver G

    2015-11-18

    Smart biomimetics, a unique class of devices combining the mechanical adaptivity of soft actuators with the imperceptibility of microelectronics, is introduced. Due to their inherent ability to self-assemble, biomimetic microelectronics can firmly yet gently attach to an inorganic or biological tissue enabling enclosure of, for example, nervous fibers, or guide the growth of neuronal cells during regeneration.

  3. Touch stimulated pulse generation in biomimetic single-layer graphene

    NASA Astrophysics Data System (ADS)

    Sul, Onejae; Chun, Hyunsuk; Choi, Eunseok; Choi, Jungbong; Cho, Kyeongwon; Jang, Dongpyo; Chun, Sungwoo; Park, Wanjun; Lee, Seung-Beck

    2016-02-01

    Detecting variation in contact pressure is a separate sensing mode in the human somatosensory system that differs from the detection of pressure magnitude. If pressure magnitude and variation sensing can be achieved simultaneously, an advanced biomimetic tactile system that better emulates human senses may be developed. We report on a novel single-layer graphene based artificial mechanoreceptor that generates a resistance pulse as the contact stimulus passes a specific threshold pressure, mimicking the generation of action potentials in a biological fast-adapting mechanoreceptor. The electric field from a flexible membrane gate electrode placed above a graphene channel raises the Fermi level from the valence band as pressure deflects the membrane. The threshold pressure is reached when the Fermi level crosses the Dirac point in the graphene energy band, which generates a sharp peak in the measured resistance. We found that by changing the gate potential it was possible to modulate the threshold pressure and using a series of graphene channels, a train of pulses were generated during a transient pressurizing stimulus demonstrating biomimetic behaviour.Detecting variation in contact pressure is a separate sensing mode in the human somatosensory system that differs from the detection of pressure magnitude. If pressure magnitude and variation sensing can be achieved simultaneously, an advanced biomimetic tactile system that better emulates human senses may be developed. We report on a novel single-layer graphene based artificial mechanoreceptor that generates a resistance pulse as the contact stimulus passes a specific threshold pressure, mimicking the generation of action potentials in a biological fast-adapting mechanoreceptor. The electric field from a flexible membrane gate electrode placed above a graphene channel raises the Fermi level from the valence band as pressure deflects the membrane. The threshold pressure is reached when the Fermi level crosses the Dirac

  4. Biomimetic polyesters and their role in ion transport across cell membranes.

    PubMed

    Jedliński, Z; Kurcok, P; Adamus, G; Juzwa, M

    2000-01-01

    Syntheses of biomimetic low-molecular weight poly-(R)-3-hydroxybutanoate mediated by three types of supramolecular catalysts are presented. The utility of these synthetic polyesters for preparation of artificial channels in phospholipid bilayers capable of sodium and calcium ion transport across cell membranes, is discussed. Further studies on possible applications of these bio-polymers for manufacturing drugs of prolonged activity are under way.

  5. Biomimetics in drug delivery systems: A critical review.

    PubMed

    Sheikhpour, Mojgan; Barani, Leila; Kasaeian, Alibakhsh

    2017-03-18

    Today, the advanced drug delivery systems have been focused on targeted drug delivery fields. The novel drug delivery is involved with the improvement of the capacity of drug loading in drug carriers, cellular uptake of drug carriers, and the sustained release of drugs within target cells. In this review, six groups of therapeutic drug carriers including biomimetic hydrogels, biomimetic micelles, biomimetic liposomes, biomimetic dendrimers, biomimetic polymeric carriers and biomimetic nanostructures, are studied. The subject takes advantage of the biomimetic methods of productions or the biomimetic techniques for the surface modifications, similar to what accrues in natural cells. Moreover, the effects of these biomimetic approaches for promoting the drug efficiency in targeted drug delivery are visible. The study demonstrates that the fabrication of biomimetic nanocomposite drug carriers could noticeably promote the efficiency of drugs in targeted drug delivery systems.

  6. Biomimetic microenvironments for regenerative endodontics.

    PubMed

    Kaushik, Sagar N; Kim, Bogeun; Walma, Alexander M Cruz; Choi, Sung Chul; Wu, Hui; Mao, Jeremy J; Jun, Ho-Wook; Cheon, Kyounga

    2016-01-01

    Regenerative endodontics has been proposed to replace damaged and underdeveloped tooth structures with normal pulp-dentin tissue by providing a natural extracellular matrix (ECM) mimicking environment; stem cells, signaling molecules, and scaffolds. In addition, clinical success of the regenerative endodontic treatments can be evidenced by absence of signs and symptoms; no bony pathology, a disinfected pulp, and the maturation of root dentin in length and thickness. In spite of the various approaches of regenerative endodontics, there are several major challenges that remain to be improved: a) the endodontic root canal is a strong harbor of the endodontic bacterial biofilm and the fundamental etiologic factors of recurrent endodontic diseases, (b) tooth discolorations are caused by antibiotics and filling materials, (c) cervical root fractures are caused by endodontic medicaments, (d) pulp tissue is not vascularized nor innervated, and (e) the dentin matrix is not developed with adequate root thickness and length. Generally, current clinical protocols and recent studies have shown a limited success of the pulp-dentin tissue regeneration. Throughout the various approaches, the construction of biomimetic microenvironments of pulp-dentin tissue is a key concept of the tissue engineering based regenerative endodontics. The biomimetic microenvironments are composed of a synthetic nano-scaled polymeric fiber structure that mimics native pulp ECM and functions as a scaffold of the pulp-dentin tissue complex. They will provide a framework of the pulp ECM, can deliver selective bioactive molecules, and may recruit pluripotent stem cells from the vicinity of the pulp apex. The polymeric nanofibers are produced by methods of self-assembly, electrospinning, and phase separation. In order to be applied to biomedical use, the polymeric nanofibers require biocompatibility, stability, and biodegradability. Therefore, this review focuses on the development and application of the

  7. Biomimetics: its practice and theory.

    PubMed

    Vincent, Julian F V; Bogatyreva, Olga A; Bogatyrev, Nikolaj R; Bowyer, Adrian; Pahl, Anja-Karina

    2006-08-22

    Biomimetics, a name coined by Otto Schmitt in the 1950s for the transfer of ideas and analogues from biology to technology, has produced some significant and successful devices and concepts in the past 50 years, but is still empirical. We show that TRIZ, the Russian system of problem solving, can be adapted to illuminate and manipulate this process of transfer. Analysis using TRIZ shows that there is only 12% similarity between biology and technology in the principles which solutions to problems illustrate, and while technology solves problems largely by manipulating usage of energy, biology uses information and structure, two factors largely ignored by technology.

  8. Calixarenes and Their Biomimetic Applications

    PubMed Central

    Agrawal, Y. K.; Bhatt, Harshit

    2004-01-01

    The synthetic models for the structures, spectroscopic properties and catalytic activities of metalloprotein active sites have been reviewed. Calixarenes were used as new biomimetic catalysts because of their advantage of providing preorganiiation of the catalytic group, which can bind the substrate dynamically that results in fast turnover and fast release of the products. Functional and structural models based on calixarenes are presented and in addition importance of molecular recognition and non-covalent interactions e.g. hydrogen bonding and their role in biological systems are discussed with the help of synthetic systems. PMID:18365079

  9. Biomimetics: its practice and theory

    PubMed Central

    Vincent, Julian F.V; Bogatyreva, Olga A; Bogatyrev, Nikolaj R; Bowyer, Adrian; Pahl, Anja-Karina

    2006-01-01

    Biomimetics, a name coined by Otto Schmitt in the 1950s for the transfer of ideas and analogues from biology to technology, has produced some significant and successful devices and concepts in the past 50 years, but is still empirical. We show that TRIZ, the Russian system of problem solving, can be adapted to illuminate and manipulate this process of transfer. Analysis using TRIZ shows that there is only 12% similarity between biology and technology in the principles which solutions to problems illustrate, and while technology solves problems largely by manipulating usage of energy, biology uses information and structure, two factors largely ignored by technology. PMID:16849244

  10. Methane hydroxylation: a biomimetic approach

    NASA Astrophysics Data System (ADS)

    Shilov, Aleksandr E.; Shteinman, Al'bert A.

    2012-04-01

    The review addresses direct methane oxidation — an important fundamental problem, which has attracted much attention of researchers in recent years. Analysis of the available results on biomimetic and bio-inspired methane oxygenation has demonstrated that assimilating of the experience of Nature on oxidation of methane and other alkanes significantly enriches the arsenal of chemistry and can radically change the character of the entire chemical production, as well as enables the solution of many material, energetic and environmental problems. The bibliography includes 310 references.

  11. Challenges in Commercializing Biomimetic Membranes

    PubMed Central

    Perry, Mark; Madsen, Steen Ulrik; Jørgensen, Tine; Braekevelt, Sylvie; Lauritzen, Karsten; Hélix-Nielsen, Claus

    2015-01-01

    The discovery of selective water channel proteins—aquaporins—has prompted growing interest in using these proteins, as the building blocks for designing new types of membranes. However, as with any other new and potentially disruptive technology, barriers for successful market entry exist. One category includes customer-related barriers, which can be influenced to some extent. Another category includes market-technical-related barriers, which can be very difficult to overcome by an organization/company aiming at successfully introducing their innovation on the market—in particular if both the organization and the technology are at early stages. Often, one faces barriers from both these categories at the same time, which makes it necessary to gain insight of the particular market when introducing a new innovative product. In this review we present the basic concepts and discuss some of these barriers and challenges associated with introducing biomimetic aquaporin membranes. These include technical issues in membrane production and product testing. Then we discuss possible business models for introducing new technologies in general, followed by a presentation of beach-head market segments relevant for biomimetic aquaporin membranes. PMID:26556379

  12. Biomimetic Photonic Crystals based on Diatom Algae Frustules

    NASA Astrophysics Data System (ADS)

    Mishler, Jonathan; Alverson, Andrew; Herzog, Joseph

    2015-03-01

    Diatom algae are unicellular, photosynthetic microorganisms with a unique external shell known as a frustule. Frustules, which are composed of amorphous silica, exhibit a unique periodic nano-patterning, distinguishing diatoms from other types of phytoplankton. Diatoms have been studied for their distinctive optical properties due to their resemblance of photonic crystals. In this regard, diatoms are not only considered for their applications as photonic crystals, but also for their use as biomimetic templates for artificially fabricated photonic crystals. Through the examination and measurement of the physical characteristics of many scanning electron microscope (SEM) images of diatom frustules, a biomimetic photonic crystal derived from diatom frustules can be recreated and modeled with the finite element method. In this approach, the average geometries of the diatom frustules are used to recreate a 2-dimensional photonic crystal, after which the electric field distribution and optical transmission through the photonic crystal are both measured. The optical transmission is then compared to the transmission spectra of a regular hexagonal photonic crystal, revealing the effects of diatom geometry on their optical properties. Finally, the dimensions of the photonic crystal are parametrically swept, allowing for further control over the transmission of light through the photonic crystal.

  13. Biomimetics inspired surfaces for drag reduction and oleophobicity/philicity.

    PubMed

    Bhushan, Bharat

    2011-01-01

    The emerging field of biomimetics allows one to mimic biology or nature to develop nanomaterials, nanodevices, and processes which provide desirable properties. Hierarchical structures with dimensions of features ranging from the macroscale to the nanoscale are extremely common in nature and possess properties of interest. There are a large number of objects including bacteria, plants, land and aquatic animals, and seashells with properties of commercial interest. Certain plant leaves, such as lotus (Nelumbo nucifera) leaves, are known to be superhydrophobic and self-cleaning due to the hierarchical surface roughness and presence of a wax layer. In addition to a self-cleaning effect, these surfaces with a high contact angle and low contact angle hysteresis also exhibit low adhesion and drag reduction for fluid flow. An aquatic animal, such as a shark, is another model from nature for the reduction of drag in fluid flow. The artificial surfaces inspired from the shark skin and lotus leaf have been created, and in this article the influence of structure on drag reduction efficiency is reviewed. Biomimetic-inspired oleophobic surfaces can be used to prevent contamination of the underwater parts of ships by biological and organic contaminants, including oil. The article also reviews the wetting behavior of oil droplets on various superoleophobic surfaces created in the lab.

  14. Biomimetics inspired surfaces for drag reduction and oleophobicity/philicity

    PubMed Central

    2011-01-01

    Summary The emerging field of biomimetics allows one to mimic biology or nature to develop nanomaterials, nanodevices, and processes which provide desirable properties. Hierarchical structures with dimensions of features ranging from the macroscale to the nanoscale are extremely common in nature and possess properties of interest. There are a large number of objects including bacteria, plants, land and aquatic animals, and seashells with properties of commercial interest. Certain plant leaves, such as lotus (Nelumbo nucifera) leaves, are known to be superhydrophobic and self-cleaning due to the hierarchical surface roughness and presence of a wax layer. In addition to a self-cleaning effect, these surfaces with a high contact angle and low contact angle hysteresis also exhibit low adhesion and drag reduction for fluid flow. An aquatic animal, such as a shark, is another model from nature for the reduction of drag in fluid flow. The artificial surfaces inspired from the shark skin and lotus leaf have been created, and in this article the influence of structure on drag reduction efficiency is reviewed. Biomimetic-inspired oleophobic surfaces can be used to prevent contamination of the underwater parts of ships by biological and organic contaminants, including oil. The article also reviews the wetting behavior of oil droplets on various superoleophobic surfaces created in the lab. PMID:21977417

  15. Synthetic biology and biomimetic chemistry as converging technologies fostering a new generation of smart biosensors.

    PubMed

    Scognamiglio, Viviana; Antonacci, Amina; Lambreva, Maya D; Litescu, Simona C; Rea, Giuseppina

    2015-12-15

    Biosensors are powerful tunable systems able to switch between an ON/OFF status in response to an external stimulus. This extraordinary property could be engineered by adopting synthetic biology or biomimetic chemistry to obtain tailor-made biosensors having the desired requirements of robustness, sensitivity and detection range. Recent advances in both disciplines, in fact, allow to re-design the configuration of the sensing elements - either by modifying toggle switches and gene networks, or by producing synthetic entities mimicking key properties of natural molecules. The present review considered the role of synthetic biology in sustaining biosensor technology, reporting examples from the literature and reflecting on the features that make it a useful tool for designing and constructing engineered biological systems for sensing application. Besides, a section dedicated to bioinspired synthetic molecules as powerful tools to enhance biosensor potential is reported, and treated as an extension of the concept of biomimetic chemistry, where organic synthesis is used to generate artificial molecules that mimic natural molecules. Thus, the design of synthetic molecules, such as aptamers, biomimetics, molecular imprinting polymers, peptide nucleic acids, and ribozymes were encompassed as "products" of biomimetic chemistry.

  16. Enzymatically active biomimetic micropropellers for the penetration of mucin gels

    PubMed Central

    Walker, Debora; Käsdorf, Benjamin T.; Jeong, Hyeon-Ho; Lieleg, Oliver; Fischer, Peer

    2015-01-01

    In the body, mucus provides an important defense mechanism by limiting the penetration of pathogens. It is therefore also a major obstacle for the efficient delivery of particle-based drug carriers. The acidic stomach lining in particular is difficult to overcome because mucin glycoproteins form viscoelastic gels under acidic conditions. The bacterium Helicobacter pylori has developed a strategy to overcome the mucus barrier by producing the enzyme urease, which locally raises the pH and consequently liquefies the mucus. This allows the bacteria to swim through mucus and to reach the epithelial surface. We present an artificial system of reactive magnetic micropropellers that mimic this strategy to move through gastric mucin gels by making use of surface-immobilized urease. The results demonstrate the validity of this biomimetic approach to penetrate biological gels, and show that externally propelled microstructures can actively and reversibly manipulate the physical state of their surroundings, suggesting that such particles could potentially penetrate native mucus. PMID:26824056

  17. Biomimetic Yeast Cell Typing-Application of QCMs.

    PubMed

    Seidler, Karin; Polreichová, Miroslava; Lieberzeit, Peter A; Dickert, Franz L

    2009-01-01

    Artificial antibodies represent a key factor in the generation of sensing systems for the selective detection of bioanalytes of variable sizes. With biomimetic surfaces, the important model organism Saccharomyces cerevisiae and several of its growth stages may be detected. Quartz crystal microbalances (QCM) with 10 MHz fundamental frequency and coated with polymers imprinted with synchronized yeast cells are presented, which are able to detect duplex cells with high selectivity. Furthermore, a multichannel quartz crystal microbalance (MQCM) was designed and optimized for the measurement in liquids. This one-chip system based on four-electrode geometry allows the simultaneous detection of four analytes and, thus, provides a monitoring system for biotechnology and process control. For further standardization of the method, synthetic stamps containing plastic yeast cells in different growth stages were produced and utilized for imprinting. Mass-sensitive measurements with such MIPs resulted in the same sensor characteristics as obtained for those imprinted with native yeast cells.

  18. Biomimetic electrospun nanofibrous structures for tissue engineering

    PubMed Central

    Wang, Xianfeng; Ding, Bin; Li, Bingyun

    2013-01-01

    Biomimetic nanofibrous scaffolds mimicking important features of the native extracellular matrix provide a promising strategy to restore functions or achieve favorable responses for tissue regeneration. This review provides a brief overview of current state-of-the-art research designing and using biomimetic electrospun nanofibers as scaffolds for tissue engineering. It begins with a brief introduction of electrospinning and nanofibers, with a focus on issues related to the biomimetic design aspects. The review next focuses on several typical biomimetic nanofibrous structures (e.g. aligned, aligned to random, spiral, tubular, and sheath membrane) that have great potential for tissue engineering scaffolds, and describes their fabrication, advantages, and applications in tissue engineering. The review concludes with perspectives on challenges and future directions for design, fabrication, and utilization of scaffolds based on electrospun nanofibers. PMID:25125992

  19. Dopamine modulated ionic permeability in mesoporous silica sphere based biomimetic compartment.

    PubMed

    Liu, Wei; Yang, Xiaohai; He, Dinggeng; He, Leiliang; Li, Li; Liu, Yu; Liu, Jianbo; Wang, Kemin

    2016-06-01

    The building of artificial systems with similar structure and function as cellular compartments will expand our understanding of compartmentalization related biological process and facilitate the construction of biomimetic highly functional structures. Herein, surface phenylboronic acid functionalized mesoporous silica sphere was developed as a biomimetic dopamine gated compartment, in which the ionic permeability can be well modulated through the dopamine-binding induced charge reversal. As the phenylboronic acid is negatively charged, the negatively charged 1, 3, 6, 8-pyrenetetrasulfonic acid (TPSA) was hindered from permeation into the biomimetic compartment. However, the presence of dopamine and its binding with phenylboronic acid reversed the gatekeeper shell from negative to positive charged and gated the permeation of TPSA into the interior. The dopamine gated permeation phenomenon resembles that in biological system, and thus the phenylboronic acid functionalized mesoporous silica sphere was taken as a simple model for dopamine gated ion channel decorated biological compartment. It will also contribute to the development of artificial cell and responsive nanoreactor.

  20. Molecular biomimetics: nanotechnology through biology

    NASA Astrophysics Data System (ADS)

    Sarikaya, Mehmet; Tamerler, Candan; Jen, Alex K.-Y.; Schulten, Klaus; Baneyx, François

    2003-09-01

    Proteins, through their unique and specific interactions with other macromolecules and inorganics, control structures and functions of all biological hard and soft tissues in organisms. Molecular biomimetics is an emerging field in which hybrid technologies are developed by using the tools of molecular biology and nanotechnology. Taking lessons from biology, polypeptides can now be genetically engineered to specifically bind to selected inorganic compounds for applications in nano- and biotechnology. This review discusses combinatorial biological protocols, that is, bacterial cell surface and phage-display technologies, in the selection of short sequences that have affinity to (noble) metals, semiconducting oxides and other technological compounds. These genetically engineered proteins for inorganics (GEPIs) can be used in the assembly of functional nanostructures. Based on the three fundamental principles of molecular recognition, self-assembly and DNA manipulation, we highlight successful uses of GEPI in nanotechnology.

  1. Contact kinematics of biomimetic scales

    SciTech Connect

    Ghosh, Ranajay; Ebrahimi, Hamid; Vaziri, Ashkan

    2014-12-08

    Dermal scales, prevalent across biological groups, considerably boost survival by providing multifunctional advantages. Here, we investigate the nonlinear mechanical effects of biomimetic scale like attachments on the behavior of an elastic substrate brought about by the contact interaction of scales in pure bending using qualitative experiments, analytical models, and detailed finite element (FE) analysis. Our results reveal the existence of three distinct kinematic phases of operation spanning linear, nonlinear, and rigid behavior driven by kinematic interactions of scales. The response of the modified elastic beam strongly depends on the size and spatial overlap of rigid scales. The nonlinearity is perceptible even in relatively small strain regime and without invoking material level complexities of either the scales or the substrate.

  2. Silica-supported biomimetic membranes.

    PubMed

    Ariga, Katsuhiko

    2004-01-01

    The hybridization of lipid membranes with inorganic silica-based framework results in mechanically stable biomembrane mimics. This account describes three types of silica-based biomimetic membranes. As the first example, a Langmuir monolayer of dialkylalkoxysilane was polymerized and immobilized onto a porous glass plate. Permeability through the monolayer-immobilized glass was regulated by phase transition of the immobilized monolayer. In the second example, spherical vesicles covalently attached to a silica cover layer (Cerasome) were prepared. The Cerasome was stable enough to be assembled into layer-by-layer films without destruction of its vesicular structure. This material could be an example of the multicellular assembly. Mesoporous silica films densely filling peptide assemblies (Proteosilica) are introduced as the third example. The Proteosilica was synthesized as a transparent film through template sol-gel reaction using amphiphilic peptides.

  3. Biological and biomimetic molecular machines.

    PubMed

    Huang, Tony J; Juluri, Bala K

    2008-02-01

    The evolution of life facilitates the creation of biological molecular machines. In these so-called 'nanomachines,' nature elegantly shows that when precisely organized and assembled, simple molecular mechanical components can link motions efficiently from the nanometer scale to the macroscopic world, and achieve complex functions such as powering skeletal muscles, synthesizing ATP and producing DNA/RNA. Inspired by nature, researchers are creating artifical molecular machines with tailored structures and properties, with the aim of realizing man-made active nanosystems that operate with the same efficiency and complexity as biological nanomachines. It is anticipated that in the not-too-distant future, unique applications of biological and biomimetic molecular machines will emerge in areas such as biochemical instrumentation and nanomedicine.

  4. Biomimetic design in microparticulate vaccines.

    PubMed

    Keegan, Mark E; Whittum-Hudson, Judith A; Mark Saltzman, W

    2003-11-01

    Current efforts to improve the effectiveness of microparticle vaccines include incorporating biomimetic features into the particles. Many pathogens use surface molecules to target specific cell types in the gut for host invasion. This observation has inspired efforts to chemically conjugate cell-type targeting ligands to the surfaces of microparticles in order to increase the efficiency of uptake, and therefore the effectiveness, of orally administered microparticles. Bio-mimicry is not limited to the exterior surface of the microparticles. Anti-idiotypic antibodies, cytokines or other biological modifiers can be encapsulated for delivery to sites of interest as vaccines or other therapeutics. Direct mucosal delivery of microparticle vaccines or immunomodulatory agents may profoundly enhance mucosal and systemic immune responses compared to other delivery routes.

  5. Biomimetic mechanism for micro aircraft

    NASA Technical Reports Server (NTRS)

    Pines, Darryll J. (Inventor); Bohorquez, Felipe A. (Inventor); Sirohi, Jayant (Inventor)

    2005-01-01

    A biomimetic pitching and flapping mechanism including a support member, at least two blade joints for holding blades and operatively connected to the support member. An outer shaft member is concentric with the support member, and an inner shaft member is concentric with the outer shaft member. The mechanism allows the blades of a small-scale rotor to be actuated in the flap and pitch degrees of freedom. The pitching and the flapping are completely independent from and uncoupled to each other. As such, the rotor can independently flap, or independently pitch, or flap and pitch simultaneously with different amplitudes and/or frequencies. The mechanism can also be used in a non-rotary wing configuration, such as an ornithopter, in which case the rotational degree of freedom would be suppressed.

  6. Biomimetic and Bioinspired Synthesis of Nanomaterials/Nanostructures.

    PubMed

    Zan, Guangtao; Wu, Qingsheng

    2016-03-16

    In recent years, due to its unparalleled advantages, the biomimetic and bioinspired synthesis of nanomaterials/nanostructures has drawn increasing interest and attention. Generally, biomimetic synthesis can be conducted either by mimicking the functions of natural materials/structures or by mimicking the biological processes that organisms employ to produce substances or materials. Biomimetic synthesis is therefore divided here into "functional biomimetic synthesis" and "process biomimetic synthesis". Process biomimetic synthesis is the focus of this review. First, the above two terms are defined and their relationship is discussed. Next different levels of biological processes that can be used for process biomimetic synthesis are compiled. Then the current progress of process biomimetic synthesis is systematically summarized and reviewed from the following five perspectives: i) elementary biomimetic system via biomass templates, ii) high-level biomimetic system via soft/hard-combined films, iii) intelligent biomimetic systems via liquid membranes, iv) living-organism biomimetic systems, and v) macromolecular bioinspired systems. Moreover, for these five biomimetic systems, the synthesis procedures, basic principles, and relationships are discussed, and the challenges that are encountered and directions for further development are considered.

  7. Optimized biomimetic antireflection nanostructure for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Tao, Fei; Chen, Jiacheng; Zhou, Hang

    2012-11-01

    Minimizing surface reflection loss is critical when designing high efficiency solar cells. In recent years, biomimetic antireflection nanostructures (such as moth-eye structures), with their extraordinary broadband and omnidirectional antireflection properties, have caught much attention. Single side biomimetic antireflection (AR) coatings show good performance in suppressing broadband reflection between air and glass interface. However, reflection from the interface between absorption layer and transparent window layer still remains. In this study, we proposed a double-side gradient-index nanostructure, and examined its reflection spectrum in comparison with different biomimetic nanostructures using a finite-difference time-domain (FDTD) simulation and effective medium theory (EMT). In order to minimize surface reflection, all abrupt interfaces were replaced by gradientindex biomimetic nanostructures, including air/glass interface and absorber/glass interface. Monolayer of silica spheres serve as double-side gradient-index nanostructures, partially immersed into photoabsorbing material. Spheres with diameter smaller than incoming light wavelength show excellent antireflection properties. From simulation results, in normal incidence, average reflection rate of optimized AR coating structure was lower to around 5% compared to originally above 25% within visible spectrum region (350nm - 850nm). Details of how to apply such biomimetic nanostructures in thin film solar cells were also discussed.

  8. Biomimetic materials design for cardiac tissue regeneration.

    PubMed

    Dunn, David A; Hodge, Alexander J; Lipke, Elizabeth A

    2014-01-01

    Cardiovascular disease is the leading cause of death worldwide. In the absence of sufficient numbers of organs for heart transplant, alternate approaches for healing or replacing diseased heart tissue are under investigation. Designing biomimetic materials to support these approaches will be essential to their overall success. Strategies for cardiac tissue engineering include injection of cells, implantation of three-dimensional tissue constructs or patches, injection of acellular materials, and replacement of valves. To replicate physiological function and facilitate engraftment into native tissue, materials used in these approaches should have properties that mimic those of the natural cardiac environment. Multiple aspects of the cardiac microenvironment have been emulated using biomimetic materials including delivery of bioactive factors, presentation of cell-specific adhesion sites, design of surface topography to guide tissue alignment and dictate cell shape, modulation of mechanical stiffness and electrical conductivity, and fabrication of three-dimensional structures to guide tissue formation and function. Biomaterials can be engineered to assist in stem cell expansion and differentiation, to protect cells during injection and facilitate their retention and survival in vivo, and to provide mechanical support and guidance for engineered tissue formation. Numerous studies have investigated the use of biomimetic materials for cardiac regeneration. Biomimetic material design will continue to exploit advances in nanotechnology to better recreate the cellular environment and advance cardiac regeneration. Overall, biomimetic materials are moving the field of cardiac regenerative medicine forward and promise to deliver new therapies in combating heart disease.

  9. Biomimetic utilization of solar energy

    NASA Astrophysics Data System (ADS)

    Dzhabiev, T. S.; Shilov, Aleksandr E.

    2012-12-01

    The most interesting recent publications dealing with so-called artificial photosynthesis, i.e., the development of photocatalytic converters of solar energy to the chemical bond energy using the fundamental principles of natural oxygenic photosynthesis, are discussed. The key stages of photosynthesis that should be reproduced in the artificial converters include light harvesting and transport of the light quantum to reaction centres where photoinduced charge separation occurs to give elementary reducing agents and oxidants (electrons and holes). The dark catalytic reactions involving the elementary reducing agents and oxidants give stable end products, namely, dioxygen and carbohydrates in the natural photosynthesis or dioxygen and hydrogen in the artificial photosynthesis. The bibliography includes 99 references.

  10. Biomimetics, color, and the arts

    NASA Astrophysics Data System (ADS)

    Schenk, Franziska

    2015-03-01

    Color as dramatic, dynamic and dazzling as the iridescent hues on the wings of certain butterflies has never been encountered in the art world. Unlike and unmatched by the chemical pigments of the artists' palette, this changeable color is created by transparent, colorless nanostructures that, as with prisms, diffract and reflect light to render spectral color visible. Until now, iridescent colors, by their very nature, have defied artists' best efforts to fully capture these rainbow hues. Now, for the first time, the artist and researcher Franziska Schenk employs latest nature-inspired color-shift technology to actually simulate the iridescence of butterflies and beetles on canvas. Crucially, studying the ingenious ways in which a range of such displays are created by insects has provided the artist with vital clues on how to adapt and adopt these challenging optical nano-materials for painting. And indeed, after years of meticulous and painstaking research both in the lab and studio, the desired effect is achieved. The resulting paintings, like an iridescent insect, do in fact fluctuate in perceived color - depending on the light and viewing angle. In tracing the artist's respective biomimetic approach, the paper not only provides an insight into the new color technology's evolution and innovative artistic possibilities, but also suggests what artists can learn from nature.

  11. Forisome as biomimetic smart materials

    NASA Astrophysics Data System (ADS)

    Shen, Amy; Hamlington, Benjamin; Knoblauch, Michael; Peters, Winfried; Pickard, William

    2005-05-01

    With the discovery in plants of the proteinaceous forisome crystalloid (Knoblauch et al. 2003), a novel nastic non-living, ATP-independent biological material became available to the designer of smart materials for advanced actuating and sensing. The in vitro studies of Knoblauch et al. show that forisomes (1-3 micron wide and 10-30 micron long) can be repeatedly stimulated to contract and expand anisotropically by shifting either the ambient pH or the ambient calcium ion concentration. In a device, the energy required for the transformations would be provided electrochemically by mini-electrodes inducing pH variation. Because of their unique abilities to develop and reverse strains greater than 20% in time periods less than 1s , forisomes have the potential to outperform current smart materials (such as ATP-dependent actuators or synthetic hydrogels/polymers) as advanced, biomimetic, multi-functional, smart sensors or valves or actuators. To date, studies have been limited to questions of protein engineering explored by Knaublach et al. Probing forisome material properties is therefore an immediate need to lay the foundation for synthesizing forisome-based smart materials for health monitoring of structural integrity in civil infrastructure and aerospace hardware. Here, we use microfluidics to study the surface interaction between forisome and substrate and the conformational dynamics of forisomes within a confined geometry to lay the foundation for forisome-based smart materials synthesis with controlled and repeatable environment.

  12. Biomimetic Culture Reactor for Whole-Lung Engineering

    PubMed Central

    Raredon, Micha Sam Brickman; Rocco, Kevin A.; Gheorghe, Ciprian P.; Sivarapatna, Amogh; Ghaedi, Mahboobe; Balestrini, Jenna L.; Raredon, Thomas L.; Calle, Elizabeth A.; Niklason, Laura E.

    2016-01-01

    Abstract Decellularized organs are now established as promising scaffolds for whole-organ regeneration. For this work to reach therapeutic practice, techniques and apparatus are necessary for doing human-scale clinically applicable organ cultures. We have designed and constructed a bioreactor system capable of accommodating whole human or porcine lungs, and we describe in this study relevant technical details, means of assembly and operation, and validation. The reactor has an artificial diaphragm that mimics the conditions found in the chest cavity in vivo, driving hydraulically regulated negative pressure ventilation and custom-built pulsatile perfusion apparatus capable of driving pressure-regulated or volume-regulated vascular flow. Both forms of mechanical actuation can be tuned to match specific physiologic profiles. The organ is sealed in an elastic artificial pleura that mounts to a support architecture. This pleura reduces the fluid volume required for organ culture, maintains the organ's position during mechanical conditioning, and creates a sterile barrier allowing disassembly and maintenance outside of a biosafety cabinet. The combination of fluid suspension, negative-pressure ventilation, and physiologic perfusion allows the described system to provide a biomimetic mechanical environment not found in existing technologies and especially suited to whole-organ regeneration. In this study, we explain the design and operation of this apparatus and present data validating intended functions. PMID:27088061

  13. Biomimetic self-cleaning surfaces: synthesis, mechanism and applications

    PubMed Central

    Zhang, Wenwen; Dong, Chenbo; Sreeprasad, Theruvakkattil Sreenivasan

    2016-01-01

    With millions of years of natural evolution, organisms have achieved sophisticated structures, patterns or textures with complex, spontaneous multifunctionality. Among all the fascinating characteristics observed in biosystems, self-cleaning ability is regarded as one of the most interesting topics in biomimicry because of its potential applications in various fields such as aerospace, energy conversion and biomedical and environmental protection. Recently, in-depth studies have been carried out on various compelling biostructures including lotus leaves, shark skins, butterfly wings and gecko feet. To understand and mimic their self-cleaning mechanisms in artificial structures, in this article, recent progress in self-cleaning techniques is discussed and summarized. Based on the underlying self-cleaning mechanisms, the methods are classified into two categories: self-cleaning with water and without water. The review gives a succinct account of the detailed mechanisms and biomimetic processes applied to create artificial self-cleaning materials and surfaces, and provides some examples of cutting-edge applications such as anti-reflection, water repellence, self-healing, anti-fogging and micro-manipulators. The prospectives and directions of future development are also briefly proposed. PMID:27628170

  14. Biomimetic self-cleaning surfaces: synthesis, mechanism and applications.

    PubMed

    Xu, Quan; Zhang, Wenwen; Dong, Chenbo; Sreeprasad, Theruvakkattil Sreenivasan; Xia, Zhenhai

    2016-09-01

    With millions of years of natural evolution, organisms have achieved sophisticated structures, patterns or textures with complex, spontaneous multifunctionality. Among all the fascinating characteristics observed in biosystems, self-cleaning ability is regarded as one of the most interesting topics in biomimicry because of its potential applications in various fields such as aerospace, energy conversion and biomedical and environmental protection. Recently, in-depth studies have been carried out on various compelling biostructures including lotus leaves, shark skins, butterfly wings and gecko feet. To understand and mimic their self-cleaning mechanisms in artificial structures, in this article, recent progress in self-cleaning techniques is discussed and summarized. Based on the underlying self-cleaning mechanisms, the methods are classified into two categories: self-cleaning with water and without water. The review gives a succinct account of the detailed mechanisms and biomimetic processes applied to create artificial self-cleaning materials and surfaces, and provides some examples of cutting-edge applications such as anti-reflection, water repellence, self-healing, anti-fogging and micro-manipulators. The prospectives and directions of future development are also briefly proposed.

  15. An acetylcholinesterase-inspired biomimetic toxicity sensor.

    PubMed

    Wujcik, Evan K; Londoño, Nicolas J; Duirk, Stephen E; Monty, Chelsea N; Masel, Richard I

    2013-05-01

    This work demonstrates the ability of an acetylcholinesterase-inspired biomimetic sensor to accurately predict the toxicity of acetylcholinesterase (AChE) inhibitors. In surface waters used for municipal drinking water supplies, numerous pesticides and other anthropogenic chemicals have been found that inhibit AChE; however, there is currently no portable toxicity assay capable of determining the potential neurotoxicity of water samples and complex mixtures. Biological assays have been developed to determine the toxicity of unknown samples, but the short shelf-life of cells and other biological materials often make them undesirable for use in portable assays. Chemical methods and structure-activity-relationships, on the other hand, require prior knowledge on the compounds of interest that is often unavailable when analyzing environmental samples. In the toxicity assay presented here, the acetylcholinesterase enzyme has been replaced with 1-phenyl-1,2,3-butanetrione 2-oxime (PBO) a biomimetic compound that is structurally similar to the AChE active site. Using a biomimetic compound in place of the native enzyme allows for a longer shelf-life while maintaining the selective and kinetic ability of the enzyme itself. Previous work has shown the success of oxime-based sensors in the selective detection of AChE inhibitors and this work highlights the ability of an AChE-inspired biomimetic sensor to accurately predict the toxicity (LD50 and LC50) for a range of AChE inhibitors. The biomimetic assay shows strong linear correlations to LD50 (oral, rat) and LC50 (fish) values. Using a test set of eight AChE inhibitors, the biomimetic assay accurately predicted the LC50 value for 75% of the inhibitors within one order of magnitude.

  16. Biomimetic and microbial approaches to solar fuel generation.

    PubMed

    Magnuson, Ann; Anderlund, Magnus; Johansson, Olof; Lindblad, Peter; Lomoth, Reiner; Polivka, Tomas; Ott, Sascha; Stensjö, Karin; Styring, Stenbjörn; Sundström, Villy; Hammarström, Leif

    2009-12-21

    Photosynthesis is performed by a multitude of organisms, but in nearly all cases, it is variations on a common theme: absorption of light followed by energy transfer to a reaction center where charge separation takes place. This initial form of chemical energy is stabilized by the biosynthesis of carbohydrates. To produce these energy-rich products, a substrate is needed that feeds in reductive equivalents. When photosynthetic microorganisms learned to use water as a substrate some 2 billion years ago, a fundamental barrier against unlimited use of solar energy was overcome. The possibility of solar energy use has inspired researchers to construct artificial photosynthetic systems that show analogy to parts of the intricate molecular machinery of photosynthesis. Recent years have seen a reorientation of efforts toward creating integrated light-to-fuel systems that can use solar energy for direct synthesis of energy-rich compounds, so-called solar fuels. Sustainable production of solar fuels is a long awaited development that promises extensive solar energy use combined with long-term storage. The stoichiometry of water splitting into molecular oxygen, protons, and electrons is deceptively simple; achieving it by chemical catalysis has proven remarkably difficult. The reaction center Photosystem II couples light-induced charge separation to an efficient molecular water-splitting catalyst, a Mn(4)Ca complex, and is thus an important template for biomimetic chemistry. In our aims to design biomimetic manganese complexes for light-driven water oxidation, we link photosensitizers and charge-separation motifs to potential catalysts in supramolecular assemblies. In photosynthesis, production of carbohydrates demands the delivery of multiple reducing equivalents to CO(2). In contrast, the two-electron reduction of protons to molecular hydrogen is much less demanding. Virtually all microorganisms have enzymes called hydrogenases that convert protons to hydrogen, many of

  17. Tissue bionics: examples in biomimetic tissue engineering.

    PubMed

    Green, David W

    2008-09-01

    Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed 'tissue bionics'. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic.

  18. Biomimetic membranes for sensor and separation applications.

    PubMed

    Nielsen, Claus Hélix

    2009-10-01

    Biological membranes constitute the set of membranes defining boundaries and organelles in living cells--the structural and functional building blocks of all known living organisms. The integrity of the cell depends on its ability to separate inside from outside and yet at the same time allow massive transport of matter in and out the cell. Nature has elegantly met this challenge by developing membranes in the form of lipid bilayers in which specialized and highly efficient transport proteins are incorporated. This raises the question: is it possible to mimic biological membranes and create membrane-based sensor and/or separation devices? In the development of biomimetic sensor/separation technology, both channels (ion and water channels) and carriers (transporters) are important. Generally, each class of transport proteins conducts specific molecular species in and out of the cell while preventing the passage of others, a property critical for the overall conservation of the cells internal pH and salt concentration. Both ion and water channels are highly efficient membrane pore proteins capable of transporting solutes at very high rates, up to 10(9) molecules per second. Carrier proteins generally have a lower turnover but are capable of transport against gradients. For both classes of proteins, their unique flux-properties make them interesting as candidates in biomimetic sensor/separation devices. An ideal sensor/separation device requires the supporting biomimetic matrix to be virtually impermeable to anything but the solute in question. In practice, however, a biomimetic support matrix will generally have finite permeabilities to water, electrolytes, and non-electrolytes. The feasibility of a biomimetic device thus depends on the relative transport contribution from both protein and biomimetic support matrix. Also the stability of the incorporated protein must be addressed and the protein-biomimetic matrix must be encapsulated in order to protect it and make

  19. Evaporation-induced assembly of biomimetic polypeptides

    SciTech Connect

    Keyes, Joseph; Junkin, Michael; Cappello, Joseph; Wu Xiaoyi; Wong, Pak Kin

    2008-07-14

    We report an evaporation assisted plasma lithography (EAPL) process for guided self-assembly of a biomimetic silk-elastinlike protein (SELP). We demonstrate the formation of SELP structures from millimeter to submicrometer range on plasma-treatment surface templates during an evaporation-induced self-assembly process. The self-assembly processes at different humidities and droplet volumes were investigated. The process occurs efficiently in a window of optimized operating conditions found to be at 70% relative humidity and 8 {mu}l volume of SELP solution. The EAPL approach provides a useful technique for the realization of functional devices and systems using these biomimetic materials.

  20. Artificial Intelligence.

    ERIC Educational Resources Information Center

    Waltz, David L.

    1982-01-01

    Describes kinds of results achieved by computer programs in artificial intelligence. Topics discussed include heuristic searches, artificial intelligence/psychology, planning program, backward chaining, learning (focusing on Winograd's blocks to explore learning strategies), concept learning, constraint propagation, language understanding…

  1. Artificial Limbs

    MedlinePlus

    ... you are missing an arm or leg, an artificial limb can sometimes replace it. The device, which is ... activities such as walking, eating, or dressing. Some artificial limbs let you function nearly as well as before.

  2. Biomimetic control for DEA arrays

    NASA Astrophysics Data System (ADS)

    O'Brien, Benjamin; Gisby, Todd; Xie, Sheng Q.; Calius, Emilio; Anderson, Iain

    2010-04-01

    Arrays of actuators are ubiquitous in nature for manipulation, pumping and propulsion. Often these arrays are coordinated in a multi-level fashion with distributed sensing and feedback manipulated by higher level controllers. In this paper we present a biologically inspired multi-level control strategy and apply it to control an array of Dielectric Elastomer Actuators (DEA). A test array was designed consisting of three DEA arranged to tilt a set of rails on which a ball rolls. At the local level the DEA were controlled using capacitive self-sensing state machines that switched the actuator off and on when capacitive thresholds were exceeded, resulting in the steady rolling of the ball around the rails. By varying the voltage of the actuators in the on state, it was possible to control the speed of the ball to match a set point. A simple integral derivative controller was used to do this and an observer law was formulated to track the speed of the ball. The array demonstrated the ability to self start, roll the ball in either direction, and run at a range of speeds determined by the maximum applied voltage. The integral derivative controller successfully tracked a square wave set point. Whilst the test application could have been controlled with a classic centralised controller, the real benefit of the multi-level strategy becomes apparent when applied to larger arrays and biomimetic applications that are ideal for DEA. Three such applications are discussed; a robotic heart, a peristaltic pump and a ctenophore inspired propulsion array.

  3. Exceptionally High Rates of Biological Hydrogen Production by Biomimetic In Vitro Synthetic Enzymatic Pathways.

    PubMed

    Kim, Eui-Jin; Wu, Chang-Hao; Adams, Michael W W; Zhang, Y-H Percival

    2016-11-02

    Hydrogen production by water splitting energized by biomass sugars is one of the most promising technologies for distributed green H2 production. Direct H2 generation from NADPH, catalysed by an NADPH-dependent, soluble [NiFe]-hydrogenase (SH1) is thermodynamically unfavourable, resulting in slow volumetric productivity. We designed the biomimetic electron transport chain from NADPH to H2 by the introduction of an oxygen-insensitive electron mediator benzyl viologen (BV) and an enzyme (NADPH rubredoxin oxidoreductase, NROR), catalysing electron transport between NADPH and BV. The H2 generation rates using this biomimetic chain increased by approximately five-fold compared to those catalysed only by SH1. The peak volumetric H2 productivity via the in vitro enzymatic pathway comprised of hyperthermophilic glucose 6-phosphate dehydrogenase, 6-phosphogluconolactonase, and 6-phosphogluconate dehydrogenase, NROR, and SH1 was 310 mmol H2 /L h(-1) , the highest rate yet reported. The concept of biomimetic electron transport chains could be applied to both in vitro and in vivo H2 production biosystems and artificial photosynthesis.

  4. Progressive macromolecular self-assembly: from biomimetic chemistry to bio-inspired materials.

    PubMed

    Zhao, Yu; Sakai, Fuji; Su, Lu; Liu, Yijiang; Wei, Kongchang; Chen, Guosong; Jiang, Ming

    2013-10-04

    Macromolecular self-assembly (MSA) has been an active and fruitful research field since the 1980s, especially in this new century, which is promoted by the remarkable developments in controlled radical polymerization in polymer chemistry, etc. and driven by the demands in bio-related investigations and applications. In this review, we try to summarize the trends and recent progress in MSA in relation to biomimetic chemistry and bio-inspired materials. Our paper covers representative achievements in the fabrication of artificial building blocks for life, cell-inspired biomimetic materials, and macromolecular assemblies mimicking the functions of natural materials and their applications. It is true that the current status of the deliberately designed and obtained nano-objects based on MSA including a variety of micelles, multicompartment vesicles, and some hybrid and complex nano-objects is at their very first stage to mimic nature, but significant and encouraging progress has been made in achieving a certain similarity in morphologies or properties to that of natural ones. Such achievements also demonstrate that MSA has played an important and irreplaceable role in the grand and long-standing research of biomimetic and bio-inspired materials, the future success of which depends on mutual and persistent efforts in polymer science, material science, supramolecular chemistry, and biology.

  5. Experimental parametric study of a biomimetic fish robot actuated by piezoelectric actuators

    NASA Astrophysics Data System (ADS)

    Wiguna, T.; Park, Hoon C.; Heo, S.; Goo, Nam S.

    2007-04-01

    This paper presents an experiment and parametric study of a biomimetic fish robot actuated by the Lightweight Piezocomposite Actuator (LIPCA). The biomimetic aspects in this work are the oscillating tail beat motion and shape of caudal fin. Caudal fins that resemble fins of BCF (Body and Caudal Fin) mode fish were made in order to perform parametric study concerning the effect of caudal fin characteristics on thrust production at an operating frequency range. The observed caudal fin characteristics are the shape, stiffness, area, and aspect ratio. It is found that a high aspect ratio caudal fin contributes to high swimming speed. The robotic fish propelled by artificial caudal fins shaped after thunniform-fish and mackerel caudal fins, which have relatively high aspect ratio, produced swimming speed as high as 2.364 cm/s and 2.519 cm/s, respectively, for a 300 V p-p input voltage excited at 0.9 Hz. Thrust performance of the biomimetic fish robot is examined by calculating Strouhal number, Froude number, Reynolds number, and power consumption.

  6. Artificial Intelligence.

    ERIC Educational Resources Information Center

    Information Technology Quarterly, 1985

    1985-01-01

    This issue of "Information Technology Quarterly" is devoted to the theme of "Artificial Intelligence." It contains two major articles: (1) Artificial Intelligence and Law" (D. Peter O'Neill and George D. Wood); (2) "Artificial Intelligence: A Long and Winding Road" (John J. Simon, Jr.). In addition, it contains two sidebars: (1) "Calculating and…

  7. Evolving application of biomimetic nanostructured hydroxyapatite

    PubMed Central

    Roveri, Norberto; Iafisco, Michele

    2010-01-01

    By mimicking Nature, we can design and synthesize inorganic smart materials that are reactive to biological tissues. These smart materials can be utilized to design innovative third-generation biomaterials, which are able to not only optimize their interaction with biological tissues and environment, but also mimic biogenic materials in their functionalities. The biomedical applications involve increasing the biomimetic levels from chemical composition, structural organization, morphology, mechanical behavior, nanostructure, and bulk and surface chemical–physical properties until the surface becomes bioreactive and stimulates cellular materials. The chemical–physical characteristics of biogenic hydroxyapatites from bone and tooth have been described, in order to point out the elective sides, which are important to reproduce the design of a new biomimetic synthetic hydroxyapatite. This review outlines the evolving applications of biomimetic synthetic calcium phosphates, details the main characteristics of bone and tooth, where the calcium phosphates are present, and discusses the chemical–physical characteristics of biomimetic calcium phosphates, methods of synthesizing them, and some of their biomedical applications. PMID:24198477

  8. Biomimetic flavin-catalyzed aldehyde oxidation.

    PubMed

    Murray, Alexander T; Matton, Pascal; Fairhurst, Nathan W G; John, Matthew P; Carbery, David R

    2012-07-20

    The oxidation of alkyl and aryl aldehydes to their corresponding carboxylic acids has been achieved through the action of a biomimetic bridged flavin catalyst. The reaction uses readily available 35% aqueous hydrogen peroxide and is operationally simple. The oxidation is a green and sustainable reaction, obviating chlorinated solvents with minimal byproducts.

  9. Major intrinsic proteins in biomimetic membranes.

    PubMed

    Nielsen, Claus Hélix

    2010-01-01

    Biological membranes define the structural and functional boundaries in living cells and their organelles. The integrity of the cell depends on its ability to separate inside from outside and yet at the same time allow massive transport of matter in and out the cell. Nature has elegantly met this challenge by developing membranes in the form of lipid bilayers in which specialized transport proteins are incorporated. This raises the question: is it possible to mimic biological membranes and create a membrane based sensor and/or separation device? In the development of a biomimetic sensor/separation technology, a unique class of membrane transport proteins is especially interesting-the major intrinsic proteins (MIPs). Generally, MIPs conduct water molecules and selected solutes in and out of the cell while preventing the passage of other solutes, a property critical for the conservation of the cells internal pH and salt concentration. Also known as water channels or aquaporins they are highly efficient membrane pore proteins some of which are capable of transporting water at very high rates up to 10(9) molecules per second. Some MIPs transport other small, uncharged solutes, such as glycerol and other permeants such as carbon dioxide, nitric oxide, ammonia, hydrogen peroxide and the metalloids antimonite, arsenite, silicic and boric acid depending on the effective restriction mechanism of the protein. The flux properties of MIPs thus lead to the question ifMIPs can be used in separation devices or as sensor devices based on, e.g., the selective permeation of metalloids. In principle a MIP based membrane sensor/separation device requires the supporting biomimetic matrix to be virtually impermeable to anything but water or the solute in question. In practice, however, a biomimetic support matrix will generally have finite permeabilities to both electrolytes and non-electrolytes. The feasibility of a biomimetic MIP device thus depends on the relative transport

  10. Biomimetics of human movement: functional or aesthetic?

    PubMed

    Harris, Christopher M

    2009-09-01

    How should robotic or prosthetic arms be programmed to move? Copying human smooth movements is popular in synthetic systems, but what does this really achieve? We cannot address these biomimetic issues without a deep understanding of why natural movements are so stereotyped. In this article, we distinguish between 'functional' and 'aesthetic' biomimetics. Functional biomimetics requires insight into the problem that nature has solved and recognition that a similar problem exists in the synthetic system. In aesthetic biomimetics, nature is copied for its own sake and no insight is needed. We examine the popular minimum jerk (MJ) model that has often been used to generate smooth human-like point-to-point movements in synthetic arms. The MJ model was originally justified as maximizing 'smoothness'; however, it is also the limiting optimal trajectory for a wide range of cost functions for brief movements, including the minimum variance (MV) model, where smoothness is a by-product of optimizing the speed-accuracy trade-off imposed by proportional noise (PN: signal-dependent noise with the standard deviation proportional to mean). PN is unlikely to be dominant in synthetic systems, and the control objectives of natural movements (speed and accuracy) would not be optimized in synthetic systems by human-like movements. Thus, employing MJ or MV controllers in robotic arms is just aesthetic biomimetics. For prosthetic arms, the goal is aesthetic by definition, but it is still crucial to recognize that MV trajectories and PN are deeply embedded in the human motor system. Thus, PN arises at the neural level, as a recruitment strategy of motor units and probably optimizes motor neuron noise. Human reaching is under continuous adaptive control. For prosthetic devices that do not have this natural architecture, natural plasticity would drive the system towards unnatural movements. We propose that a truly neuromorphic system with parallel force generators (muscle fibres) and noisy

  11. A review of selected pumping systems in nature and engineering--potential biomimetic concepts for improving displacement pumps and pulsation damping.

    PubMed

    Bach, D; Schmich, F; Masselter, T; Speck, T

    2015-09-03

    The active transport of fluids by pumps plays an essential role in engineering and biology. Due to increasing energy costs and environmental issues, topics like noise reduction, increase of efficiency and enhanced robustness are of high importance in the development of pumps in engineering. The study compares pumps in biology and engineering and assesses biomimetic potentials for improving man-made pumping systems. To this aim, examples of common challenges, applications and current biomimetic research for state-of-the art pumps are presented. The biomimetic research is helped by the similar configuration of many positive displacement pumping systems in biology and engineering. In contrast, the configuration and underlying pumping principles for fluid dynamic pumps (FDPs) differ to a greater extent in biology and engineering. However, progress has been made for positive displacement as well as for FDPs by developing biomimetic devices with artificial muscles and cilia that improve energetic efficiency and fail-safe operation or reduce noise. The circulatory system of vertebrates holds a high biomimetic potential for the damping of pressure pulsations, a common challenge in engineering. Damping of blood pressure pulsation results from a nonlinear viscoelastic behavior of the artery walls which represent a complex composite material. The transfer of the underlying functional principle could lead to an improvement of existing technical solutions and be used to develop novel biomimetic damping solutions. To enhance efficiency or thrust of man-made fluid transportation systems, research on jet propulsion in biology has shown that a pulsed jet can be tuned to either maximize thrust or efficiency. The underlying principle has already been transferred into biomimetic applications in open channel water systems. Overall there is a high potential to learn from nature in order to improve pumping systems for challenges like the reduction of pressure pulsations, increase of jet

  12. High-strength mineralized collagen artificial bone

    NASA Astrophysics Data System (ADS)

    Qiu, Zhi-Ye; Tao, Chun-Sheng; Cui, Helen; Wang, Chang-Ming; Cui, Fu-Zhai

    2014-03-01

    Mineralized collagen (MC) is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal's cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in vivo implantation assay demonstrated good biocompatibility of the material, and in vivo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load-bearing sites.

  13. Artificial Intelligence,

    DTIC Science & Technology

    PATTERN RECOGNITION, * ARTIFICIAL INTELLIGENCE , *TEXTBOOKS, COMPUTER PROGRAMMING, MATHEMATICAL LOGIC, ROBOTS, PROBLEM SOLVING, STATISTICAL ANALYSIS, GAME THEORY, NATURAL LANGUAGE, SELF ORGANIZING SYSTEMS.

  14. Structured light enables biomimetic swimming and versatile locomotion of photoresponsive soft microrobots

    NASA Astrophysics Data System (ADS)

    Palagi, Stefano; Mark, Andrew G.; Reigh, Shang Yik; Melde, Kai; Qiu, Tian; Zeng, Hao; Parmeggiani, Camilla; Martella, Daniele; Sanchez-Castillo, Alberto; Kapernaum, Nadia; Giesselmann, Frank; Wiersma, Diederik S.; Lauga, Eric; Fischer, Peer

    2016-06-01

    Microorganisms move in challenging environments by periodic changes in body shape. In contrast, current artificial microrobots cannot actively deform, exhibiting at best passive bending under external fields. Here, by taking advantage of the wireless, scalable and spatiotemporally selective capabilities that light allows, we show that soft microrobots consisting of photoactive liquid-crystal elastomers can be driven by structured monochromatic light to perform sophisticated biomimetic motions. We realize continuum yet selectively addressable artificial microswimmers that generate travelling-wave motions to self-propel without external forces or torques, as well as microrobots capable of versatile locomotion behaviours on demand. Both theoretical predictions and experimental results confirm that multiple gaits, mimicking either symplectic or antiplectic metachrony of ciliate protozoa, can be achieved with single microswimmers. The principle of using structured light can be extended to other applications that require microscale actuation with sophisticated spatiotemporal coordination for advanced microrobotic technologies.

  15. μ-Biomimetic flow-sensors--introducing light-guiding PDMS structures into MEMS.

    PubMed

    Herzog, Hendrik; Klein, Adrian; Bleckmann, Horst; Holik, Peter; Schmitz, Sam; Siebke, Georg; Tätzner, Simon; Lacher, Manfred; Steltenkamp, Siegfried

    2015-04-16

    In the area of biomimetics, engineers use inspiration from natural systems to develop technical devices, such as sensors. One example is the lateral line system of fish. It is a mechanoreceptive system consisting of up to several thousand individual sensors called neuromasts, which enable fish to sense prey, predators, or conspecifics. So far, the small size and high sensitivity of the lateral line is unmatched by man-made sensor devices. Here, we describe an artificial lateral line system based on an optical detection principle. We developed artificial canal neuromasts using MEMS technology including thick film techniques. In this work, we describe the MEMS fabrication and characterize a sensor prototype. Our sensor consists of a silicon chip, a housing, and an electronic circuit. We demonstrate the functionality of our μ-biomimetic flow sensor by analyzing its response to constant water flow and flow fluctuations. Furthermore, we discuss the sensor robustness and sensitivity of our sensor and its suitability for industrial and medical applications. In sum, our sensor can be used for many tasks, e.g. for monitoring fluid flow in medical applications, for detecting leakages in tap water systems or for air and gas flow measurements. Finally, our flow sensor can even be used to improve current knowledge about the functional significance of the fish lateral line.

  16. Miniature curved artificial compound eyes

    PubMed Central

    Floreano, Dario; Pericet-Camara, Ramon; Viollet, Stéphane; Ruffier, Franck; Brückner, Andreas; Leitel, Robert; Buss, Wolfgang; Menouni, Mohsine; Expert, Fabien; Juston, Raphaël; Dobrzynski, Michal Karol; L’Eplattenier, Geraud; Recktenwald, Fabian; Mallot, Hanspeter A.; Franceschini, Nicolas

    2013-01-01

    In most animal species, vision is mediated by compound eyes, which offer lower resolution than vertebrate single-lens eyes, but significantly larger fields of view with negligible distortion and spherical aberration, as well as high temporal resolution in a tiny package. Compound eyes are ideally suited for fast panoramic motion perception. Engineering a miniature artificial compound eye is challenging because it requires accurate alignment of photoreceptive and optical components on a curved surface. Here, we describe a unique design method for biomimetic compound eyes featuring a panoramic, undistorted field of view in a very thin package. The design consists of three planar layers of separately produced arrays, namely, a microlens array, a neuromorphic photodetector array, and a flexible printed circuit board that are stacked, cut, and curved to produce a mechanically flexible imager. Following this method, we have prototyped and characterized an artificial compound eye bearing a hemispherical field of view with embedded and programmable low-power signal processing, high temporal resolution, and local adaptation to illumination. The prototyped artificial compound eye possesses several characteristics similar to the eye of the fruit fly Drosophila and other arthropod species. This design method opens up additional vistas for a broad range of applications in which wide field motion detection is at a premium, such as collision-free navigation of terrestrial and aerospace vehicles, and for the experimental testing of insect vision theories. PMID:23690574

  17. Miniature curved artificial compound eyes.

    PubMed

    Floreano, Dario; Pericet-Camara, Ramon; Viollet, Stéphane; Ruffier, Franck; Brückner, Andreas; Leitel, Robert; Buss, Wolfgang; Menouni, Mohsine; Expert, Fabien; Juston, Raphaël; Dobrzynski, Michal Karol; L'Eplattenier, Geraud; Recktenwald, Fabian; Mallot, Hanspeter A; Franceschini, Nicolas

    2013-06-04

    In most animal species, vision is mediated by compound eyes, which offer lower resolution than vertebrate single-lens eyes, but significantly larger fields of view with negligible distortion and spherical aberration, as well as high temporal resolution in a tiny package. Compound eyes are ideally suited for fast panoramic motion perception. Engineering a miniature artificial compound eye is challenging because it requires accurate alignment of photoreceptive and optical components on a curved surface. Here, we describe a unique design method for biomimetic compound eyes featuring a panoramic, undistorted field of view in a very thin package. The design consists of three planar layers of separately produced arrays, namely, a microlens array, a neuromorphic photodetector array, and a flexible printed circuit board that are stacked, cut, and curved to produce a mechanically flexible imager. Following this method, we have prototyped and characterized an artificial compound eye bearing a hemispherical field of view with embedded and programmable low-power signal processing, high temporal resolution, and local adaptation to illumination. The prototyped artificial compound eye possesses several characteristics similar to the eye of the fruit fly Drosophila and other arthropod species. This design method opens up additional vistas for a broad range of applications in which wide field motion detection is at a premium, such as collision-free navigation of terrestrial and aerospace vehicles, and for the experimental testing of insect vision theories.

  18. Biomimetics of Bone Implants: The Regenerative Road

    PubMed Central

    Brett, Elizabeth; Flacco, John; Blackshear, Charles; Longaker, Michael T.; Wan, Derrick C.

    2017-01-01

    Abstract The current strategies for healing bone defects are numerous and varied. At the core of each bone healing therapy is a biomimetic mechanism, which works to enhance bone growth. These range from porous scaffolds, bone mineral usage, collagen, and glycosaminoglycan substitutes to transplanted cell populations. Bone defects face a range of difficulty in their healing, given the composite of dense outer compact bone and blood-rich inner trabecular bone. As such, the tissue possesses a number of inherent characteristics, which may be clinically harnessed as promoters of bone healing. These include mechanical characteristics, mineral composition, native collagen content, and cellular fraction of bone. This review charts multiple biomimetic strategies to help heal bony defects in large and small osseous injury sites, with a special focus on cell transplantation. PMID:28163982

  19. Designing Biomimetic Materials from Marine Organisms.

    PubMed

    Nichols, William T

    2015-01-01

    Two biomimetic design approaches that apply biological solutions to engineering problems are discussed. In the first case, motivation comes from an engineering problem and the key challenge is to find analogous biological functions and map them into engineering materials. We illustrate with an example of water pollution remediation through appropriate design of a biomimetic sponge. In the second case, a biological function is already known and the challenge is to identify the appropriate engineering problem. We demonstrate the biological approach with marine diatoms that control energy and materials at their surface providing inspiration for a number of engineering applications. In both cases, it is essential to select materials and structures at the nanoscale to control energy and materials flows at interfaces.

  20. Biomimetic affinity ligands for protein purification.

    PubMed

    Sousa, Isabel T; Taipa, M Angela

    2014-01-01

    The development of sophisticated molecular modeling software and new bioinformatic tools, as well as the emergence of data banks containing detailed information about a huge number of proteins, enabled the de novo intelligent design of synthetic affinity ligands. Such synthetic compounds can be tailored to mimic natural biological recognition motifs or to interact with key surface-exposed residues on target proteins and are designated as "biomimetic ligands." A well-established methodology for generating biomimetic or synthetic affinity ligands integrates rational design with combinatorial solid-phase synthesis and screening, using the triazine scaffold and analogues of amino acids side chains to create molecular diversity.Triazine-based synthetic ligands are nontoxic, low-cost, highly stable compounds that can replace advantageously natural biological ligands in the purification of proteins by affinity-based methodologies.

  1. Biomimetic autonomous robot inspired by the Cyanea capillata (Cyro).

    PubMed

    Villanueva, Alex A; Marut, Kenneth J; Michael, Tyler; Priya, Shashank

    2013-12-01

    A biomimetic robot inspired by Cyanea capillata, termed as 'Cyro', was developed to meet the functional demands of underwater surveillance in defense and civilian applications. The vehicle was designed to mimic the morphology and swimming mechanism of the natural counterpart. The body of the vehicle consists of a rigid support structure with linear DC motors which actuate eight mechanical arms. The mechanical arms in conjunction with artificial mesoglea create the hydrodynamic force required for propulsion. The full vehicle measures 170 cm in diameter and has a total mass of 76 kg. An analytical model of the mechanical arm kinematics was developed. The analytical and experimental bell kinematics were analyzed and compared to the C. capillata. Cyro was found to reach the water surface untethered and autonomously from a depth of 182 cm in five actuation cycles. It achieved an average velocity of 8.47 cm s(-1) while consuming an average power of 70 W. A two-axis thrust stand was developed to calculate the thrust directly from a single bell segment yielding an average thrust of 27.9 N for the whole vehicle. Steady state velocity during Cyro's swimming test was not reached but the measured performance during its last swim cycle resulted in a cost of transport of 10.9 J (kg ⋅ m)(-1) and total efficiency of 0.03.

  2. Biomimetic synthesis of materials for technology.

    PubMed

    Galloway, Johanna M; Bramble, Jonathan P; Staniland, Sarah S

    2013-07-01

    In a world with ever decreasing natural reserves, researchers are striving to find sustainable methods of producing components for technology. Bioinspired, biokleptic and biomimetic materials can be used to form a wide range of technologically relevant materials under environmentally friendly conditions. Here we investigate a range of biotemplated and bioinspired materials that can be used to develop components for devices, such as optics, photonics, photovoltaics, circuits and data storage.

  3. Self-fueled biomimetic liquid metal mollusk.

    PubMed

    Zhang, Jie; Yao, Youyou; Sheng, Lei; Liu, Jing

    2015-04-24

    A liquid metal motor that can "eat" aluminum food and then move spontaneously and swiftly in various solution configurations and structured channels for more than 1 h is discovered. Such a biomimetic mollusk is highly shape self-adaptive by closely conforming to the geometrical space it voyages in. The first ever self-fueled pump is illustrated as one of its typical practical utilizations.

  4. Artificial Intelligence.

    ERIC Educational Resources Information Center

    Thornburg, David D.

    1986-01-01

    Overview of the artificial intelligence (AI) field provides a definition; discusses past research and areas of future research; describes the design, functions, and capabilities of expert systems and the "Turing Test" for machine intelligence; and lists additional sources for information on artificial intelligence. Languages of AI are…

  5. Embedded SMA wire actuated biomimetic fin: a module for biomimetic underwater propulsion

    NASA Astrophysics Data System (ADS)

    Wang, Zhenlong; Hang, Guanrong; Wang, Yangwei; Li, Jian; Du, Wei

    2008-04-01

    An embedded shape memory alloy (SMA) wire actuated biomimetic fin is presented, and based on this module for biomimetic underwater propulsion, a micro robot fish (146 mm in length, 30 g in weight) and a robot squid (242 mm in length, 360 g in weight) were developed. Fish swim by undulating their body and/or fins. Squid and cuttlefish can also swim by undulating their fins. To simplify engineering modeling, the undulating swimming movement is assumed to be the integration of the movements of many flexible bending segments connected in parallel or in series. According to this idea, a biomimetic fin which can bend flexibly was developed. The musculature of a cuttlefish fin was investigated to aid the design of the biomimetic fin. SMA wires act as 'muscle fibers' to drive the biomimetic fin just like the transverse muscles of the cuttlefish fin. During the bending phase, elastic energy is stored in the elastic substrate and skin, and during the return phase, elastic energy is released to power the return movement. Theorem analysis of the bending angle was performed to estimate the bending performance of the biomimetic fin. Experiments were carried out on single-face fins with latex rubber skin and silicone skin (SF-L and SF-S) to compare the bending angle, return time, elastic energy storage and reliability. Silicone was found to be the better skin. A dual-face fin with silicone skin (DF-S) was tested in water to evaluate the actuating performance and to validate the reliability. Thermal analysis of the SMA temperature was performed to aid the control strategy. The micro robot fish and robot squid employ one and ten DF-S, respectively. Swimming experiments with different actuation frequencies were carried out. The speed and steering radius of the micro robot fish reached 112 mm s-1 and 136 mm, respectively, and the speed and rotary speed of the robot squid reached 40 mm s-1 and 22° s-1, respectively.

  6. The promise of microfluidic artificial lungs.

    PubMed

    Potkay, Joseph A

    2014-11-07

    Microfluidic or microchannel artificial lungs promise to enable a new class of truly portable, therapeutic artificial lungs through feature sizes and blood channel designs that closely mimic those found in their natural counterpart. These new artificial lungs could potentially: 1) have surface areas and priming volumes that are a fraction of current technologies thereby decreasing device size and reducing the foreign body response; 2) contain blood flow networks in which cells and platelets experience pressures, shear stresses, and branching angles that copy those in the human lung thereby improving biocompatibility; 3) operate efficiently with room air, eliminating the need for gas cylinders and complications associated with hyperoxemia; 4) exhibit biomimetic hydraulic resistances, enabling operation with natural pressures and eliminating the need for blood pumps; and, 5) provide increased gas exchange capacity enabling respiratory support for active patients. This manuscript reviews recent research efforts in microfluidic artificial lungs targeted at achieving the advantages above, investigates the ultimate performance and scaling limits of these devices using a proven mathematical model, and discusses the future challenges that must be overcome in order for microfluidic artificial lungs to be applied in the clinic. If all of these promising advantages are realized and the remaining challenges are met, microfluidic artificial lungs could revolutionize the field of pulmonary rehabilitation.

  7. Self-assembly and interactions of biomimetic thin films

    NASA Astrophysics Data System (ADS)

    Handa, Hitesh

    Bilayer lipid membranes create the natural environment for the immobilization of functional proteins and have been used as a model for understanding structure and properties of cell membranes. The development of biomimetic surfaces requires in depth knowledge of surface science, self-assembly, immobilization techniques, nanofabrication, biomolecular interactions and analytical techniques. This research is focused on synthesizing and characterizing biomimetic artificial surfaces for fundamental studies in membrane structure and better understanding of specific and non-specific interactions. The other main focus is on surface engineering of self-assembled, nanostructured interfaces that mimic cell membranes. These structures provide a powerful bottom-up approach to the studies of the structure and functionality of cell membranes and their interactions with other molecules. One of the advantages of this approach is that the complexity of the system can be controlled and gradually increased to add functionalities. This dissertation provides a first single molecule force measurement of the specific interactions between Salmonella typhimurium and P22 bacteriophage. This dissertation also provides a novel model system for the confined crystallization of drug molecules such as aspirin using the concept of phospholipid bilayer assembly at surfaces. The results will impact the development of biosensors and drug delivery. The defense will focus on the preparation and bio-recognition interactions between a monolayer of bacteriophage P22, covalently bound to glass substrates through a bifunctional cross linker 3-aminopropyltrimethoxysilane, and the outer membrane of Salmonella, lipopolysaccharides (LPS). The LPS bilayer was deposited on poly (ethylenimine)-modified mica from their sonicated unilamellar vesicle solution. The specific binding of Salmonella typhimurium to the phage monolayer was studied by enzyme-linked immunosorbent assay (ELISA) and atomic force microscopy (AFM

  8. Structure, biomimetics, and fluid dynamics of fish skin surfaces*

    NASA Astrophysics Data System (ADS)

    Lauder, George V.; Wainwright, Dylan K.; Domel, August G.; Weaver, James C.; Wen, Li; Bertoldi, Katia

    2016-10-01

    The interface between the fluid environment and the surface of the body in swimming fishes is critical for both physiological and hydrodynamic functions. The skin surface in most species of fishes is covered with bony scales or toothlike denticles (in sharks). Despite the apparent importance of fish surfaces for understanding aquatic locomotion and near-surface boundary layer flows, relatively little attention has been paid to either the nature of surface textures in fishes or possible hydrodynamic effects of variation in roughness around the body surface within an individual and among species. Fish surfaces are remarkably diverse and in many bony fishes scales can have an intricate surface texture with projections, ridges, and comblike extensions. Shark denticles (or scales) are toothlike and project out of the skin to form a complexly textured surface that interacts with free-stream flow. Manufacturing biomimetic foils with fishlike surfaces allows hydrodynamic testing and we emphasize here the importance of dynamic test conditions where the effect of surface textures is assessed under conditions of self-propulsion. We show that simple two-dimensional foils with patterned cuts do not perform as well as a smooth control surface, but that biomimetic shark skin foils can swim at higher self-propelled speeds than smooth controls. When the arrangement of denticles on the foil surface is altered, we find that a staggered-overlapped pattern outperforms other arrangements. Flexible foils made of real shark skin outperform sanded controls when foils are moved with a biologically realistic motion program. We suggest that focus on the mechanisms of drag reduction by fish surfaces has been too limiting and an additional role of fish surface textures may be to alter leading edge vortices and flow patterns on moving surfaces in a way that enhances thrust. Analysis of water flow over an artificial shark skin foil under both static and dynamic conditions shows that a shear layer

  9. Synthetic Biology: A Bridge between Artificial and Natural Cells

    PubMed Central

    Ding, Yunfeng; Wu, Fan; Tan, Cheemeng

    2014-01-01

    Artificial cells are simple cell-like entities that possess certain properties of natural cells. In general, artificial cells are constructed using three parts: (1) biological membranes that serve as protective barriers, while allowing communication between the cells and the environment; (2) transcription and translation machinery that synthesize proteins based on genetic sequences; and (3) genetic modules that control the dynamics of the whole cell. Artificial cells are minimal and well-defined systems that can be more easily engineered and controlled when compared to natural cells. Artificial cells can be used as biomimetic systems to study and understand natural dynamics of cells with minimal interference from cellular complexity. However, there remain significant gaps between artificial and natural cells. How much information can we encode into artificial cells? What is the minimal number of factors that are necessary to achieve robust functioning of artificial cells? Can artificial cells communicate with their environments efficiently? Can artificial cells replicate, divide or even evolve? Here, we review synthetic biological methods that could shrink the gaps between artificial and natural cells. The closure of these gaps will lead to advancement in synthetic biology, cellular biology and biomedical applications. PMID:25532531

  10. Better than Nature: Nicotinamide Biomimetics That Outperform Natural Coenzymes.

    PubMed

    Knaus, Tanja; Paul, Caroline E; Levy, Colin W; de Vries, Simon; Mutti, Francesco G; Hollmann, Frank; Scrutton, Nigel S

    2016-01-27

    The search for affordable, green biocatalytic processes is a challenge for chemicals manufacture. Redox biotransformations are potentially attractive, but they rely on unstable and expensive nicotinamide coenzymes that have prevented their widespread exploitation. Stoichiometric use of natural coenzymes is not viable economically, and the instability of these molecules hinders catalytic processes that employ coenzyme recycling. Here, we investigate the efficiency of man-made synthetic biomimetics of the natural coenzymes NAD(P)H in redox biocatalysis. Extensive studies with a range of oxidoreductases belonging to the "ene" reductase family show that these biomimetics are excellent analogues of the natural coenzymes, revealed also in crystal structures of the ene reductase XenA with selected biomimetics. In selected cases, these biomimetics outperform the natural coenzymes. "Better-than-Nature" biomimetics should find widespread application in fine and specialty chemicals production by harnessing the power of high stereo-, regio-, and chemoselective redox biocatalysts and enabling reactions under mild conditions at low cost.

  11. Reverse Engineering Nature to Design Biomimetic Total Knee Implants.

    PubMed

    Varadarajan, Kartik Mangudi; Zumbrunn, Thomas; Rubash, Harry E; Malchau, Henrik; Muratoglu, Orhun K; Li, Guoan

    2015-10-01

    While contemporary total knee arthroplasty (TKA) provides tremendous clinical benefits, the normal feel and function of the knee is not fully restored. To address this, a novel design process was developed to reverse engineer "biomimetic" articular surfaces that are compatible with normal soft-tissue envelope and kinematics of the knee. The biomimetic articular surface is created by moving the TKA femoral component along in vivo kinematics of normal knees and carving out the tibial articular surface from a rectangular tibial block. Here, we describe the biomimetic design process. In addition, we utilize geometric comparisons and kinematic simulations to show that; (1) tibial articular surfaces of conventional implants are fundamentally incompatible with normal knee motion, and (2) the anatomic geometry of the biomimetic surface contributes directly to restoration of normal knee kinematics. Such biomimetic implants may enable us to achieve the long sought after goal of a "normal" knee post-TKA surgery.

  12. Biomimetics: forecasting the future of science, engineering, and medicine

    PubMed Central

    Hwang, Jangsun; Jeong, Yoon; Park, Jeong Min; Lee, Kwan Hong; Hong, Jong Wook; Choi, Jonghoon

    2015-01-01

    Biomimetics is the study of nature and natural phenomena to understand the principles of underlying mechanisms, to obtain ideas from nature, and to apply concepts that may benefit science, engineering, and medicine. Examples of biomimetic studies include fluid-drag reduction swimsuits inspired by the structure of shark’s skin, velcro fasteners modeled on burrs, shape of airplanes developed from the look of birds, and stable building structures copied from the backbone of turban shells. In this article, we focus on the current research topics in biomimetics and discuss the potential of biomimetics in science, engineering, and medicine. Our report proposes to become a blueprint for accomplishments that can stem from biomimetics in the next 5 years as well as providing insight into their unseen limitations. PMID:26388692

  13. Biomimetics: forecasting the future of science, engineering, and medicine.

    PubMed

    Hwang, Jangsun; Jeong, Yoon; Park, Jeong Min; Lee, Kwan Hong; Hong, Jong Wook; Choi, Jonghoon

    2015-01-01

    Biomimetics is the study of nature and natural phenomena to understand the principles of underlying mechanisms, to obtain ideas from nature, and to apply concepts that may benefit science, engineering, and medicine. Examples of biomimetic studies include fluid-drag reduction swimsuits inspired by the structure of shark's skin, velcro fasteners modeled on burrs, shape of airplanes developed from the look of birds, and stable building structures copied from the backbone of turban shells. In this article, we focus on the current research topics in biomimetics and discuss the potential of biomimetics in science, engineering, and medicine. Our report proposes to become a blueprint for accomplishments that can stem from biomimetics in the next 5 years as well as providing insight into their unseen limitations.

  14. Special section on biomimetics of movement.

    PubMed

    Carpi, Federico; Erb, Rainer; Jeronimidis, George

    2011-12-01

    Movement in biology is an essential aspect of survival for many organisms, animals and plants. Implementing movement efficiently to meet specific needs is a key attribute of natural living systems, and can provide ideas for man-made developments. If we had to find a subtitle able to essentially convey the aim of this special section, it could read as follows: 'taking inspiration from nature for new materials, actuators, structures and controls for systems that move'. Our world is characterized by a huge variety of technical, engineering systems that move. They surround us in countless products that integrate actuators for different kinds of purposes. Basically, any kind of mechatronic system, such as those used for consumer products, machines, vehicles, industrial systems, robots, etc, is based on one or more devices that move, according to different implementations and motion ranges, often in response to external and internal stimuli. Despite this, technical solutions to develop systems that move do not evolve very quickly as they rely on traditional and well consolidated actuation technologies, which are implemented according to known architectures and with established materials. This fact limits our capability to overcome challenges related to the needs continuously raised by new fields of application, either at small or at large scales. Biomimetics-based approaches may provide innovative thinking and technologies in the field, taking inspiration from nature for smart and effective solutions. In an effort to disseminate current advances in this field, this special section collects some papers that cover different topics. A brief synopsis of the content of each contribution is presented below. The first paper, by Lienhard et al [1], deals with bioinspiration for the realization of structural parts in systems that passively move. It presents a bioinspired hingeless flapping mechanism, considered as a solution to the kinematics of deployable systems for

  15. Sensitivity enhancement of a micro-scale biomimetic tactile sensor with epidermal ridges

    NASA Astrophysics Data System (ADS)

    Zhang, Yuhua

    2010-08-01

    A microscale biomimetic tactile sensor with epidermal ridges is proposed to enhance the sensitivity of force detection. Guided by the principles of the human tactile perception mechanism, specifically the epidermal ridges, artificial epidermal ridges made of polydimethylsiloxane (PDMS) were designed and placed on micro-fabricated metal strain gauge arrays. A polyimide layer was fabricated to facilitate attachment between the metal and PDMS, so that patterned copper could be deposited on the polyimide to function as the strain gauges. The aspect ratio of the artificial epidermal ridges was optimized using material stability calculations and finite element method (FEM) simulations, and the optimal structure obtained was 400 µm in width and 110 µm in height. Experiments verified the effectiveness of enhancing the sensitivity of such a tactile sensor with the artificial epidermal ridges, in that the outputs of the strain gauges were 1.8 times more sensitive than those of a tactile sensor without ridges. The proposed artificial epidermal ridges are readily applicable to any developed tactile sensors for performance enhancement.

  16. Large-Deformation Curling Actuators Based on Carbon Nanotube Composite: Advanced-Structure Design and Biomimetic Application.

    PubMed

    Chen, Luzhuo; Weng, Mingcen; Zhou, Zhiwei; Zhou, Yi; Zhang, Lingling; Li, Jiaxin; Huang, Zhigao; Zhang, Wei; Liu, Changhong; Fan, Shoushan

    2015-12-22

    In recent years, electroactive polymers have been developed as actuator materials. As an important branch of electroactive polymers, electrothermal actuators (ETAs) demonstrate potential applications in the fields of artificial muscles, biomimetic devices, robotics, and so on. Large-shape deformation, low-voltage-driven actuation, and ultrafast fabrication are critical to the development of ETA. However, a simultaneous optimization of all of these advantages has not been realized yet. Practical biomimetic applications are also rare. In this work, we introduce an ultrafast approach to fabricate a curling actuator based on a newly designed carbon nanotube and polymer composite, which completely realizes all of the above required advantages. The actuator shows an ultralarge curling actuation with a curvature greater than 1.0 cm(-1) and bending angle larger than 360°, even curling into a tubular structure. The driving voltage is down to a low voltage of 5 V. The remarkable actuation is attributed not only to the mismatch in the coefficients of thermal expansion but also to the mechanical property changes of materials during temperature change. We also construct an S-shape actuator to show the possibility of building advanced-structure actuators. A weightlifting walking robot is further designed that exhibits a fast-moving motion while lifting a sample heavier than itself, demonstrating promising biomimetic applications.

  17. Biomimetic High-Density Lipoproteins from a Gold Nanoparticle Template

    NASA Astrophysics Data System (ADS)

    Luthi, Andrea Jane

    For hundreds of years the field of chemistry has looked to nature for inspiration and insight to develop novel solutions for the treatment of human diseases. The ability of chemists to identify, mimic, and modifiy small molecules found in nature has led to the discovery and development of many important therapeutics. Chemistry on the nanoscale has made it possible to mimic natural, macromolecular structures that may also be useful for understanding and treating diseases. One example of such a structure is high-density lipoprotein (HDL). The goal of this work is to use a gold nanoparticle (Au NP) as a template to synthesize functional mimics of HDL and characterize their structure and function. Chapter 1 details the structure and function of natural HDL and how chemistry on the nanoscale provides new strategies for mimicking HDL. This Chapter also describes the first examples of using nanoparticles to mimic HDL. Chapter 2 reports the synthesis and characterization of biomimetic HDL using different sizes of Au NPs and different surface chemistries and how these variables can be used to tailor the properties of biomimetic HDL. From these studies the optimal strategy for synthesizing biomimetic HDL was determined. In Chapter 3, the optimization of the synthesis of biomimetic HDL is discussed as well as a full characterization of its structure. In addition, the work in this chapter shows that biomimetic HDL can be synthesized on a large scale without alterations to its structure or function. Chapter 4 focuses on understanding the pathways by which biomimetic HDL accepts cholesterol from macrophage cells. The results of these studies demonstrate that biomimetic HDL is able to accept cholesterol by both active and passive pathways of cholesterol efflux. In Chapter 5 the preliminary results of in vivo studies to characterize the pharmacokinetics and pharmacodynamics of biomimetic HDL are presented. These studies suggest that biomimetic HDL traffics through tissues prone to

  18. Imprinting Technology in Electrochemical Biomimetic Sensors.

    PubMed

    Frasco, Manuela F; Truta, Liliana A A N A; Sales, M Goreti F; Moreira, Felismina T C

    2017-03-06

    Biosensors are a promising tool offering the possibility of low cost and fast analytical screening in point-of-care diagnostics and for on-site detection in the field. Most biosensors in routine use ensure their selectivity/specificity by including natural receptors as biorecognition element. These materials are however too expensive and hard to obtain for every biochemical molecule of interest in environmental and clinical practice. Molecularly imprinted polymers have emerged through time as an alternative to natural antibodies in biosensors. In theory, these materials are stable and robust, presenting much higher capacity to resist to harsher conditions of pH, temperature, pressure or organic solvents. In addition, these synthetic materials are much cheaper than their natural counterparts while offering equivalent affinity and sensitivity in the molecular recognition of the target analyte. Imprinting technology and biosensors have met quite recently, relying mostly on electrochemical detection and enabling a direct reading of different analytes, while promoting significant advances in various fields of use. Thus, this review encompasses such developments and describes a general overview for building promising biomimetic materials as biorecognition elements in electrochemical sensors. It includes different molecular imprinting strategies such as the choice of polymer material, imprinting methodology and assembly on the transduction platform. Their interface with the most recent nanostructured supports acting as standard conductive materials within electrochemical biomimetic sensors is pointed out.

  19. Imprinting Technology in Electrochemical Biomimetic Sensors

    PubMed Central

    Frasco, Manuela F.; Truta, Liliana A. A. N. A.; Sales, M. Goreti F.; Moreira, Felismina T. C.

    2017-01-01

    Biosensors are a promising tool offering the possibility of low cost and fast analytical screening in point-of-care diagnostics and for on-site detection in the field. Most biosensors in routine use ensure their selectivity/specificity by including natural receptors as biorecognition element. These materials are however too expensive and hard to obtain for every biochemical molecule of interest in environmental and clinical practice. Molecularly imprinted polymers have emerged through time as an alternative to natural antibodies in biosensors. In theory, these materials are stable and robust, presenting much higher capacity to resist to harsher conditions of pH, temperature, pressure or organic solvents. In addition, these synthetic materials are much cheaper than their natural counterparts while offering equivalent affinity and sensitivity in the molecular recognition of the target analyte. Imprinting technology and biosensors have met quite recently, relying mostly on electrochemical detection and enabling a direct reading of different analytes, while promoting significant advances in various fields of use. Thus, this review encompasses such developments and describes a general overview for building promising biomimetic materials as biorecognition elements in electrochemical sensors. It includes different molecular imprinting strategies such as the choice of polymer material, imprinting methodology and assembly on the transduction platform. Their interface with the most recent nanostructured supports acting as standard conductive materials within electrochemical biomimetic sensors is pointed out. PMID:28272314

  20. Designing biomimetic pores based on carbon nanotubes

    PubMed Central

    García-Fandiño, Rebeca; Sansom, Mark S. P.

    2012-01-01

    Biomimetic nanopores based on membrane-spanning single-walled carbon nanotubes have been designed to include selectivity filters based on combinations of anionic and cationic groups mimicking those present in bacterial porins and in voltage-gated sodium and calcium channels. The ion permeation and selectivity properties of these nanopores when embedded in a phospholipid bilayer have been explored by molecular dynamics simulations and free energy profile calculations. The interactions of the nanopores with sodium, potassium, calcium, and chloride ions have been explored as a function of the number of anionic and cationic groups within the selectivity filter. Unbiased molecular dynamics simulations show that the overall selectivity is largely determined by the net charge of the filter. Analysis of distribution functions reveals considerable structuring of the distribution of ions and water within the nanopores. The distributions of ions along the pore axis reveal local selectivity for cations around filter, even in those nanopores (C0) where the net filter charge is zero. Single ion free energy profiles also reveal clear evidence for cation selectivity, even in the C0 nanopores. Detailed analysis of the interactions of the C0 nanopore with Ca2+ ions reveals that local interactions with the anionic (carboxylate) groups of the selectivity filter lead to (partial) replacement of solvating water as the ion passes through the pore. These studies suggest that a computational biomimetic approach can be used to evaluate our understanding of the design principles of nanopores and channels. PMID:22509000

  1. Swimming performance of biomimetic trapezoidal elastic fins

    NASA Astrophysics Data System (ADS)

    Spadaro, Michael; Yeh, Peter; Alexeev, Alexander

    2016-11-01

    Using three-dimensional computer simulations, we probe the biomimetic free-swimming of trapezoidal elastic plates plunging sinusoidally in a viscous fluid, varying the frequency of oscillations and plate geometry. We choose the elastic trapezoidal plate geometry because it more closely approximates the shape of real caudal fish fins. Indeed, caudal fins are found in nature in a variety of trapezoidal shapes with different aspect ratios. Because of this, we perform our simulations using plates with aspect ratios varying from the cases where the plate has a longer leading edge and to plates with a longer trailing edge. We find that the trapezoidal fins with the longer trailing edge are less efficient than the rectangular fins at the equivalent oscillation frequencies. This is surprising because many fish found in nature have a widening tail. We relate this to the fact that our model considers fins with uniform thickness whereas fish uses tapered fins. Our results will be useful for the design of biomimetic swimming devices as well as understanding more closely the physics of fish swimming.

  2. Biomimetic cavity-based metal complexes.

    PubMed

    Rebilly, Jean-Noël; Colasson, Benoit; Bistri, Olivia; Over, Diana; Reinaud, Olivia

    2015-01-21

    The design of biomimetic complexes for the modeling of metallo-enzyme active sites is a fruitful strategy for obtaining fundamental information and a better understanding of the molecular mechanisms at work in Nature's chemistry. The classical strategy for modeling metallo-sites relies on the synthesis of metal complexes with polydentate ligands that mimic the coordination environment encountered in the natural systems. However, it is well recognized that metal ion embedment in the proteic cavity has key roles not only in the recognition events but also in generating transient species and directing their reactivity. Hence, this review focuses on an important aspect common to enzymes, which is the presence of a pocket surrounding the metal ion reactive sites. Through selected examples, the following points are stressed: (i) the design of biomimetic cavity-based complexes, (ii) their corresponding host-guest chemistry, with a special focus on problems related to orientation and exchange mechanisms of the ligand within the host, (iii) cavity effects on the metal ion binding properties, including 1st, 2nd, and 3rd coordination spheres and hydrophobic effects and finally (iv) the impact these factors have on the reactivity of embedded metal ions. Important perspectives lie in the use of this knowledge for the development of selective and sensitive probes, new reactions, and green and efficient catalysts with bio-inspired systems.

  3. Biomimetic phantom for cardiac diffusion MRI

    PubMed Central

    Teh, Irvin; Zhou, Feng‐Lei; Hubbard Cristinacce, Penny L.; Parker, Geoffrey J.M.

    2015-01-01

    Purpose Diffusion magnetic resonance imaging (MRI) is increasingly used to characterize cardiac tissue microstructure, necessitating the use of physiologically relevant phantoms for methods development. Existing phantoms are generally simplistic and mostly simulate diffusion in the brain. Thus, there is a need for phantoms mimicking diffusion in cardiac tissue. Materials and Methods A biomimetic phantom composed of hollow microfibers generated using co‐electrospinning was developed to mimic myocardial diffusion properties and fiber and sheet orientations. Diffusion tensor imaging was carried out at monthly intervals over 4 months at 9.4T. 3D fiber tracking was performed using the phantom and compared with fiber tracking in an ex vivo rat heart. Results The mean apparent diffusion coefficient and fractional anisotropy of the phantom remained stable over the 4‐month period, with mean values of 7.53 ± 0.16 × 10‐4 mm2/s and 0.388 ± 0.007, respectively. Fiber tracking of the 1st and 3rd eigenvectors generated analogous results to the fiber and sheet‐normal direction respectively, found in the left ventricular myocardium. Conclusion A biomimetic phantom simulating diffusion in the heart was designed and built. This could aid development and validation of novel diffusion MRI methods for investigating cardiac microstructure, decrease the number of animals and patients needed for methods development, and improve quality control in longitudinal and multicenter cardiac diffusion MRI studies. J. MAGN. RESON. IMAGING 2016;43:594–600. PMID:26213152

  4. Long range excitonic transport in a biomimetic system inspired by the bacterial light-harvesting apparatus.

    PubMed

    Harel, Elad

    2012-05-07

    Photosynthesis, the process by which energy from sunlight drives cellular metabolism, relies on a unique organization of light-harvesting and reaction center complexes. Recently, the organization of light-harvesting LH2 complexes and dimeric reaction center-light-harvesting I-PufX core complexes in membranes of purple non-sulfur bacteria was revealed by atomic force microscopy [S. Bahatyrova et al., Nature (London) 430, 1058 (2004)]. Here, we discuss optimal exciton transfer in a biomimetic system closely modeled on the structure of LH2 and its organization within the membrane using a Markovian quantum model with dissipation and trapping added phenomenologically. In a deliberate manner, we neglect the high level detail of the bacterial light-harvesting complex and its interaction with the phonon bath in order to elucidate a set of design principles that may be incorporated in artificial pigment-scaffold constructs in a supramolecular assembly. We show that our scheme reproduces many of the most salient features found in their natural counterpart and may be largely explained by simple electrostatic considerations. Most importantly, we show that quantum effects act primarily to enforce robustness with respect to spatial and spectral disorder between and within complexes. The implications of such an arrangement are discussed in the context of biomimetic photosynthetic analogs capable of transferring energy efficiently across tens to hundreds of nanometers.

  5. Biomimetic interfaces based on S-layer proteins, lipid membranes and functional biomolecules

    PubMed Central

    Schuster, Bernhard; Sleytr, Uwe B.

    2014-01-01

    Designing and utilization of biomimetic membrane systems generated by bottom-up processes is a rapidly growing scientific and engineering field. Elucidation of the supramolecular construction principle of archaeal cell envelopes composed of S-layer stabilized lipid membranes led to new strategies for generating highly stable functional lipid membranes at meso- and macroscopic scale. In this review, we provide a state-of-the-art survey of how S-layer proteins, lipids and polymers may be used as basic building blocks for the assembly of S-layer-supported lipid membranes. These biomimetic membrane systems are distinguished by a nanopatterned fluidity, enhanced stability and longevity and, thus, provide a dedicated reconstitution matrix for membrane-active peptides and transmembrane proteins. Exciting areas in the (lab-on-a-) biochip technology are combining composite S-layer membrane systems involving specific membrane functions with the silicon world. Thus, it might become possible to create artificial noses or tongues, where many receptor proteins have to be exposed and read out simultaneously. Moreover, S-layer-coated liposomes and emulsomes copying virus envelopes constitute promising nanoformulations for the production of novel targeting, delivery, encapsulation and imaging systems. PMID:24812051

  6. Long range excitonic transport in a biomimetic system inspired by the bacterial light-harvesting apparatus

    SciTech Connect

    Harel, Elad

    2012-05-07

    Photosynthesis, the process by which energy from sunlight drives cellular metabolism, relies on a unique organization of light-harvesting and reaction center complexes. Recently, the organization of light-harvesting LH2 complexes and dimeric reaction center-light-harvesting I-PufX core complexes in membranes of purple non-sulfur bacteria was revealed by atomic force microscopy [S. Bahatyrova et al., Nature (London) 430, 1058 (2004)]. Here, we discuss optimal exciton transfer in a biomimetic system closely modeled on the structure of LH2 and its organization within the membrane using a Markovian quantum model with dissipation and trapping added phenomenologically. In a deliberate manner, we neglect the high level detail of the bacterial light-harvesting complex and its interaction with the phonon bath in order to elucidate a set of design principles that may be incorporated in artificial pigment-scaffold constructs in a supramolecular assembly. We show that our scheme reproduces many of the most salient features found in their natural counterpart and may be largely explained by simple electrostatic considerations. Most importantly, we show that quantum effects act primarily to enforce robustness with respect to spatial and spectral disorder between and within complexes. The implications of such an arrangement are discussed in the context of biomimetic photosynthetic analogs capable of transferring energy efficiently across tens to hundreds of nanometers.

  7. Long range excitonic transport in a biomimetic system inspired by the bacterial light-harvesting apparatus

    NASA Astrophysics Data System (ADS)

    Harel, Elad

    2012-05-01

    Photosynthesis, the process by which energy from sunlight drives cellular metabolism, relies on a unique organization of light-harvesting and reaction center complexes. Recently, the organization of light-harvesting LH2 complexes and dimeric reaction center-light-harvesting I-PufX core complexes in membranes of purple non-sulfur bacteria was revealed by atomic force microscopy [S. Bahatyrova et al., Nature (London) 430, 1058 (2004)]. Here, we discuss optimal exciton transfer in a biomimetic system closely modeled on the structure of LH2 and its organization within the membrane using a Markovian quantum model with dissipation and trapping added phenomenologically. In a deliberate manner, we neglect the high level detail of the bacterial light-harvesting complex and its interaction with the phonon bath in order to elucidate a set of design principles that may be incorporated in artificial pigment-scaffold constructs in a supramolecular assembly. We show that our scheme reproduces many of the most salient features found in their natural counterpart and may be largely explained by simple electrostatic considerations. Most importantly, we show that quantum effects act primarily to enforce robustness with respect to spatial and spectral disorder between and within complexes. The implications of such an arrangement are discussed in the context of biomimetic photosynthetic analogs capable of transferring energy efficiently across tens to hundreds of nanometers.

  8. Biomimetic interfaces based on S-layer proteins, lipid membranes and functional biomolecules.

    PubMed

    Schuster, Bernhard; Sleytr, Uwe B

    2014-07-06

    Designing and utilization of biomimetic membrane systems generated by bottom-up processes is a rapidly growing scientific and engineering field. Elucidation of the supramolecular construction principle of archaeal cell envelopes composed of S-layer stabilized lipid membranes led to new strategies for generating highly stable functional lipid membranes at meso- and macroscopic scale. In this review, we provide a state-of-the-art survey of how S-layer proteins, lipids and polymers may be used as basic building blocks for the assembly of S-layer-supported lipid membranes. These biomimetic membrane systems are distinguished by a nanopatterned fluidity, enhanced stability and longevity and, thus, provide a dedicated reconstitution matrix for membrane-active peptides and transmembrane proteins. Exciting areas in the (lab-on-a-) biochip technology are combining composite S-layer membrane systems involving specific membrane functions with the silicon world. Thus, it might become possible to create artificial noses or tongues, where many receptor proteins have to be exposed and read out simultaneously. Moreover, S-layer-coated liposomes and emulsomes copying virus envelopes constitute promising nanoformulations for the production of novel targeting, delivery, encapsulation and imaging systems.

  9. Hydrated silica exterior produced by biomimetic silicification confers viral vaccine heat-resistance.

    PubMed

    Wang, Guangchuan; Wang, Hong-Jiang; Zhou, Hangyu; Nian, Qing-Gong; Song, Zhiyong; Deng, Yong-Qiang; Wang, Xiaoyu; Zhu, Shun-Ya; Li, Xiao-Feng; Qin, Cheng-Feng; Tang, Ruikang

    2015-01-27

    Heat-lability is a key roadblock that strangles the widespread applications of many biological products. In nature, archaeal and extremophilic organisms utilize amorphous silica as a protective biomineral and exhibit considerable thermal tolerance. Here we present a bioinspired approach to generate thermostable virus by introducing an artificial hydrated silica exterior on individual virion. Similar to thermophiles, silicified viruses can survive longer at high temperature than their wild-type relatives. Virus inactivation assays showed that silica hydration exterior of the modified virus effectively prolonged infectivity of viruses by ∼ 10-fold at room temperature, achieving a similar result as that obtained by storing native ones at 4 °C. Mechanistic studies indicate that amorphous silica nanoclusters stabilize the inner virion structure by forming a layer that restricts molecular mobility, acting as physiochemical nanoanchors. Notably, we further evaluate the potential application of this biomimetic strategy in stabilizing clinically approved vaccine, and the silicified polio vaccine that can retain 90% potency after the storage at room temperature for 35 days was generated by this biosilicification approach and validated with in vivo experiments. This approach not only biomimetically connects inorganic material and living virus but also provides an innovative resolution to improve the thermal stability of biological agents using nanomaterials.

  10. Applying Biomimetic Algorithms for Extra-Terrestrial Habitat Generation

    NASA Technical Reports Server (NTRS)

    Birge, Brian

    2012-01-01

    The objective is to simulate and optimize distributed cooperation among a network of robots tasked with cooperative excavation on an extra-terrestrial surface. Additionally to examine the concept of directed Emergence among a group of limited artificially intelligent agents. Emergence is the concept of achieving complex results from very simple rules or interactions. For example, in a termite mound each individual termite does not carry a blueprint of how to make their home in a global sense, but their interactions based strictly on local desires create a complex superstructure. Leveraging this Emergence concept applied to a simulation of cooperative agents (robots) will allow an examination of the success of non-directed group strategy achieving specific results. Specifically the simulation will be a testbed to evaluate population based robotic exploration and cooperative strategies while leveraging the evolutionary teamwork approach in the face of uncertainty about the environment and partial loss of sensors. Checking against a cost function and 'social' constraints will optimize cooperation when excavating a simulated tunnel. Agents will act locally with non-local results. The rules by which the simulated robots interact will be optimized to the simplest possible for the desired result, leveraging Emergence. Sensor malfunction and line of sight issues will be incorporated into the simulation. This approach falls under Swarm Robotics, a subset of robot control concerned with finding ways to control large groups of robots. Swarm Robotics often contains biologically inspired approaches, research comes from social insect observation but also data from among groups of herding, schooling, and flocking animals. Biomimetic algorithms applied to manned space exploration is the method under consideration for further study.

  11. Nanothorn electrodes for ionic polymer-metal composite artificial muscles

    NASA Astrophysics Data System (ADS)

    Palmre, Viljar; Pugal, David; Kim, Kwang J.; Leang, Kam K.; Asaka, Kinji; Aabloo, Alvo

    2014-08-01

    Ionic polymer-metal composites (IPMCs) have recently received tremendous interest as soft biomimetic actuators and sensors in various bioengineering and human affinity applications, such as artificial muscles and actuators, aquatic propulsors, robotic end-effectors, and active catheters. Main challenges in developing biomimetic actuators are the attainment of high strain and actuation force at low operating voltage. Here we first report a nanostructured electrode surface design for IPMC comprising platinum nanothorn assemblies with multiple sharp tips. The newly developed actuator with the nanostructured electrodes shows a new way to achieve highly enhanced electromechanical performance over existing flat-surfaced electrodes. We demonstrate that the formation and growth of the nanothorn assemblies at the electrode interface lead to a dramatic improvement (3- to 5-fold increase) in both actuation range and blocking force at low driving voltage (1-3 V). These advances are related to the highly capacitive properties of nanothorn assemblies, increasing significantly the charge transport during the actuation process.

  12. Biomimetic apatite formation on Ultra-High Molecular Weight Polyethylene (UHMWPE) using modified biomimetic solution.

    PubMed

    Aparecida, Anahi H; Fook, Marcus V L; Guastaldi, Antonio C

    2009-06-01

    Modifications were performed on a biomimetic solution (SBF), according to previous knowledge on the behavior of ions present in its composition, in order to obtain apatite coatings onto Ultra-High Molecular Weight Polyethylene (UHMWPE) without having to use polymer pre-treatments that could compromise its properties. UHMWPE substrates were immersed into a 30% H(2)O(2) solution for a 24-h period and then submitted to a biomimetic coating method using standard SBF and two other modified SBF solutions. Apatite coatings were only obtained onto UHMWPE when the modified SBF solutions were used. Based on these results, apatite coatings of biological importance (calcium-deficient hydroxyapatite-CDHA, amorphous calcium phosphate-ACP, octacalcium phosphate-OCP, and carbonated HA) can be obtained onto UHMWPE substrates, allowing an adequate conciliation between bonelike mechanical properties and bioactivity.

  13. Design of biomimetic super-lubricants by hydrogel-biopolymer aggregates

    NASA Astrophysics Data System (ADS)

    Seekell, Raymond; Dever, Rachel; Zhu, Yingxi

    2013-03-01

    Inspired by the superb lubricity of natural synovial fluids for moving articular cartilage joints, we investigate a biomimetic artificial lubricant based on a hydrogel-biopolymer mixture with optimized rheological properties at a microscopic level. Specifically, we examine the structure and rheological relationship of stimuli-responsive poly (N-isopropylacrylamide) (PNIPAM) hydrogel added with hyaluronic acid (HA) to simulate the complexes of HA with a globule protein, lubricin, which are credited as the two key lubricious constituents in natural synovial fluids. By combined microscopic structural characterization and rheology measurement, we tune the rheological and frictional behaviors of HA solutions by optimizing the content of added micron-sized PNIPAM hydrogel particles to form stable PNIPAM-HA network. In a recent work on using zwitterionic hydrogel particles instead of negatively charged PNIPAM, comparable structure and rheological properties of hydrogel-HA aggregates are observed, which may give insight to design new biocompatible lubricants and lubricious coatings for medical ramification.

  14. A biomimetic adaptive algorithm and low-power architecture for implantable neural decoders.

    PubMed

    Rapoport, Benjamin I; Wattanapanitch, Woradorn; Penagos, Hector L; Musallam, Sam; Andersen, Richard A; Sarpeshkar, Rahul

    2009-01-01

    Algorithmically and energetically efficient computational architectures that operate in real time are essential for clinically useful neural prosthetic devices. Such devices decode raw neural data to obtain direct control signals for external devices. They can also perform data compression and vastly reduce the bandwidth and consequently power expended in wireless transmission of raw data from implantable brain-machine interfaces. We describe a biomimetic algorithm and micropower analog circuit architecture for decoding neural cell ensemble signals. The decoding algorithm implements a continuous-time artificial neural network, using a bank of adaptive linear filters with kernels that emulate synaptic dynamics. The filters transform neural signal inputs into control-parameter outputs, and can be tuned automatically in an on-line learning process. We provide experimental validation of our system using neural data from thalamic head-direction cells in an awake behaving rat.

  15. Biomimetic Planetary Rovers for Ocean Exploration in Space

    NASA Astrophysics Data System (ADS)

    Babu Mannam, N. P.; Krishnankutty, P.

    2016-10-01

    Conventional planetary rover designs are wheel operated on firm ground surfaces and proved successful in the exploration of Mars environment. In order to explore liquid medium on Jupiter's Europa, biomimetic planetary rovers are discussed in the current research.

  16. Biomimetics - using nature as an inspiring model for innovation

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph

    2006-01-01

    In this presentation, various aspects of the field of biomimetics will be reviewed, examples of inspiring biological models and practical applications will be described, and challenges and potential direction of the field will be discussed.

  17. Lessons from nature: computational design of biomimetic compounds and processes.

    PubMed

    Bozkurt, Esra; Ashari, Negar; Browning, Nicholas; Brunk, Elizabeth; Campomanesa, Pablo; Perez, Marta A S; Rothlisberger, Ursula

    2014-09-01

    Through millions of years of evolution, Nature has accomplished the development of highly efficient and sustainable processes and the idea to understand and copy natural strategies is therefore very appealing. However, in spite of intense experimental and computational research, it has turned out to be a difficult task to design efficient biomimetic systems. Here we discuss a novel strategy for the computational design of biomimetic compounds and processes that consists of i) target selection; ii) atomistic and electronic characterization of the wild type system and the biomimetic compounds; iii) identification of key descriptors through feature selection iv) choice of biomimetic template and v) efficient search of chemical and sequence space for optimization of the biomimetic system. As a proof-of-principles study, this general approach is illustrated for the computational design of a 'green' catalyst mimicking the action of the zinc metalloenzyme Human Carbonic Anhydrase (HCA). HCA is a natural model for CO2 fixation since the enzyme is able to convert CO2 into bicarbonate. Very recently, a weakly active HCA mimic based on a trihelical peptide bundle was synthetized. We have used quantum mechanical/molecular mechanical (QM/MM) Car-Parrinello simulations to study the mechanisms of action of HCA and its peptidic mimic and employed the obtained information to guide the design of improved biomimetic analogues. Applying a genetic algorithm based optimization procedure, we were able to re-engineer and optimize the biomimetic system towards its natural counter part. In a second example, we discuss a similar strategy for the design of biomimetic sensitizers for use in dye-sensitized solar cells.

  18. Artificial ribonucleases.

    PubMed

    Morrow, J R

    1994-01-01

    Many inorganic and organic compounds promote the reactions catalyzed by RNase A. Both the transesterification step, where a 2',3'-cyclic phosphate is formed with concomitant cleavage of RNA, and the hydrolysis step, where the 2',3'-cyclic phosphate is converted to a phosphate monoester, may be mimicked with compounds that are readily synthesized in the laboratory. Electrophilic activation of the phosphate ester and charge neutralization are generally important means by which artificial RNases promote phosphate diester displacement reactions. Several artificial RNases operate by a bifunctional general acid/general base mechanism, as does RNase A. Provision of an intramolecular nucleophile appears to be an important pathway for metal complex promoted phosphate diester hydrolysis. In contrast to the successful design of compounds that promote the reactions catalyzed by RNase A, there are no artificial nucleases to date that will cleave the 3' P-O bond of RNA or hydrolyze an oligonucleotide of DNA. Artificial RNases based on both metal complexes and organic compounds have been described. Metal complexes may be particularly effective catalysts for both transesterification and hydrolysis reactions of phosphate diesters. Under physiological conditions (37 degrees C and neutral pH), several metal complexes catalyze the transesterification of RNA. Future work should involve the development of metal complexes which are inert to metal ion release but which maintain open coordination sites for catalytic activity. The design of compounds containing multiple amine or imidazole groups that may demonstrate bifunctional catalysis is a promising route to new artificial RNases. Further design of these compounds and careful placement of catalytic groups may yield new RNase mimics that operate under physiological conditions. The attachment of artificial RNases to recognition agents such as oligodeoxynucleotides to create new sequence-specific endoribonucleases is an exciting field of

  19. Biomimetic silicification of demineralized hierarchical collagenous tissues

    PubMed Central

    Ryou, Heonjune; Diogenes, Anibal; Yiu, Cynthia K.Y.; Mazzoni, Annalisa; Chen, Ji-hua; Arola, Dwayne D.; Hargreaves, Kenneth M.; Pashley, David H.; Tay, Franklin R.

    2013-01-01

    Unlike man-made composite materials, natural biominerals containing composites usually demonstrate different levels of sophisticated hierarchical structures which are responsible for their mechanical properties and other metabolic functions. However, the complex spatial organizations of the organic-inorganic phases are far beyond what they be achieved by contemporary engineering techniques. Here, we demonstrate that carbonated apatite present in collagen matrices derived from fish scale and bovine bone may be replaced by amorphous silica, using an approach that simulates what is utilized by phylogenetically ancient glass sponges. The structural hierarchy of these collagen-based biomaterials is replicated by the infiltration and condensation of fluidic polymer-stabilized silicic acid precursors within the intrafibrillar milieu of type I collagen fibrils. This facile biomimetic silicification strategy may be used for fabricating silica-based, three-dimensional functional materials with specific morphological and hierarchical requirements. PMID:23586938

  20. Biomimetic biphasic scaffolds for osteochondral defect repair

    PubMed Central

    Li, Xuezhou; Ding, Jianxun; Wang, Jincheng; Zhuang, Xiuli; Chen, Xuesi

    2015-01-01

    The osteochondral defects caused by vigorous trauma or physical disease are difficult to be managed. Tissue engineering provides a possible option to regenerate the damaged osteochondral tissues. For osteochondral reconstruction, one intact scaffold should be considered to support the regeneration of both cartilage and subchondral bone. Therefore, the biphasic scaffolds with the mimic structures of osteochondral tissues have been developed to close this chasm. A variety of biomimetic bilayer scaffolds fabricated from natural or synthetic polymers, or the ones loading with growth factors, cells, or both of them make great progresses in osteochondral defect repair. In this review, the preparation and in vitro and/or in vivo verification of bioinspired biphasic scaffolds are summarized and discussed, as well as the prospect is predicted. PMID:26816644

  1. Biomimetic Hybrid Nanocontainers with Selective Permeability

    PubMed Central

    Messager, Lea; Burns, Jonathan R.; Kim, Jungyeon; Cecchin, Denis; Hindley, James; Pyne, Alice L. B.; Gaitzsch, Jens

    2016-01-01

    Abstract Chemistry plays a crucial role in creating synthetic analogues of biomacromolecular structures. Of particular scientific and technological interest are biomimetic vesicles that are inspired by natural membrane compartments and organelles but avoid their drawbacks, such as membrane instability and limited control over cargo transport across the boundaries. In this study, completely synthetic vesicles were developed from stable polymeric walls and easy‐to‐engineer membrane DNA nanopores. The hybrid nanocontainers feature selective permeability and permit the transport of organic molecules of 1.5 nm size. Larger enzymes (ca. 5 nm) can be encapsulated and retained within the vesicles yet remain catalytically active. The hybrid structures constitute a new type of enzymatic nanoreactor. The high tunability of the polymeric vesicles and DNA pores will be key in tailoring the nanocontainers for applications in drug delivery, bioimaging, biocatalysis, and cell mimicry. PMID:27560310

  2. Bio-microfluidics: biomaterials and biomimetic designs.

    PubMed

    Domachuk, Peter; Tsioris, Konstantinos; Omenetto, Fiorenzo G; Kaplan, David L

    2010-01-12

    Bio-microfluidics applies biomaterials and biologically inspired structural designs (biomimetics) to microfluidic devices. Microfluidics, the techniques for constraining fluids on the micrometer and sub-micrometer scale, offer applications ranging from lab-on-a-chip to optofluidics. Despite this wealth of applications, the design of typical microfluidic devices imparts relatively simple, laminar behavior on fluids and is realized using materials and techniques from silicon planar fabrication. On the other hand, highly complex microfluidic behavior is commonplace in nature, where fluids with nonlinear rheology flow through chaotic vasculature composed from a range of biopolymers. In this Review, the current state of bio-microfluidic materials, designs and applications are examined. Biopolymers enable bio-microfluidic devices with versatile functionalization chemistries, flexibility in fabrication, and biocompatibility in vitro and in vivo. Polymeric materials such as alginate, collagen, chitosan, and silk are being explored as bulk and film materials for bio-microfluidics. Hydrogels offer options for mechanically functional devices for microfluidic systems such as self-regulating valves, microlens arrays and drug release systems, vital for integrated bio-microfluidic devices. These devices including growth factor gradients to study cell responses, blood analysis, biomimetic capillary designs, and blood vessel tissue culture systems, as some recent examples of inroads in the field that should lead the way in a new generation of microfluidic devices for bio-related needs and applications. Perhaps one of the most intriguing directions for the future will be fully implantable microfluidic devices that will also integrate with existing vasculature and slowly degrade to fully recapitulate native tissue structure and function, yet serve critical interim functions, such as tissue maintenance, drug release, mechanical support, and cell delivery.

  3. Protein-templated biomimetic silica nanoparticles.

    PubMed

    Jackson, Erienne; Ferrari, Mariana; Cuestas-Ayllon, Carlos; Fernández-Pacheco, Rodrigo; Perez-Carvajal, Javier; de la Fuente, Jesús M; Grazú, Valeria; Betancor, Lorena

    2015-03-31

    Biomimetic silica particles can be synthesized as a nanosized material within minutes in a process mimicked from living organisms such as diatoms and sponges. In this work, we have studied the effect of bovine serum albumin (BSA) as a template to direct the synthesis of silica nanoparticles (NPs) with the potential to associate proteins on its surface. Our approach enables the formation of spheres with different physicochemical properties. Particles using BSA as a protein template were smaller (∼250-380 nm) and were more monodisperse than those lacking the proteic core (∼700-1000 nm) as seen by dynamic light scattering (DLS), scanning electron microscopy (SEM), and environmental scanning electron microscopy (ESEM) analysis. The absence of BSA during synthesis produced silica nanoparticles without any porosity that was detectable by nitrogen adsorption, whereas particles containing BSA developed porosity in the range of 4 to 5 nm which collapsed on the removal of BSA, thus producing smaller pores. These results were in accordance with the pore size calculated by high-resolution transmission electron microscopy (HTEM). The reproducibility of the BSA-templated nanoparticle properties was determined by analyzing four batches of independent synthesizing experiments that maintained their properties. The high positive superficial charge of the nanoparticles facilitated adsorption under mild conditions of a range of proteins from an E. coli extract and a commercial preparation of laccase from Trametes versicolor. All of the proteins were quantitatively desorbed. Experiments conducted showed the reusability of the particles as supports for the ionic adsorption of the biomolecules. The protein loading capacity of the BSA-based biomimetic particles was determined using laccase as 98.7 ± 6.6 mg·g(-1) of particles.

  4. Biomimetic oral mucin from polymer micelle networks

    NASA Astrophysics Data System (ADS)

    Authimoolam, Sundar Prasanth

    Mucin networks are formed by the complexation of bottlebrush-like mucin glycoprotein with other small molecule glycoproteins. These glycoproteins create nanoscale strands that then arrange into a nanoporous mesh. These networks play an important role in ensuring surface hydration, lubricity and barrier protection. In order to understand the functional behavior in mucin networks, it is important to decouple their chemical and physical effects responsible for generating the fundamental property-function relationship. To achieve this goal, we propose to develop a synthetic biomimetic mucin using a layer-by-layer (LBL) deposition approach. In this work, a hierarchical 3-dimensional structures resembling natural mucin networks was generated using affinity-based interactions on synthetic and biological surfaces. Unlike conventional polyelectrolyte-based LBL methods, pre-assembled biotin-functionalized filamentous (worm-like) micelles was utilized as the network building block, which from complementary additions of streptavidin generated synthetic networks of desired thickness. The biomimetic nature in those synthetic networks are studied by evaluating its structural and bio-functional properties. Structurally, synthetic networks formed a nanoporous mesh. The networks demonstrated excellent surface hydration property and were able capable of microbial capture. Those functional properties are akin to that of natural mucin networks. Further, the role of synthetic mucin as a drug delivery vehicle, capable of providing localized and tunable release was demonstrated. By incorporating antibacterial curcumin drug loading within synthetic networks, bacterial growth inhibition was also demonstrated. Thus, such bioactive interfaces can serve as a model for independently characterizing mucin network properties and through its role as a drug carrier vehicle it presents exciting future opportunities for localized drug delivery, in regenerative applications and as bio

  5. Artificial Intelligence.

    PubMed

    Lawrence, David R; Palacios-González, César; Harris, John

    2016-04-01

    It seems natural to think that the same prudential and ethical reasons for mutual respect and tolerance that one has vis-à-vis other human persons would hold toward newly encountered paradigmatic but nonhuman biological persons. One also tends to think that they would have similar reasons for treating we humans as creatures that count morally in our own right. This line of thought transcends biological boundaries-namely, with regard to artificially (super)intelligent persons-but is this a safe assumption? The issue concerns ultimate moral significance: the significance possessed by human persons, persons from other planets, and hypothetical nonorganic persons in the form of artificial intelligence (AI). This article investigates why our possible relations to AI persons could be more complicated than they first might appear, given that they might possess a radically different nature to us, to the point that civilized or peaceful coexistence in a determinate geographical space could be impossible to achieve.

  6. A Rational Biomimetic Approach to Structure Defect Generation in Colloidal Nanocrystals

    DTIC Science & Technology

    2014-07-01

    principles to NC synthesis for diverse property tailoring. 2 A Rational Biomimetic Approach to Structure Defect Generation in Colloidal Nanocrystals Approved...dodecahedron, icosahe- dron, etc.), which have implied influences on NC properties such as catalytic performance, plasmonic response, etc.5,1114...biomimetic synthesis and the broad applicability of biomimetic principles to NC synthesis for diverse property tailoring. KEYWORDS: noble metal

  7. Designing artificial enzymes from scratch: Experimental study and mesoscale simulation

    NASA Astrophysics Data System (ADS)

    Komarov, Pavel V.; Zaborina, Olga E.; Klimova, Tamara P.; Lozinsky, Vladimir I.; Khalatur, Pavel G.; Khokhlov, Alexey R.

    2016-09-01

    We present a new concept for designing biomimetic analogs of enzymatic proteins; these analogs are based on the synthetic protein-like copolymers. α-Chymotrypsin is used as a prototype of the artificial catalyst. Our experimental study shows that in the course of free radical copolymerization of hydrophobic and hydrophilic monomers the target globular nanostructures of a "core-shell" morphology appear in a selective solvent. Using a mesoscale computer simulation, we show that the protein-like globules can have a large number of catalytic centers located at the hydrophobic core/hydrophilic shell interface.

  8. Biomimetic synthesis of noble metal nanocrystals

    NASA Astrophysics Data System (ADS)

    Chiu, Chin-Yi

    At the nanometer scale, the physical and chemical properties of materials heavily depend on their sizes and shapes. This fact has triggered considerable efforts in developing controllable nanomaterial synthesis. The controlled growth of colloidal nanocrystal is a kinetic process, in which high-energy facets grow faster and then vanish, leading to a nanocrystal enclosed by low-energy facets. Identifying a surfactant that can selectively bind to a particular crystal facet and thus lower its surface energy, is critical and challenging in shape controlled synthesis of nanocrystals. Biomolecules exhibiting exquisite molecular recognition properties can be exploited to precisely engineer nanostructured materials. In the first part of my thesis, we employed the phage display technique to select a specific multifunctional peptide sequence which can bind on Pd surface and mediate Pd crystal nucleation and growth, achieving size controlled synthesis of Pd nanocrystals in aqueous solution. We further demonstrated a rational biomimetic approach to the predictable synthesis of nanocrystals enclosed by a particular facet in the case of Pt. Specifically, Pt {100} and Pt {111} facet-specific peptides were identified and used to synthesize Pt nanocubes and Pt nano-tetrahedrons, respectively. The mechanistic studies of Pt {111} facet-specific peptide had led us to study the facet-selective adsorption of aromatic molecules on noble metal surfaces. The discoveries had achieved the development of design strategies to select facet-selective molecules which can synthesize nanocrystals with expected shapes in both Pt and Pd system. At last, we exploited Pt facet-specific peptides and controlled the molecular interaction to produce one- and three- dimensional nanostructures composed of anisotropic nanoparticles in synthetic conditions without supramolecular pre-organization, demonstrating the full potential of biomolecules in mediating material formation process. My research on biomimetic

  9. BatSLAM: Simultaneous localization and mapping using biomimetic sonar.

    PubMed

    Steckel, Jan; Peremans, Herbert

    2013-01-01

    We propose to combine a biomimetic navigation model which solves a simultaneous localization and mapping task with a biomimetic sonar mounted on a mobile robot to address two related questions. First, can robotic sonar sensing lead to intelligent interactions with complex environments? Second, can we model sonar based spatial orientation and the construction of spatial maps by bats? To address these questions we adapt the mapping module of RatSLAM, a previously published navigation system based on computational models of the rodent hippocampus. We analyze the performance of the proposed robotic implementation operating in the real world. We conclude that the biomimetic navigation model operating on the information from the biomimetic sonar allows an autonomous agent to map unmodified (office) environments efficiently and consistently. Furthermore, these results also show that successful navigation does not require the readings of the biomimetic sonar to be interpreted in terms of individual objects/landmarks in the environment. We argue that the system has applications in robotics as well as in the field of biology as a simple, first order, model for sonar based spatial orientation and map building.

  10. Better than Nature: Nicotinamide Biomimetics That Outperform Natural Coenzymes

    PubMed Central

    2016-01-01

    The search for affordable, green biocatalytic processes is a challenge for chemicals manufacture. Redox biotransformations are potentially attractive, but they rely on unstable and expensive nicotinamide coenzymes that have prevented their widespread exploitation. Stoichiometric use of natural coenzymes is not viable economically, and the instability of these molecules hinders catalytic processes that employ coenzyme recycling. Here, we investigate the efficiency of man-made synthetic biomimetics of the natural coenzymes NAD(P)H in redox biocatalysis. Extensive studies with a range of oxidoreductases belonging to the “ene” reductase family show that these biomimetics are excellent analogues of the natural coenzymes, revealed also in crystal structures of the ene reductase XenA with selected biomimetics. In selected cases, these biomimetics outperform the natural coenzymes. “Better-than-Nature” biomimetics should find widespread application in fine and specialty chemicals production by harnessing the power of high stereo-, regio-, and chemoselective redox biocatalysts and enabling reactions under mild conditions at low cost. PMID:26727612

  11. Biomimetic chemical sensors using bioengineered olfactory and taste cells.

    PubMed

    Du, Liping; Zou, Ling; Zhao, Luhang; Wang, Ping; Wu, Chunsheng

    2014-01-01

    Biological olfactory and taste systems are natural chemical sensing systems with unique performances for the detection of environmental chemical signals. With the advances in olfactory and taste transduction mechanisms, biomimetic chemical sensors have achieved significant progress due to their promising prospects and potential applications. Biomimetic chemical sensors exploit the unique capability of biological functional components for chemical sensing, which are often sourced from sensing units of biological olfactory or taste systems at the tissue level, cellular level, or molecular level. Specifically, at the cellular level, there are mainly two categories of cells have been employed for the development of biomimetic chemical sensors, which are natural cells and bioengineered cells, respectively. Natural cells are directly isolated from biological olfactory and taste systems, which are convenient to achieve. However, natural cells often suffer from the undefined sensing properties and limited amount of identical cells. On the other hand, bioengineered cells have shown decisive advantages to be applied in the development of biomimetic chemical sensors due to the powerful biotechnology for the reconstruction of the cell sensing properties. Here, we briefly summarized the most recent advances of biomimetic chemical sensors using bioengineered olfactory and taste cells. The development challenges and future trends are discussed as well.

  12. Biomimetic chemical sensors using bioengineered olfactory and taste cells

    PubMed Central

    Du, Liping; Zou, Ling; Zhao, Luhang; Wang, Ping; Wu, Chunsheng

    2014-01-01

    Biological olfactory and taste systems are natural chemical sensing systems with unique performances for the detection of environmental chemical signals. With the advances in olfactory and taste transduction mechanisms, biomimetic chemical sensors have achieved significant progress due to their promising prospects and potential applications. Biomimetic chemical sensors exploit the unique capability of biological functional components for chemical sensing, which are often sourced from sensing units of biological olfactory or taste systems at the tissue level, cellular level, or molecular level. Specifically, at the cellular level, there are mainly two categories of cells have been employed for the development of biomimetic chemical sensors, which are natural cells and bioengineered cells, respectively. Natural cells are directly isolated from biological olfactory and taste systems, which are convenient to achieve. However, natural cells often suffer from the undefined sensing properties and limited amount of identical cells. On the other hand, bioengineered cells have shown decisive advantages to be applied in the development of biomimetic chemical sensors due to the powerful biotechnology for the reconstruction of the cell sensing properties. Here, we briefly summarized the most recent advances of biomimetic chemical sensors using bioengineered olfactory and taste cells. The development challenges and future trends are discussed as well. PMID:25482234

  13. A Review Paper on Biomimetic Calcium Phosphate Coatings

    PubMed Central

    Lin, X.; de Groot, K.; Wang, D.; Hu, Q.; Wismeijer, D.; Liu, Y.

    2015-01-01

    Biomimetic calcium phosphate coatings have been developed for bone regeneration and repair because of their biocompatibility, osteoconductivity, and easy preparation. They can be rendered osteoinductive by incorporating an osteogenic agent, such as bone morphogenetic protein 2 (BMP-2), into the crystalline lattice work in physiological situations. The biomimetic calcium phosphate coating enables a controlled, slow and local release of BMP-2 when it undergoes cell mediated coating degradation induced by multinuclear cells, such as osteoclasts and foreign body giant cells, which mimics a physiologically similar release mode, to achieve sustained ectopic or orthotopic bone formation. Therefore, biomimetic calcium phosphate coatings are considered to be a promising delivery vehicle for osteogenic agents. In this review, we present an overview of biomimetic calcium phosphate coatings including their preparation techniques, physico-chemical properties, potential as drug carrier, and their pre-clinical application both in ectopic and orthotopic animal models. We briefly review some features of hydroxyapatite coatings and their clinical applications to gain insight into the clinical applications of biomimetic calcium phosphate coatings in the near future. PMID:25893016

  14. Conventional vs Biomimetic Approaches to the Exploration of Mars

    NASA Astrophysics Data System (ADS)

    Ellery, A.

    It is not usual to refer to convention in planetary exploration missions by virtue of the innovation required for such projects. The term conventional refers to the methodologies, tools and approaches typically adopted in engineering that are applied to such missions. Presented is a "conventional" Mars rover mission in which the author was involved - ExoMars - into which is interspersed references to examples where biomimetic approaches may yield superior capabilities. Biomimetics is a relatively recently active area of research which seeks to examine how biological systems solve the problem of survival in the natural environment. Biological organisms are autonomous entities that must survive in a hostile world adapting both adaptivity and robustness. It is not then surprising that biomimetics is particularly useful when applied to robotic elements of a Mars exploration mission. I present a number of areas in which biomimetics may yield new solutions to the problem of Mars exploration - optic flow navigation, potential field navigation, genetically-evolved neuro-controllers, legged locomotion, electric motors implementing muscular behaviour, and a biomimetic drill based on the wood wasp ovipositor. Each of these techniques offers an alternative approach to conventional ones. However, the perceptive hurdles are likely to dwarf the technical hurdles in implementing many of these methods in the near future.

  15. Sustainability assessment of a lightweight biomimetic ceiling structure.

    PubMed

    Antony, Florian; Grießhammer, Rainer; Speck, Thomas; Speck, Olga

    2014-03-01

    An intensive and continuous debate centres on the question of whether biomimetics has a specific potential to contribute to sustainability. In the context of a case study, the objective of this paper is to contribute to this debate by presenting the first systematic approach to assess the sustainability of a complex biomimetic product. The object of inquiry is a lecture hall's ribbed slab. Based on criteria suggested by the Association of German Engineers (VDI), it has been verified that the slab has been correctly defined as biomimetic. Moreover, a systematic comparative product sustainability assessment has been carefully carried out. For purposes of comparison, estimated static calculations have been performed for conceivable current state-of-the-art lightweight ceiling structures. Alternative options are a hollow article slab and a pre-stressed flat slab. Besides a detailed benefit analysis and a discussion of social effects, their costs have also been compared. A particularly detailed life cycle assessment on the respective environmental impacts has also been performed. Results show that the biomimetic ribbed slab built in the 1960s is able to keep up with the current state-of-the-art lightweight solutions in terms of sustainability. These promising results encourage a systematic search for a broad range of sustainable biomimetic solutions.

  16. Biomimetic Polymers for Cardiac Tissue Engineering

    PubMed Central

    2016-01-01

    Heart failure is a morbid disorder characterized by progressive cardiomyocyte (CM) dysfunction and death. Interest in cell-based therapies is growing, but sustainability of injected CMs remains a challenge. To mitigate this, we developed an injectable biomimetic Reverse Thermal Gel (RTG) specifically engineered to support long-term CM survival. This RTG biopolymer provided a solution-based delivery vehicle of CMs, which transitioned to a gel-based matrix shortly after reaching body temperature. In this study we tested the suitability of this biopolymer to sustain CM viability. The RTG was biomolecule-functionalized with poly-l-lysine or laminin. Neonatal rat ventricular myocytes (NRVM) and adult rat ventricular myocytes (ARVM) were cultured in plain-RTG and biomolecule-functionalized-RTG both under 3-dimensional (3D) conditions. Traditional 2D biomolecule-coated dishes were used as controls. We found that the RTG-lysine stimulated NRVM to spread and form heart-like functional syncytia. Regarding cell contraction, in both RTG and RTG-lysine, beating cells were recorded after 21 days. Additionally, more than 50% (p value < 0.05; n = 5) viable ARVMs, characterized by a well-defined cardiac phenotype represented by sarcomeric cross-striations, were found in the RTG-laminin after 8 days. These results exhibit the tremendous potential of a minimally invasive CM transplantation through our designed RTG-cell therapy platform. PMID:27073119

  17. Software architecture of biomimetic underwater vehicle

    NASA Astrophysics Data System (ADS)

    Praczyk, Tomasz; Szymak, Piotr

    2016-05-01

    Autonomous underwater vehicles are vehicles that are entirely or partly independent of human decisions. In order to obtain operational independence, the vehicles have to be equipped with a specialized software. The main task of the software is to move the vehicle along a trajectory with collision avoidance. Moreover, the software has also to manage different devices installed on the vehicle board, e.g. to start and stop cameras, sonars etc. In addition to the software embedded on the vehicle board, the software responsible for managing the vehicle by the operator is also necessary. Its task is to define mission of the vehicle, to start, to stop the mission, to send emergency commands, to monitor vehicle parameters, and to control the vehicle in remotely operated mode. An important objective of the software is also to support development and tests of other software components. To this end, a simulation environment is necessary, i.e. simulation model of the vehicle and all its key devices, the model of the sea environment, and the software to visualize behavior of the vehicle. The paper presents architecture of the software designed for biomimetic autonomous underwater vehicle (BAUV) that is being constructed within the framework of the scientific project financed by Polish National Center of Research and Development.

  18. Biomimetic synthesis of aragonite superstructures using hexamethylenetetramine

    SciTech Connect

    Chen Long; Huang Fangzhi; Li Shikuo; Shen Yuhua; Xie Anjian; Pan Jian; Zhang Yaping; Cai Yan

    2011-11-15

    In this paper, biomimetic synthesis of aragonite superstructures using a low molecular weight organic-hexamethylenetetramine (HMT) as an additive in the presence of CO{sub 2} supplied by an ammonium carbonate ((NH{sub 4}){sub 2}CO{sub 3}) diffusion method at room temperature was studied. The products were characterized by scanning or transmission electron microscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray powder diffractometry, and selected area electron diffraction. The results showed the aragonite superstructures especially dumbbell-flower-like ones were obtained. The formation process of calcium carbonate (CaCO{sub 3}) in HMT aqueous solution was investigated, suggesting that the products transformed from calcite to vaterite primarily, and then changed into a mixture of aragonite and calcite with an increase of reaction time. The formation mechanism of CaCO{sub 3} in HMT solution was also discussed, revealing that aragonite might be controlled by HMT molecules and NH{sub 4}{sup +} ions together. - Graphical abstract: The well-defined aragonite hierarchical superstructures are formed using hexamethylenetetramine in aqueous solution. Highlights: > Aragonite superstructures are formed with hexamethylenetetramine at about 25 deg. C. > Dumbbell-flower-like aragonite produces when hexamethylenetetramine/Ca{sup 2+}=10:1. > CaCO{sub 3} formation in hexamethylenetetramine solution violates the Ostwald ripening. > Hexamethylenetetramine and NH{sub 4}{sup +} might control the growth of aragonite together.

  19. Biomimetic and microbial reduction of nitric oxide

    SciTech Connect

    Potter, W.T.; Le, U.; Ronda, S.

    1995-12-31

    The biomimetic reduction of nitric oxide (NO) to nitrous oxide (N{sub 2}O) by dithiothreitol in the presence of cyanocobalamin and cobalt-centered porphyrins has been investigated. Reactions were monitored directly using Fourier Transform Infrared (FTIR) Spectroscopy vapor-phase spectra. Reaction rates were twofold faster for the corrin than for the cobalt-centered porphyrins. The stoichiometry showed the loss of two molecules of NO per molecule of N{sub 2}O produced. We have also demonstrated that the facultative anaerobe and chemoautotroph, Thiobacillus denitrificans, can be cultured anoxically in batch reactors using NO as a terminal electron acceptor with reduction to elemental nitrogen (N{sub 2}). We have proposed that the concentrated stream of NO{sub x}, as obtained from certain regenerable processes for the gas desulfurization and NO{sub x} removal, could be converted to N{sub 2} for disposal by contact with a culture of T. denitrificans. Four heterotrophic bacteria have also been identified that may be grown in batch cultures with succinate, yeast extract, or heat and alkali pretreated sewage sludge as carbon and energy sources and NO as a terminal electron acceptor. These are Paracoccus dentrificans, Pseudomonas denitrificans, Alcaligens denitrificans, and Thiophaera pantotropha.

  20. Biomimetic micromechanical adaptive flow-sensor arrays

    NASA Astrophysics Data System (ADS)

    Krijnen, Gijs; Floris, Arjan; Dijkstra, Marcel; Lammerink, Theo; Wiegerink, Remco

    2007-05-01

    We report current developments in biomimetic flow-sensors based on flow sensitive mechano-sensors of crickets. Crickets have one form of acoustic sensing evolved in the form of mechanoreceptive sensory hairs. These filiform hairs are highly perceptive to low-frequency sound with energy sensitivities close to thermal threshold. In this work we describe hair-sensors fabricated by a combination of sacrificial poly-silicon technology, to form silicon-nitride suspended membranes, and SU8 polymer processing for fabrication of hairs with diameters of about 50 μm and up to 1 mm length. The membranes have thin chromium electrodes on top forming variable capacitors with the substrate that allow for capacitive read-out. Previously these sensors have been shown to exhibit acoustic sensitivity. Like for the crickets, the MEMS hair-sensors are positioned on elongated structures, resembling the cercus of crickets. In this work we present optical measurements on acoustically and electrostatically excited hair-sensors. We present adaptive control of flow-sensitivity and resonance frequency by electrostatic spring stiffness softening. Experimental data and simple analytical models derived from transduction theory are shown to exhibit good correspondence, both confirming theory and the applicability of the presented approach towards adaptation.

  1. Bactericidal activity of biomimetic diamond nanocone surfaces.

    PubMed

    Fisher, Leanne E; Yang, Yang; Yuen, Muk-Fung; Zhang, Wenjun; Nobbs, Angela H; Su, Bo

    2016-03-17

    The formation of biofilms on implant surfaces and the subsequent development of medical device-associated infections are difficult to resolve and can cause considerable morbidity to the patient. Over the past decade, there has been growing recognition that physical cues, such as surface topography, can regulate biological responses and possess bactericidal activity. In this study, diamond nanocone-patterned surfaces, representing biomimetic analogs of the naturally bactericidal cicada fly wing, were fabricated using microwave plasma chemical vapor deposition, followed by bias-assisted reactive ion etching. Two structurally distinct nanocone surfaces were produced, characterized, and the bactericidal ability examined. The sharp diamond nanocone features were found to have bactericidal capabilities with the surface possessing the more varying cone dimension, nonuniform array, and decreased density, showing enhanced bactericidal ability over the more uniform, highly dense nanocone surface. Future research will focus on using the fabrication process to tailor surface nanotopographies on clinically relevant materials that promote both effective killing of a broader range of microorganisms and the desired mammalian cell response. This study serves to introduce a technology that may launch a new and innovative direction in the design of biomaterials with capacity to reduce the risk of medical device-associated infections.

  2. A multi-electrode biomimetic electrolocation sensor

    NASA Astrophysics Data System (ADS)

    Mayekar, K.; Damalla, D.; Gottwald, M.; Bousack, H.; von der Emde, G.

    2012-04-01

    We present the concept of an active multi-electrode catheter inspired by the electroreceptive system of the weakly electric fish, Gnathonemus petersii. The skin of this fish exhibits numerous electroreceptor organs which are capable of sensing a self induced electrical field. Our sensor is composed of a sending electrode and sixteen receiving electrodes. The electrical field produced by the sending electrode was measured by the receiving electrodes and objects were detected by the perturbation of the electrical field they induce. The intended application of such a sensor is in coronary diagnostics, in particular in distinguishing various types of plaques, which are major causes of heart attack. For calibration of the sensor system, finite element modeling (FEM) was performed. To validate the model, experimental measurements were carried out with two different systems. The physical system was glass tubing with metal and plastic wall insertions as targets. For the control of the experiment and for data acquisition, the software LabView designed for 17 electrodes was used. Different parameters of the electric images were analyzed for the prediction of the electrical properties and size of the inserted targets in the tube. Comparisons of the voltage modulations predicted from the FEM model and the experiments showed a good correspondence. It can be concluded that this novel biomimetic method can be further developed for detailed investigations of atherosclerotic lesions. Finally, we discuss various design strategies to optimize the output of the sensor using different simulated models to enhance target recognition.

  3. Designing a hydrophobic barrier within biomimetic nanopores.

    PubMed

    Trick, Jemma L; Wallace, E Jayne; Bayley, Hagan; Sansom, Mark S P

    2014-11-25

    Nanopores in membranes have a range of potential applications. Biomimetic design of nanopores aims to mimic key functions of biological pores within a stable template structure. Molecular dynamics simulations have been used to test whether a simple β-barrel protein nanopore can be modified to incorporate a hydrophobic barrier to permeation. Simulations have been used to evaluate functional properties of such nanopores, using water flux as a proxy for ionic conductance. The behavior of these model pores has been characterized as a function of pore size and of the hydrophobicity of the amino acid side chains lining the narrow central constriction of the pore. Potential of mean force calculations have been used to calculate free energy landscapes for water and for ion permeation in selected models. These studies demonstrate that a hydrophobic barrier can indeed be designed into a β-barrel protein nanopore, and that the height of the barrier can be adjusted by modifying the number of consecutive rings of hydrophobic side chains. A hydrophobic barrier prevents both water and ion permeation even though the pore is sterically unoccluded. These results both provide insights into the nature of hydrophobic gating in biological pores and channels, and furthermore demonstrate that simple design features may be computationally transplanted into β-barrel membrane proteins to generate functionally complex nanopores.

  4. Biomimetic optical sensor for aerospace applications

    NASA Astrophysics Data System (ADS)

    Frost, Susan A.; Gorospe, George E.; Wright, Cameron H. G.; Barrett, Steven F.

    2015-05-01

    We report on a fiber optic sensor based on the physiological aspects of the eye and vision-related neural layers of the common housefly (Musca domestica) that has been developed and built for aerospace applications. The intent of the research is to reproduce select features from the fly's vision system that are desirable in image processing, including high functionality in low-light and low-contrast environments, sensitivity to motion, compact size, lightweight, and low power and computation requirements. The fly uses a combination of overlapping photoreceptor responses that are well approximated by Gaussian distributions and neural superposition to detect image features, such as object motion, to a much higher degree than just the photoreceptor density would imply. The Gaussian overlap in the biomimetic sensor comes from the front-end optical design, and the neural superposition is accomplished by subsequently combining the signals using analog electronics. The fly eye sensor is being developed to perform real-time tracking of a target on a flexible aircraft wing experiencing bending and torsion loads during flight. We report on results of laboratory experiments using the fly eye sensor to sense a target moving across its field of view.

  5. PEM Fuel Cells Redesign Using Biomimetic and TRIZ Design Methodologies

    NASA Astrophysics Data System (ADS)

    Fung, Keith Kin Kei

    Two formal design methodologies, biomimetic design and the Theory of Inventive Problem Solving, TRIZ, were applied to the redesign of a Proton Exchange Membrane (PEM) fuel cell. Proof of concept prototyping was performed on two of the concepts for water management. The liquid water collection with strategically placed wicks concept demonstrated the potential benefits for a fuel cell. Conversely, the periodic flow direction reversal concepts might cause a potential reduction water removal from a fuel cell. The causes of this water removal reduction remain unclear. In additional, three of the concepts generated with biomimetic design were further studied and demonstrated to stimulate more creative ideas in the thermal and water management of fuel cells. The biomimetic design and the TRIZ methodologies were successfully applied to fuel cells and provided different perspectives to the redesign of fuel cells. The methodologies should continue to be used to improve fuel cells.

  6. The biomimetic apatite-cefalotin coatings on modified titanium.

    PubMed

    Kang, Min-Kyung; Lee, Sang-Bae; Moon, Seung-Kyun; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2012-02-03

    Dental implant failure often occurs due to oral bacterial infection. The aim of this study was to demonstrate that antibiotic efficacy could be enhanced with modified titanium. First, the titanium was modified by anodization and heat-treatment. Then, a biomimetic coating process was completed in two steps. Surface characterization was performed with scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. Release of antibiotic was evaluated by UV/VIS spectrometry, and the antibacterial effect was evaluated on Streptococcus mutans. After the second coating step, we observed a thick homogeneous apatite layer that contained the antibiotic, cefalotin. The titanium formed a rutile phase after the heat treatment, and a carbonated apatite phase appeared after biomimetic coating. We found that the modified titanium increased the loading of cefalotin onto the hydroxyapatite coated surface. The results suggested that modified titanium coated with a cefalotin using biomimetic coating method might be useful for preventing local post-surgical implant infections.

  7. A biomimetic synthesis of (±)-basiliolide B.

    PubMed

    Min, Long; Zhang, Yang; Liang, Xuefeng; Huang, Junrong; Bao, Wenli; Lee, Chi-Sing

    2014-10-13

    A highly diastereoselective and practical biomimetic total synthesis of (±)-basiliolide B has been achieved through the study of the two proposed biosynthetic pathways (O-methylation and O-acylation) for the unprecedented 7-methoxy-4,5-dihydro-3H-oxepin-2-one (C ring). The synthesis featured a cyclopropanation/ring opening strategy for establishing the stereogenic centers at C8 and C9, a biomimetic 2-pyrone Diels-Alder cycloaddition for the synthesis of the ABD ring system, and finally a highly efficient biomimetic intramolecular O-acylation for the C ring formation. This result provides an important perspective on the biosynthetic origin of the unprecedented 7-membered acyl ketene acetal moiety of the C ring.

  8. Aggregation of inorganic nanoparticles mediated by biomimetic oligomers.

    PubMed

    Tigger-Zaborov, Hagar; Maayan, Galia

    2015-09-14

    Assemblies of nanoparticles (NPs) have been broadly used for the construction of materials with unique spectroscopic and chiral properties for applications in various scientific disciplines such as sensing, bio-nanotechnology and medicine. Mediating the aggregation of NPs by synthetic biomimetic oligomers, namely, DNA, PNA, peptides and peptide mimics, rather than by small organic molecules has been shown to produce interesting supramolecular structures and enable the combination of the biocompatibility of the mediators and the spectroscopic properties of the NPs. Yet, the key to using this powerful approach for designing new functional materials is to understand the NPs aggregation patterns induced by biopolymers and biomimetic oligomers. Herein we describe the important developments in this field, from early studies to recent work with an emphasis on synthetic methods and tools for controlled assembly of metal NPs by biomimetic polymers and oligomers.

  9. Self-assembled chromophores within mesoporous nanocrystalline TiO2: towards biomimetic solar cells.

    PubMed

    Marek, Peter L; Sieger, Hermann; Scherer, Torsten; Hahn, Horst; Balaban, Teodor Silviu

    2009-06-01

    Artificial light-harvesting antennas consisting of self-assembled chromophores that mimic the natural pigments of photosynthetic bacteria have been inserted into voids induced in porous titania (TiO2, anatase) in order to investigate their suitability for hybrid solar cells. Mesoporous nanocrystalline TiO2 with additional uniform macropores was treated with precursor solutions of the pigment which was then induced to self-assemble within the voids. The chromophores were tailored to combine the self-assembly characteristics of the natural bacteriochlorophylls with the robustness of artificial Zn-porphyrins being stable for prolonged periods even upon heating to over 200 degrees C. They assemble on the TiO2 surface to form nano- to micro-crystalline structures with lengths from tens of nm up to several microm and show a photosensitization effect which is supposed to be dependent on the assembly size. The natural examples of these antennas are found in green sulfur bacteria which are able to use photosynthesis in deep water regions with minute light intensities. The implementation of biomimetic antennas for light harvesting and a better photon management may lead to a rise in efficiency of dye-sensitized solar cells also under low light illumination conditions.

  10. Biomimetic micro∕nanostructured functional surfaces for microfluidic and tissue engineering applications.

    PubMed

    Stratakis, E; Ranella, A; Fotakis, C

    2011-03-30

    This paper reviews our work on the application of ultrafast pulsed laser micro∕nanoprocessing for the three-dimensional (3D) biomimetic modification of materials surfaces. It is shown that the artificial surfaces obtained by femtosecond-laser processing of Si in reactive gas atmosphere exhibit roughness at both micro- and nanoscales that mimics the hierarchical morphology of natural surfaces. Along with the spatial control of the topology, defining surface chemistry provides materials exhibiting notable wetting characteristics which are potentially useful for open microfluidic applications. Depending on the functional coating deposited on the laser patterned 3D structures, we can achieve artificial surfaces that are (a) of extremely low surface energy, thus water-repellent and self-cleaned, and (b) responsive, i.e., showing the ability to change their surface energy in response to different external stimuli such as light, electric field, and pH. Moreover, the behavior of different kinds of cells cultured on laser engineered substrates of various wettabilities was investigated. Experiments showed that it is possible to preferentially tune cell adhesion and growth through choosing proper combinations of surface topography and chemistry. It is concluded that the laser textured 3D micro∕nano-Si surfaces with controllability of roughness ratio and surface chemistry can advantageously serve as a novel means to elucidate the 3D cell-scaffold interactions for tissue engineering applications.

  11. Biomimetic micro∕nanostructured functional surfaces for microfluidic and tissue engineering applications

    PubMed Central

    Stratakis, E.; Ranella, A.; Fotakis, C.

    2011-01-01

    This paper reviews our work on the application of ultrafast pulsed laser micro∕nanoprocessing for the three-dimensional (3D) biomimetic modification of materials surfaces. It is shown that the artificial surfaces obtained by femtosecond-laser processing of Si in reactive gas atmosphere exhibit roughness at both micro- and nanoscales that mimics the hierarchical morphology of natural surfaces. Along with the spatial control of the topology, defining surface chemistry provides materials exhibiting notable wetting characteristics which are potentially useful for open microfluidic applications. Depending on the functional coating deposited on the laser patterned 3D structures, we can achieve artificial surfaces that are (a) of extremely low surface energy, thus water-repellent and self-cleaned, and (b) responsive, i.e., showing the ability to change their surface energy in response to different external stimuli such as light, electric field, and pH. Moreover, the behavior of different kinds of cells cultured on laser engineered substrates of various wettabilities was investigated. Experiments showed that it is possible to preferentially tune cell adhesion and growth through choosing proper combinations of surface topography and chemistry. It is concluded that the laser textured 3D micro∕nano-Si surfaces with controllability of roughness ratio and surface chemistry can advantageously serve as a novel means to elucidate the 3D cell-scaffold interactions for tissue engineering applications. PMID:21522501

  12. Colour gamuts in polychromatic dielectric elastomer artificial chromatophores

    NASA Astrophysics Data System (ADS)

    Rossiter, Jonathan; Conn, Andrew; Cerruto, Antonio; Winters, Amy; Roke, Calum

    2014-03-01

    Chromatophores are the colour changing organelles in the skins of animals including fish and cephalopods. The ability of cephalopods in particular to rapidly change their colouration in response to environmental changes, for example to camouflage against a new background, and in social situations, for example to attract a mate or repel a rival, is extremely attractive for engineering, medical, active clothing and biomimetic robotic applications. The rapid response of these chromatophores is possible by the direct coupling of fast acting muscle and pigmented saccules. In artificial chromatophores we are able to mimic this structure using electroactive polymer artificial muscles. In contrast to prior research which has demonstrated monochromatic artificial chromatophores, here we consider a novel multi-colour, multi-layer, artificial chromatophore structure inspired by the complex dermal chromatophore unit in nature and which exploits dielectric elastomer artificial muscles as the electroactive actuation mechanism. We investigate the optical properties of this chromatophore unit and explore the range of colours and effects that a single unit and a matrix of chromatophores can produce. The colour gamut of the multi-colour chromatophore is analysed and shows its suitability for practical display and camouflage applications. It is demonstrated how, by varying actuator strain and chromatophore base colour, the gamut can be shifted through colour space, thereby tuning the artificial chromatophore to a specific environment or application.

  13. Hydrodynamic function of biomimetic shark skin: effect of denticle pattern and spacing.

    PubMed

    Wen, Li; Weaver, James C; Thornycroft, Patrick J M; Lauder, George V

    2015-11-18

    The structure of shark skin has been the subject of numerous studies and recently biomimetic shark skin has been fabricated with rigid denticles (scales) on a flexible substrate. This artificial skin can bend and generate thrust when attached to a mechanical controller. The ability to control the manufacture of biomimetic shark skin facilitates manipulation of surface parameters and understanding the effects of changing denticle patterns on locomotion. In this paper we investigate the effect of changing the spacing and arrangement of denticles on the surface of biomimetic shark skin on both static and dynamic locomotor performance. We designed 3D-printed flexible membranes with different denticle patterns and spacings: (1) staggered-overlapped, (2) linear-overlapped, and (3) linear-non-overlapped, and compared these to a 3D-printed smooth-surfaced control. These 3D printed shark skin models were then tested in a flow tank with a mechanical flapping device that allowed us to either hold the models in a stationary position or move them dynamically. We swam the membranes at a frequency of 1 Hz with different heave amplitudes (from ±1 cm to ±3 cm) while measuring forces, torques, self-propelled swimming speed, and cost of transport (COT). Static tests revealed drag reduction of denticle patterns compared to a smooth control at low speeds, but increased drag at speeds above 25 cm s(-1). However, during dynamic (swimming) tests, the staggered-overlapped pattern produced the fastest swimming speeds with no significant increase in the COT at lower heave values. For instance, at a heave frequency of 1 Hz and amplitude of ±1 cm, swimming speed of the staggered-overlapped pattern increased by 25.2% over the smooth control. At higher heave amplitudes, significantly faster self-propelled swimming speeds were achieved by the staggered-overlapped pattern, but with higher COT. Only the staggered-overlapped pattern provides a significant swimming performance advantage over the

  14. Development of biomimetic nano-hydroxyapatite/poly(hexamethylene adipamide) composites.

    PubMed

    Wang, Xuejiang; Li, Yubao; Wei, Jie; de Groot, Klass

    2002-12-01

    In this study, acicular nano-hydroxyapatite (n-HA) was used to make a new biomimetic composite with polyamide (poly hexamethylene adipamide) by a unique technique. The physical and chemical characteristics of the composites were tested. It was found that these synthesized n-HA crystals were similar to bone apatite in size, phase composition and crystal structure. The biomimetic n-HA crystals were uniformly distributed in the polymer matrix and its content can reach 65%, close to that in natural bone. Chemical binding between inorganic n-HA and polyamide was investigated and discussed. The mechanical properties of the composites were found to match well with those of natural bone.

  15. Real-time biomimetic Central Pattern Generators in an FPGA for hybrid experiments

    PubMed Central

    Ambroise, Matthieu; Levi, Timothée; Joucla, Sébastien; Yvert, Blaise; Saïghi, Sylvain

    2013-01-01

    This investigation of the leech heartbeat neural network system led to the development of a low resources, real-time, biomimetic digital hardware for use in hybrid experiments. The leech heartbeat neural network is one of the simplest central pattern generators (CPG). In biology, CPG provide the rhythmic bursts of spikes that form the basis for all muscle contraction orders (heartbeat) and locomotion (walking, running, etc.). The leech neural network system was previously investigated and this CPG formalized in the Hodgkin–Huxley neural model (HH), the most complex devised to date. However, the resources required for a neural model are proportional to its complexity. In response to this issue, this article describes a biomimetic implementation of a network of 240 CPGs in an FPGA (Field Programmable Gate Array), using a simple model (Izhikevich) and proposes a new synapse model: activity-dependent depression synapse. The network implementation architecture operates on a single computation core. This digital system works in real-time, requires few resources, and has the same bursting activity behavior as the complex model. The implementation of this CPG was initially validated by comparing it with a simulation of the complex model. Its activity was then matched with pharmacological data from the rat spinal cord activity. This digital system opens the way for future hybrid experiments and represents an important step toward hybridization of biological tissue and artificial neural networks. This CPG network is also likely to be useful for mimicking the locomotion activity of various animals and developing hybrid experiments for neuroprosthesis development. PMID:24319408

  16. Real-time biomimetic Central Pattern Generators in an FPGA for hybrid experiments.

    PubMed

    Ambroise, Matthieu; Levi, Timothée; Joucla, Sébastien; Yvert, Blaise; Saïghi, Sylvain

    2013-01-01

    This investigation of the leech heartbeat neural network system led to the development of a low resources, real-time, biomimetic digital hardware for use in hybrid experiments. The leech heartbeat neural network is one of the simplest central pattern generators (CPG). In biology, CPG provide the rhythmic bursts of spikes that form the basis for all muscle contraction orders (heartbeat) and locomotion (walking, running, etc.). The leech neural network system was previously investigated and this CPG formalized in the Hodgkin-Huxley neural model (HH), the most complex devised to date. However, the resources required for a neural model are proportional to its complexity. In response to this issue, this article describes a biomimetic implementation of a network of 240 CPGs in an FPGA (Field Programmable Gate Array), using a simple model (Izhikevich) and proposes a new synapse model: activity-dependent depression synapse. The network implementation architecture operates on a single computation core. This digital system works in real-time, requires few resources, and has the same bursting activity behavior as the complex model. The implementation of this CPG was initially validated by comparing it with a simulation of the complex model. Its activity was then matched with pharmacological data from the rat spinal cord activity. This digital system opens the way for future hybrid experiments and represents an important step toward hybridization of biological tissue and artificial neural networks. This CPG network is also likely to be useful for mimicking the locomotion activity of various animals and developing hybrid experiments for neuroprosthesis development.

  17. Biomimetic processing of oriented crystalline ceramic layers

    SciTech Connect

    Cesarano, J.; Shelnutt, J.A.

    1997-10-01

    The aim of this project was to develop the capabilities for Sandia to fabricate self assembled Langmuir-Blodgett (LB) films of various materials and to exploit their two-dimensional crystalline structure to promote the growth of oriented thin films of inorganic materials at room temperature. This includes the design and synthesis of Langmuir-active (amphiphilic) organic molecules with end groups offering high nucleation potential for various ceramics. A longer range goal is that of understanding the underlying principles, making it feasible to use the techniques presented in this report to fabricate unique oriented films of various materials for electronic, sensor, and membrane applications. Therefore, whenever possible, work completed in this report was completed with the intention of addressing the fundamental phenomena underlying the growth of crystalline, inorganic films on template layers of highly organized organic molecules. This problem was inspired by biological processes, which often produce exquisitely engineered structures via templated growth on polymeric layers. Seashells, for example, exhibit great toughness owing to their fine brick-and-mortar structure that results from templated growth of calcium carbonate on top of layers of ordered organic proteins. A key goal in this work, therefore, is to demonstrate a positive correlation between the order and orientation of the template layer and that of the crystalline ceramic material grown upon it. The work completed was comprised of several parallel efforts that encompassed the entire spectrum of biomimetic growth from solution. Studies were completed on seashells and the mechanisms of growth for calcium carbonate. Studies were completed on the characterization of LB films and the capability developed for the in-house fabrication of these films. Standard films of fatty acids were studied as well as novel polypeptides and porphyrins that were synthesized.

  18. Biomimetic photo-actuation: progress and challenges

    NASA Astrophysics Data System (ADS)

    Dicker, Michael P. M.; Weaver, Paul M.; Rossiter, Jonathan M.; Bond, Ian P.; Faul, Charl F. J.

    2016-04-01

    Photo-actuation, such as that observed in the reversible sun-tracking movements of heliotropic plants, is produced by a complex, yet elegant series of processes. In the heliotropic leaf movements of the Cornish Mallow, photo-actuation involves the generation, transport and manipulation of chemical signals from a distributed network of sensors in the leaf veins to a specialized osmosis driven actuation region in the leaf stem. It is theorized that such an arrangement is both efficient in terms of materials use and operational energy conversion, as well as being highly robust. We concern ourselves with understanding and mimicking these light driven, chemically controlled actuating systems with the aim of generating intelligent structures which share the properties of efficiency and robustness that are so important to survival in Nature. In this work we present recent progress in mimicking these photo-actuating systems through remote light exposure of a metastable state photoacid and the resulting signal and energy transfer through solution to a pH-responsive hydrogel actuator. Reversible actuation strains of 20% were achieved from this arrangement, with modelling then employed to reveal the critical influence hydrogel pKa has on this result. Although the strong actuation achieved highlights the progress that has been made in replicating the principles of biomimetic photo-actuation, challenges such as photoacid degradation were also revealed. It is anticipated that current work can directly lead to the development of high-performance and low-cost solartrackers for increased photovoltaic energy capture and to the creation of new types of intelligent structures employing chemical control systems.

  19. Developing a biomimetic tooth bud model.

    PubMed

    Smith, Elizabeth E; Zhang, Weibo; Schiele, Nathan R; Khademhosseini, Ali; Kuo, Catherine K; Yelick, Pamela C

    2017-01-08

    A long-term goal is to bioengineer, fully functional, living teeth for regenerative medicine and dentistry applications. Biologically based replacement teeth would avoid insufficiencies of the currently used dental implants. Using natural tooth development as a guide, a model was fabricated using post-natal porcine dental epithelial (pDE), porcine dental mesenchymal (pDM) progenitor cells, and human umbilical vein endothelial cells (HUVEC) encapsulated within gelatin methacrylate (GelMA) hydrogels. Previous publications have shown that post-natal DE and DM cells seeded onto synthetic scaffolds exhibited mineralized tooth crowns composed of dentin and enamel. However, these tooth structures were small and formed within the pores of the scaffolds. The present study shows that dental cell-encapsulated GelMA constructs can support mineralized dental tissue formation of predictable size and shape. Individually encapsulated pDE or pDM cell GelMA constructs were analysed to identify formulas that supported pDE and pDM cell attachment, spreading, metabolic activity, and neo-vasculature formation with co-seeded endothelial cells (HUVECs). GelMa constructs consisting of pDE-HUVECS in 3% GelMA and pDM-HUVECs within 5% GelMA supported dental cell differentiation and vascular mineralized dental tissue formation in vivo. These studies are the first to demonstrate the use of GelMA hydrogels to support the formation of post-natal dental progenitor cell-derived mineralized and functionally vascularized tissues of specified size and shape. These results introduce a novel three-dimensional biomimetic tooth bud model for eventual bioengineered tooth replacement teeth in humans. Copyright © 2017 John Wiley & Sons, Ltd.

  20. Biomimetic catalysts responsive to specific chemical signals

    SciTech Connect

    Zhao, Yan

    2015-03-04

    Part 1. Design of Biomimetic Catalysts Based on Amphiphilic Systems The overall objective of our research is to create biomimetic catalysts from amphiphilic molecules. More specifically, we aim to create supramolecular systems that can be used to control the microenvironment around a catalytic center in a biomimetic fashion and apply the learning to construct supramolecular catalysts with novel functions found in enzymatic catalysts. We have prepared synthetic molecules (i.e., foldamers) that could fold into helical structures with nanometer-sized internal hydrophilic cavities. Cavities of this size are typically observed only in the tertiary and quaternary structures of proteins but were formed in our foldamer prepared in just a few steps from the monomer. Similar to many proteins, our foldamers displayed cooperativity in the folding/unfolding equilibrium and followed a two-state conformational transition. In addition, their conformational change could be triggered by solvent polarity, pH, or presence of metal ions and certain organic molecules. We studied their environmentally dependent conformational changes in solutions, surfactant micelles, and lipid bilayer membranes. Unlike conventional rigid supramolecular host, a foldamer undergoes conformational change during guest binding. Our study in the molecular recognition of an oligocholate host yielded some extremely exciting results. Cooperativity between host conformation and host–guest interactions was found to “magnify” weak binding interactions. In other words, since binding affinity is determined by the overall change of free energy during the binding, guest-induced conformational change of the host, whether near or far from the binding site, affects the binding. This study has strong implications in catalysis because enzymes have been hypothesized to harvest similar intramolecular forces to strengthen their binding with the transition state of an enzyme-catalyzed reaction. The supramolecular and

  1. A biomimetic tactile sensing system based on polyvinylidene fluoride film

    NASA Astrophysics Data System (ADS)

    Xin, Yi; Tian, Hongying; Guo, Chao; Li, Xiang; Sun, Hongshuai; Wang, Peiyuan; Qian, Chenghui; Wang, Shuhong; Wang, Cheng

    2016-02-01

    Polyvinylidene fluoride (PVDF) film has been widely investigated as a sensing material due to its outstanding properties such as biocompatibility, high thermal stability, good chemical resistance, high piezo-, pyro- and ferro-electric properties. This paper reports on the design, test, and analysis of a biomimetic tactile sensor based on PVDF film. This sensor consists of a PVDF film with aluminum electrodes, a pair of insulating layers, and a "handprint" friction layer with a copper foil. It is designed for easy fabrication and high reliability in outputting signals. In bionics, the fingerprint of the glabrous skin plays an important role during object handling. Therefore, in order to enhance friction and to provide better manipulation, the ridges of the fingertips were introduced into the design of the proposed tactile sensor. And, a basic experimental study on the selection of the high sensitivity fingerprint type for the biomimetic sensor was performed. In addition, we proposed a texture distinguish experiment to verify the sensor sensitivity. The experiment's results show that the novel biomimetic sensor is effective in discriminating object surface characteristics. Furthermore, an efficient visual application program (LabVIEW) and a quantitative evaluation method were proposed for the verification of the biomimetic sensor. The proposed tactile sensor shows great potential for contact force and slip measurements.

  2. On the Biomimetic Design of Agile-Robot Legs

    PubMed Central

    Garcia, Elena; Arevalo, Juan Carlos; Muñoz, Gustavo; Gonzalez-de-Santos, Pablo

    2011-01-01

    The development of functional legged robots has encountered its limits in human-made actuation technology. This paper describes research on the biomimetic design of legs for agile quadrupeds. A biomimetic leg concept that extracts key principles from horse legs which are responsible for the agile and powerful locomotion of these animals is presented. The proposed biomimetic leg model defines the effective leg length, leg kinematics, limb mass distribution, actuator power, and elastic energy recovery as determinants of agile locomotion, and values for these five key elements are given. The transfer of the extracted principles to technological instantiations is analyzed in detail, considering the availability of current materials, structures and actuators. A real leg prototype has been developed following the biomimetic leg concept proposed. The actuation system is based on the hybrid use of series elasticity and magneto-rheological dampers which provides variable compliance for natural motion. From the experimental evaluation of this prototype, conclusions on the current technological barriers to achieve real functional legged robots to walk dynamically in agile locomotion are presented. PMID:22247667

  3. Phospholipid-sepiolite biomimetic interfaces for the immobilization of enzymes.

    PubMed

    Wicklein, Bernd; Darder, Margarita; Aranda, Pilar; Ruiz-Hitzky, Eduardo

    2011-11-01

    Biomimetic interfaces based on phosphatidylcholine (PC) assembled to the natural silicate sepiolite were prepared for the stable immobilization of the urease and cholesterol oxidase enzymes. This is an important issue in practical advanced applications such as biocatalysis or biosensing. The supported lipid bilayer (BL-PC), prepared from PC adsorption, was used for immobilization of enzymes and the resulting biomimetic systems were compared to several other supported layers including a lipid monolayer (ML-PC), a mixed phosphatidylcholine/octyl-galactoside layer (PC-OGal), a cetyltrimethylammonium monolayer (CTA), and also to the bare sepiolite surface. Interfacial characteristics of these layers were investigated with a focus on layer packing density, hydrophilicity/hydrophobicity, and surface charge, which are being considered as key points for enzyme immobilization and stabilization of their biological activity. Cytoplasmic urease and membrane-bound cholesterol oxidase, which served as model enzymes, were immobilized on the different PC-based hybrid materials to probe their biomimetic character. Enzymatic activity was assessed by cyclic voltammetry and UV-vis spectrophotometry. The resulting enzyme/bio-organoclay hybrids were applied as active phase of a voltammetric urea biosensor and cholesterol bioreactor, respectively. Urease supported on sepiolite/BL-PC proved to maintain its enzymatic activity over several months while immobilized cholesterol oxidase demonstrated high reusability as biocatalyst. The results emphasize the good preservation of bioactivity due to the accommodation of the enzymatic system within the biomimetic lipid interface on sepiolite.

  4. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring

    PubMed Central

    Han, Chuanjun

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal. PMID:27019582

  5. Biomimetic smart sensors for autonomous robotic behavior I: acoustic processing

    NASA Astrophysics Data System (ADS)

    Deligeorges, Socrates; Xue, Shuwan; Soloway, Aaron; Lichtenstein, Lee; Gore, Tyler; Hubbard, Allyn

    2009-05-01

    Robotics are rapidly becoming an integral tool on the battlefield and in homeland security, replacing humans in hazardous conditions. To enhance the effectiveness of robotic assets and their interaction with human operators, smart sensors are required to give more autonomous function to robotic platforms. Biologically inspired sensors are an essential part of this development of autonomous behavior and can increase both capability and performance of robotic systems. Smart, biologically inspired acoustic sensors have the potential to extend autonomous capabilities of robotic platforms to include sniper detection, vehicle tracking, personnel detection, and general acoustic monitoring. The key to enabling these capabilities is biomimetic acoustic processing using a time domain processing method based on the neural structures of the mammalian auditory system. These biologically inspired algorithms replicate the extremely adaptive processing of the auditory system yielding high sensitivity over broad dynamic range. The algorithms provide tremendous robustness in noisy and echoic spaces; properties necessary for autonomous function in real world acoustic environments. These biomimetic acoustic algorithms also provide highly accurate localization of both persistent and transient sounds over a wide frequency range, using baselines on the order of only inches. A specialized smart sensor has been developed to interface with an iRobot Packbot® platform specifically to enhance its autonomous behaviors in response to personnel and gunfire. The low power, highly parallel biomimetic processor, in conjunction with a biomimetic vestibular system (discussed in the companion paper), has shown the system's autonomous response to gunfire in complicated acoustic environments to be highly effective.

  6. A Laboratory Exercise to Introduce Inorganic Biomimetic Compounds.

    ERIC Educational Resources Information Center

    Baird, Donald M.

    1985-01-01

    Biomimetic chemistry is concerned with the synthesis of small, molecular weight molecules which mimic the properties of metal-containing sites within certain biologically significant species. A series of experiments for an advanced undergraduate laboratory is described as a way to introduce this area into the chemistry curriculum. (JN)

  7. On the biomimetic design of agile-robot legs.

    PubMed

    Garcia, Elena; Arevalo, Juan Carlos; Muñoz, Gustavo; Gonzalez-de-Santos, Pablo

    2011-01-01

    The development of functional legged robots has encountered its limits in human-made actuation technology. This paper describes research on the biomimetic design of legs for agile quadrupeds. A biomimetic leg concept that extracts key principles from horse legs which are responsible for the agile and powerful locomotion of these animals is presented. The proposed biomimetic leg model defines the effective leg length, leg kinematics, limb mass distribution, actuator power, and elastic energy recovery as determinants of agile locomotion, and values for these five key elements are given. The transfer of the extracted principles to technological instantiations is analyzed in detail, considering the availability of current materials, structures and actuators. A real leg prototype has been developed following the biomimetic leg concept proposed. The actuation system is based on the hybrid use of series elasticity and magneto-rheological dampers which provides variable compliance for natural motion. From the experimental evaluation of this prototype, conclusions on the current technological barriers to achieve real functional legged robots to walk dynamically in agile locomotion are presented.

  8. A novel biomimetic polymer scaffold design enhances bone ingrowth.

    PubMed

    Geffre, Chris P; Margolis, David S; Ruth, John T; DeYoung, Donald W; Tellis, Brandi C; Szivek, John A

    2009-12-01

    There has been recent interest in treating large bone defects with polymer scaffolds because current modalities such as autographs and allographs have limitations. Additionally, polymer scaffolds are utilized in tissue engineering applications to implant and anchor tissues in place, promoting integration with surrounding native tissue. In both applications, rapid and increased bone growth is crucial to the success of the implant. Recent studies have shown that mimicking native bone tissue morphology leads to increased osteoblastic phenotype and more rapid mineralization. The purpose of this study was to compare bone ingrowth into polymer scaffolds created with a biomimetic porous architecture to those with a simple porous design. The biomimetic architecture was designed from the inverse structure of native trabecular bone and manufactured using solid free form fabrication. Histology and muCT analysis demonstrated a 500-600% increase in bone growth into and adjacent to the biomimetic scaffold at five months post-op. This is in agreement with previous studies in which biomimetic approaches accelerated bone formation. It also supports the applicability of polymer scaffolds for the treatment of large tissue defects when implanting tissue-engineering constructs. (c) 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009.

  9. Textile Processes for Engineering Tissues with Biomimetic Architectures and Properties.

    PubMed

    Fallahi, Afsoon; Khademhosseini, Ali; Tamayol, Ali

    2016-09-01

    Textile technologies in which fibers containing biological factors and cells are formed and assembled into constructs with biomimetic properties have attracted significant attention in the field of tissue engineering. This Forum article highlights the most prominent advances of the field in the areas of fiber fabrication and construct engineering.

  10. Hiding the squid: patterns in artificial cephalopod skin

    PubMed Central

    Fishman, Aaron; Rossiter, Jonathan; Homer, Martin

    2015-01-01

    Cephalopods employ their chromomorphic skins for rapid and versatile active camouflage and signalling effects. This is achieved using dense networks of pigmented, muscle-driven chromatophore cells which are neurally stimulated to actuate and affect local skin colouring. This allows cephalopods to adopt numerous dynamic and complex skin patterns, most commonly used to blend into the environment or to communicate with other animals. Our ultimate goal is to create an artificial skin that can mimic such pattern generation techniques, and that could produce a host of novel and compliant devices such as cloaking suits and dynamic illuminated clothing. This paper presents the design, mathematical modelling and analysis of a dynamic biomimetic pattern generation system using bioinspired artificial chromatophores. The artificial skin is made from electroactive dielectric elastomer: a soft, planar-actuating smart material that we show can be effective at mimicking the actuation of biological chromatophores. The proposed system achieves dynamic pattern generation by imposing simple local rules into the artificial chromatophore cells so that they can sense their surroundings in order to manipulate their actuation. By modelling sets of artificial chromatophores in linear arrays of cells, we explore the capability of the system to generate a variety of dynamic pattern types. We show that it is possible to mimic patterning seen in cephalopods, such as the passing cloud display, and other complex dynamic patterning. PMID:26063823

  11. Hiding the squid: patterns in artificial cephalopod skin.

    PubMed

    Fishman, Aaron; Rossiter, Jonathan; Homer, Martin

    2015-07-06

    Cephalopods employ their chromomorphic skins for rapid and versatile active camouflage and signalling effects. This is achieved using dense networks of pigmented, muscle-driven chromatophore cells which are neurally stimulated to actuate and affect local skin colouring. This allows cephalopods to adopt numerous dynamic and complex skin patterns, most commonly used to blend into the environment or to communicate with other animals. Our ultimate goal is to create an artificial skin that can mimic such pattern generation techniques, and that could produce a host of novel and compliant devices such as cloaking suits and dynamic illuminated clothing. This paper presents the design, mathematical modelling and analysis of a dynamic biomimetic pattern generation system using bioinspired artificial chromatophores. The artificial skin is made from electroactive dielectric elastomer: a soft, planar-actuating smart material that we show can be effective at mimicking the actuation of biological chromatophores. The proposed system achieves dynamic pattern generation by imposing simple local rules into the artificial chromatophore cells so that they can sense their surroundings in order to manipulate their actuation. By modelling sets of artificial chromatophores in linear arrays of cells, we explore the capability of the system to generate a variety of dynamic pattern types. We show that it is possible to mimic patterning seen in cephalopods, such as the passing cloud display, and other complex dynamic patterning.

  12. Biphasic and boundary lubrication mechanisms in artificial hydrogel cartilage: A review.

    PubMed

    Murakami, Teruo; Yarimitsu, Seido; Nakashima, Kazuhiro; Sakai, Nobuo; Yamaguchi, Tetsuo; Sawae, Yoshinori; Suzuki, Atsushi

    2015-12-01

    Various studies on the application of artificial hydrogel cartilage to cartilage substitutes and artificial joints have been conducted. It is expected in clinical application of artificial hydrogel cartilage that not only soft-elastohydrodynamic lubrication but biphasic, hydration, gel-film and boundary lubrication mechanisms will be effective to sustain extremely low friction and minimal wear in daily activities similar to healthy natural synovial joints with adaptive multimode lubrication. In this review article, the effectiveness of biphasic lubrication and boundary lubrication in hydrogels in thin film condition is focused in relation to the structures and properties of hydrogels. As examples, the tribological behaviors in three kinds of poly(vinyl alcohol) hydrogels with high water content are compared, and the importance of lubrication mechanism in biomimetic artificial hydrogel cartilage is discussed to extend the durability of cartilage substitute.

  13. Coupled electron transfers in artificial photosynthesis

    PubMed Central

    Hammarström, Leif; Styring, Stenbjörn

    2007-01-01

    Light-induced charge separation in molecular assemblies has been widely investigated in the context of artificial photosynthesis. Important progress has been made in the fundamental understanding of electron and energy transfer and in stabilizing charge separation by multi-step electron transfer. In the Swedish Consortium for Artificial Photosynthesis, we build on principles from the natural enzyme photosystem II and Fe-hydrogenases. An important theme in this biomimetic effort is that of coupled electron-transfer reactions, which have so far received only little attention. (i) Each absorbed photon leads to charge separation on a single-electron level only, while catalytic water splitting and hydrogen production are multi-electron processes; thus there is the need for controlling accumulative electron transfer on molecular components. (ii) Water splitting and proton reduction at the potential catalysts necessarily require the management of proton release and/or uptake. Far from being just a stoichiometric requirement, this controls the electron transfer processes by proton-coupled electron transfer (PCET). (iii) Redox-active links between the photosensitizers and the catalysts are required to rectify the accumulative electron-transfer reactions, and will often be the starting points of PCET. PMID:17954432

  14. Flexidrive: a soft artificial muscle motor

    NASA Astrophysics Data System (ADS)

    Anderson, Iain A.; Tse, Tony C. H.; Inamura, Tokushu; O'Brien, Benjamin; McKay, Thomas; Gisby, Todd

    2011-04-01

    We use our thumbs and forefingers to rotate an object such as a control knob on a stereo system by moving our finger relative to our thumb. Motion is imparted without sliding and in a precise manner. In this paper we demonstrate how an artificial muscle membrane can be used to mimic this action. This is achieved by embedding a soft gear within the membrane. Deformation of the membrane results in deformation of the polymer gear and this can be used for motor actuation by rotating the shaft. The soft motors were fabricated from 3M VHB4905 membranes 0.5mm thick that were pre-stretched equibiaxially to a final thickness of 31 μm. Each membrane had polymer acrylic soft gears inserted at the center. Sectors of each membrane (60° sector) were painted on both sides with conducting carbon grease leaving gaps between adjoining sectors to avoid arcing between them. Each sector was electrically connected to a power supply electrode on the rigid acrylic frame via narrow avenues of carbon-grease. The motors were supported in rigid acrylic frames aligned concentrically. A flexible shaft was inserted through both gears. Membranes were charged using a step wave PWM voltage signal delivered using a Biomimetics Lab EAP Control unit. Both membrane viscoelasticity and the resisting torque on the shaft influence motor speed by changing the effective circumference of the flexible gear. This new soft motor opens the door to artificial muscle machines molded as a single part.

  15. Artificial photosynthesis: understanding water splitting in nature

    PubMed Central

    Cox, Nicholas; Pantazis, Dimitrios A.; Neese, Frank; Lubitz, Wolfgang

    2015-01-01

    In the context of a global artificial photosynthesis (GAP) project, we review our current work on nature's water splitting catalyst. In a recent report (Cox et al. 2014 Science 345, 804–808 (doi:10.1126/science.1254910)), we showed that the catalyst—a Mn4O5Ca cofactor—converts into an ‘activated’ form immediately prior to the O–O bond formation step. This activated state, which represents an all MnIV complex, is similar to the structure observed by X-ray crystallography but requires the coordination of an additional water molecule. Such a structure locates two oxygens, both derived from water, in close proximity, which probably come together to form the product O2 molecule. We speculate that formation of the activated catalyst state requires inherent structural flexibility. These features represent new design criteria for the development of biomimetic and bioinspired model systems for water splitting catalysts using first-row transition metals with the aim of delivering globally deployable artificial photosynthesis technologies. PMID:26052426

  16. Artificial photosynthesis: understanding water splitting in nature.

    PubMed

    Cox, Nicholas; Pantazis, Dimitrios A; Neese, Frank; Lubitz, Wolfgang

    2015-06-06

    In the context of a global artificial photosynthesis (GAP) project, we review our current work on nature's water splitting catalyst. In a recent report (Cox et al. 2014 Science 345, 804-808 (doi:10.1126/science.1254910)), we showed that the catalyst-a Mn4O5Ca cofactor-converts into an 'activated' form immediately prior to the O-O bond formation step. This activated state, which represents an all Mn(IV) complex, is similar to the structure observed by X-ray crystallography but requires the coordination of an additional water molecule. Such a structure locates two oxygens, both derived from water, in close proximity, which probably come together to form the product O2 molecule. We speculate that formation of the activated catalyst state requires inherent structural flexibility. These features represent new design criteria for the development of biomimetic and bioinspired model systems for water splitting catalysts using first-row transition metals with the aim of delivering globally deployable artificial photosynthesis technologies.

  17. Forisome performance in artificial sieve tubes.

    PubMed

    Knoblauch, Michael; Stubenrauch, Mike; van Bel, Aart J E; Peters, Winfried S

    2012-08-01

    In the legume phloem, sieve element occlusion (SEO) proteins assemble into Ca(2+)-dependent contractile bodies. These forisomes presumably control phloem transport by forming reversible sieve tube plugs. This function, however, has never been directly demonstrated, and appears questionable as forisomes were reported to be too small to plug sieve tubes, and failed to block flow efficiently in artificial microchannels. Moreover, plugs of SEO-related proteins in Arabidopsis sieve tubes do not affect phloem translocation. We improved existing procedures for forisome isolation and storage, and found that the degree of Ca(2+)-driven deformation that is possible in forisomes of Vicia faba, the standard object of earlier research, has been underestimated substantially. Forisomes deform particularly strongly under reducing conditions and high sugar concentrations, as typically found in sieve tubes. In contrast to our previous inference, Ca(2+)-inducible forisome swelling certainly seems sufficient to plug sieve tubes. This conclusion was supported by 3D-reconstructions of forisome plugs in Canavalia gladiata. For a direct test, we built microfluidics chips with artificial sieve tubes. Using fluorescent dyes to visualize flow, we demonstrated the complete blockage of these biomimetic microtubes by Ca(2+)-induced forisome plugs, and concluded by analogy that forisomes are capable of regulating phloem flow in vivo.

  18. WO3/Pt nanoparticles are NADPH oxidase biomimetics that mimic effector cells in vitro and in vivo

    NASA Astrophysics Data System (ADS)

    Clark, Andrea J.; Coury, Emma L.; Meilhac, Alexandra M.; Petty, Howard R.

    2016-02-01

    To provide a means of delivering an artificial immune effector cell-like attack on tumor cells, we report the tumoricidal ability of inorganic WO3/Pt nanoparticles that mimic a leukocyte’s functional abilities. These nanoparticles route electrons from organic structures and electron carriers to form hydroxyl radicals within tumor cells. During visible light exposure, WO3/Pt nanoparticles manufacture hydroxyl radicals, degrade organic compounds, use NADPH, trigger lipid peroxidation, promote lysosomal membrane disruption, promote the loss of reduced glutathione, and activate apoptosis. In a model of advanced breast cancer metastasis to the eye’s anterior chamber, we show that WO3/Pt nanoparticles prolong the survival of 4T1 tumor-bearing Balb/c mice. This new generation of inorganic photosensitizers do not photobleach, and therefore should provide an important therapeutic advance in photodynamic therapy. As biomimetic nanoparticles destroy targeted cells, they may be useful in treating ocular and other forms of cancer.

  19. Aquaporin, forward osmosis and biomimetic membranes.

    PubMed

    Kocherginsky, Nikolai

    2013-12-01

    Aquaporin attracted attention not only of physiologists and biophysicists, but also of chemical engineers. Here we critically analyze a paper describing aquaporin-based artificial membranes, suggested for forward osmosis-based water purification (Wang et al. 2012, Small 8, pp. 1185-1190). Related papers published later by the same group are also discussed. We indicate recently developed general approach to describe membrane transport, membrane permeability and selectivity, which is applicable for forward osmosis. In addition, we also mention our papers describing simple nitrocellulose-based membranes, which have selective aqueous channels without proteins, but successfully imitate many properties of biomembranes.

  20. A Biomimetic Algorithm for Flight Stabilization in Airborne Vehicles, Based on Dragonfly Ocellar Vision

    DTIC Science & Technology

    2006-07-27

    Australia Email: gert.stange@anu.edu.au A biomimetic algorithm for flight stabilization in airborne vehicles, based on dragonfly ocellar vision...27 JUL 2006 2. REPORT TYPE Final Report (Technical) 3. DATES COVERED 10-06-2005 to 01-03-2006 4. TITLE AND SUBTITLE A Biomimetic Algorithm for...anatomy of the dragonfly occeli, it can be concluded that they are simple lens eyes designed for attitude stabilization. 15. SUBJECT TERMS Biomimetics

  1. Systematic Investigations of Biomimetic Catalysts in the Synthesis of Reactive Metal Oxide Nanoparticle Networks

    DTIC Science & Technology

    2012-09-01

    titania and alumina, (2) to entrap biological agents within the matrixes of these oxides, and (3) to control the morphology of the biomimetically...precipitated titania through biomimetic agent composition. These metal oxides are of interest as potential decontaminating substrates for the hydrolysis...biomimetic agents will precipitate metal oxides beyond silica, show that it is possible to entrap enzymes within the titania matrix and retain activity

  2. Biomimetic Synthesis of Noble Metal Nanocrystals and the Mechanism Studies

    NASA Astrophysics Data System (ADS)

    Ruan, Lingyan

    Nanostructured materials with dimensions reaching the nanoscale possess novel properties different from their bulk counterparts. Engineering nanomaterials to exploit their improved functions show important applications in catalysis, electrocatalysis, electronics, optoelectronics, and energy devices. One of the challenges to date is to develop methods for producing nanomaterials in a controllable and predictable fashion. We seek to develop novel biomimetic synthetic protocols for programmable nanomaterial synthesis, i.e., using biomolecules with specific material recognition properties to manipulate nanomaterial morphologies and structures. Starting with three Pt binding peptides with distinct recognition properties, i.e., a Pt material specific peptide BP7A and two Pt facet specific peptides T7 (Pt {100} facet specific) and S7 (Pt {111} facet specific), we demonstrate a rational creation of Pt bipyramids, a new type of shape for Pt nanocrystals. The BP7A peptide is found to be able to introduce twinning during Pt nanocrystal growth. We use it to generate single twinned seeds for Pt nanocrystals. Together with targeted facet stabilization using T7/S7 peptides, Pt {100} bipyramid and {111} bipyramid are successfully synthesized for the first time. We further utilize the twin introducing property of the BP7A peptide to generate ultrathin Pt nanowire with high twin densities. We show that the Pt nanowire possesses higher electrocatalytic activity and durability in oxygen reduction and methanol oxidation reactions due to its one-dimensional nanostructure and the presence of dense twin defects, demonstrating the concept of defect engineering in nanocrystals as a strategy in the design of novel electrocatalyst. The organic-inorganic interface is a key issue in many fields including colloidal syntheses and biomimetics, the understanding of which can enable the design of new material synthetic strategies. We aim to understand how the Pt binding peptides modulate the

  3. Biomimetic FAA-certifiable, artificial muscle structures for commercial aircraft wings

    NASA Astrophysics Data System (ADS)

    Barrett, Ronald M.; Barrett, Cassandra M.

    2014-07-01

    This paper is centered on a new form of adaptive material which functions much in the same way as skeletal muscle tissue, is structurally modeled on plant actuator cells and capable of rapidly expanding or shrinking by as much as an order of magnitude in prescribed directions. Rapid changes of plant cell shape and sizes are often initiated via ion-transport driven fluid migration and resulting turgor pressure variation. Certain plant cellular structures like those in Mimosa pudica (sensitive plant), Albizia julibrissin (Mimosa tree), or Dionaea muscipula (Venus Flytrap) all exhibit actuation physiology which employs such turgor pressure manipulation. The paper begins with dynamic micrographs of a sectioned basal articulation joint from A. julibrissin. These figures show large cellular dimensional changes as the structure undergoes foliage articulation. By mimicking such structures in aircraft flight control mechanisms, extremely lightweight pneumatic control surface actuators can be designed. This paper shows several fundamental layouts of such surfaces with actuator elements made exclusively from FAA-certifiable materials, summarizes their structural mechanics and shows actuator power and energy densities that are higher than nearly all classes of conventional adaptive materials available today. A sample flap structure is shown to possess the ability to change its shape and structural stiffness as its cell pressures are manipulated, which in turn changes the surface lift-curve slope when exposed to airflows. Because the structural stiffness can be altered, it is also shown that the commanded section lift-curve slope can be similarly controlled between 1.2 and 6.2 rad-1. Several aircraft weight reduction principles are also shown to come into play as the need to concentrate loads to pass through point actuators is eliminated. The paper concludes with a summary of interrelated performance and airframe-level improvements including enhanced gust rejection, load alleviation, ride quality, fatigue life and flight safety.

  4. Nano-sized manganese oxides as biomimetic catalysts for water oxidation in artificial photosynthesis: a review.

    PubMed

    Najafpour, Mohammad Mahdi; Rahimi, Fahimeh; Aro, Eva-Mari; Lee, Choon-Hwan; Allakhverdiev, Suleyman I

    2012-10-07

    There has been a tremendous surge in research on the synthesis of various metal compounds aimed at simulating the water-oxidizing complex (WOC) of photosystem II (PSII). This is crucial because the water oxidation half reaction is overwhelmingly rate-limiting and needs high over-voltage (approx. 1 V), which results in low conversion efficiencies when working at current densities required for hydrogen production via water splitting. Particular attention has been given to the manganese compounds not only because manganese has been used by nature to oxidize water but also because manganese is cheap and environmentally friendly. The manganese-calcium cluster in PSII has a dimension of about approximately 0.5 nm. Thus, nano-sized manganese compounds might be good structural and functional models for the cluster. As in the nanometre-size of the synthetic models, most of the active sites are at the surface, these compounds could be more efficient catalysts than micrometre (or bigger) particles. In this paper, we focus on nano-sized manganese oxides as functional and structural models of the WOC of PSII for hydrogen production via water splitting and review nano-sized manganese oxides used in water oxidation by some research groups.

  5. Recent progress on electroelastomer artificial muscles and their application for biomimetic robots

    NASA Astrophysics Data System (ADS)

    Pei, Qibing; Pelrine, Ron; Rosenthal, Marcus A.; Stanford, Scott; Prahlad, Harsha; Kornbluh, Roy D.

    2004-07-01

    Electroelastomers (electroactive elastomers, a.k.a. dielectric elastomers) such as those based on acrylic elastomer films with compliant electrodes, when highly prestrained, exhibited up to 380% electromechanical strain in area expansion at 5 to 6 kV. By rolling highly prestrained acrylic films around a compression spring, multifunctional electroelastomer rolls (MERs, or spring rolls) were obtained that combined load bearing, actuation, and sensing functions. The design was extended to two-degree-of-freedom (2-DOF) and 3-DOF spring rolls by patterning the electrodes along the circumferential spans of the rolls. Multiple-DOF spring rolls retained the linear actuation of 1-DOF spring rolls with additional bending actuation. New electroelastomers were developed that preserved the high strain and energy capability of the acrylic films but could respond one order of magnitude faster. One-DOF spring rolls using this new material exhibited response speeds up to 100 Hz, and power densities as high as 400 W/kg of actuator mass and 2000 W/kg of electroelastomer mass based on maximum force, stroke, and frequency. Further, new electroelastomers were prepared that exhibited 200% strain without the need for prestrain. These materials may enable new actuators containing no prestrain-supporting structures that are even lighter, more compact, and compliant. The new actuators would have a higher percentage of active mass and higher energy and power densities than those based on the prestrained acrylic films matching the characteristics of animals. A roll actuator containing no supporting structure was fabricated to output 33% strain. Preliminary lifetime measurements confirmed the potentially long lifetime of the electroelastomers. Improvements in MER design and materials have enabled a new generation of small walking robots, MERbot, with a multi-DOF spring roll as each of its six legs, as well as a new type of robot that can be quickly fabricated from a single flat multifunctional actuator structure. Such small flat robots can hop or jump two to three times their height and have been able to quickly clear obstacles equal to the robots' height.

  6. Nano-sized manganese oxides as biomimetic catalysts for water oxidation in artificial photosynthesis: a review

    PubMed Central

    Najafpour, Mohammad Mahdi; Rahimi, Fahimeh; Aro, Eva-Mari; Lee, Choon-Hwan; Allakhverdiev, Suleyman I.

    2012-01-01

    There has been a tremendous surge in research on the synthesis of various metal compounds aimed at simulating the water-oxidizing complex (WOC) of photosystem II (PSII). This is crucial because the water oxidation half reaction is overwhelmingly rate-limiting and needs high over-voltage (approx. 1 V), which results in low conversion efficiencies when working at current densities required for hydrogen production via water splitting. Particular attention has been given to the manganese compounds not only because manganese has been used by nature to oxidize water but also because manganese is cheap and environmentally friendly. The manganese–calcium cluster in PSII has a dimension of about approximately 0.5 nm. Thus, nano-sized manganese compounds might be good structural and functional models for the cluster. As in the nanometre-size of the synthetic models, most of the active sites are at the surface, these compounds could be more efficient catalysts than micrometre (or bigger) particles. In this paper, we focus on nano-sized manganese oxides as functional and structural models of the WOC of PSII for hydrogen production via water splitting and review nano-sized manganese oxides used in water oxidation by some research groups. PMID:22809849

  7. Biomimetic tissue-engineered systems for advancing cancer research: NCI Strategic Workshop report.

    PubMed

    Schuessler, Teresa K; Chan, Xin Yi; Chen, Huanhuan Joyce; Ji, Kyungmin; Park, Kyung Min; Roshan-Ghias, Alireza; Sethi, Pallavi; Thakur, Archana; Tian, Xi; Villasante, Aranzazu; Zervantonakis, Ioannis K; Moore, Nicole M; Nagahara, Larry A; Kuhn, Nastaran Z

    2014-10-01

    Advanced technologies and biomaterials developed for tissue engineering and regenerative medicine present tractable biomimetic systems with potential applications for cancer research. Recently, the National Cancer Institute convened a Strategic Workshop to explore the use of tissue biomanufacturing for development of dynamic, physiologically relevant in vitro and ex vivo biomimetic systems to study cancer biology and drug efficacy. The workshop provided a forum to identify current progress, research gaps, and necessary steps to advance the field. Opportunities discussed included development of tumor biomimetic systems with an emphasis on reproducibility and validation of new biomimetic tumor models, as described in this report.

  8. Biomimetic photonic materials with tunable structural colors.

    PubMed

    Xu, Jun; Guo, Zhiguang

    2013-09-15

    Nature is a huge gallery of art involving nearly perfect structures and forms over the millions of years developing. Inspiration from natural structures exhibiting structural colors is first discussed. We give some examples of natural one-, two-, and three-dimensional photonic structures. This review article presents a brief summary of recent progress on bio-inspired photonic materials with variable structural colors, including the different facile and efficient routes to construct the nano-architectures, and the development of the artificial variable structural color photonic materials. Besides the superior optical properties, the excellent functions such as robust mechanical strength, good wettability are also mentioned, as well as the technical importance in various applications. This review will provide significant insight into the fabrication, design and application of the structural color materials.

  9. Biomimetic adhesive materials containing cyanoacryl group for medical application.

    PubMed

    Jo, Sueng Hwan; Sohn, Jeong Sun

    2014-10-17

    For underwater adhesives with biocompatible and more flexible bonds using biomimetic adhesive groups, DOPA-like adhesive molecules were modified with cyanoacrylates to obtain different repeating units and chain length copolymers. The goal of this work is to copy the mechanisms of underwater bonding to create synthetic water-borne underwater medical adhesives through blending of the modified DOPA and a triblock copolymer (PEO-PPO-PEO) for practical application to repair wet living tissues and bones, and in turn, to use the synthetic adhesives to test mechanistic hypotheses about the natural adhesive. The highest values in stress and modulus of the biomimetic adhesives prepared in wet state were 165 kPa and 33 MPa, respectively.

  10. Osteoclastic resorption of biomimetic calcium phosphate coatings in vitro.

    PubMed

    Leeuwenburgh, S; Layrolle, P; Barrère, F; de Bruijn, J; Schoonman, J; van Blitterswijk, C A; de Groot, K

    2001-08-01

    A new biomimetic method for coating metal implants enables the fast formation of dense and homogeneous calcium phosphate coatings. Titanium alloy (Ti6Al4V) disks were coated with a thin, carbonated, amorphous calcium phosphate (ACP) by immersion in a saturated solution of calcium, phosphate, magnesium, and carbonate. The ACP-coated disks then were processed further by incubation in calcium phosphate solutions to produce either crystalline carbonated apatite (CA) or octacalcium phosphate (OCP). The resorption behavior of these three biomimetic coatings was studied using osteoclast-enriched mouse bone-marrow cell cultures for 7 days. Cell-mediated degradation was observed for both carbonated apatite and octacalcium phosphate coatings. Numerous resorption lacunae characteristic of osteoclastic resorption were found on carbonated apatite after cell culture. The results showed that carbonated apatite coatings are resorbed by osteoclasts in a manner consistent with normal osteoclastic resorption. Osteoclasts also degraded the octacalcium phosphate coatings but not by classical pit formation.

  11. Effects of PEGylation on biomimetic synthesis of magnetoferritin nanoparticles

    NASA Astrophysics Data System (ADS)

    Yang, Caiyun; Cao, Changqian; Cai, Yao; Xu, Huangtao; Zhang, Tongwei; Pan, Yongxin

    2017-03-01

    Recent studies have demonstrated that ferrimagnetic magnetoferritin nanoparticles are a promising novel magnetic nanomaterial in biomedical applications, including biocatalysis, imaging, diagnostics, and tumor therapy. Here we investigated the PEGylation of human H-ferritin (HFn) proteins and the possible influence on biomimetic synthesis of magnetoferritin nanoparticles. The outer surface of HFn proteins was chemically modified with different PEG molecular weights (PEG10K and PEG20K) and different modification ratios (HFn subunit:PEG20K = 1:1, 1:2, 1:4). The PEGylated HFn proteins were used for biomimetic synthesis of ferrimagnetic magnetoferritin nanoparticles. We found that, compared with magnetoferritin using non-PEGylated HFn protein templates, the synthesized magnetoferritin using the PEGylated HFn protein templates possessed larger magnetite cores, higher magnetization and relaxivity values, and improved thermal stability. These results suggest that the PEGylation of H-ferritin may improve the biomineralization of magnetoferritin nanoparticles and enhance their biomedical applications.

  12. Biological activity of lactoferrin-functionalized biomimetic hydroxyapatite nanocrystals

    PubMed Central

    Nocerino, Nunzia; Fulgione, Andrea; Iannaccone, Marco; Tomasetta, Laura; Ianniello, Flora; Martora, Francesca; Lelli, Marco; Roveri, Norberto; Capuano, Federico; Capparelli, Rosanna

    2014-01-01

    The emergence of bacterial strains resistant to antibiotics is a general public health problem. Progress in developing new molecules with antimicrobial properties has been made. In this study, we evaluated the biological activity of a hybrid nanocomposite composed of synthetic biomimetic hydroxyapatite surface-functionalized by lactoferrin (LF-HA). We evaluated the antimicrobial, anti-inflammatory, and antioxidant properties of LF-HA and found that the composite was active against both Gram-positive and Gram-negative bacteria, and that it modulated proinflammatory and anti-inflammatory responses and enhanced antioxidant properties as compared with LF alone. These results indicate the possibility of using LF-HA as an antimicrobial system and biomimetic hydroxyapatite as a candidate for innovative biomedical applications. PMID:24623976

  13. Biomimetic design processes in architecture: morphogenetic and evolutionary computational design.

    PubMed

    Menges, Achim

    2012-03-01

    Design computation has profound impact on architectural design methods. This paper explains how computational design enables the development of biomimetic design processes specific to architecture, and how they need to be significantly different from established biomimetic processes in engineering disciplines. The paper first explains the fundamental difference between computer-aided and computational design in architecture, as the understanding of this distinction is of critical importance for the research presented. Thereafter, the conceptual relation and possible transfer of principles from natural morphogenesis to design computation are introduced and the related developments of generative, feature-based, constraint-based, process-based and feedback-based computational design methods are presented. This morphogenetic design research is then related to exploratory evolutionary computation, followed by the presentation of two case studies focusing on the exemplary development of spatial envelope morphologies and urban block morphologies.

  14. Biomimetic remineralization of human enamel in the presence of polyamidoamine dendrimers in vitro.

    PubMed

    Chen, Liang; Yuan, He; Tang, Bei; Liang, Kunneng; Li, Jiyao

    2015-01-01

    Poly(amidoamine) (PAMAM) dendrimers, known as artificial proteins, have unique and well-defined molecular size and structure. It has previously been used to mimic protein-crystal interaction during biomineralization. In this study, generation 4.5 (4.5G) PAMAM with carboxylic acid (PAMAM-COOH) was synthesized and utilized to remineralize the surface of etched enamel in vitro. Using confocal laser scanning microscopy, Fourier transform infrared spectroscopy, X-ray diffraction analysis and scanning electron microscopy we observed that 4.5G PAMAM-COOH can be absorbed on the etched enamel surface and that it can induce the formation of hydroxyapatite crystals with the same orientation as that of the enamel prisms on longitudinal and transversal enamel surfaces. The self-assembly behavior of PAMAM in the mineralization solution was also investigated and the result showed that 4.5G PAMAM can assemble to microribbon structure similar to the behavior of amelogenins. Therefore, we concluded that 4.5G PAMAM-COOH assemblies can act as the organic template on enamel surface and in mineralization solution to control the nucleation site and morphology of new-grown crystals to form the biomimetic structure of human enamel, which may open a new way for repairing damaged enamel.

  15. Directional, passive liquid transport: the Texas horned lizard as a model for a biomimetic 'liquid diode'.

    PubMed

    Comanns, Philipp; Buchberger, Gerda; Buchsbaum, Andreas; Baumgartner, Richard; Kogler, Alexander; Bauer, Siegfried; Baumgartner, Werner

    2015-08-06

    Moisture-harvesting lizards such as the Texas horned lizard (Iguanidae: Phrynosoma cornutum) live in arid regions. Special skin adaptations enable them to access water sources such as moist sand and dew: their skin is capable of collecting and transporting water directionally by means of a capillary system between the scales. This fluid transport is passive, i.e. requires no external energy, and directs water preferentially towards the lizard's snout. We show that this phenomenon is based on geometric principles, namely on a periodic pattern of interconnected half-open capillary channels that narrow and widen. Following a biomimetic approach, we used these principles to develop a technical prototype design. Building upon the Young-Laplace equation, we derived a theoretical model for the local behaviour of the liquid in such capillaries. We present a global model for the penetration velocity validated by experimental data. Artificial surfaces designed in accordance with this model prevent liquid flow in one direction while sustaining it in the other. Such passive directional liquid transport could lead to process improvements and reduction of resources in many technical applications.

  16. Multifunctional electroelastomer roll actuators and their application for biomimetic walking robots

    NASA Astrophysics Data System (ADS)

    Pei, Qibing; Rosenthal, Marcus A.; Pelrine, Ron; Stanford, Scott; Kornbluh, Roy D.

    2003-07-01

    Dielectric elastomer artificial muscles (electroelastomers) have been shown to exhibit excellent performance in a variety of actuator configurations. By rolling highly prestrained electroelastomer films onto a central compression spring, we have demonstrated multifunctional electroelastomer rolls (MERs) that combine load bearing, actuation, and sensing functions. The rolls are compact, have a potentially high electroelastomer-to-structure weight ratio, and can be configured to actuate in several ways including axial extension and bending, and as multiple degree-of-freedom (DOF) actuators that combine both extension and bending. 1-DOF, 2-DOF, and 3-DOF MERs have all been demonstrated through suitable electrode patterning on a single monolithic substrate. The bending MER actuators can act as leg and knee joints to produce biomimetic walking that is adaptable to many environments. Results of animation and the fabrications of a robot model of a synthetic bug or animal based on the MERs are presented. A new concept for an antagonist actuator for more precise control is introduced.

  17. UV photofunctionalization promotes nano-biomimetic apatite deposition on titanium

    PubMed Central

    Saita, Makiko; Ikeda, Takayuki; Yamada, Masahiro; Kimoto, Katsuhiko; Lee, Masaichi Chang-Il; Ogawa, Takahiro

    2016-01-01

    Background Although biomimetic apatite coating is a promising way to provide titanium with osteoconductivity, the efficiency and quality of deposition is often poor. Most titanium implants have microscale surface morphology, and an addition of nanoscale features while preserving the micromorphology may provide further biological benefit. Here, we examined the effect of ultraviolet (UV) light treatment of titanium, or photofunctionalization, on the efficacy of biomimetic apatite deposition on titanium and its biological capability. Methods and results Micro-roughed titanium disks were prepared by acid-etching with sulfuric acid. Micro-roughened disks with or without photofunctionalization (20-minute exposure to UV light) were immersed in simulated body fluid (SBF) for 1 or 5 days. Photofunctionalized titanium disks were superhydrophilic and did not form surface air bubbles when immersed in SBF, whereas non-photofunctionalized disks were hydrophobic and largely covered with air bubbles during immersion. An apatite-related signal was observed by X-ray diffraction on photofunctionalized titanium after 1 day of SBF immersion, which was equivalent to the one observed after 5 days of immersion of control titanium. Scanning electron microscopy revealed nodular apatite deposition in the valleys and at the inclines of micro-roughened structures without affecting the existing micro-configuration. Micro-roughened titanium and apatite-deposited titanium surfaces had similar roughness values. The attachment, spreading, settling, proliferation, and alkaline phosphate activity of bone marrow-derived osteoblasts were promoted on apatite-coated titanium with photofunctionalization. Conclusion UV-photofunctionalization of titanium enabled faster deposition of nanoscale biomimetic apatite, resulting in the improved biological capability compared to the similarly prepared apatite-deposited titanium without photofunctionalization. Photofunctionalization-assisted biomimetic apatite

  18. Tetracycline-loaded biomimetic apatite: an adsorption study.

    PubMed

    Cazalbou, Sophie; Bertrand, Ghislaine; Drouet, Christophe

    2015-02-19

    Biomimetic apatites are appealing compounds for the elaboration of bioactive bone-repair scaffolds due to their intrinsic similarity to bone mineral. Bone surgeries are however often heavy procedures, and the infiltration of pathogens may not be totally avoided. To prevent their development, systemic antibiotic prophylaxis is widespread but does not specifically target surgical sites and involves doses not always optimized. A relevant alternative is a preliminary functionalization by an infection-fighting agent. In this work, we investigated from a physicochemical viewpoint the association of a wide-spectrum antibiotic, tetracycline (TC), and a biomimetic nanocrystalline apatite previously characterized. TC adsorption kinetics and isotherm were thoroughly explored. Kinetic data were fitted to various models (pseudo-first-order, pseudo-second-order, general kinetic model of order n, Elovich, double-exponential, and purely diffusive models). The best fit was found for a double-exponential kinetic model or with a decimal reaction order of 1.4, highlighting a complex process with such TC molecules which do not expose high-affinity end groups for the surface of apatite. The adsorption isotherm was perfectly fitted to the Sips (Langmuir-Freundlich) model, while other models failed to describe it, and the Sips exponent greater than unity (1.08) suggested a joint impact of surface heterogeneity and positive cooperativity between adsorbed molecules. Finally, preliminary insights on TC release from pelletized nanocrystalline apatite, in aqueous medium and neutral pH, were obtained using a recirculation cell, indicating a release profile mainly following a Higuchi-like diffusion-limited rate. This work is intended to shed more light on the interaction between polar molecules not exhibiting high-affinity end groups and biomimetic apatites and is a starting point in view of the elaboration of biomimetic apatite-based bone scaffolds functionalized with polar organic drugs for a

  19. Biomimetic Total Synthesis of Malbrancheamide and Malbrancheamide B

    PubMed Central

    Miller, Kenneth A.; Welch, Timothy R.; Greshock, Thomas J.; Ding, Yousong; Sherman, David H.; Williams, Robert M.

    2010-01-01

    The biomimetic total syntheses of both malbrancheamide and malbrancheamide B are reported. The synthesis of the two mono-chloro species enabled the structure of malbrancheamide B to be unambiguously assigned. The syntheses each feature an intramolecular Diels-Alder reaction of a 5-hydroxypyrazin-2(1H)-one to construct the bicyclo[2.2.2]diazaoctane core, which has also been proposed as the biosynthetic route to these compounds. PMID:18345688

  20. Biomimetic propulsion under random heaving conditions, using active pitch control

    NASA Astrophysics Data System (ADS)

    Politis, Gerasimos; Politis, Konstantinos

    2014-05-01

    Marine mammals travel long distances by utilizing and transforming wave energy to thrust through proper control of their caudal fin. On the other hand, manmade ships traveling in a wavy sea store large amounts of wave energy in the form of kinetic energy for heaving, pitching, rolling and other ship motions. A natural way to extract this energy and transform it to useful propulsive thrust is by using a biomimetic wing. The aim of this paper is to show how an actively pitched biomimetic wing could achieve this goal when it performs a random heaving motion. More specifically, we consider a biomimetic wing traveling with a given translational velocity in an infinitely extended fluid and performing a random heaving motion with a given energy spectrum which corresponds to a given sea state. A formula is invented by which the instantaneous pitch angle of the wing is determined using the heaving data of the current and past time steps. Simulations are then performed for a biomimetic wing at different heave energy spectra, using an indirect Source-Doublet 3-D-BEM, together with a time stepping algorithm capable to track the random motion of the wing. A nonlinear pressure type Kutta condition is applied at the trailing edge of the wing. With a mollifier-based filtering technique, the 3-D unsteady rollup pattern created by the random motion of the wing is calculated without any simplifying assumptions regarding its geometry. Calculated unsteady forces, moments and useful power, show that the proposed active pitch control always results in thrust producing motions, with significant propulsive power production and considerable beneficial stabilizing action to ship motions. Calculation of the power required to set the pitch angle prove it to be a very small percentage of the useful power and thus making the practical application of the device very tractable.

  1. Artificial Intelligence and Robotics.

    DTIC Science & Technology

    1984-02-01

    D-Ai42 488 ARTIFICIAL INEELLIGENCE AND ROBOTICS (U) MASSACHUSETTS i/1 INST OF TECH CAMBRIDGE ARTIFICIAL INTELLIGENCE LAB M BRADY FEB 84 AI-M-756...Subtile) S. TYPE OF REPORT A PERIOD COVERED Artificial Intelligence and Robotics 6. PERFORMING ORG. REPORT NUMBER 7. AUTHOR(*) S. CONTRACT OR GRANT NUMBER...Identify by block niiniber) -. Since Robotics is the field concerned with the connection of perception to action, Artificial Intelligence must have a

  2. Artificial life and Piaget.

    PubMed

    Mueller, Ulrich; Grobman, K H.

    2003-04-01

    Artificial life provides important theoretical and methodological tools for the investigation of Piaget's developmental theory. This new method uses artificial neural networks to simulate living phenomena in a computer. A recent study by Parisi and Schlesinger suggests that artificial life might reinvigorate the Piagetian framework. We contrast artificial life with traditional cognitivist approaches, discuss the role of innateness in development, and examine the relation between physiological and psychological explanations of intelligent behaviour.

  3. Biomimetic systems for studying actin-based motility.

    PubMed

    Upadhyaya, Arpita; van Oudenaarden, Alexander

    2003-09-16

    Actin polymerization provides a major driving force for eukaryotic cell motility. Successive intercalation of monomeric actin subunits between the plasma membrane and the filamentous actin network results in protrusions of the membrane enabling the cell to move or to change shape. One of the challenges in understanding eukaryotic cell motility is to dissect the elementary biochemical and biophysical steps that link actin polymerization to mechanical force generation. Recently, significant progress was made using biomimetic, in vitro systems that are inspired by the actin-based motility of bacterial pathogens such as Listeria monocytogenes. Polystyrene microspheres and synthetic phospholipid vesicles coated with proteins that initiate actin polymerization display motile behavior similar to Listeria, mimicking the leading edge of lamellipodia and filopodia. A major advantage of these biomimetic systems is that both biochemical and physical parameters can be controlled precisely. These systems provide a test bed for validating theoretical models on force generation and polarity establishment resulting from actin polymerization. In this review, we discuss recent experimental progress using biomimetic systems propelled by actin polymerization and discuss these results in the light of recent theoretical models on actin-based motility.

  4. Methods for Biomimetic Remineralization of Human Dentine: A Systematic Review

    PubMed Central

    Cao, Chris Ying; Mei, May Lei; Li, Quan-Li; Lo, Edward Chin Man; Chu, Chun Hung

    2015-01-01

    This study aimed to review the laboratory methods on biomimetic remineralization of demineralized human dentine. A systematic search of the publications in the PubMed, TRIP, and Web of Science databases was performed. Titles and abstracts of initially identified publications were screened. Clinical trials, reviews, non-English articles, resin-dentine interface studies, hybrid layer studies, hybrid scaffolds studies, and irrelevant studies were excluded. The remaining papers were retrieved with full texts. Manual screening was conducted on the bibliographies of remaining papers to identify relevant articles. A total of 716 studies were found, and 690 were excluded after initial screening. Two articles were identified from the bibliographies of the remaining papers. After retrieving the full text, 23 were included in this systematic review. Sixteen studies used analogues to mimic the functions of non-collagenous proteins in biomineralization of dentine, and four studies used bioactive materials to induce apatite formation on demineralized dentine surface. One study used zinc as a bioactive element, one study used polydopamine, and another study constructed an agarose hydrogel system for biomimetic mineralization of dentine. Many studies reported success in biomimetic mineralization of dentine, including the use of non-collagenous protein analogues, bioactive materials, or elements and agarose hydrogel system. PMID:25739078

  5. Strategies in biomimetic surface engineering of nanoparticles for biomedical applications

    NASA Astrophysics Data System (ADS)

    Gong, Yong-Kuan; Winnik, Françoise M.

    2012-01-01

    Engineered nanoparticles (NPs) play an increasingly important role in biomedical sciences and in nanomedicine. Yet, in spite of significant advances, it remains difficult to construct drug-loaded NPs with precisely defined therapeutic effects, in terms of release time and spatial targeting. The body is a highly complex system that imposes multiple physiological and cellular barriers to foreign objects. Upon injection in the blood stream or following oral administation, NPs have to bypass numerous barriers prior to reaching their intended target. A particularly successful design strategy consists in masking the NP to the biological environment by covering it with an outer surface mimicking the composition and functionality of the cell's external membrane. This review describes this biomimetic approach. First, we outline key features of the composition and function of the cell membrane. Then, we present recent developments in the fabrication of molecules that mimic biomolecules present on the cell membrane, such as proteins, peptides, and carbohydrates. We present effective strategies to link such bioactive molecules to the NPs surface and we highlight the power of this approach by presenting some exciting examples of biomimetically engineered NPs useful for multimodal diagnostics and for target-specific drug/gene delivery applications. Finally, critical directions for future research and applications of biomimetic NPs are suggested to the readers.

  6. Aloe vera Induced Biomimetic Assemblage of Nucleobase into Nanosized Particles

    PubMed Central

    Chauhan, Arun; Zubair, Swaleha; Sherwani, Asif; Owais, Mohammad

    2012-01-01

    Aim Biomimetic nano-assembly formation offers a convenient and bio friendly approach to fabricate complex structures from simple components with sub-nanometer precision. Recently, biomimetic (employing microorganism/plants) synthesis of metal and inorganic materials nano-particles has emerged as a simple and viable strategy. In the present study, we have extended biological synthesis of nano-particles to organic molecules, namely the anticancer agent 5-fluorouracil (5-FU), using Aloe vera leaf extract. Methodology The 5-FU nano- particles synthesized by using Aloe vera leaf extract were characterized by UV, FT-IR and fluorescence spectroscopic techniques. The size and shape of the synthesized nanoparticles were determined by TEM, while crystalline nature of 5-FU particles was established by X-ray diffraction study. The cytotoxic effects of 5-FU nanoparticles were assessed against HT-29 and Caco-2 (human adenocarcinoma colorectal) cell lines. Results Transmission electron microscopy and atomic force microscopic techniques confirmed nano-size of the synthesized particles. Importantly, the nano-assembled 5-FU retained its anticancer action against various cancerous cell lines. Conclusion In the present study, we have explored the potential of biomimetic synthesis of nanoparticles employing organic molecules with the hope that such developments will be helpful to introduce novel nano-particle formulations that will not only be more effective but would also be devoid of nano-particle associated putative toxicity constraints. PMID:22403622

  7. An efficient biomimetic coating methodology for a prosthetic alloy.

    PubMed

    Adawy, Alaa; Abdel-Fattah, Wafa I

    2013-04-01

    The combination of the load-bearing metallic implants with the bioactive materials in the design of synthetic implants is an important aspect in the biomaterials research. Biomimetic coating of bioinert alloys with calcium phosphate phases provides a good alternative to the prerequisite for the continual replacement of implants because of the failure of bone-implant integration. We attempted to accelerate the biomimetic coating process of stainless steel alloy (316L) with biomimetic apatite. In addition, we investigated the incorporation of functioning minerals such as strontianite and smithsonite into the deposited layer. In order to develop a highly mature apatite coating, our method requires soaking of the pre-treated alloy in highly concentrated synthetic body fluid for only few hours. Surface characterizations were performed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). Also, the deposited apatitic layers were analysed by powder diffraction X-ray analysis (XRD). 316L surface showed the growth of highly crystalline, low carbonated hydroxyapatite, after only 6h of the whole soaking process.

  8. Methods for biomimetic remineralization of human dentine: a systematic review.

    PubMed

    Cao, Chris Ying; Mei, May Lei; Li, Quan-Li; Lo, Edward Chin Man; Chu, Chun Hung

    2015-03-02

    This study aimed to review the laboratory methods on biomimetic remineralization of demineralized human dentine. A systematic search of the publications in the PubMed, TRIP, and Web of Science databases was performed. Titles and abstracts of initially identified publications were screened. Clinical trials, reviews, non-English articles, resin-dentine interface studies, hybrid layer studies, hybrid scaffolds studies, and irrelevant studies were excluded. The remaining papers were retrieved with full texts. Manual screening was conducted on the bibliographies of remaining papers to identify relevant articles. A total of 716 studies were found, and 690 were excluded after initial screening. Two articles were identified from the bibliographies of the remaining papers. After retrieving the full text, 23 were included in this systematic review. Sixteen studies used analogues to mimic the functions of non-collagenous proteins in biomineralization of dentine, and four studies used bioactive materials to induce apatite formation on demineralized dentine surface. One study used zinc as a bioactive element, one study used polydopamine, and another study constructed an agarose hydrogel system for biomimetic mineralization of dentine. Many studies reported success in biomimetic mineralization of dentine, including the use of non-collagenous protein analogues, bioactive materials, or elements and agarose hydrogel system.

  9. Artificial Behavior: An Idea.

    ERIC Educational Resources Information Center

    Steinhauer, Gene D.; Peden, Blaine F.

    1985-01-01

    Contrasts artificial behavior with artificial intelligence, traces Law of Effect's development from a verbal statement into a mathematical model providing algorithms for artificial behavior programs, and describes an attempt to use computer graphics and animation to simulate behavior and teach abstract concepts. (MBR)

  10. Biomimetic silica encapsultation of living cells

    NASA Astrophysics Data System (ADS)

    Jaroch, David Benjamin

    Living cells perform complex chemical processes on size and time scales that artificial systems cannot match. Cells respond dynamically to their environment, acting as biological sensors, factories, and drug delivery devices. To facilitate the use of living systems in engineered constructs, we have developed several new approaches to create stable protective microenvironments by forming bioinspired cell-membrane-specific silica-based encapsulants. These include vapor phase deposition of silica gels, use of endogenous membrane proteins and polysaccharides as a site for silica nucleation and polycondensation in a saturated environment, and protein templated ordered silica shell formation. We demonstrate silica layer formation at the surface of pluripotent stem-like cells, bacterial biofilms, and primary murine and human pancreatic islets. Materials are characterized by AFM, SEM and EDS. Viability assays confirm cell survival, and metabolite flux measurements demonstrate normal function and no major diffusion limitations. Real time PCR mRNA analysis indicates encapsulated islets express normal levels of genetic markers for β-cells and insulin production. The silica glass encapsulant produces a secondary bone like calcium phosphate mineral layer upon exposure to media. Such bioactive materials can improve device integration with surrounding tissue upon implantation. Given the favorable insulin response, bioactivity, and long-term viability observed in silica-coated islets, we are currently testing the encapsulant's ability to prevent immune system recognition of foreign transplants for the treatment of diabetes. Such hybrid silica-cellular constructs have a wide range of industrial, environmental, and medical applications.

  11. Design of a biomimetic robotic octopus arm.

    PubMed

    Laschi, C; Mazzolai, B; Mattoli, V; Cianchetti, M; Dario, P

    2009-03-01

    This paper reports the rationale and design of a robotic arm, as inspired by an octopus arm. The octopus arm shows peculiar features, such as the ability to bend in all directions, to produce fast elongations, and to vary its stiffness. The octopus achieves these unique motor skills, thanks to its peculiar muscular structure, named muscular hydrostat. Different muscles arranged on orthogonal planes generate an antagonistic action on each other in the muscular hydrostat, which does not change its volume during muscle contractions, and allow bending and elongation of the arm and stiffness variation. By drawing inspiration from natural skills of octopus, and by analysing the geometry and mechanics of the muscular structure of its arm, we propose the design of a robot arm consisting of an artificial muscular hydrostat structure, which is completely soft and compliant, but also able to stiffen. In this paper, we discuss the design criteria of the robotic arm and how this design and the special arrangement of its muscular structure may bring the building of a robotic arm into being, by showing the results obtained by mathematical models and prototypical mock-ups.

  12. Nature as a model for biomimetic sensors

    NASA Astrophysics Data System (ADS)

    Bleckmann, H.

    2012-04-01

    Mammals, like humans, rely mainly on acoustic, visual and olfactory information. In addition, most also use tactile and thermal cues for object identification and spatial orientation. Most non-mammalian animals also possess a visual, acoustic and olfactory system. However, besides these systems they have developed a large variety of highly specialized sensors. For instance, pyrophilous insects use infrared organs for the detection of forest fires while boas, pythons and pit vipers sense the infrared radiation emitted by prey animals. All cartilaginous and bony fishes as well as some amphibians have a mechnaosensory lateral line. It is used for the detection of weak water motions and pressure gradients. For object detection and spatial orientation many species of nocturnal fish employ active electrolocation. This review describes certain aspects of the detection and processing of infrared, mechano- and electrosensory information. It will be shown that the study of these seemingly exotic sensory systems can lead to discoveries that are useful for the construction of technical sensors and artificial control systems.

  13. Advances in artificial lungs.

    PubMed

    Ota, Kei

    2010-04-01

    Artificial lungs have already been developed as complete artificial organs, and results of many investigations based on innovative concepts have been reported continuously. In open-heart surgery, artificial lungs are used for extracorporeal circulation to maintain gas exchange, and the commercial products currently available perform adequately, including providing for antithrombogenicity. However, patients after cardiopulmonary arrest or severe respiratory/circulatory failure have required long-term assist with extracorporeal membrane oxygenation (ECMO). The number of artificial lungs used for ECMO in those cases has shown significant growth in recent years. Therefore, it is expected that durability and antithrombogenicity will ensure the prolonged use of an artificial lung for several weeks or months. Furthermore, interests in research are shifting to use of oxygenators as a bridge to lung transplantation and an implantable artificial lung. This paper discusses recent advances in artificial lungs, focusing on the current state and on trends in research and development.

  14. Nanothorn electrodes for ionic polymer-metal composite artificial muscles.

    PubMed

    Palmre, Viljar; Pugal, David; Kim, Kwang J; Leang, Kam K; Asaka, Kinji; Aabloo, Alvo

    2014-08-22

    Ionic polymer-metal composites (IPMCs) have recently received tremendous interest as soft biomimetic actuators and sensors in various bioengineering and human affinity applications, such as artificial muscles and actuators, aquatic propulsors, robotic end-effectors, and active catheters. Main challenges in developing biomimetic actuators are the attainment of high strain and actuation force at low operating voltage. Here we first report a nanostructured electrode surface design for IPMC comprising platinum nanothorn assemblies with multiple sharp tips. The newly developed actuator with the nanostructured electrodes shows a new way to achieve highly enhanced electromechanical performance over existing flat-surfaced electrodes. We demonstrate that the formation and growth of the nanothorn assemblies at the electrode interface lead to a dramatic improvement (3- to 5-fold increase) in both actuation range and blocking force at low driving voltage (1-3 V). These advances are related to the highly capacitive properties of nanothorn assemblies, increasing significantly the charge transport during the actuation process.

  15. Catalytically active nanomaterials: a promising candidate for artificial enzymes.

    PubMed

    Lin, Youhui; Ren, Jinsong; Qu, Xiaogang

    2014-04-15

    Natural enzymes, exquisite biocatalysts mediating every biological process in living organisms, are able to accelerate the rate of chemical reactions up to 10(19) times for specific substrates and reactions. However, the practical application of enzymes is often hampered by their intrinsic drawbacks, such as low operational stability, sensitivity of catalytic activity to environmental conditions, and high costs in preparation and purification. Therefore, the discovery and development of artificial enzymes is highly desired. Recently, the merging of nanotechnology with biology has ignited extensive research efforts for designing functional nanomaterials that exhibit various properties intrinsic to enzymes. As a promising candidate for artificial enzymes, catalytically active nanomaterials (nanozymes) show several advantages over natural enzymes, such as controlled synthesis in low cost, tunability in catalytic activities, as well as high stability against stringent conditions. In this Account, we focus on our recent progress in exploring and constructing such nanoparticulate artificial enzymes, including graphene oxide, graphene-hemin nanocomposites, carbon nanotubes, carbon nanodots, mesoporous silica-encapsulated gold nanoparticles, gold nanoclusters, and nanoceria. According to their structural characteristics, these enzyme mimics are categorized into three classes: carbon-, metal-, and metal-oxide-based nanomaterials. We aim to highlight the important role of catalytic nanomaterials in the fields of biomimetics. First, we provide a practical introduction to the identification of these nanozymes, the source of the enzyme-like activities, and the enhancement of activities via rational design and engineering. Then we briefly describe new or enhanced applications of certain nanozymes in biomedical diagnosis, environmental monitoring, and therapeutics. For instance, we have successfully used these biomimetic catalysts as colorimetric probes for the detection of

  16. Dielectric elastomer pump for artificial organisms

    NASA Astrophysics Data System (ADS)

    Bowers, Amy E.; Rossiter, Jonathan M.; Walters, Peter J.; Ieropoulos, Ioannis A.

    2011-04-01

    This paper presents a bio-inspired, dielectric elastomer (DE) based tubular pumping unit, developed for eventual use as a component of an artificial digestive tract onboard a microbial fuel cell powered robot (EcoBot). The pump effects fluid displacement by direct actuation of the tube wall as opposed to excitation by an external body. The actuator consists of a DE tube moulded from silicone, held in a negative pressure chamber, which is used for prestraining the tube. The pump is coupled with custom designed polymeric check valves in order to rectify the fluid flow and assess the performance of the unit. The valves exhibited the necessary low opening pressures required for use with the actuator. The tube's actuation characteristics were measured both with and without liquid in the system. Based on these data the optimal operating conditions for the pump are discussed. The pump and valve system has achieved flowrates in excess of 40μl/s. This radially contracting/expanding actuator element is the fundamental component of a peristaltic pump. This 'soft pump' concept is suitable for biomimetic robotic systems, or for the medical or food industries where hard contact with the delivered substrate may be undesirable. Future work will look at connecting multiple tubes in series in order to achieve peristalsis.

  17. Biomimetic apatite coatings--carbonate substitution and preferred growth orientation.

    PubMed

    Müller, Lenka; Conforto, Egle; Caillard, Daniel; Müller, Frank A

    2007-11-01

    Biomimetic apatite coatings were obtained by soaking chemically treated titanium in SBF with different HCO(3)(-) concentration. XRD, FTIR and Raman analyses were used to characterize phase composition and degree of carbonate substitution. The microstructure, elemental composition and preferred alignment of biomimetically precipitated crystallites were characterized by cross-sectional TEM analyses. According to XRD, the phase composition of precipitated coatings on chemically pre-treated titanium after exposure to SBF was identified as hydroxy carbonated apatite (HCA). A preferred c-axis orientation of the deposited crystals can be supposed due to the high relative peak intensities of the (002) diffraction line at 2theta=26 degrees compared to the 100% intensity peak of the (211) plane at 2theta=32 degrees . The crystallite size in direction of the c-axis of HCA decreased from 26 nm in SBF5 with a HCO(3)(-) concentration of 5 mmol/l to 19 nm in SBF27 with a HCO(3)(-) concentration of 27 mmol/l. Cross-sectional TEM analyses revealed that all distances correspond exactly to the hexagonal structure of hydroxyapatite. The HCO(3)(-) content in SBF also influences the composition of precipitated calcium phosphates. Biomimetic apatites were shown to have a general formula of Ca(10-x-y)Mg(y)(HPO(4))(x-z)(CO(3))(z)(PO(4))(6-x)(OH)(2-x-w)(CO(3))(w/2). According to FTIR and Raman analyses, it can be supposed that as long as the HCO(3)(-) concentration in the testing solutions is below 20 mmol/l, only B-type HCA (0

  18. A Novel Soft Biomimetic Microrobot with Two Motion Attitudes

    PubMed Central

    Shi, Liwei; Guo, Shuxiang; Li, Maoxun; Mao, Shilian; Xiao, Nan; Gao, Baofeng; Song, Zhibin; Asaka, Kinji

    2012-01-01

    A variety of microrobots have commonly been used in the fields of biomedical engineering and underwater operations during the last few years. Thanks to their compact structure, low driving power, and simple control systems, microrobots can complete a variety of underwater tasks, even in limited spaces. To accomplish our objectives, we previously designed several bio-inspired underwater microrobots with compact structure, flexibility, and multi-functionality, using ionic polymer metal composite (IPMC) actuators. To implement high-position precision for IPMC legs, in the present research, we proposed an electromechanical model of an IPMC actuator and analysed the deformation and actuating force of an equivalent IPMC cantilever beam, which could be used to design biomimetic legs, fingers, or fins for an underwater microrobot. We then evaluated the tip displacement of an IPMC actuator experimentally. The experimental deflections fit the theoretical values very well when the driving frequency was larger than 1 Hz. To realise the necessary multi-functionality for adapting to complex underwater environments, we introduced a walking biomimetic microrobot with two kinds of motion attitudes: a lying state and a standing state. The microrobot uses eleven IPMC actuators to move and two shape memory alloy (SMA) actuators to change its motion attitude. In the lying state, the microrobot implements stick-insect-inspired walking/rotating motion, fish-like swimming motion, horizontal grasping motion, and floating motion. In the standing state, it implements inchworm-inspired crawling motion in two horizontal directions and grasping motion in the vertical direction. We constructed a prototype of this biomimetic microrobot and evaluated its walking, rotating, and floating speeds experimentally. The experimental results indicated that the robot could attain a maximum walking speed of 3.6 mm/s, a maximum rotational speed of 9°/s, and a maximum floating speed of 7.14 mm/s. Obstacle

  19. A novel soft biomimetic microrobot with two motion attitudes.

    PubMed

    Shi, Liwei; Guo, Shuxiang; Li, Maoxun; Mao, Shilian; Xiao, Nan; Gao, Baofeng; Song, Zhibin; Asaka, Kinji

    2012-12-06

     A variety of microrobots have commonly been used in the fields of biomedical engineering and underwater operations during the last few years. Thanks to their compact structure, low driving power, and simple control systems, microrobots can complete a variety of underwater tasks, even in limited spaces. To accomplish our objectives, we previously designed several bio-inspired underwater microrobots with compact structure, flexibility, and multi-functionality, using ionic polymer metal composite (IPMC) actuators. To implement high-position precision for IPMC legs, in the present research, we proposed an electromechanical model of an IPMC actuator and analysed the deformation and actuating force of an equivalent IPMC cantilever beam, which could be used to design biomimetic legs, fingers, or fins for an underwater microrobot. We then evaluated the tip displacement of an IPMC actuator experimentally. The experimental deflections fit the theoretical values very well when the driving frequency was larger than 1 Hz. To realise the necessary multi-functionality for adapting to complex underwater environments, we introduced a walking biomimetic microrobot with two kinds of motion attitudes: a lying state and a standing state. The microrobot uses eleven IPMC actuators to move and two shape memory alloy (SMA) actuators to change its motion attitude. In the lying state, the microrobot implements stick-insect-inspired walking/rotating motion, fish-like swimming motion, horizontal grasping motion, and floating motion. In the standing state, it implements inchworm-inspired crawling motion in two horizontal directions and grasping motion in the vertical direction. We constructed a prototype of this biomimetic microrobot and evaluated its walking, rotating, and floating speeds experimentally. The experimental results indicated that the robot could attain a maximum walking speed of 3.6 mm/s, a maximum rotational speed of 9°/s, and a maximum floating speed of 7.14 mm/s. Obstacle

  20. Biomimetic proopiomelanocortin suppresses capsaicin-induced sensory irritation in humans

    PubMed Central

    Fatemi, Sayed Ali; Jafarian-Dehkordi, Abbas; Hajhashemi, Valiollah; Asilian-Mahabadi, Ali

    2016-01-01

    Sensitive skin is a frequently mentioned cosmetic complaint. Addition of a biomimetic of neuromediator has recently appeared as a promising new way to cure skin care product problems. This study was aimed to assess the inhibitory effect of a biomimetic lipopeptide derived from proopiomelanocortin (bPOMC) on capsaicin-induced sensory irritation in human volunteers and also to compare its protective effect with that of the well-known anti irritant strontium chloride. The effect of each test compound was studied on 28 selected healthy volunteers with sensitive skin in accordance with a double-blind vehicle-controlled protocol. From day 1 to day 13 each group was applied the test compound (bPOMC or strontium chloride) to one wing of the nose and the corresponding placebo (vehicle) to the other side twice daily. On days 0 and 14, acute skin irritation was induced by capsaicin solution and quantified using clinical stinging test assessments. Following the application of capsaicin solution, sensory irritation was evaluated using a 4-point numeric scale. The sensations perceived before and after treatment (on days 0 and 14) was calculated for the two zones (test materials and vehicle). Ultimately the percentage of variation between each sample and the placebo and also the inhibitory effect of bPOMC compared to that of strontium chloride were reported. Clinical results showed that after two weeks treatment, the levels of skin comfort reported in the group treated with bPOMC were significantly higher than those obtained in the placebo group and the inhibitory effect of bPOMC was about 47% higher than that of strontium chloride. The results of the present study support the hypothesis that biomimetic peptides may be effective on sensitive skin. PMID:28003842

  1. STANFORD ARTIFICIAL INTELLIGENCE PROJECT.

    DTIC Science & Technology

    ARTIFICIAL INTELLIGENCE , GAME THEORY, DECISION MAKING, BIONICS, AUTOMATA, SPEECH RECOGNITION, GEOMETRIC FORMS, LEARNING MACHINES, MATHEMATICAL MODELS, PATTERN RECOGNITION, SERVOMECHANISMS, SIMULATION, BIBLIOGRAPHIES.

  2. The artificial womb.

    PubMed

    Bulletti, Carlo; Palagiano, Antonio; Pace, Caterina; Cerni, Angelica; Borini, Andrea; de Ziegler, Dominique

    2011-03-01

    The availability of computer-controlled artificial hearts, kidneys, and lungs, as well as the possibility of implanting human embryos in ex vivo uterus models or an artificial endometrium, presents new perspectives for creating an artificial uterus. Survival rates have also improved, with fetuses surviving from as early as 24 weeks of gestation. These advances bring new opportunities for complete or partial ectogenesis through the creation of an artificial womb, one that could sustain the growth and development of fetuses outside of the human body.

  3. Nanoengineering approaches to the design of artificial antigen-presenting cells

    PubMed Central

    Sunshine, Joel C; Green, Jordan J

    2014-01-01

    Artificial antigen-presenting cells (aAPCs) have shown great initial promise for ex vivo activation of cytotoxic T cells. The development of aAPCs has focused mainly on the choice of proteins to use for surface presentation to T cells when conjugated to various spherical, microscale particles. We review here biomimetic nanoengineering approaches that have been applied to the development of aAPCs that move beyond initial concepts about aAPC development. This article also discusses key technologies that may be enabling for the development of nano- and micro-scale aAPCs with nanoscale features, and suggests several future directions for the field. PMID:23837856

  4. Acoustic beam control in biomimetic projector via velocity gradient

    NASA Astrophysics Data System (ADS)

    Gao, Xiaowei; Zhang, Yu; Cao, Wenwu; Dong, Erqian; Song, Zhongchang; Li, Songhai; Tang, Liguo; Zhang, Sai

    2016-07-01

    A biomimetic projector (BioP) based on computerized tomography of pygmy sperm whale's biosonar system has been designed using gradient-index (GRIN) material. The directivity of this BioP device was investigated as function of frequency and the velocity gradient of the GRIN material. A strong beam control over a broad bandwidth at the subwavelength scale has been achieved. Compared with a bare subwavelength source, the main lobe pressure of the BioP is about five times as high and the angular resolution is one order of magnitude better. Our results indicate that this BioP has excellent application potential in miniaturized underwater sonars.

  5. Selective Change Driven Imaging: A Biomimetic Visual Sensing Strategy

    PubMed Central

    Boluda, Jose A.; Zuccarello, Pedro; Pardo, Fernando; Vegara, Francisco

    2011-01-01

    Selective Change Driven (SCD) Vision is a biologically inspired strategy for acquiring, transmitting and processing images that significantly speeds up image sensing. SCD vision is based on a new CMOS image sensor which delivers, ordered by the absolute magnitude of its change, the pixels that have changed after the last time they were read out. Moreover, the traditional full frame processing hardware and programming methodology has to be changed, as a part of this biomimetic approach, to a new processing paradigm based on pixel processing in a data flow manner, instead of full frame image processing. PMID:22346684

  6. Advances in modelling of biomimetic fluid flow at different scales

    PubMed Central

    2011-01-01

    The biomimetic flow at different scales has been discussed at length. The need of looking into the biological surfaces and morphologies and both geometrical and physical similarities to imitate the technological products and processes has been emphasized. The complex fluid flow and heat transfer problems, the fluid-interface and the physics involved at multiscale and macro-, meso-, micro- and nano-scales have been discussed. The flow and heat transfer simulation is done by various CFD solvers including Navier-Stokes and energy equations, lattice Boltzmann method and molecular dynamics method. Combined continuum-molecular dynamics method is also reviewed. PMID:21711847

  7. Biomimetic surface patterning for long-term transmembrane access

    PubMed Central

    VanDersarl, Jules J.; Renaud, Philippe

    2016-01-01

    Here we present a planar patch clamp chip based on biomimetic cell membrane fusion. This architecture uses nanometer length-scale surface patterning to replicate the structure and function of membrane proteins, creating a gigaohm seal between the cell and a planar electrode array. The seal is generated passively during cell spreading, without the application of a vacuum to the cell surface. This interface can enable cell-attached and whole-cell recordings that are stable to 72 hours, and generates no visible damage to the cell. The electrodes can be very small (<5 μm) and closely packed, offering a high density platform for cellular measurement. PMID:27577519

  8. Self-assembled biomimetic nanoreactors II: Noble metal active centers

    NASA Astrophysics Data System (ADS)

    McTaggart, Matt; Malardier-Jugroot, Cecile; Jugroot, Manish

    2015-09-01

    The structure and stability of polymer-metal nanoreactors is detailed, including a complete characterization of the first successful synthesis of stable, dispersible, atomically thin gold nanosheets. Further developments in the synthesis of monodisperse, ∼2.5 nm platinum nanoclusters in aqueous solution and ambient conditions are described and pH stability of the composite material is established. The facile nanoreactor synthesis, environmentally friendly reaction conditions, and structural stability makes these biomimetic systems attractive for applications ranging from chemical detoxification to nanoelectronics.

  9. Multiwalled carbon nanotube reinforced biomimetic bundled gel fibres.

    PubMed

    Kim, Young-Jin; Yamamoto, Seiichiro; Takahashi, Haruko; Sasaki, Naruo; Matsunaga, Yukiko T

    2016-08-19

    This work describes the fabrication and characterization of hydroxypropyl cellulose (HPC)-based biomimetic bundled gel fibres. The bundled gel fibres were reinforced with multiwalled carbon nanotubes (MWCNTs). A phase-separated aqueous solution with MWCNT and HPC was transformed into a bundled fibrous structure after being injected into a co-flow microfluidic device and applying the sheath flow. The resulting MWCNT-bundled gel fibres consist of multiple parallel microfibres. The mechanical and electrical properties of MWCNT-bundled gel fibres were improved and their potential for tissue engineering applications as a cell scaffold was demonstrated.

  10. Anisotropic Liquid Microcapsules from Biomimetic Self-Folding Polymer Films.

    PubMed

    Zakharchenko, Svetlana; Ionov, Leonid

    2015-06-17

    We demonstrated a novel approach for the fabrication of anisotropic capsules with liquid content using biomimetic self-folding thermoresponsive polymer films. The behavior of self-folding films is very similar to actuation in plants, where nonhomogenous swelling results in complex movements such as twisting, bending, or folding. This approach allows the design of anisotropic liquid capsules with rodlike and dumbbell-like morphologies. We found that these capsules are able to assemble into different complex structures, such as nematic-like one and 3D network depending on their morphology.

  11. Preparation, anti-biofouling and drag-reduction properties of a biomimetic shark skin surface

    PubMed Central

    Pu, Xia; Li, Guangji; Huang, Hanlu

    2016-01-01

    ABSTRACT Shark skin surfaces show non-smoothness characteristics due to the presence of a riblet structure. In this study, biomimetic shark skin was prepared by using the polydimethylsiloxane (PDMS)-embedded elastomeric stamping (PEES) method. Scanning electron microscopy (SEM) was used to examine the surface microstructure and fine structure of shark skin and biomimetic shark skin. To analyse the hydrophobic mechanism of the shark skin surface microstructure, the effect of biomimetic shark skin surface microstructure on surface wettability was evaluated by recording water contact angle. Additionally, protein adhesion experiments and anti-algae adhesion performance testing experiments were used to investigate and evaluate the anti-biofouling properties of the surface microstructure of biomimetic shark skin. The recorded values of the water contact angle of differently microstructured surfaces revealed that specific microstructures have certain effects on surface wettability. The anti-biofouling properties of the biomimetic shark skin surface with microstructures were superior to a smooth surface using the same polymers as substrates. Moreover, the air layer fixed on the surface of the biomimetic shark skin was found to play a key role in their antibiont adhesion property. An experiment into drag reduction was also conducted. Based on the experimental results, the microstructured surface of the prepared biomimetic shark skin played a significant role in reducing drag. The maximum of drag reduction rate is 12.5%, which is higher than the corresponding maximum drag reduction rate of membrane material with a smooth surface. PMID:26941105

  12. Artificial intelligence: Recent developments

    SciTech Connect

    Not Available

    1987-01-01

    This book presents the papers given at a conference on artificial intelligence. Topics considered at the conference included knowledge representation for expert systems, the use of robots in underwater vehicles for resource management, precision logic, an expert system for arc welding, data base management, a knowledge based approach to fault trees, and computer-aided manufacturing using simulation combined with artificial intelligence.

  13. Artificial insemination in poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Artificial insemination is a relative simple yet powerful tool geneticists can employ for the propagation of economically important traits in livestock and poultry. In this chapter, we address the fundamental methods of the artificial insemination of poultry, including semen collection, semen evalu...

  14. Rapid prototyping of biomimetic vascular phantoms for hyperspectral reflectance imaging

    PubMed Central

    Ghassemi, Pejhman; Wang, Jianting; Melchiorri, Anthony J.; Ramella-Roman, Jessica C.; Mathews, Scott A.; Coburn, James C.; Sorg, Brian S.; Chen, Yu; Joshua Pfefer, T.

    2015-01-01

    Abstract. The emerging technique of rapid prototyping with three-dimensional (3-D) printers provides a simple yet revolutionary method for fabricating objects with arbitrary geometry. The use of 3-D printing for generating morphologically biomimetic tissue phantoms based on medical images represents a potentially major advance over existing phantom approaches. Toward the goal of image-defined phantoms, we converted a segmented fundus image of the human retina into a matrix format and edited it to achieve a geometry suitable for printing. Phantoms with vessel-simulating channels were then printed using a photoreactive resin providing biologically relevant turbidity, as determined by spectrophotometry. The morphology of printed vessels was validated by x-ray microcomputed tomography. Channels were filled with hemoglobin (Hb) solutions undergoing desaturation, and phantoms were imaged with a near-infrared hyperspectral reflectance imaging system. Additionally, a phantom was printed incorporating two disjoint vascular networks at different depths, each filled with Hb solutions at different saturation levels. Light propagation effects noted during these measurements—including the influence of vessel density and depth on Hb concentration and saturation estimates, and the effect of wavelength on vessel visualization depth—were evaluated. Overall, our findings indicated that 3-D-printed biomimetic phantoms hold significant potential as realistic and practical tools for elucidating light–tissue interactions and characterizing biophotonic system performance. PMID:26662064

  15. Rapid prototyping of biomimetic vascular phantoms for hyperspectral reflectance imaging

    NASA Astrophysics Data System (ADS)

    Ghassemi, Pejhman; Wang, Jianting; Melchiorri, Anthony J.; Ramella-Roman, Jessica C.; Mathews, Scott A.; Coburn, James C.; Sorg, Brian S.; Chen, Yu; Joshua Pfefer, T.

    2015-12-01

    The emerging technique of rapid prototyping with three-dimensional (3-D) printers provides a simple yet revolutionary method for fabricating objects with arbitrary geometry. The use of 3-D printing for generating morphologically biomimetic tissue phantoms based on medical images represents a potentially major advance over existing phantom approaches. Toward the goal of image-defined phantoms, we converted a segmented fundus image of the human retina into a matrix format and edited it to achieve a geometry suitable for printing. Phantoms with vessel-simulating channels were then printed using a photoreactive resin providing biologically relevant turbidity, as determined by spectrophotometry. The morphology of printed vessels was validated by x-ray microcomputed tomography. Channels were filled with hemoglobin (Hb) solutions undergoing desaturation, and phantoms were imaged with a near-infrared hyperspectral reflectance imaging system. Additionally, a phantom was printed incorporating two disjoint vascular networks at different depths, each filled with Hb solutions at different saturation levels. Light propagation effects noted during these measurements-including the influence of vessel density and depth on Hb concentration and saturation estimates, and the effect of wavelength on vessel visualization depth-were evaluated. Overall, our findings indicated that 3-D-printed biomimetic phantoms hold significant potential as realistic and practical tools for elucidating light-tissue interactions and characterizing biophotonic system performance.

  16. A biomimetic gelatin-calcium phosphate bone cement.

    PubMed

    Bigi, A; Torricelli, P; Fini, M; Bracci, B; Panzavolta, S; Sturba, L; Giardino, R

    2004-08-01

    The interest in new bone substitutes is rapidly increasing in the field of orthopedic surgery. A variety of calcium phosphate bone cement has been developed and different additives have been used to improve their biocompatibility and bioactivity. Following a biomimetic strategy aimed at reproducing bone characteristics, this study investigates the biological properties of a new gelatin enriched calcium phosphate cement (GEL-CP) that exhibits improved mechanical properties with respect to cement prepared without gelatin (C-CP). Human osteoblast MG63 were cultured on the surfaces of GEL-CP and were compared to cells cultured on C-CP samples, and on polystyrene of plate culture as control (C). Cell attachment, proliferation and differentiation were evaluated up to 21 days. SEM revealed that osteoblasts grown on GEL-CP showed a normal morphology and biological tests demonstrated very good rate of proliferation and viability in every experimental time. The presence of gelatin stimulated alkaline phosphatase activity, collagen and transforming growth factor 31 production. The data indicate that the new cement GEL-CP favors osteoblast proliferation, activation of their metabolism and differentiation. The remarkable improvement of the setting properties of the calcium phosphate cement due to the presence of gelatin suggest that the biomimetic composite material could be successfully applied as bone substitute.

  17. Small-Scale Fabrication of Biomimetic Structures for Periodontal Regeneration

    PubMed Central

    Green, David W.; Lee, Jung-Seok; Jung, Han-Sung

    2016-01-01

    The periodontium is the supporting tissues for the tooth organ and is vulnerable to destruction, arising from overpopulating pathogenic bacteria and spirochaetes. The presence of microbes together with host responses can destroy large parts of the periodontium sometimes leading tooth loss. Permanent tissue replacements are made possible with tissue engineering techniques. However, existing periodontal biomaterials cannot promote proper tissue architectures, necessary tissue volumes within the periodontal pocket and a “water-tight” barrier, to become clinically acceptable. New kinds of small-scale engineered biomaterials, with increasing biological complexity are needed to guide proper biomimetic regeneration of periodontal tissues. So the ability to make compound structures with small modules, filled with tissue components, is a promising design strategy for simulating the anatomical complexity of the periodotium attachment complexes along the tooth root and the abutment with the tooth collar. Anatomical structures such as, intima, adventitia, and special compartments such as the epithelial cell rests of Malassez or a stellate reticulum niche need to be engineered from the start of regeneration to produce proper periodontium replacement. It is our contention that the positioning of tissue components at the origin is also necessary to promote self-organizing cell–cell connections, cell–matrix connections. This leads to accelerated, synchronized and well-formed tissue architectures and anatomies. This strategy is a highly effective preparation for tackling periodontitis, periodontium tissue resorption, and to ultimately prevent tooth loss. Furthermore, such biomimetic tissue replacements will tackle problems associated with dental implant support and perimimplantitis. PMID:26903872

  18. Lessons from nature: biomimetic organocatalytic carbon-carbon bond formations.

    PubMed

    Enders, Dieter; Narine, Arun A

    2008-10-17

    Nature utilizes simple C2 and C3 building blocks, such as dihydroxyacetone phosphate (DHAP), phosphoenolpyruvate (PEP), and the "active aldehyde" in various enzyme-catalyzed carbon-carbon bond formations to efficiently build up complex organic molecules. In this Perspective, we describe the transition from using enantiopure chemical synthetic equivalents of these building blocks, employing our SAMP/RAMP hydrazone methodology and metalated chiral alpha-amino nitriles, to the asymmetric organocatalytic versions developed in our laboratory. Following this biomimetic strategy, the DHAP equivalent 2,2-dimethyl-1,3-dioxan-5-one (dioxanone) has been used in the proline-catalyzed synthesis of carbohydrates, aminosugars, carbasugars, polyoxamic acid, and various sphingosines. Proline-catalyzed aldol reactions involving a PEP-like equivalent have also allowed for the asymmetric synthesis of ulosonic acid precursors. By mimicking the "active aldehyde" nucleophilic acylations in Nature catalyzed by the thiamine-dependent enzyme, transketolase, enantioselective N-heterocyclic carbene-catalyzed benzoin and Stetter reactions have been developed. Finally, based on Nature's use of domino reactions to convert simple building blocks into complex and highly functionalized molecules, we report on our development of biomimetic asymmetric multicomponent domino reactions which couple enamine and iminium catalysis.

  19. Biomimetic Acoustically-Responsive Vesicles for Theranostic Applications

    PubMed Central

    Hsieh, Chen-Chan; Kang, Shih-Tsung; Lin, Yee-Hsien; Ho, Yi-Ju; Wang, Chung-Hsin; Yeh, Chih-Kuang; Chang, Chien-Wen

    2015-01-01

    In recent years, biomimetic cell membrane-derived particles have emerged as a new class of drug delivery system with advantages of biocompatibility, ease of isolation and long circulation profile. Here we report the development and potential theranostic applications of a new biomimetic acoustically-responsive droplet system derived from mammalian red blood cell membrane (RBCM). We hypothesized that drug-loaded RBCM droplets (RBCMDs) would undergo a transition from liquid (droplets) to gas (bubbles) upon high intensity focused ultrasound (HIFU) insonation, resulting in on-demand drug release. The generated microbubbles could also serve as a contrast agent to enhance ultrasound imaging. As-synthesized RBCMDs exhibited uniform size, good dispersity and preservation of RBCM-associated proteins that prevented uptake by macrophages. Camptothecin (CPT), an anti-cancer drug, was successfully loaded in the RBCMDs with a loading efficiency of 2-3% and an encapsulation efficiency of 62-97%. A short (3 min) exposure to HIFU irradiation triggered release of CPT from the RBCMDs and the physical explosion of droplets damaged nearby cancer cells resulting in significant cell death. In addition, the acoustically vaporized RBCMDs significantly increased the ultrasound echo signal to 30 dB. Lastly, we demonstrated that RBCMDs could be acoustically vaporized in vivo in target tissues, and enhancing ultrasound imaging. Taken together, we have developed a new class of naturally derived RBCMDs which show great potential for future application in remotely triggered drug delivery and ultrasound imaging enhancement. PMID:26379791

  20. Development of autonomous eating mechanism for biomimetic robots

    NASA Astrophysics Data System (ADS)

    Jeong, Kil-Woong; Cho, Ik-Jin; Lee, Yun-Jung

    2005-12-01

    Most of the recently developed robots are human friendly robots which imitate animals or humans such as entertainment robot, bio-mimetic robot and humanoid robot. Interest for these robots are being increased because the social trend is focused on health, welfare, and graying. Autonomous eating functionality is most unique and inherent behavior of pets and animals. Most of entertainment robots and pet robots make use of internal-type battery. Entertainment robots and pet robots with internal-type battery are not able to operate during charging the battery. Therefore, if a robot has an autonomous function for eating battery as its feeds, the robot is not only able to operate during recharging energy but also become more human friendly like pets. Here, a new autonomous eating mechanism was introduced for a biomimetic robot, called ELIRO-II(Eating LIzard RObot version 2). The ELIRO-II is able to find a food (a small battery), eat and evacuate by itself. This work describe sub-parts of the developed mechanism such as head-part, mouth-part, and stomach-part. In addition, control system of autonomous eating mechanism is described.

  1. Small-Scale Fabrication of Biomimetic Structures for Periodontal Regeneration.

    PubMed

    Green, David W; Lee, Jung-Seok; Jung, Han-Sung

    2016-01-01

    The periodontium is the supporting tissues for the tooth organ and is vulnerable to destruction, arising from overpopulating pathogenic bacteria and spirochaetes. The presence of microbes together with host responses can destroy large parts of the periodontium sometimes leading tooth loss. Permanent tissue replacements are made possible with tissue engineering techniques. However, existing periodontal biomaterials cannot promote proper tissue architectures, necessary tissue volumes within the periodontal pocket and a "water-tight" barrier, to become clinically acceptable. New kinds of small-scale engineered biomaterials, with increasing biological complexity are needed to guide proper biomimetic regeneration of periodontal tissues. So the ability to make compound structures with small modules, filled with tissue components, is a promising design strategy for simulating the anatomical complexity of the periodotium attachment complexes along the tooth root and the abutment with the tooth collar. Anatomical structures such as, intima, adventitia, and special compartments such as the epithelial cell rests of Malassez or a stellate reticulum niche need to be engineered from the start of regeneration to produce proper periodontium replacement. It is our contention that the positioning of tissue components at the origin is also necessary to promote self-organizing cell-cell connections, cell-matrix connections. This leads to accelerated, synchronized and well-formed tissue architectures and anatomies. This strategy is a highly effective preparation for tackling periodontitis, periodontium tissue resorption, and to ultimately prevent tooth loss. Furthermore, such biomimetic tissue replacements will tackle problems associated with dental implant support and perimimplantitis.

  2. In vitro remineralization of hybrid layers using biomimetic analogs*

    PubMed Central

    Lin, Hui-ping; Lin, Jun; Li, Juan; Xu, Jing-hong; Mehl, Christian

    2016-01-01

    Resin-dentin bond degradation is a major cause of restoration failures. The major aim of the current study was to evaluate the impact of a remineralization medium on collagen matrices of hybrid layers of three different adhesive resins using nanotechnology methods. Coronal dentin surfaces were prepared from freshly extracted premolars and bonded to composite resin using three adhesive resins (FluoroBond II, Xeno-III-Bond, and iBond). From each tooth, two central slabs were selected for the study. The slabs used as controls were immersed in a simulated body fluid (SBF). The experimental slabs were immersed in a Portland cement-based remineralization medium that contained two biomimetic analogs (biomineralization medium (BRM)). Eight slabs per group were retrieved after 1, 2, 3, and 4 months, respectively and immersed in Rhodamine B for 24 h. Confocal laser scanning microscopy was used to evaluate the permeability of hybrid layers to Rhodamine B. Data were analyzed by analysis of variance (ANOVA) and Tukey’s honest significant difference (HSD) tests. After four months, all BRM specimens exhibited a significantly smaller fluorescent area than SBF specimens, indicating a remineralization of the hybrid layer (P≤0.05). A clinically applicable biomimetic remineralization delivery system could potentially slow down bond degradation. PMID:27819133

  3. Biomimetic optical system using polymer lenses with tunable focus

    NASA Astrophysics Data System (ADS)

    Liang, Dan; Xiang, Ke; Du, Jia-Wei; Yang, Jun-Nan; Wang, Xuan-Yin

    2014-10-01

    A biomimetic system using polymer lenses for the optical design and application is developed. The system mainly consisted of a bionic cornea lens, voice coil motor, compression ring, bionic crystalline lens, substrate, and CCD sensor. By controlling the current of the voice coil motor, we could change the motion of the compression ring to alter the curvature radius of the bionic crystalline lens, thus adjusting the focal length of the whole system. The integrated constructure of the optical system was presented, as well as the detailed description of the lens composition, material, and fabrication process. Images under different displacement loads were captured, the relationship among the curvature radius, observed back focal length, and predicted effective focal length was analyzed, and the spot diagram of the optical system was simulated using ZEMAX software. The focal length of the optical system ranged from 17.3 to 24.5 mm under a tiny displacement load from 0 to 0.14 mm. Besides, the images captured at different rotating angles presented almost identical patterns and the same image quality, which showed good robustness to the gravity. The biomimetic optical system is of interest to develop an integrated, low-cost, and stable imaging system.

  4. Biomimetic and synthetic interfaces to tune immune responses (Review)

    PubMed Central

    Garapaty, Anusha; Champion, Julie A.

    2015-01-01

    Organisms depend upon complex intercellular communication to initiate, maintain, or suppress immune responses during infection or disease. Communication occurs not only between different types of immune cells, but also between immune cells and nonimmune cells or pathogenic entities. It can occur directly at the cell–cell contact interface, or indirectly through secreted signals that bind cell surface molecules. Though secreted signals can be soluble, they can also be particulate in nature and direct communication at the cell–particle interface. Secreted extracellular vesicles are an example of native particulate communication, while viruses are examples of foreign particulates. Inspired by communication at natural immunological interfaces, biomimetic materials and designer molecules have been developed to mimic and direct the type of immune response. This review describes the ways in which native, biomimetic, and designer materials can mediate immune responses. Examples include extracellular vesicles, particles that mimic immune cells or pathogens, and hybrid designer molecules with multiple signaling functions, engineered to target and bind immune cell surface molecules. Interactions between these materials and immune cells are leading to increased understanding of natural immune communication and function, as well as development of immune therapeutics for the treatment of infection, cancer, and autoimmune disease. PMID:26178262

  5. Biomimetic nanocrystalline apatites: Emerging perspectives in cancer diagnosis and treatment.

    PubMed

    Al-Kattan, Ahmed; Girod-Fullana, Sophie; Charvillat, Cédric; Ternet-Fontebasso, Hélène; Dufour, Pascal; Dexpert-Ghys, Jeannette; Santran, Véronique; Bordère, Julie; Pipy, Bernard; Bernad, José; Drouet, Christophe

    2012-02-14

    Nanocrystalline calcium phosphate apatites constitute the mineral part of hard tissues, and the synthesis of biomimetic analogs is now well-mastered at the lab-scale. Recent advances in the fine physico-chemical characterization of these phases enable one to envision original applications in the medical field along with a better understanding of the underlying chemistry and related pharmacological features. In this contribution, we specifically focused on applications of biomimetic apatites in the field of cancer diagnosis or treatment. We first report on the production and first biological evaluations (cytotoxicity, pro-inflammatory potential, internalization by ZR-75-1 breast cancer cells) of individualized luminescent nanoparticles based on Eu-doped apatites, eventually associated with folic acid, for medical imaging purposes. We then detail, in a first approach, the preparation of tridimensional constructs associating nanocrystalline apatite aqueous gels and drug-loaded pectin microspheres. Sustained releases of a fluorescein analog (erythrosin) used as model molecule were obtained over 7 days, in comparison with the ceramic or microsphere reference compounds. Such systems could constitute original bone-filling materials for in situ delivery of anticancer drugs.

  6. Interaction between a bisphosphonate, tiludronate, and biomimetic nanocrystalline apatites.

    PubMed

    Pascaud, Patricia; Gras, Pierre; Coppel, Yannick; Rey, Christian; Sarda, Stéphanie

    2013-02-19

    Bisphosphonates (BPs) are well established as successful antiresorptive agents for the prevention and treatment of bone diseases such as osteoporosis and Paget's disease. The aim of this work was to clarify the reaction mechanisms between a BP molecule, tiludronate, and the nanocrystalline apatite surface. The adsorption of tiludronate on well-characterized synthetic biomimetic nanocrystalline apatites with homogeneous but different compositions and surface characteristics was investigated to determine the effect of the nanocrystalline apatite substrate on the adsorption behavior. The results show that the adsorption of tiludronate on nanocrystalline biomimetic apatite surfaces varies over a large range. The most immature apatitic samples exhibited the highest affinity and the greatest amount adsorbed at saturation. Maturation of the nanocrystals induces a decrease of these values. The amount of phosphate ion released per adsorbed BP molecule varied, depending on the nanocrystalline substrate considered. The adsorption mechanism, although associated with a release of phosphate ions, cannot be considered as a simple ion exchange process involving one or two phosphate ions on the surface. A two-step process is proposed consisting of a surface binding of BP groups to calcium ions associated with a proton release inducing the protonation of surface orthophosphate ions and their eventual solubilization.

  7. Gambogic acid-loaded biomimetic nanoparticles in colorectal cancer treatment

    PubMed Central

    Zhang, Zhen; Qian, Hanqing; Yang, Mi; Li, Rutian; Hu, Jing; Li, Li; Yu, Lixia; Liu, Baorui; Qian, Xiaoping

    2017-01-01

    Gambogic acid (GA) is expected to be a potential new antitumor drug, but its poor aqueous solubility and inevitable side effects limit its clinical application. Despite these inhe rent defects, various nanocarriers can be used to promote the solubility and tumor targeting of GA, improving antitumor efficiency. In addition, a cell membrane-coated nanoparticle platform that was reported recently, unites the customizability and flexibility of a synthetic copolymer, as well as the functionality and complexity of natural membrane, and is a new synthetic biomimetic nanocarrier with improved stability and biocompatibility. Here, we combined poly(lactic-co-glycolic acid) (PLGA) with red blood-cell membrane (RBCm), and evaluated whether GA-loaded RBCm nanoparticles can retain and improve the antitumor efficacy of GA with relatively lower toxicity in colorectal cancer treatment compared with free GA. We also confirmed the stability, biocompatibility, passive targeting, and few side effects of RBCm-GA/PLGA nanoparticles. We expect to provide a new drug carrier in the treatment of colorectal cancer, which has strong clinical application prospects. In addition, the potential antitumor drug GA and other similar drugs could achieve broader clinical applications via this biomimetic nanocarrier. PMID:28280328

  8. Advances in surfaces and osseointegration in implantology. Biomimetic surfaces

    PubMed Central

    Albertini, Matteo; Fernandez-Yague, Marc; Lázaro, Pedro; Herrero-Climent, Mariano; Bullon, Pedro; Gil, Francisco-Javier

    2015-01-01

    The present work is a revision of the processes occurring in osseointegration of titanium dental implants according to different types of surfaces -namely, polished surfaces, rough surfaces obtained from subtraction methods, as well as the new hydroxyapatite biomimetic surfaces obtained from thermochemical processes. Hydroxyapatite’s high plasma-projection temperatures have proven to prevent the formation of crystalline apatite on the titanium dental implant, but lead to the formation of amorphous calcium phosphate (i.e., with no crystal structure) instead. This layer produce some osseointegration yet the calcium phosphate layer will eventually dissolve and leave a gap between the bone and the dental implant, thus leading to osseointegration failure due to bacterial colonization. A new surface -recently obtained by thermochemical processes- produces, by crystallization, a layer of apatite with the same mineral content as human bone that is chemically bonded to the titanium surface. Osseointegration speed was tested by means of minipigs, showing bone formation after 3 to 4 weeks, with the security that a dental implant can be loaded. This surface can be an excellent candidate for immediate or early loading procedures. Key words:Dental implants, implants surfaces, osseointegration, biomimetics surfaces. PMID:25662555

  9. Towards Biomimetic Virtual Constraint Control of a Powered Prosthetic Leg

    PubMed Central

    Sensinger, Jonathon W.

    2014-01-01

    This brief presents a novel control strategy for a powered prosthetic ankle based on a biomimetic virtual constraint. We first derive a kinematic constraint for the “effective shape” of the human ankle-foot complex during locomotion. This shape characterizes ankle motion as a function of the Center of Pressure (COP)–the point on the foot sole where the resultant ground reaction force is imparted. Since the COP moves monotonically from heel to toe during steady walking, we adopt the COP as a mechanical representation of the gait cycle phase in an autonomous feedback controller. We show that our kinematic constraint can be enforced as a virtual constraint by an output linearizing controller that uses only feedback available to sensors onboard a prosthetic leg. Using simulations of a passive walking model with feet, we show that this novel controller exactly enforces the desired effective shape whereas a standard impedance (i.e., proportional-derivative) controller cannot. This work provides a single, biomimetic control law for the entire single-support period during robot-assisted locomotion. PMID:25552894

  10. Alkane Oxidation: Methane Monooxygenases, Related Enzymes, and Their Biomimetics.

    PubMed

    Wang, Vincent C-C; Maji, Suman; Chen, Peter P-Y; Lee, Hung Kay; Yu, Steve S-F; Chan, Sunney I

    2017-02-16

    Methane monooxygenases (MMOs) mediate the facile conversion of methane into methanol in methanotrophic bacteria with high efficiency under ambient conditions. Because the selective oxidation of methane is extremely challenging, there is considerable interest in understanding how these enzymes carry out this difficult chemistry. The impetus of these efforts is to learn from the microbes to develop a biomimetic catalyst to accomplish the same chemical transformation. Here, we review the progress made over the past two to three decades toward delineating the structures and functions of the catalytic sites in two MMOs: soluble methane monooxygenase (sMMO) and particulate methane monooxygenase (pMMO). sMMO is a water-soluble three-component protein complex consisting of a hydroxylase with a nonheme diiron catalytic site; pMMO is a membrane-bound metalloenzyme with a unique tricopper cluster as the site of hydroxylation. The metal cluster in each of these MMOs harnesses O2 to functionalize the C-H bond using different chemistry. We highlight some of the common basic principles that they share. Finally, the development of functional models of the catalytic sites of MMOs is described. These efforts have culminated in the first successful biomimetic catalyst capable of efficient methane oxidation without overoxidation at room temperature.

  11. Interplay of static and dynamic features in biomimetic smart ears.

    PubMed

    Pannala, Mittu; Meymand, Sajjad Zeinoddini; Müller, Rolf

    2013-06-01

    Horseshoe bats (family Rhinolophidae) have sophisticated biosonar systems with outer ears (pinnae) that are characterized by static local shape features as well as dynamic non-rigid changes to their overall shapes. Here, biomimetic prototypes fabricated from elastic rubber sheets have been used to study the impact of these static and dynamic features on the acoustic device characteristics. The basic shape of the prototypes was an obliquely truncated horn augmented with three static local shape features: vertical ridge, pinna-rim incision and frontal flap (antitragus). The prototype shape was deformed dynamically using a one-point actuation mechanism to produce a biomimetic bending of the prototype's tip. In isolation, the local shape features had little impact on the device beampattern. However, strong interactions were observed between these features and the overall deformation. The further the prototype tip was bent down, the stronger the beampatterns associated with combinations of multiple features differed from the upright configuration in the prominence of sidelobes. This behavior was qualitatively similar to numerical predictions for horseshoe bats. Hence, the interplay between static and dynamic features could be a bioinspired principle for affecting large changes through the dynamic manipulations of interactions that are sensitive to small geometrical changes.

  12. Biomimetic surface modification of polyurethane with phospholipids grafted carbon nanotubes.

    PubMed

    Tan, Dongsheng; Liu, Liuxu; Li, Zhen; Fu, Qiang

    2015-08-01

    To improve blood compatibility of polyurethane (PU), phospholipids grafted carbon nanotubes (CNTs) were prepared through zwitterion-mediated cycloaddition reaction and amide condensation, and then were added to the PU as fillers via solution mixing to form biomimetic surface. The properties of phospholipids grafted CNTs (CNT-PC) were investigated by thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and proton nuclear magnetic resonance ((1) H NMR). The results indicated that the phospholipids were grafted onto CNTs in high efficiency, and the hydrophilicity and dispersibility of the modified CNTs were improved effectively. The structures and properties of composites containing CNT-PC were investigated by optical microscope, XPS, and water contact angles. The results indicated that phospholipids were enriched on the surface with addition of 0.1 wt % of CNT-PC, which significantly reduced protein adsorption and platelet adhesion. The method of carrying phospholipids on the nanofiller to modify polymers has provided a promising way of constructing biomimetic phospholipid membrane on the surface to improve blood compatibility.

  13. An organic electronic biomimetic neuron enables auto-regulated neuromodulation.

    PubMed

    Simon, Daniel T; Larsson, Karin C; Nilsson, David; Burström, Gustav; Galter, Dagmar; Berggren, Magnus; Richter-Dahlfors, Agneta

    2015-09-15

    Current therapies for neurological disorders are based on traditional medication and electric stimulation. Here, we present an organic electronic biomimetic neuron, with the capacity to precisely intervene with the underlying malfunctioning signalling pathway using endogenous substances. The fundamental function of neurons, defined as chemical-to-electrical-to-chemical signal transduction, is achieved by connecting enzyme-based amperometric biosensors and organic electronic ion pumps. Selective biosensors transduce chemical signals into an electric current, which regulates electrophoretic delivery of chemical substances without necessitating liquid flow. Biosensors detected neurotransmitters in physiologically relevant ranges of 5-80 µM, showing linear response above 20 µm with approx. 0.1 nA/µM slope. When exceeding defined threshold concentrations, biosensor output signals, connected via custom hardware/software, activated local or distant neurotransmitter delivery from the organic electronic ion pump. Changes of 20 µM glutamate or acetylcholine triggered diffusive delivery of acetylcholine, which activated cells via receptor-mediated signalling. This was observed in real-time by single-cell ratiometric Ca(2+) imaging. The results demonstrate the potential of the organic electronic biomimetic neuron in therapies involving long-range neuronal signalling by mimicking the function of projection neurons. Alternatively, conversion of glutamate-induced descending neuromuscular signals into acetylcholine-mediated muscular activation signals may be obtained, applicable for bridging injured sites and active prosthetics.

  14. Biomimetic design of a brush-like nanopore: simulation studies.

    PubMed

    Pongprayoon, Prapasiri; Beckstein, Oliver; Sansom, Mark S P

    2012-01-12

    Combining a high degree of selectivity and nanoscale dimensions, biological pores are attractive potential components for nanotechnology devices and applications. Biomimetic design will facilitate production of stable synthetic nanopores with defined functionality. Bacterial porins offer a good source of possible templates for such nanopores as they form stable, selective pores in lipid bilayers. Molecular dynamics simulations have been used to design simple model nanopores with permeation free energy profiles that can be made to mimic a template protein, the OprP porin, which forms pores selective for anions. In particular, we explored the effects of varying the nature of pore-lining groups on free energy profiles for phosphate and chloride ions along the pore axis and the total charge of the permeation pathway of the pore. Cationic side chains lining the model nanopore are required to model the local detail of the OprP permeation landscape, whereas the total charge contributes to its magnitude. These studies indicate that a locally accurate biomimetic design has captured the essentials of the structure/function relationship of the parent protein.

  15. Biomimetic Acoustically-Responsive Vesicles for Theranostic Applications.

    PubMed

    Hsieh, Chen-Chan; Kang, Shih-Tsung; Lin, Yee-Hsien; Ho, Yi-Ju; Wang, Chung-Hsin; Yeh, Chih-Kuang; Chang, Chien-Wen

    2015-01-01

    In recent years, biomimetic cell membrane-derived particles have emerged as a new class of drug delivery system with advantages of biocompatibility, ease of isolation and long circulation profile. Here we report the development and potential theranostic applications of a new biomimetic acoustically-responsive droplet system derived from mammalian red blood cell membrane (RBCM). We hypothesized that drug-loaded RBCM droplets (RBCMDs) would undergo a transition from liquid (droplets) to gas (bubbles) upon high intensity focused ultrasound (HIFU) insonation, resulting in on-demand drug release. The generated microbubbles could also serve as a contrast agent to enhance ultrasound imaging. As-synthesized RBCMDs exhibited uniform size, good dispersity and preservation of RBCM-associated proteins that prevented uptake by macrophages. Camptothecin (CPT), an anti-cancer drug, was successfully loaded in the RBCMDs with a loading efficiency of 2-3% and an encapsulation efficiency of 62-97%. A short (3 min) exposure to HIFU irradiation triggered release of CPT from the RBCMDs and the physical explosion of droplets damaged nearby cancer cells resulting in significant cell death. In addition, the acoustically vaporized RBCMDs significantly increased the ultrasound echo signal to 30 dB. Lastly, we demonstrated that RBCMDs could be acoustically vaporized in vivo in target tissues, and enhancing ultrasound imaging. Taken together, we have developed a new class of naturally derived RBCMDs which show great potential for future application in remotely triggered drug delivery and ultrasound imaging enhancement.

  16. 9-Fluorenylmethyl (Fm) Disulfides: Biomimetic Precursors for Persulfides

    SciTech Connect

    Park, Chung-Min; Johnson, Brett A.; Duan, Jicheng; Park, Jeong-Jin; Day, Jacob J.; Gang, David; Qian, Wei-Jun; Xian, Ming

    2016-03-04

    Protein S-sulfhydration has been recognized as an important post-translational modification that regulates H2S signals. However, the reactivity and biological implications of the products of S-sulfhydration, i.e. persulfides, are still unclear. This is mainly due to the instability of persulfides and difficulty to access these molecules. Under physiological conditions persulfides mainly exist in anionic forms because of their low pKa values. However, current methods do not allow for the direct generation of persulfide anions under biomimetic and non-H2S conditions. Herein we report the development of a functional disulfide, FmSSPy-A (Fm =9-fluorenylmethyl; Py = pyridinyl). This reagent can effectively convert both small molecule and protein thiols (-SH) to form –S-SFm adducts under mild conditions. It allows for a H2S-free and biomimetic protocol to generate highly reactive persulfides (in their anionic forms). We also demonstrated the high nucleophilicity of persulfides toward a number of thiol-blocking reagents. This method holds promise for further understanding the chemical biology of persulfides and S-sulfhydration.

  17. Onion artificial muscles

    NASA Astrophysics Data System (ADS)

    Chen, Chien-Chun; Shih, Wen-Pin; Chang, Pei-Zen; Lai, Hsi-Mei; Chang, Shing-Yun; Huang, Pin-Chun; Jeng, Huai-An

    2015-05-01

    Artificial muscles are soft actuators with the capability of either bending or contraction/elongation subjected to external stimulation. However, there are currently no artificial muscles that can accomplish these actions simultaneously. We found that the single layered, latticed microstructure of onion epidermal cells after acid treatment became elastic and could simultaneously stretch and bend when an electric field was applied. By modulating the magnitude of the voltage, the artificial muscle made of onion epidermal cells would deflect in opposing directions while either contracting or elongating. At voltages of 0-50 V, the artificial muscle elongated and had a maximum deflection of -30 μm; at voltages of 50-1000 V, the artificial muscle contracted and deflected 1.0 mm. The maximum force response is 20 μN at 1000 V.

  18. Biomimetic rehabilitation engineering: the importance of somatosensory feedback for brain-machine interfaces

    NASA Astrophysics Data System (ADS)

    Perruchoud, David; Pisotta, Iolanda; Carda, Stefano; Murray, Micah M.; Ionta, Silvio

    2016-08-01

    Objective. Brain-machine interfaces (BMIs) re-establish communication channels between the nervous system and an external device. The use of BMI technology has generated significant developments in rehabilitative medicine, promising new ways to restore lost sensory-motor functions. However and despite high-caliber basic research, only a few prototypes have successfully left the laboratory and are currently home-deployed. Approach. The failure of this laboratory-to-user transfer likely relates to the absence of BMI solutions for providing naturalistic feedback about the consequences of the BMI’s actions. To overcome this limitation, nowadays cutting-edge BMI advances are guided by the principle of biomimicry; i.e. the artificial reproduction of normal neural mechanisms. Main results. Here, we focus on the importance of somatosensory feedback in BMIs devoted to reproducing movements with the goal of serving as a reference framework for future research on innovative rehabilitation procedures. First, we address the correspondence between users’ needs and BMI solutions. Then, we describe the main features of invasive and non-invasive BMIs, including their degree of biomimicry and respective advantages and drawbacks. Furthermore, we explore the prevalent approaches for providing quasi-natural sensory feedback in BMI settings. Finally, we cover special situations that can promote biomimicry and we present the future directions in basic research and clinical applications. Significance. The continued incorporation of biomimetic features into the design of BMIs will surely serve to further ameliorate the realism of BMIs, as well as tremendously improve their actuation, acceptance, and use.

  19. Biomimetic, Osteoconductive Non-mulberry Silk Fiber Reinforced Tricomposite Scaffolds for Bone Tissue Engineering.

    PubMed

    Gupta, Prerak; Adhikary, Mimi; M, Joseph Christakiran; Kumar, Manishekhar; Bhardwaj, Nandana; Mandal, Biman B

    2016-11-16

    Composite biomaterials as artificial bone graft materials are pushing the present frontiers of bioengineering. In this study, a biomimetic, osteoconductive tricomposite scaffold made of hydroxyapatite (HA) embedded in non-mulberry Antheraea assama (A. assama) silk fibroin fibers and its fibroin solution is explored for its osteogenic potential. Scaffolds were physico-chemically characterized for morphology, porosity, secondary structure conformation, water retention ability, biodegradability, and mechanical property. The results revealed a ∼5-fold increase in scaffold compressive modulus on addition of HA and silk fibers to liquid silk as compared to pure silk scaffolds while maintaining high scaffold porosity (∼90%) with slower degradation rates. X-ray diffraction (XRD) results confirmed deposition of HA crystals on composite scaffolds. Furthermore, the crystallite size of HA within scaffolds was strongly regulated by the intrinsic physical cues of silk fibroin. Fourier transform infrared (FTIR) spectroscopy studies indicated strong interactions between HA and silk fibroin. The fabricated tricomposite scaffolds supported enhanced cellular viability and function (ALP activity) for both MG63 osteosarcoma and human bone marrow stem cells (hBMSCs) as compared to pure silk scaffolds without fiber or HA addition. In addition, higher expression of osteogenic gene markers such as collagen I (Col-I), osteocalcin (OCN), osteopontin (OPN), and bone sialoprotein (BSP) further substantiated the applicability of HA composite silk scaffolds for bone related applications. Immunostaining studies confirmed localization of Col-I and BSP and were in agreement with real-time gene expression results. These findings demonstrate the osteogenic potential of developed biodegradable tricomposite scaffolds with the added advantage of the affordability of its components as bone graft substitute materials.

  20. Catalytic molecularly imprinted polymer membranes: development of the biomimetic sensor for phenols detection.

    PubMed

    Sergeyeva, T A; Slinchenko, O A; Gorbach, L A; Matyushov, V F; Brovko, O O; Piletsky, S A; Sergeeva, L M; Elska, G V

    2010-02-05

    Portable biomimetic sensor devices for the express control of phenols content in water were developed. The synthetic binding sites mimicking active site of the enzyme tyrosinase were formed in the structure of free-standing molecularly imprinted polymer membranes. Molecularly imprinted polymer membranes with the catalytic activity were obtained by co-polymerization of the complex Cu(II)-catechol-urocanic acid ethyl ester with (tri)ethyleneglycoldimethacrylate, and oligourethaneacrylate. Addition of the elastic component oligourethaneacrylate provided formation of the highly cross-linked polymer with the catalytic activity in a form of thin, flexible, and mechanically stable membrane. High accessibility of the artificial catalytic sites for the interaction with the analyzed phenol molecules was achieved due to addition of linear polymer (polyethyleneglycol Mw 20,000) to the initial monomer mixture before the polymerization. As a result, typical semi-interpenetrating polymer networks (semi-IPNs) were formed. The cross-linked component of the semi-IPN was represented by the highly cross-linked catalytic molecularly imprinted polymer, while the linear one was represented by polyethyleneglycol Mw 20,000. Extraction of the linear polymer from the fully formed semi-IPN resulted in formation of large pores in the membranes' structure. Concentration of phenols in the analyzed samples was detected using universal portable device oxymeter with the oxygen electrode in a close contact with the catalytic molecularly imprinted polymer membrane as a transducer. The detection limit of phenols detection using the developed sensor system based on polymers-biomimics with the optimized composition comprised 0.063 mM, while the linear range of the sensor comprised 0.063-1 mM. The working characteristics of the portable sensor devices were investigated. Storage stability of sensor systems at room temperature comprised 12 months (87%). As compared to traditional methods of phenols

  1. Cruciate Retaining Implant With Biomimetic Articular Surface to Reproduce Activity Dependent Kinematics of the Normal Knee.

    PubMed

    Varadarajan, Kartik Mangudi M; Zumbrunn, Thomas; Rubash, Harry E; Malchau, Henrik; Li, Guoan; Muratoglu, Orhun K

    2015-12-01

    Alterations in normal knee kinematics following total knee arthroplasty (TKA) arise in part from the non-anatomic articular geometry of contemporary implants. In this study, the kinematics of a novel posterior cruciate-retaining (CR) implant with anatomic (biomimetic) articular surface, were compared to that of contemporary CR implants during various simulated activities. Across different simulated activities the biomimetic-CR mimicked normal kinematic patterns more closely than contemporary CR implants. In particular, during deep knee bend and chair-sit, the biomimetic-CR showed medial pivot motion, while other CR implants showed abnormal motion including lateral pivot or no pivot, and paradoxical anterior sliding. Further in vivo and clinical studies are needed to determine whether such biomimetic implants can truly help to achieve a more normal feeling knee and improved patient satisfaction.

  2. Regaining Native Knee Kinematics Following Joint Arthroplasty: A Novel Biomimetic Design with ACL and PCL Preservation.

    PubMed

    Zumbrunn, Thomas; Varadarajan, Kartik Mangudi; Rubash, Harry E; Malchau, Henrik; Li, Guoan; Muratoglu, Orhun K

    2015-12-01

    Lack of ACL and non-anatomic articular surfaces in contemporary total knee implants result in kinematic abnormalities. We hypothesized that such abnormalities may be addressed with a biomimetic bi-cruciate retaining (BCR) design having anatomical articular surfaces. We used dynamic computer simulations to compare kinematics among the biomimetic BCR, a contemporary BCR and cruciate-retaining implant for activities of daily living. During simulated deep knee bend, chair-sit and walking, the biomimetic BCR implant showed activity dependent kinematics similar to healthy knees in vivo. Restoring native knee geometry together with ACL preservation provided these kinematic improvements over contemporary ACL-preserving and ACL-sacrificing implants. Further clinical studies are required to determine if such biomimetic implants can result in more normal feeling knees and improve quality of life for active patients.

  3. Artificial Intelligence and Robotics.

    DTIC Science & Technology

    1982-09-20

    8217’AD-A122 414 ARTIFICIAL INTELLIGENCE AND ROBOTICS (.) ARMY SCIENCE 1/j 13OARD WA SH INGTON Od I C PEDEN ET AL. 20 SEP 82 UNCLASSIFIED F/G 15/3 NL LEE...AND ACQUISITION WASHINGTON, D. C. 20310 A RMY CIENCE BOARD AD HOC SUBGROUP REPORT ON ARTIFICIAL INTELLIGENCE AND ROBOTICS SEPTEMBER 1982 DTIC DEC 1 5...TITLE (aid Subtitle) S TYPE OF REPORT & PERIOD COVERED Army Science Board AHSG Report Final Artificial Intelligence and Robotics S. PERFORMING ORG

  4. Enzyme encapsulation in zeolitic imidazolate frameworks: a comparison between controlled co-precipitation and biomimetic mineralisation.

    PubMed

    Liang, Kang; Coghlan, Campbell J; Bell, Stephen G; Doonan, Christian; Falcaro, Paolo

    2016-01-11

    Recent studies have demonstrated that metal-organic frameworks can be employed as protective coatings for enzymes. Two efficient strategies have been reported for the synthesis of such composite materials: biomimetic mineralisation and controlled co-precipitation using polyvinylpyrrolidone. We assessed the relative efficacy of each approach by comparing the thermal stability of encapsulated urease. The resulting data shows that over a range of temperatures biomimetic mineralisation offers superior protection than the co-precipitation method.

  5. Biomimetic Total Syntheses of (-)-Leucoridines A and C through the Dimerization of (-)-Dihydrovalparicine.

    PubMed

    Kokkonda, Praveen; Brown, Keaon R; Seguin, Trevor J; Wheeler, Steven E; Vaddypally, Shivaiah; Zdilla, Michael J; Andrade, Rodrigo B

    2015-10-19

    Concise biomimetic syntheses of the Strychnos-Strychnos-type bis-indole alkaloids (-)-leucoridine A (1) and C (2) were accomplished through the biomimetic dimerization of (-)-dihydrovalparicine (3). En route to 3, the known alkaloids (+)-geissoschizoline (8) and (-)-dehydrogeissoschizoline (10) were also prepared. DFT calculations were employed to elucidate the mechanism, which favors a stepwise aza-Michael/spirocyclization sequence over the alternate hetero-Diels-Alder cycloaddition reaction.

  6. Intelligence: Real or artificial?

    PubMed Central

    Schlinger, Henry D.

    1992-01-01

    Throughout the history of the artificial intelligence movement, researchers have strived to create computers that could simulate general human intelligence. This paper argues that workers in artificial intelligence have failed to achieve this goal because they adopted the wrong model of human behavior and intelligence, namely a cognitive essentialist model with origins in the traditional philosophies of natural intelligence. An analysis of the word “intelligence” suggests that it originally referred to behavior-environment relations and not to inferred internal structures and processes. It is concluded that if workers in artificial intelligence are to succeed in their general goal, then they must design machines that are adaptive, that is, that can learn. Thus, artificial intelligence researchers must discard their essentialist model of natural intelligence and adopt a selectionist model instead. Such a strategic change should lead them to the science of behavior analysis. PMID:22477051

  7. Artificial upwelling and mixing

    SciTech Connect

    Not Available

    1989-01-01

    The authors present results related to artificial upwelling and coastal mariculture using deep ocean water and mixing in coastal waters. They discuss the application of research results for marine waste disposal.

  8. Inflatable artificial sphincter

    MedlinePlus

    ... wall repair Urethral bulking with artificial material Retropubic suspension Tension-free vaginal tape Description This procedure may ... PA: Elsevier; 2016:chap 145. Chapple CR. Retropubic suspension surgery for incontinence in women. In: Wein AJ, ...

  9. Bibliography: Artificial Intelligence.

    ERIC Educational Resources Information Center

    Smith, Richard L.

    1986-01-01

    Annotates reference material on artificial intelligence, mostly at an introductory level, with applications to education and learning. Topics include: (1) programing languages; (2) expert systems; (3) language instruction; (4) tutoring systems; and (5) problem solving and reasoning. (JM)

  10. Introduction to artificial intelligence

    NASA Technical Reports Server (NTRS)

    Cheeseman, P.; Gevarter, W.

    1986-01-01

    This paper presents an introductory view of Artificial Intelligence (AI). In addition to defining AI, it discusses the foundations on which it rests, research in the field, and current and potential applications.

  11. Inflatable artificial sphincter - slideshow

    MedlinePlus

    ... presentations/100115.htm Inflatable artificial sphincter - series—Normal anatomy To use the sharing features on this page, ... Bethesda, MD 20894 U.S. Department of Health and Human Services National Institutes of Health Page last updated: ...

  12. Friction and wear behaviors of compacted graphite iron with different biomimetic units fabricated by laser cladding

    NASA Astrophysics Data System (ADS)

    Sun, Na; Shan, Hongyu; Zhou, Hong; Chen, Darong; Li, Xiaoyan; Xia, Wen; Ren, Luquan

    2012-07-01

    Mimicking the biological characters on the cuticles of pangolin scales, biomimetic units were fabricated on the surfaces of compacted graphite cast iron (CGI) with different unit materials using laser cladding process. The influences of various unit materials including TiC, WC, B4C and Al2O3 powders on the friction and wear behaviors of CGI were investigated. The wear resistance mechanism of biomimetic specimens was discussed. The results indicated that the wear resistance of biomimetic specimens cladding TiC was the best; the specimens cladding WC or B4C were in the middle; and the specimens cladding Al2O3 was the worst. The sequence of friction coefficient values of biomimetic specimens cladding different ceramic powders from high to low was B4C, TiC, WC and Al2O3. The wear mechanism of untreated specimen was mainly adhesion wear, abrasive wear as well as the oxidation wear, whereas the adhesive wear and abrasive wear was the main wear mechanism of the regions of substrate in biomimetic specimens and slight adhesion, abrasive wear and fatigue wear on the regions of biomimetic units.

  13. Biomimetic microchannels of planar reactors for optimized photocatalytic efficiency of water purification.

    PubMed

    Liao, Wuxia; Wang, Ning; Wang, Taisheng; Xu, Jia; Han, Xudong; Liu, Zhenyu; Zhang, Xuming; Yu, Weixing

    2016-01-01

    This paper reports a biomimetic design of microchannels in the planar reactors with the aim to optimize the photocatalytic efficiency of water purification. Inspired from biology, a bifurcated microchannel has been designed based on the Murray's law to connect to the reaction chamber for photocatalytic reaction. The microchannels are designed to have a constant depth of 50 μm but variable aspect ratios ranging from 0.015 to 0.125. To prove its effectiveness for photocatalytic water purification, the biomimetic planar reactors have been tested and compared with the non-biomimetic ones, showing an improvement of the degradation efficiency by 68%. By employing the finite element method, the flow process of the designed microchannel reactors has been simulated and analyzed. It is found that the biomimetic design owns a larger flow velocity fluctuation than that of the non-biomimetic one, which in turn results in a faster photocatalytic reaction speed. Such a biomimetic design paves the way for the design of more efficient planar reactors and may also find applications in other microfluidic systems that involve the use of microchannels.

  14. Biomimetic microchannels of planar reactors for optimized photocatalytic efficiency of water purification

    PubMed Central

    Liao, Wuxia; Wang, Ning; Wang, Taisheng; Xu, Jia; Han, Xudong; Liu, Zhenyu; Yu, Weixing

    2016-01-01

    This paper reports a biomimetic design of microchannels in the planar reactors with the aim to optimize the photocatalytic efficiency of water purification. Inspired from biology, a bifurcated microchannel has been designed based on the Murray's law to connect to the reaction chamber for photocatalytic reaction. The microchannels are designed to have a constant depth of 50 μm but variable aspect ratios ranging from 0.015 to 0.125. To prove its effectiveness for photocatalytic water purification, the biomimetic planar reactors have been tested and compared with the non-biomimetic ones, showing an improvement of the degradation efficiency by 68%. By employing the finite element method, the flow process of the designed microchannel reactors has been simulated and analyzed. It is found that the biomimetic design owns a larger flow velocity fluctuation than that of the non-biomimetic one, which in turn results in a faster photocatalytic reaction speed. Such a biomimetic design paves the way for the design of more efficient planar reactors and may also find applications in other microfluidic systems that involve the use of microchannels. PMID:26958102

  15. Cosmeceutical product consisting of biomimetic peptides: antiaging effects in vivo and in vitro

    PubMed Central

    Gazitaeva, Zarema I; Drobintseva, Anna O; Chung, Yongji; Polyakova, Victoria O; Kvetnoy, Igor M

    2017-01-01

    Background Biomimetic peptides are synthetic compounds that are identical to amino acid sequence synthesized by an organism and can interact with growth factor receptors and provide antiaging clinical effects. Purpose The purpose of this study was to investigate the effects of biomimetic peptides on the repair processes in the dermis using a model of cell cultures and in vivo. Patients and methods Five female volunteers were subjected to the injection of biomimetic peptides 1 month prior to the abdominoplasty procedure. Cell culture, immunocytochemistry, and confocal microscopy methods were used in this study. Results Biomimetic peptides regulate the synthesis of proteins Ki-67, type I procollagen, AP-1, and SIRT6 in cell cultures of human fibroblasts. They contribute to the activation of regeneration processes and initiation of mechanisms that prevent aging. Intradermal administration of complex of biomimetic peptides produces a more dense arrangement of collagen fibers in the dermis and increased size of the fibers after 2 weeks. The complex of biomimetic peptides was effective in the in vivo experiments, where an increase in the proliferative and synthetic activities of fibroblasts was observed. Conclusion This investigation showed that the studied peptides have biological effects, testifying the stimulation of reparative processes in the skin under their control. PMID:28123310

  16. Physics of Artificial Gravity

    NASA Technical Reports Server (NTRS)

    Bukley, Angie; Paloski, William; Clement, Gilles

    2006-01-01

    This chapter discusses potential technologies for achieving artificial gravity in a space vehicle. We begin with a series of definitions and a general description of the rotational dynamics behind the forces ultimately exerted on the human body during centrifugation, such as gravity level, gravity gradient, and Coriolis force. Human factors considerations and comfort limits associated with a rotating environment are then discussed. Finally, engineering options for designing space vehicles with artificial gravity are presented.

  17. Self-Monitoring Artificial Red Cells with Sufficient Oxygen Supply for Enhanced Photodynamic Therapy

    NASA Astrophysics Data System (ADS)

    Luo, Zhenyu; Zheng, Mingbin; Zhao, Pengfei; Chen, Ze; Siu, Fungming; Gong, Ping; Gao, Guanhui; Sheng, Zonghai; Zheng, Cuifang; Ma, Yifan; Cai, Lintao

    2016-03-01

    Photodynamic therapy has been increasingly applied in clinical cancer treatments. However, native hypoxic tumoural microenvironment and lacking oxygen supply are the major barriers hindering photodynamic reactions. To solve this problem, we have developed biomimetic artificial red cells by loading complexes of oxygen-carrier (hemoglobin) and photosensitizer (indocyanine green) for boosted photodynamic strategy. Such nanosystem provides a coupling structure with stable self-oxygen supply and acting as an ideal fluorescent/photoacoustic imaging probe, dynamically monitoring the nanoparticle biodistribution and the treatment of PDT. Upon exposure to near-infrared laser, the remote-triggered photosensitizer generates massive cytotoxic reactive oxygen species (ROS) with sufficient oxygen supply. Importantly, hemoglobin is simultaneously oxidized into the more active and resident ferryl-hemoglobin leading to persistent cytotoxicity. ROS and ferryl-hemoglobin synergistically trigger the oxidative damage of xenograft tumour resulting in complete suppression. The artificial red cells with self-monitoring and boosted photodynamic efficacy could serve as a versatile theranostic platform.

  18. Development of artificial muscles based on electroactive ionomeric polymer-metal composites.

    PubMed

    Hirano, Laos A; Escote, Márcia T; Martins-Filho, Luiz S; Mantovani, Gerson L; Scuracchio, Carlos H

    2011-05-01

    This work contextualizes the research of materials that can be applied as artificial muscles. The main motivation of this research is the importance of the development of mechatronic systems for the replacement of traditional devices of actuation and motion based on rotational electrical motors by other devices that reproduce biological muscle movements. Electroactive polymers (EAPs) are materials that respond to electric stimuli with shape and/or dimension changes, and accomplish movements that are smooth enough to mimic biological muscles. Among EAPs, the ionomeric polymer-metal composites (IPMCs) are an interesting alternative to biomimetic devices due to large displacements when submitted to low applied voltage. This article presents a brief review of IPMCs, a sample preparation procedure, and some electromechanical experimental results. We also discuss the applicability of this technology in medical devices and as artificial muscles.

  19. Mesoporous silica-encapsulated gold nanoparticles as artificial enzymes for self-activated cascade catalysis.

    PubMed

    Lin, Youhui; Li, Zhenhua; Chen, Zhaowei; Ren, Jinsong; Qu, Xiaogang

    2013-04-01

    A significant challenge in chemistry is to create synthetic structures that mimic the complexity and function of natural systems. Here, a self-activated, enzyme-mimetic catalytic cascade has been realized by utilizing expanded mesoporous silica-encapsulated gold nanoparticles (EMSN-AuNPs) as both glucose oxidase- and peroxidase-like artificial enzymes. Specifically, EMSN helps the formation of a high degree of very small and well-dispersed AuNPs, which exhibit an extraordinarily stability and dual enzyme-like activities. Inspired by these unique and attractive properties, we further piece them together into a self-organized artificial cascade reaction, which is usually completed by the oxidase-peroxidase coupled enzyme system. Our finding may pave the way to use matrix as the structural component for the design and development of biomimetic catalysts and to apply enzyme mimics for realizing higher functions.

  20. Design and simulation of a cable-pulley-based transmission for artificial ankle joints

    NASA Astrophysics Data System (ADS)

    Liu, Huaxin; Ceccarelli, Marco; Huang, Qiang

    2016-06-01

    In this paper, a mechanical transmission based on cable pulley is proposed for human-like actuation in the artificial ankle joints of human-scale. The anatomy articular characteristics of the human ankle is discussed for proper biomimetic inspiration in designing an accurate, efficient, and robust motion control of artificial ankle joint devices. The design procedure is presented through the inclusion of conceptual considerations and design details for an interactive solution of the transmission system. A mechanical design is elaborated for the ankle joint angular with pitch motion. A multi-body dynamic simulation model is elaborated accordingly and evaluated numerically in the ADAMS environment. Results of the numerical simulations are discussed to evaluate the dynamic performance of the proposed design solution and to investigate the feasibility of the proposed design in future applications for humanoid robots.

  1. A biomimetic nanosponge that absorbs pore-forming toxins.

    PubMed

    Hu, Che-Ming J; Fang, Ronnie H; Copp, Jonathan; Luk, Brian T; Zhang, Liangfang

    2013-05-01

    Detoxification treatments such as toxin-targeted anti-virulence therapy offer ways to cleanse the body of virulence factors that are caused by bacterial infections, venomous injuries and biological weaponry. Because existing detoxification platforms such as antisera, monoclonal antibodies, small-molecule inhibitors and molecularly imprinted polymers act by targeting the molecular structures of toxins, customized treatments are required for different diseases. Here, we show a biomimetic toxin nanosponge that functions as a toxin decoy in vivo. The nanosponge, which consists of a polymeric nanoparticle core surrounded by red blood cell membranes, absorbs membrane-damaging toxins and diverts them away from their cellular targets. In a mouse model, the nanosponges markedly reduce the toxicity of staphylococcal alpha-haemolysin (α-toxin) and thus improve the survival rate of toxin-challenged mice. This biologically inspired toxin nanosponge presents a detoxification treatment that can potentially treat a variety of injuries and diseases caused by pore-forming toxins.

  2. Replaying the evolutionary tape: biomimetic reverse engineering of gene networks.

    PubMed

    Marbach, Daniel; Mattiussi, Claudio; Floreano, Dario

    2009-03-01

    In this paper, we suggest a new approach for reverse engineering gene regulatory networks, which consists of using a reconstruction process that is similar to the evolutionary process that created these networks. The aim is to integrate prior knowledge into the reverse-engineering procedure, thus biasing the search toward biologically plausible solutions. To this end, we propose an evolutionary method that abstracts and mimics the natural evolution of gene regulatory networks. Our method can be used with a wide range of nonlinear dynamical models. This allows us to explore novel model types such as the log-sigmoid model introduced here. We apply the biomimetic method to a gold-standard dataset from an in vivo gene network. The obtained results won a reverse engineering competition of the second DREAM conference (Dialogue on Reverse Engineering Assessments and Methods 2007, New York, NY).

  3. Biomimetic Nanotubes Based on Cyclodextrins for Ion-Channel Applications.

    PubMed

    Mamad-Hemouch, Hajar; Ramoul, Hassen; Abou Taha, Mohammad; Bacri, Laurent; Huin, Cécile; Przybylski, Cédric; Oukhaled, Abdelghani; Thiébot, Bénédicte; Patriarche, Gilles; Jarroux, Nathalie; Pelta, Juan

    2015-11-11

    Biomimetic membrane channels offer a great potential for fundamental studies and applications. Here, we report the fabrication and characterization of short cyclodextrin nanotubes, their insertion into membranes, and cytotoxicity assay. Mass spectrometry and high-resolution transmission electron microscopy were used to confirm the synthesis pathway leading to the formation of short nanotubes and to describe their structural parameters in terms of length, diameter, and number of cyclodextrins. Our results show the control of the number of cyclodextrins threaded on the polyrotaxane leading to nanotube synthesis. Structural parameters obtained by electron microscopy are consistent with the distribution of the number of cyclodextrins evaluated by mass spectrometry from the initial polymer distribution. An electrophysiological study at single molecule level demonstrates the ion channel formation into lipid bilayers, and the energy penalty for the entry of ions into the confined nanotube. In the presence of nanotubes, the cell physiology is not altered.

  4. Aquaporin-Based Biomimetic Polymeric Membranes: Approaches and Challenges.

    PubMed

    Habel, Joachim; Hansen, Michael; Kynde, Søren; Larsen, Nanna; Midtgaard, Søren Roi; Jensen, Grethe Vestergaard; Bomholt, Julie; Ogbonna, Anayo; Almdal, Kristoffer; Schulz, Alexander; Hélix-Nielsen, Claus

    2015-07-31

    In recent years, aquaporin biomimetic membranes (ABMs) for water separation have gained considerable interest. Although the first ABMs are commercially available, there are still many challenges associated with further ABM development. Here, we discuss the interplay of the main components of ABMs: aquaporin proteins (AQPs), block copolymers for AQP reconstitution, and polymer-based supporting structures. First, we briefly cover challenges and review recent developments in understanding the interplay between AQP and block copolymers. Second, we review some experimental characterization methods for investigating AQP incorporation including freeze-fracture transmission electron microscopy, fluorescence correlation spectroscopy, stopped-flow light scattering, and small-angle X-ray scattering. Third, we focus on recent efforts in embedding reconstituted AQPs in membrane designs that are based on conventional thin film interfacial polymerization techniques. Finally, we describe some new developments in interfacial polymerization using polyhedral oligomeric silsesquioxane cages for increasing the physical and chemical durability of thin film composite membranes.

  5. Efficient Enzyme-Free Biomimetic Sensors for Natural Phenol Detection.

    PubMed

    Ferreira Garcia, Luane; Ribeiro Souza, Aparecido; Sanz Lobón, Germán; Dos Santos, Wallans Torres Pio; Alecrim, Morgana Fernandes; Fontes Santiago, Mariângela; de Sotomayor, Rafael Luque Álvarez; de Souza Gil, Eric

    2016-08-13

    The development of sensors and biosensors based on copper enzymes and/or copper oxides for phenol sensing is disclosed in this work. The electrochemical properties were studied by cyclic and differential pulse voltammetry using standard solutions of potassium ferrocyanide, phosphate/acetate buffers and representative natural phenols in a wide pH range (3.0 to 9.0). Among the natural phenols herein investigated, the highest sensitivity was observed for rutin, a powerful antioxidant widespread in functional foods and ubiquitous in the plant kingdom. The calibration curve for rutin performed at optimum pH (7.0) was linear in a broad concentration range, 1 to 120 µM (r = 0.99), showing detection limits of 0.4 µM. The optimized biomimetic sensor was also applied in total phenol determination in natural samples, exhibiting higher stability and sensitivity as well as distinct selectivity for antioxidant compounds.

  6. Biomimetic approaches with smart interfaces for bone regeneration.

    PubMed

    Sailaja, G S; Ramesh, P; Vellappally, Sajith; Anil, Sukumaran; Varma, H K

    2016-11-05

    A 'smart tissue interface' is a host tissue-biomaterial interface capable of triggering favourable biochemical events inspired by stimuli responsive mechanisms. In other words, biomaterial surface is instrumental in dictating the interface functionality. This review aims to investigate the fundamental and favourable requirements of a 'smart tissue interface' that can positively influence the degree of healing and promote bone tissue regeneration. A biomaterial surface when interacts synergistically with the dynamic extracellular matrix, the healing process become accelerated through development of a smart interface. The interface functionality relies equally on bound functional groups and conjugated molecules belonging to the biomaterial and the biological milieu it interacts with. The essential conditions for such a special biomimetic environment are discussed. We highlight the impending prospects of smart interfaces and trying to relate the design approaches as well as critical factors that determine species-specific functionality with special reference to bone tissue regeneration.

  7. Aquaporin-Based Biomimetic Polymeric Membranes: Approaches and Challenges

    PubMed Central

    Habel, Joachim; Hansen, Michael; Kynde, Søren; Larsen, Nanna; Midtgaard, Søren Roi; Jensen, Grethe Vestergaard; Bomholt, Julie; Ogbonna, Anayo; Almdal, Kristoffer; Schulz, Alexander; Hélix-Nielsen, Claus

    2015-01-01

    In recent years, aquaporin biomimetic membranes (ABMs) for water separation have gained considerable interest. Although the first ABMs are commercially available, there are still many challenges associated with further ABM development. Here, we discuss the interplay of the main components of ABMs: aquaporin proteins (AQPs), block copolymers for AQP reconstitution, and polymer-based supporting structures. First, we briefly cover challenges and review recent developments in understanding the interplay between AQP and block copolymers. Second, we review some experimental characterization methods for investigating AQP incorporation including freeze-fracture transmission electron microscopy, fluorescence correlation spectroscopy, stopped-flow light scattering, and small-angle X-ray scattering. Third, we focus on recent efforts in embedding reconstituted AQPs in membrane designs that are based on conventional thin film interfacial polymerization techniques. Finally, we describe some new developments in interfacial polymerization using polyhedral oligomeric silsesquioxane cages for increasing the physical and chemical durability of thin film composite membranes. PMID:26264033

  8. Plasmonic nanoparticles tuned thermal sensitive photonic polymer for biomimetic chameleon

    NASA Astrophysics Data System (ADS)

    Yan, Yang; Liu, Lin; Cai, Zihe; Xu, Jiwen; Xu, Zhou; Zhang, Di; Hu, Xiaobin

    2016-08-01

    Among many thermo-photochromic materials, the color-changing behavior caused by temperature and light is usually lack of a full color response. And the study on visible light-stimuli chromic response is rarely reported. Here, we proposed a strategy to design a thermo-photochromic chameleon biomimetic material consisting of photonic poly(N-isopropylacrylamide-co-methacrylic acid) copolymer and plasmonic nanoparticles which has a vivid color change triggered by temperature and light like chameleons. We make use of the plasmonic nanoparticles like gold nanoparticles and silver nanoparticles to increase the sensitivity of the responsive behavior and control the lower critical solution temperature of the thermosensitive films by tuning the polymer chain conformation transition. Finally, it is possible that this film would have colorimetric responses to the entire VIS spectrum by the addition of different plasmonic nanoparticles to tune the plasmonic excitation wavelength. As a result, this method provides a potential use in new biosensors, military and many other aspects.

  9. Crustacean-derived biomimetic components and nanostructured composites.

    PubMed

    Grunenfelder, Lessa Kay; Herrera, Steven; Kisailus, David

    2014-08-27

    Over millions of years, the crustacean exoskeleton has evolved into a rigid, tough, and complex cuticle that is used for structural support, mobility, protection of vital organs, and defense against predation. The crustacean cuticle is characterized by a hierarchically arranged chitin fiber scaffold, mineralized predominately by calcium carbonate and/or calcium phosphate. The structural organization of the mineral and organic within the cuticle occurs over multiple length scales, resulting in a strong and tough biological composite. Here, the ultrastructural details observed in three species of crustacean are reviewed: the American lobster (Homarus americanus), the edible crab (Cancer pagurus), and the peacock mantis shrimp (Odontodactylus scyllarus). The Review concludes with a discussion of recent advances in the development of biomimetics with controlled organic scaffolding, mineralization, and the construction of nanoscale composites, inspired by the organization and formation of the crustacean cuticle.

  10. A biomimetic nanosponge that absorbs pore-forming toxins

    NASA Astrophysics Data System (ADS)

    Hu, Che-Ming J.; Fang, Ronnie H.; Copp, Jonathan; Luk, Brian T.; Zhang, Liangfang

    2013-05-01

    Detoxification treatments such as toxin-targeted anti-virulence therapy offer ways to cleanse the body of virulence factors that are caused by bacterial infections, venomous injuries and biological weaponry. Because existing detoxification platforms such as antisera, monoclonal antibodies, small-molecule inhibitors and molecularly imprinted polymers act by targeting the molecular structures of toxins, customized treatments are required for different diseases. Here, we show a biomimetic toxin nanosponge that functions as a toxin decoy in vivo. The nanosponge, which consists of a polymeric nanoparticle core surrounded by red blood cell membranes, absorbs membrane-damaging toxins and diverts them away from their cellular targets. In a mouse model, the nanosponges markedly reduce the toxicity of staphylococcal alpha-haemolysin (α-toxin) and thus improve the survival rate of toxin-challenged mice. This biologically inspired toxin nanosponge presents a detoxification treatment that can potentially treat a variety of injuries and diseases caused by pore-forming toxins.

  11. CPG Network Optimization for a Biomimetic Robotic Fish via PSO.

    PubMed

    Yu, Junzhi; Wu, Zhengxing; Wang, Ming; Tan, Min

    2016-09-01

    In this brief, we investigate the parameter optimization issue of a central pattern generator (CPG) network governed forward and backward swimming for a fully untethered, multijoint biomimetic robotic fish. Considering that the CPG parameters are tightly linked to the propulsive performance of the robotic fish, we propose a method for determination of relatively optimized control parameters. Within the framework of evolutionary computation, we use a combination of dynamic model and particle swarm optimization (PSO) algorithm to seek the CPG characteristic parameters for an enhanced performance. The PSO-based optimization scheme is validated with extensive experiments conducted on the actual robotic fish. Noticeably, the optimized results are shown to be superior to previously reported forward and backward swimming speeds.

  12. Locomotion Performance of Biomimetic Fish-like Swimming Devices

    NASA Astrophysics Data System (ADS)

    Epps, Brenden P.; Valdivia Y Alvarado, Pablo; Techet, Alexandra H.

    2007-11-01

    The swimming performance of a biomimetic, fish-like swimming device, designed to exploit the natural dynamics of its compliant body to achieve locomotion, is studied experimentally. A theoretical model combines beam-bending stress analysis and unsteady hydrodynamic forcing with known material properties of the robot to reveal desired geometry distributions and actuation modes. Swimming kinematics and corresponding performance of the device are also predicted and tested for a carangiform prototype device in a quiescent tank of water. Experimental swimming tests show good agreement with the simplified theoretical models. The hydrodynamic characteristics of the wake behind the device are investigated using time-resolved particle imaging velocimetry (PIV) over a range of tail beat frequencies, from 1 to 4 Hz, to asses vortical wake patterns and hydrodynamic forces. PIV data are compared to theoretical model predictions. Reynolds numbers for the swimming device are between 2500 and 8500 based on body length.

  13. Biomimetic Antigenic Nanoparticles Elicit Controlled Protective Immune Response to Influenza

    PubMed Central

    Patterson, Dustin P.; Rynda-Apple, Agnieszka; Harmsen, Ann L.; Harmsen, Allen G.; Douglas, Trevor

    2013-01-01

    Here we present a biomimetic strategy towards nanoparticle design for controlled immune response through encapsulation of conserved internal influenza proteins on the interior of virus like particles (VLPs) to direct CD8+ cytotoxic T cell protection. Programmed encapsulation and sequestration of the conserved nucleoprotein (NP) from influenza on the interior of a VLP, derived from the bacteriophage P22, results in a vaccine that provides multi-strain protection against 100 times lethal doses of influenza in an NP specific CD8+ T cell-dependent manner. VLP assembly and encapsulation of the immunogenic NP cargo protein is the result of a genetically programmed self-assembly making this strategy amendable to the quick production of vaccines to rapidly emerging pathogens. Addition of adjuvants or targeting molecules were not required for eliciting the protective response. PMID:23540530

  14. A biomimetic accelerometer inspired by the cricket's clavate hair.

    PubMed

    Droogendijk, H; de Boer, M J; Sanders, R G P; Krijnen, G J M

    2014-08-06

    Crickets use so-called clavate hairs to sense (gravitational) acceleration to obtain information on their orientation. Inspired by this clavate hair system, a one-axis biomimetic accelerometer has been developed and fabricated using surface micromachining and SU-8 lithography. An analytical model is presented for the design of the accelerometer, and guidelines are derived to reduce responsivity due to flow-induced contributions to the accelerometer's output. Measurements show that this microelectromechanical systems (MEMS) hair-based accelerometer has a resonance frequency of 320 Hz, a detection threshold of 0.10 ms(-2) and a dynamic range of more than 35 dB. The accelerometer exhibits a clear directional response to external accelerations and a low responsivity to airflow. Further, the accelerometer's physical limits with respect to noise levels are addressed and the possibility for short-term adaptation of the sensor to the environment is discussed.

  15. Regenerated cellulose/wool blend enhanced biomimetic hydroxyapatite mineralization.

    PubMed

    Salama, Ahmed; El-Sakhawy, Mohamed

    2016-11-01

    The current article investigates the effect of bioactive cellulose/wool blend on calcium phosphate biomimetic mineralization. Regenerated cellulose/wool blend was prepared by dissolution-regeneration of neat cellulose and natural wool in 1-butyl-3-methyl imidazolium chloride [Bmim][Cl], as a solvent for the two polymers. Crystalline hydroxyapatite nanofibers with a uniform size, shape and dimension were formed after immersing the bioactive blend in simulated body fluid. The cytotoxicity of cellulose/wool/hydroxyapatite was studied using animal fibroblast baby hamster kidney cells (BHK-21) and the result displayed good cytocompatability. This research work presents a green processing method for the development of novel cellulose/wool/hydroxyapatite hybrid materials for tissue engineering applications.

  16. Biomimetic approaches to the control of underwater walking machines.

    PubMed

    Ayers, Joseph; Witting, Jan

    2007-01-15

    We have developed a biomimetic robot based on the American lobster. The robot is designed to achieve the performance advantages of the animal model by adopting biomechanical features and neurobiological control principles. Three types of controllers are described. The first is a state machine based on the connectivity and dynamics of the lobster central pattern generator (CPG). The state machine controls myomorphic actuators based on shape memory alloys (SMAs) and responds to environmental perturbation through sensors that employ a labelled-line code. The controller supports a library of action patterns and exteroceptive reflexes to mediate tactile navigation, obstacle negotiation and adaptation to surge. We are extending this controller to neuronal network-based models. A second type of leg CPG is based on synaptic networks of electronic neurons and has been adapted to control the SMA actuated leg. A brain is being developed using layered reflexes based on discrete time map-based neurons.

  17. Nanofibril scaffold assisted MEMS artificial hydrogel neuromasts for enhanced sensitivity flow sensing

    PubMed Central

    Kottapalli, Ajay Giri Prakash; Bora, Meghali; Asadnia, Mohsen; Miao, Jianmin; Venkatraman, Subbu S.; Triantafyllou, Michael

    2016-01-01

    We present the development and testing of superficial neuromast-inspired flow sensors that also attain high sensitivity and resolution through a biomimetic hyaulronic acid-based hydrogel cupula dressing. The inspiration comes from the spatially distributed neuromasts of the blind cavefish that live in completely dark undersea caves; the sensors enable the fish to form three-dimensional flow and object maps, enabling them to maneuver efficiently in cluttered environments. A canopy shaped electrospun nanofibril scaffold, inspired by the cupular fibrils, assists the drop-casting process allowing the formation of a prolate spheroid-shaped artificial cupula. Rheological and nanoindentation characterizations showed that the Young’s modulus of the artificial cupula closely matches the biological cupula (10–100 Pa). A comparative experimental study conducted to evaluate the sensitivities of the naked hair cell sensor and the cupula-dressed sensor in sensing steady-state flows demonstrated a sensitivity enhancement by 3.5–5 times due to the presence of hydrogel cupula. The novel strategies of sensor development presented in this report are applicable to the design and fabrication of other biomimetic sensors as well. The developed sensors can be used in the navigation and maneuvering of underwater robots, but can also find applications in biomedical and microfluidic devices. PMID:26763299

  18. Nanofibril scaffold assisted MEMS artificial hydrogel neuromasts for enhanced sensitivity flow sensing

    NASA Astrophysics Data System (ADS)

    Kottapalli, Ajay Giri Prakash; Bora, Meghali; Asadnia, Mohsen; Miao, Jianmin; Venkatraman, Subbu S.; Triantafyllou, Michael

    2016-01-01

    We present the development and testing of superficial neuromast-inspired flow sensors that also attain high sensitivity and resolution through a biomimetic hyaulronic acid-based hydrogel cupula dressing. The inspiration comes from the spatially distributed neuromasts of the blind cavefish that live in completely dark undersea caves; the sensors enable the fish to form three-dimensional flow and object maps, enabling them to maneuver efficiently in cluttered environments. A canopy shaped electrospun nanofibril scaffold, inspired by the cupular fibrils, assists the drop-casting process allowing the formation of a prolate spheroid-shaped artificial cupula. Rheological and nanoindentation characterizations showed that the Young’s modulus of the artificial cupula closely matches the biological cupula (10–100 Pa). A comparative experimental study conducted to evaluate the sensitivities of the naked hair cell sensor and the cupula-dressed sensor in sensing steady-state flows demonstrated a sensitivity enhancement by 3.5–5 times due to the presence of hydrogel cupula. The novel strategies of sensor development presented in this report are applicable to the design and fabrication of other biomimetic sensors as well. The developed sensors can be used in the navigation and maneuvering of underwater robots, but can also find applications in biomedical and microfluidic devices.

  19. Heidegger and artificial intelligence

    SciTech Connect

    Diaz, G.

    1987-01-01

    The discipline of Artificial Intelligence, in its quest for machine intelligence, showed great promise as long as its areas of application were limited to problems of a scientific and situation neutral nature. The attempts to move beyond these problems to a full simulation of man's intelligence has faltered and slowed it progress, largely because of the inability of Artificial Intelligence to deal with human characteristic, such as feelings, goals, and desires. This dissertation takes the position that an impasse has resulted because Artificial Intelligence has never been properly defined as a science: its objects and methods have never been identified. The following study undertakes to provide such a definition, i.e., the required ground for Artificial Intelligence. The procedure and methods employed in this study are based on Heidegger's philosophy and techniques of analysis as developed in Being and Time. Results of this study show that both the discipline of Artificial Intelligence and the concerns of Heidegger in Being and Time have the same object; fundamental ontology. The application of Heidegger's conclusions concerning fundamental ontology unites the various aspects of Artificial Intelligence and provides the articulation which shows the parts of this discipline and how they are related.

  20. Biomimetic shark skin: design, fabrication and hydrodynamic function.

    PubMed

    Wen, Li; Weaver, James C; Lauder, George V

    2014-05-15

    Although the functional properties of shark skin have been of considerable interest to both biologists and engineers because of the complex hydrodynamic effects of surface roughness, no study to date has successfully fabricated a flexible biomimetic shark skin that allows detailed study of hydrodynamic function. We present the first study of the design, fabrication and hydrodynamic testing of a synthetic, flexible, shark skin membrane. A three-dimensional (3D) model of shark skin denticles was constructed using micro-CT imaging of the skin of the shortfin mako (Isurus oxyrinchus). Using 3D printing, thousands of rigid synthetic shark denticles were placed on flexible membranes in a controlled, linear-arrayed pattern. This flexible 3D printed shark skin model was then tested in water using a robotic flapping device that allowed us to either hold the models in a stationary position or move them dynamically at their self-propelled swimming speed. Compared with a smooth control model without denticles, the 3D printed shark skin showed increased swimming speed with reduced energy consumption under certain motion programs. For example, at a heave frequency of 1.5 Hz and an amplitude of ± 1 cm, swimming speed increased by 6.6% and the energy cost-of-transport was reduced by 5.9%. In addition, a leading-edge vortex with greater vorticity than the smooth control was generated by the 3D printed shark skin, which may explain the increased swimming speeds. The ability to fabricate synthetic biomimetic shark skin opens up a wide array of possible manipulations of surface roughness parameters, and the ability to examine the hydrodynamic consequences of diverse skin denticle shapes present in different shark species.

  1. Nanoengineering neural stem cells on biomimetic substrates using magnetofection technology.

    PubMed

    Adams, Christopher F; Dickson, Andrew W; Kuiper, Jan-Herman; Chari, Divya M

    2016-10-20

    Tissue engineering studies are witnessing a major paradigm shift to cell culture on biomimetic materials that replicate native tissue features from which the cells are derived. Few studies have been performed in this regard for neural cells, particularly in nanomedicine. For example, platforms such as magnetic nanoparticles (MNPs) have proven efficient as multifunctional tools for cell tracking and genetic engineering of neural transplant populations. However, as far as we are aware, all current studies have been conducted using neural cells propagated on non-neuromimetic substrates that fail to represent the mechano-elastic properties of brain and spinal cord microenvironments. Accordingly, it can be predicted that such data is of less translational and physiological relevance than that derived from cells grown in neuromimetic environments. Therefore, we have performed the first test of magnetofection technology (enhancing MNP delivery using applied magnetic fields with significant potential for therapeutic application) and its utility in genetically engineering neural stem cells (NSCs; a population of high clinical relevance) propagated in biomimetic hydrogels. We demonstrate magnetic field application safely enhances MNP mediated transfection of NSCs grown as 3D spheroid structures in collagen which more closely replicates the intrinsic mechanical and structural properties of neural tissue than routinely used hard substrates. Further, as it is well known that MNP uptake is mediated by endocytosis we also investigated NSC membrane activity grown on both soft and hard substrates. Using high resolution scanning electron microscopy we were able to prove that NSCs display lower levels of membrane activity on soft substrates compared to hard, a finding which could have particular impact on MNP mediated engineering strategies of cells propagated in physiologically relevant systems.

  2. Multicompartmentalized polymeric systems: towards biomimetic cellular structure and function.

    PubMed

    Marguet, Maïté; Bonduelle, Colin; Lecommandoux, Sébastien

    2013-01-21

    The cell is certainly one of the most complex and exciting systems in Nature that scientists are still trying to fully understand. Such a challenge pushes material scientists to seek to reproduce its perfection by building biomimetic materials with high-added value and previously unmatched properties. Thanks to their versatility, their robustness and the current state of polymer chemistry science, we believe polymer-based materials to constitute or represent ideal candidates when addressing the challenge of biomimicry, which defines the focus of this review. The first step consists in mimicking the structure of the cell: its inner compartments, the organelles, with a multicompartmentalized structure, and the rest, i.e. the cytoplasm minus the organelles (mainly cytoskeleton/cytosol) with gels or particular solutions (highly concentrated for example) in one compartment, and finally the combination of both. Achieving this first structural step enables us to considerably widen the gap of possibilities in drug delivery systems. Another powerful property of the cell lies in its metabolic function. The second step is therefore to achieve enzymatic reactions in a compartment, as occurs in the organelles, in a highly controlled, selective and efficient manner. We classify the most exciting polymersome nanoreactors reported in our opinion into two different subsections, depending on their very final concept or purpose of design. We also highlight in a thorough table the experimental sections crucial to such work. Finally, after achieving control over these prerequisites, scientists are able to combine them and push the frontiers of biomimicry further: from cell structure mimics towards a controlled biofunctionality. Such a biomimetic approach in material design and the future research it will stimulate, are believed to bring considerable enrichments to the fields of drug delivery, (bio)sensors, (bio)catalysis and (bio)technology.

  3. Biomimetics on seed dispersal: survey and insights for space exploration.

    PubMed

    Pandolfi, Camilla; Izzo, Dario

    2013-06-01

    Seeds provide the vital genetic link and dispersal agent between successive generations of plants. Without seed dispersal as a means of reproduction, many plants would quickly die out. Because plants lack any sort of mobility and remain in the same spot for their entire lives, they rely on seed dispersal to transport their offspring throughout the environment. This can be accomplished either collectively or individually; in any case as seeds ultimately abdicate their movement, they are at the mercy of environmental factors. Thus, seed dispersal strategies are characterized by robustness, adaptability, intelligence (both behavioral and morphological), and mass and energy efficiency (including the ability to utilize environmental sources of energy available): all qualities that advanced engineering systems aim at in general, and in particular those that need to enable complex endeavors such as space exploration. Plants evolved and adapted their strategy according to their environment, and taken together, they enclose many desirable characteristics that a space mission needs to have. Understanding in detail how plants control the development of seeds, fabricate structural components for their dispersal, build molecular machineries to keep seeds dormant up to the right moment and monitor the environment to release them at the right time could provide several solutions impacting current space mission design practices. It can lead to miniaturization, higher integration and packing efficiency, energy efficiency and higher autonomy and robustness. Consequently, there would appear to be good reasons for considering biomimetic solutions from plant kingdom when designing space missions, especially to other celestial bodies, where solid and liquid surfaces, atmosphere, etc constitute and are obviously parallel with the terrestrial environment where plants evolved. In this paper, we review the current state of biomimetics on seed dispersal to improve space mission design.

  4. Molecular biomimetics: GEPI-based biological routes to technology.

    PubMed

    Tamerler, Candan; Khatayevich, Dmitriy; Gungormus, Mustafa; Kacar, Turgay; Oren, E Emre; Hnilova, Marketa; Sarikaya, Mehmet

    2010-01-01

    In nature, the viability of biological systems is sustained via specific interactions among the tens of thousands of proteins, the major building blocks of organisms from the simplest single-celled to the most complex multicellular species. Biomolecule-material interaction is accomplished with molecular specificity and efficiency leading to the formation of controlled structures and functions at all scales of dimensional hierarchy. Through evolution, Mother Nature developed molecular recognition by successive cycles of mutation and selection. Molecular specificity of probe-target interactions, e.g., ligand-receptor, antigen-antibody, is always based on specific peptide molecular recognition. Using biology as a guide, we can now understand, engineer, and control peptide-material interactions and exploit them as a new design tool for novel materials and systems. We adapted the protocols of combinatorially designed peptide libraries, via both cell surface or phage display methods; using these we select short peptides with specificity to a variety of practical materials. These genetically engineered peptides for inorganics (GEPI) are then studied experimentally to establish their binding kinetics and surface stability. The bound peptide structure and conformations are interrogated both experimentally and via modeling, and self-assembly characteristics are tested via atomic force microscopy. We further engineer the peptide binding and assembly characteristics using a computational biomimetics approach where bioinformatics based peptide-sequence similarity analysis is developed to design higher generation function-specific peptides. The molecular biomimetic approach opens up new avenues for the design and utilization of multifunctional molecular systems in a wide-range of applications from tissue engineering, disease diagnostics, and therapeutics to various areas of nanotechnology where integration is required among inorganic, organic and biological materials. Here, we

  5. New family of glutathionyl-biomimetic ligands for affinity chromatography of glutathione-recognising enzymes.

    PubMed

    Melissis, S C; Rigden, D J; Clonis, Y D

    2001-05-11

    Three anthraquinone glutathionyl-biomimetic dye ligands, comprising as terminal biomimetic moiety glutathione analogues (glutathionesulfonic acid, S-methyl-glutathione and glutathione) were synthesised and characterised. The biomimetic ligands were immobilised on agarose gel and the affinity adsorbents, together with a nonbiomimetic adsorbent bearing Cibacron Blue 3GA, were studied for their purifying ability for the glutathione-recognising enzymes, NAD+-dependent formaldehyde dehydrogenase (FaDH) from Candida boidinii, NAD(P)+-dependent glutathione reductase from S. cerevisiae (GSHR) and recombinant maize glutathione S-transferase I (GSTI). All biomimetic adsorbents showed higher purifying ability for the target enzymes compared to the nonbiomimetic adsorbent, thus demonstrating their superior effectiveness as affinity chromatography materials. In particular, the affinity adsorbent comprising as terminal biomimetic moiety glutathionesulfonic acid (BM1), exhibited the highest purifying ability for FaDH and GSTI, whereas, the affinity adsorbent comprising as terminal biomimetic moiety methyl-glutathione (BM2) exhibited the highest purifying ability for GSHR. The BM1 adsorbent was integrated in a facile two-step purification procedure for FaDH. The purified enzyme showed a specific activity equal to 79 U/mg and a single band after sodium dodecylsulfate-polyacrylamide gel electrophoresis analysis. Molecular modelling was employed to visualise the binding of BM1 with FaDH, indicating favourable positioning of the key structural features of the biomimetic dye. The anthraquinone moiety provides the driving force for the correct positioning of the glutathionyl-biomimetic moiety in the binding site. It is located deep in the active site cleft forming many favourable hydrophobic contacts with hydrophobic residues of the enzyme. The positioning of the glutathione-like biomimetic moiety is primarily achieved by the strong ionic interactions with the Zn2+ ion of FaDH and Arg

  6. Efficacy of amelogenin-chitosan hydrogel in biomimetic repair of human enamel in pH-cycling systems

    PubMed Central

    Ruan, Qichao; Liberman, David; Bapat, Rucha; Chandrababu, Karthik Balakrishna; Phark, Jin-Ho; Moradian-Oldak, Janet

    2016-01-01

    Amelogenin-chitosan (CS-AMEL) hydrogel has shown great potential for the prevention, restoration, and treatment of defective enamel. As a step prior to clinical trials, this study aimed to examine the efficacy of CS-AMEL hydrogel in biomimetic repair of human enamel with erosive or caries-like lesions in pH-cycling systems. Two models for enamel defects, erosion and early caries, were addressed in this study. Two pH-cycling systems were designed to simulate the daily cariogenic challenge as well as the nocturnal pH conditions in the oral cavity. After pH cycling and treatment with CS-AMEL hydrogel, a synthetic layer composed of oriented apatite crystals was formed on the eroded enamel surface. CS-AMEL repaired the artificial incipient caries by re-growing oriented crystals and reducing the depth of the lesions by up to 70% in the pH-cycling systems. The results clearly demonstrate that the CS-AMEL hydrogel is effective at the restoration of erosive and carious lesions under pH-cycling conditions. PMID:27331142

  7. Directional, passive liquid transport: the Texas horned lizard as a model for a biomimetic ‘liquid diode’

    PubMed Central

    Comanns, Philipp; Buchberger, Gerda; Buchsbaum, Andreas; Baumgartner, Richard; Kogler, Alexander; Bauer, Siegfried; Baumgartner, Werner

    2015-01-01

    Moisture-harvesting lizards such as the Texas horned lizard (Iguanidae: Phrynosoma cornutum) live in arid regions. Special skin adaptations enable them to access water sources such as moist sand and dew: their skin is capable of collecting and transporting water directionally by means of a capillary system between the scales. This fluid transport is passive, i.e. requires no external energy, and directs water preferentially towards the lizard's snout. We show that this phenomenon is based on geometric principles, namely on a periodic pattern of interconnected half-open capillary channels that narrow and widen. Following a biomimetic approach, we used these principles to develop a technical prototype design. Building upon the Young–Laplace equation, we derived a theoretical model for the local behaviour of the liquid in such capillaries. We present a global model for the penetration velocity validated by experimental data. Artificial surfaces designed in accordance with this model prevent liquid flow in one direction while sustaining it in the other. Such passive directional liquid transport could lead to process improvements and reduction of resources in many technical applications. PMID:26202685

  8. A green approach toward antibody purification: a sustainable biomimetic ligand for direct immobilization on (bio)polymeric supports.

    PubMed

    Barroso, Telma; Lourenço, Anita; Araújo, Marco; Bonifácio, Vasco D B; Roque, Ana C A; Aguiar-Ricardo, Ana

    2013-12-01

    This paper presents a sustainable strategy for improving the capture of antibodies by affinity chromatography. A novel biomimetic ligand (4-((4-chloro-6-(3-hydroxyphenoxy)-1,3,5-triazin-2-yl)oxy)naphthalen-1-ol) (TPN-BM) was synthesized using a greener and simple protocol to overcome solubility limitations associated with ligand 22/8, known as artificial protein A. Furthermore, its subsequent immobilization on chitosan-based monoliths induced by plasma surface activation allowed the design of a fast and efficient chromatographic platform for immunoglobulin G (IgG) purification. The TPN-BM functionalized monoliths exhibited high-binding capacity (160 ± 10 mg IgG per gram of support), and a selective capture of monoclonal antibodies directly from mammalian crude extracts in 85 ± 5% yield and 98% of purity. The synthesis of ligand TPN-BM and the routes followed for monoliths preparation and functionalization were inspired in the green chemistry principles allowing the reduction of processing time, solvents and purification steps involved, turning the integrated system attractive from an economical and chemical point of view.

  9. Chemotaxis of artificial microswimmers in active density waves

    NASA Astrophysics Data System (ADS)

    Geiseler, Alexander; Hänggi, Peter; Marchesoni, Fabio; Mulhern, Colm; Savel'ev, Sergey

    2016-07-01

    Living microorganisms are capable of a tactic response to external stimuli by swimming toward or away from the stimulus source; they do so by adapting their tactic signal transduction pathways to the environment. Their self-motility thus allows them to swim against a traveling tactic wave, whereas a simple fore-rear asymmetry argument would suggest the opposite. Their biomimetic counterpart, the artificial microswimmers, also propel themselves by harvesting kinetic energy from an active medium, but, in contrast, lack the adaptive capacity. Here we investigate the transport of artificial swimmers subject to traveling active waves and show, by means of analytical and numerical methods, that self-propelled particles can actually diffuse in either direction with respect to the wave, depending on its speed and waveform. Moreover, chiral swimmers, which move along spiraling trajectories, may diffuse preferably in a direction perpendicular to the active wave. Such a variety of tactic responses is explained by the modulation of the swimmer's diffusion inside traveling active pulses.

  10. The role played by acid and basic centers in the activity of biomimetic catalysts of the catalase, peroxidase, and monooxidase reactions

    NASA Astrophysics Data System (ADS)

    Magerramov, A. M.; Nagieva, I. T.

    2010-11-01

    The acid-basic centers of heterogeneous carriers of catalase, peroxidase, and monooxigenase biomimetics, in particular, iron protoporphyrin deposited on active or neutral aluminum magnesium silicate, were studied. The catalytic activity of biomimetics was stabilized, which allowed us not only to synthesize fairly effective biomimetics but also to clarify certain details of the mechanism of their action and perform a comparative analysis of the functioning of biomimetics and the corresponding enzymes.

  11. Artificial consciousness, artificial emotions, and autonomous robots.

    PubMed

    Cardon, Alain

    2006-12-01

    Nowadays for robots, the notion of behavior is reduced to a simple factual concept at the level of the movements. On another hand, consciousness is a very cultural concept, founding the main property of human beings, according to themselves. We propose to develop a computable transposition of the consciousness concepts into artificial brains, able to express emotions and consciousness facts. The production of such artificial brains allows the intentional and really adaptive behavior for the autonomous robots. Such a system managing the robot's behavior will be made of two parts: the first one computes and generates, in a constructivist manner, a representation for the robot moving in its environment, and using symbols and concepts. The other part achieves the representation of the previous one using morphologies in a dynamic geometrical way. The robot's body will be seen for itself as the morphologic apprehension of its material substrata. The model goes strictly by the notion of massive multi-agent's organizations with a morphologic control.

  12. Artificial muscles on heat

    NASA Astrophysics Data System (ADS)

    McKay, Thomas G.; Shin, Dong Ki; Percy, Steven; Knight, Chris; McGarry, Scott; Anderson, Iain A.

    2014-03-01

    Many devices and processes produce low grade waste heat. Some of these include combustion engines, electrical circuits, biological processes and industrial processes. To harvest this heat energy thermoelectric devices, using the Seebeck effect, are commonly used. However, these devices have limitations in efficiency, and usable voltage. This paper investigates the viability of a Stirling engine coupled to an artificial muscle energy harvester to efficiently convert heat energy into electrical energy. The results present the testing of the prototype generator which produced 200 μW when operating at 75°C. Pathways for improved performance are discussed which include optimising the electronic control of the artificial muscle, adjusting the mechanical properties of the artificial muscle to work optimally with the remainder of the system, good sealing, and tuning the resonance of the displacer to minimise the power required to drive it.

  13. Artificial vision workbench.

    PubMed

    Frenger, P

    1997-01-01

    Machine vision is an important component of medical systems engineering. Inexpensive miniature solid state cameras are now available. This paper describes how these devices can be used as artificial retinas, to take snapshots and moving pictures in monochrome or color. Used in pairs, they produce a stereoscopic field of vision and enable depth perception. Macular and peripheral vision can be simulated electronically. This paper also presents the author's design of an artificial orbit for this synthetic eye. The orbit supports the eye, protects it, and provides attachment points for the ocular motion control system. Convergence and image fusion can be produced, and saccades simulated, along with the other ocular motions. The use of lenses, filters, irises and focusing mechanisms are also discussed. Typical camera-computer interfaces are described, including the use of "frame grabbers" and analog-to-digital image conversion. Software programs for eye positioning, image manipulation, feature extraction and object recognition are discussed, including the application of artificial neural networks.

  14. Artificial intelligence in nanotechnology.

    PubMed

    Sacha, G M; Varona, P

    2013-11-15

    During the last decade there has been increasing use of artificial intelligence tools in nanotechnology research. In this paper we review some of these efforts in the context of interpreting scanning probe microscopy, the study of biological nanosystems, the classification of material properties at the nanoscale, theoretical approaches and simulations in nanoscience, and generally in the design of nanodevices. Current trends and future perspectives in the development of nanocomputing hardware that can boost artificial-intelligence-based applications are also discussed. Convergence between artificial intelligence and nanotechnology can shape the path for many technological developments in the field of information sciences that will rely on new computer architectures and data representations, hybrid technologies that use biological entities and nanotechnological devices, bioengineering, neuroscience and a large variety of related disciplines.

  15. Artificial recharge of groundwater

    SciTech Connect

    Asano, T.

    1985-01-01

    The vast underground reservoirs formed by aquifers constitute invaluable water supply sources as well as water storage facilities. Because natural replenishment of the supply occurs very slowly, continued excessive exploitation of it causes groundwater levels to decline with time. If not corrected this leads to an eventual depletion of a valuable natural resource. To prevent mining and groundwater pollution, the artificial recharge of groundwater basins is becoming increasingly important in groundwater management as a way to increase this natural supply of water. Artificial recharge can reduce, stop, and even reverse declining levels of groundwater. In addition, it can protect underground freshwater in coastal aquifers against salt-water intrusion from the ocean, and can be used to store surface and reclaimed water for future use. This book is a treatise of the artificial recharge of groundwater, with particular emphasis on recharge with reclaimed municipal wastewater.

  16. Artificial intelligence in nanotechnology

    NASA Astrophysics Data System (ADS)

    Sacha, G. M.; Varona, P.

    2013-11-01

    During the last decade there has been increasing use of artificial intelligence tools in nanotechnology research. In this paper we review some of these efforts in the context of interpreting scanning probe microscopy, the study of biological nanosystems, the classification of material properties at the nanoscale, theoretical approaches and simulations in nanoscience, and generally in the design of nanodevices. Current trends and future perspectives in the development of nanocomputing hardware that can boost artificial-intelligence-based applications are also discussed. Convergence between artificial intelligence and nanotechnology can shape the path for many technological developments in the field of information sciences that will rely on new computer architectures and data representations, hybrid technologies that use biological entities and nanotechnological devices, bioengineering, neuroscience and a large variety of related disciplines.

  17. Characterization of crosslinked artificial protein films

    NASA Astrophysics Data System (ADS)

    Nowatzki, Paul

    Genetically engineered artificial proteins are promising candidates for new biomaterials because their amino acid sequences can be precisely controlled. This work describes the characterization of crosslinked films of biomimetic artificial extracellular matrix (aECM) proteins with hybrid functions designed to meet materials needs in applications such as small diameter vascular grafts and corneal tissue implants. Elastin-derived polypeptides give the proteins flexibility, while RGD and CS5 peptide domains from fibronectin serve to adhere cells. Techniques were sought to crosslink aECM proteins in ways that resulted in tunable mechanical properties. Hexamethylene diisocyanate was used to crosslink aECM proteins into uniform, transparent, highly-extensible hydrogel films with low water contents characteristic of native elastin. Their elastic moduli, 0.1--1.1 MPa, depended on crosslinker concentration and aECM protein length, and spanned the observed range of elastin fibers. The suitability of biomaterials implants depends strongly on their susceptibility to proteolytic degradation in vivo. It was shown that small sequence changes in the elastin-like portion of aECM proteins were sufficient to decrease their rate of degradation by elastase sevenfold, illustrating a simple method to tune the protease sensitivity of designed proteins. The effects were seen in both soluble proteins and crosslinked films analyzed by measuring their decrease in elastic modulus during degradation. An aECM protein was examined for its effectiveness as a corneal onlay, i.e., a permanent contact lens. The protein was crosslinked into transparent, elastic, water-rich lenses and was implanted into rabbit corneas. The onlays were stable and well-tolerated, and full re-epithelialization occurred within 4-7 days. Histological examination revealed normal regenerating epithelial cell morphology on the anterior surface, good interfaces between the onlay and surrounding tissue, and only minimal

  18. Electroactive biomimetic collagen-silver nanowire composite scaffolds

    NASA Astrophysics Data System (ADS)

    Wickham, Abeni; Vagin, Mikhail; Khalaf, Hazem; Bertazzo, Sergio; Hodder, Peter; Dånmark, Staffan; Bengtsson, Torbjörn; Altimiras, Jordi; Aili, Daniel

    2016-07-01

    Electroactive biomaterials are widely explored as bioelectrodes and as scaffolds for neural and cardiac regeneration. Most electrodes and conductive scaffolds for tissue regeneration are based on synthetic materials that have limited biocompatibility and often display large discrepancies in mechanical properties with the surrounding tissue causing problems during tissue integration and regeneration. This work shows the development of a biomimetic nanocomposite material prepared from self-assembled collagen fibrils and silver nanowires (AgNW). Despite consisting of mostly type I collagen fibrils, the homogeneously embedded AgNWs provide these materials with a charge storage capacity of about 2.3 mC cm-2 and a charge injection capacity of 0.3 mC cm-2, which is on par with bioelectrodes used in the clinic. The mechanical properties of the materials are similar to soft tissues with a dynamic elastic modulus within the lower kPa range. The nanocomposites also support proliferation of embryonic cardiomyocytes while inhibiting the growth of both Gram-negative Escherichia coli and Gram-positive Staphylococcus epidermidis. The developed collagen/AgNW composites thus represent a highly attractive bioelectrode and scaffold material for a wide range of biomedical applications.Electroactive biomaterials are widely explored as bioelectrodes and as scaffolds for neural and cardiac regeneration. Most electrodes and conductive scaffolds for tissue regeneration are based on synthetic materials that have limited biocompatibility and often display large discrepancies in mechanical properties with the surrounding tissue causing problems during tissue integration and regeneration. This work shows the development of a biomimetic nanocomposite material prepared from self-assembled collagen fibrils and silver nanowires (AgNW). Despite consisting of mostly type I collagen fibrils, the homogeneously embedded AgNWs provide these materials with a charge storage capacity of about 2.3 mC cm-2

  19. Plant Surfaces: Structures and Functions for Biomimetic Innovations

    NASA Astrophysics Data System (ADS)

    Barthlott, Wilhelm; Mail, Matthias; Bhushan, Bharat; Koch, Kerstin

    2017-04-01

    An overview of plant surface structures and their evolution is presented. It combines surface chemistry and architecture with their functions and refers to possible biomimetic applications. Within some 3.5 billion years biological species evolved highly complex multifunctional surfaces for interacting with their environments: some 10 million living prototypes (i.e., estimated number of existing plants and animals) for engineers. The complexity of the hierarchical structures and their functionality in biological organisms surpasses all abiotic natural surfaces: even superhydrophobicity is restricted in nature to living organisms and was probably a key evolutionary step with the invasion of terrestrial habitats some 350-450 million years ago in plants and insects. Special attention should be paid to the fact that global environmental change implies a dramatic loss of species and with it the biological role models. Plants, the dominating group of organisms on our planet, are sessile organisms with large multifunctional surfaces and thus exhibit particular intriguing features. Superhydrophilicity and superhydrophobicity are focal points in this work. We estimate that superhydrophobic plant leaves (e.g., grasses) comprise in total an area of around 250 million km2, which is about 50% of the total surface of our planet. A survey of structures and functions based on own examinations of almost 20,000 species is provided, for further references we refer to Barthlott et al. (Philos. Trans. R. Soc. A 374: 20160191, 1). A basic difference exists between aquatic non-vascular and land-living vascular plants; the latter exhibit a particular intriguing surface chemistry and architecture. The diversity of features is described in detail according to their hierarchical structural order. The first underlying and essential feature is the polymer cuticle superimposed by epicuticular wax and the curvature of single cells up to complex multicellular structures. A descriptive terminology

  20. Biomimetic/Optical Sensors for Detecting Bacterial Species

    NASA Technical Reports Server (NTRS)

    Homer, Margie; Ksendzov, Alexander; Yen, Shiao-Pin; Ryan, Margaret; Lazazzera, Beth

    2006-01-01

    Biomimetic/optical sensors have been proposed as means of real-time detection of bacteria in liquid samples through real-time detection of compounds secreted by the bacteria. Bacterial species of interest would be identified through detection of signaling compounds unique to those species. The best-characterized examples of quorum-signaling compounds are acyl-homoserine lactones and peptides. Each compound, secreted by each bacterium of an affected species, serves as a signal to other bacteria of the same species to engage in a collective behavior when the population density of that species reaches a threshold level analogous to a quorum. A sensor according to the proposal would include a specially formulated biomimetic film, made of a molecularly imprinted polymer (MIP), that would respond optically to the signaling compound of interest. The MIP film would be integrated directly onto an opticalwaveguide- based ring resonator for optical readout. Optically, the sensor would resemble the one described in Chemical Sensors Based on Optical Ring Resonators (NPO-40601), NASA Tech Briefs, Vol. 29, No. 10 (October 2005), page 32. MIPs have been used before as molecular- recognition compounds, though not in the manner of the present proposal. Molecular imprinting is an approach to making molecularly selective cavities in a polymer matrix. These cavities function much as enzyme receptor sites: the chemical functionality and shape of a cavity in the polymer matrix cause the cavity to bind to specific molecules. An MIP matrix is made by polymerizing monomers in the presence of the compound of interest (template molecule). The polymer forms around the template. After the polymer solidifies, the template molecules are removed from the polymer matrix by decomplexing them from their binding sites and then dissolving them, leaving cavities that are matched to the template molecules in size, shape, and chemical functionality. The cavities thus become molecular-recognition sites

  1. Biomimetic materials processing: Implementation of molecular imprinting and study of biomineralization through the development of an agarose gel assay

    NASA Astrophysics Data System (ADS)

    Boggavarapu, Sajiv

    Biomimetics is defined as an approach in which naturally occurring materials processes are mimicked in laboratory situations. The ultimate goal is to develop synthetic analogues of naturally occurring materials such as bone and teeth, classified as biocomposites, which possess similar chemical and mechanical properties. The work presented here provides the initial work in furthering the progress of biomimetic materials processing. The first element of the work utilizes molecular imprinting as a selective recognition, or sensing tool, for detection of low molecular weight organic molecules. Molecular imprinting is a phenomenon in which crosslinked synthetic polymers exhibit selective binding towards small organic molecules. Initial work in the field was done in which numerous processing steps were involved with bulk polymer samples while the achievement here lies in the development of molecular imprinted polymer films which greatly facilitate the processing and characterization. Molecularly imprinted polymers are sometimes referred to as artificial antibodies due to the selective binding aspects that are highly analogous to natural antibodies. Additional work involves transforming the recognition aspects of molecular imprinting into a biomineralization analogue. Biomineralization is the process in which organisms convert freely soluble minerals (namely calcium carbonates and calcium phosphates) into solid parts, such as bones and teeth, at ambient conditions via the influence of organic molecules such as proteins and carbohydrates. The molecular imprinting approach with biomineralization led to limited success but formed the foundation for a more detailed study into the effects of small organic functional groups (COOH-, OH-) on the growth of calcium carbonates and calcium phosphates, the core components of important biocomposites such as bone. In order to study the effects of organic molecules on the calcium based crystals, a mineralization assay was developed in an

  2. Recent advances in crosslinking chemistry of biomimetic poly(ethylene glycol) hydrogels

    PubMed Central

    Lin, Chien-Chi

    2015-01-01

    The design and application of biomimetic hydrogels have become an important and integral part of modern tissue engineering and regenerative medicine. Many of these hydrogels are prepared from synthetic macromers (e.g., poly(ethylene glycol) or PEG) as they provide high degrees of tunability for matrix crosslinking, degradation, and modification. For a hydrogel to be considered biomimetic, it has to recapitulate key features that are found in the native extracellular matrix, such as the appropriate matrix mechanics and permeability, the ability to sequester and deliver drugs, proteins, and or nucleic acids, as well as the ability to provide receptor-mediated cell-matrix interactions and protease-mediated matrix cleavage. A variety of chemistries have been employed to impart these biomimetic features into hydrogel crosslinking. These chemistries, such as radical-mediated polymerizations, enzyme-mediated crosslinking, bio-orthogonal click reactions, and supramolecular assembly, may be different in their crosslinking mechanisms but are required to be efficient for gel crosslinking and ligand bioconjugation under aqueous reaction conditions. The prepared biomimetic hydrogels should display a diverse array of functionalities and should also be cytocompatible for in vitro cell culture and/or in situ cell encapsulation. The focus of this article is to review recent progress in the crosslinking chemistries of biomimetic hydrogels with a special emphasis on hydrogels crosslinked from poly(ethylene glycol)-based macromers. PMID:26029357

  3. Enzyme-functionalized biomimetic apatites: concept and perspectives in view of innovative medical approaches.

    PubMed

    Weber, Christina G; Mueller, Michaela; Vandecandelaere, Nicolas; Trick, Iris; Burger-Kentischer, Anke; Maucher, Tanja; Drouet, Christophe

    2014-03-01

    Biomimetic nanocrystalline calcium-deficient apatite compounds are particularly attractive for the setup of bioactive bone-repair scaffolds due to their high similarity to bone mineral in terms of chemical composition, structural and substructural features. As such, along with the increasingly appealing development of moderate temperature engineered routes for sample processing, they have widened the armamentarium of orthopedic and maxillofacial surgeons in the field of bone tissue engineering. This was made possible by exploiting the exceptional surface reactivity of biomimetic apatite nanocrystals, capable of easily exchanging ions or adsorbing (bio)molecules, thus leading to highly-versatile drug delivery systems. In this contribution we focus on the preparation of hybrid materials combining biomimetic nanocrystalline apatites and enzymes (lysozyme and subtilisin). This paper reports physico-chemical data as well as cytotoxicity evaluations towards Cal-72 osteoblast-like cells and finally antimicrobial assessments towards selected strains of interest in bone surgery. Biomimetic apatite/enzyme hybrids could be prepared in varying buffers. They were found to be non-cytotoxic toward osteoblastic cells and the enzymes retained their biological activity (e.g. bond cleavage or antibacterial properties) despite the immobilization and drying processes. Release properties were also examined. Beyond these illustrative examples, the concept of biomimetic apatites functionalized with enzymes is thus shown to be useable in practice, e.g. for antimicrobial purposes, thus widening possible therapeutic perspectives.

  4. Numerical study on reduction of aerodynamic noise around an airfoil with biomimetic structures

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Zhang, Chengchun; Wu, Zhengyang; Wharton, James; Ren, Luquan

    2017-04-01

    A biomimetic airfoil featuring leading edge waves, trailing edge serrations and surface ridges is proposed in this study, based on flow control with each section meeting the NACA 0012 airfoil profile. Numerical simulations have been conducted to compare aerodynamic and acoustic performances between the NACA 0012 and biomimetic airfoils. These simulations utilize the large eddy simulation (LES) method and aeroacoustic analogy at an angle of attack of 0° and a Reynolds number of 1.0×105, based on using the airfoil chord as the characteristic length. The simulation results reveal the overall sound pressure levels (OASPLs) for all frequencies and at the seven observer points around the biomimetic airfoil, and a decrease of 13.1-13.9 dB is observed, whereas the drag coefficient is almost unchanged. The biomimetic structures can transform the shedding vortices in laminar mode for the NACA 0012 airfoil to regular horseshoe-type vortices in the wake, and reduce the spanwise correlation of the large-scale vortices, thereby restrain the vortex shedding noise around the biomimetic airfoil.

  5. Artificial Gravity Research Plan

    NASA Technical Reports Server (NTRS)

    Cromwell, Ronita

    2014-01-01

    This document describes the forward working plan to identify what countermeasure resources are needed for a vehicle with an artificial gravity module (intermittent centrifugation) and what Countermeasure Resources are needed for a rotating transit vehicle (continuous centrifugation) to minimize the effects of microgravity to Mars Exploration crewmembers.

  6. Artificial Intelligence Study (AIS).

    DTIC Science & Technology

    1987-02-01

    ARTIFICIAL INTELLIGNECE HARDWARE ....... 2-50 AI Architecture ................................... 2-49 AI Hardware ....................................... 2...Epstein (1986) has suggested that this version of PROLOG has been used for business and industrial applications in Eastern Europe. The Japanese have...have been in building expert systems in the business analysis area. Expert systems for policy and rate selection for insurance (i.e., risk analysis) and

  7. Artificial intelligence and robotics

    SciTech Connect

    Peden, I.C.; Braddock, J.V.; Brown, W.; Langendorf, R.M.

    1982-09-01

    This report examines the state-of-the-art in artificial intelligence and robotics technologies and their potential in terms of Army needs. Assessment includes battlefield technology, research and technology insertions, management considerations and recommendations related to research and development personnel, and recommendations regarding the Army's involvement in the automated plant.

  8. Artificial intelligence. Second edition

    SciTech Connect

    Winston, P.H.

    1984-01-01

    This book introduces the basic concepts of the field of artificial intelligence. It contains material covering the latest advances in control, representation, language, vision, and problem solving. Problem solving in design and analysis systems is addressed. Mitcell's version-space learning procedure, Morevec's reduced-images stereo procedure, and the Strips problem solver are covered.

  9. Artificial Intelligence and CALL.

    ERIC Educational Resources Information Center

    Underwood, John H.

    The potential application of artificial intelligence (AI) to computer-assisted language learning (CALL) is explored. Two areas of AI that hold particular interest to those who deal with language meaning--knowledge representation and expert systems, and natural-language processing--are described and examples of each are presented. AI contribution…

  10. Terahertz Artificial Dielectric Lens

    NASA Astrophysics Data System (ADS)

    Mendis, Rajind; Nagai, Masaya; Wang, Yiqiu; Karl, Nicholas; Mittleman, Daniel M.

    2016-03-01

    We have designed, fabricated, and experimentally characterized a lens for the THz regime based on artificial dielectrics. These are man-made media that mimic properties of naturally occurring dielectric media, or even manifest properties that cannot generally occur in nature. For example, the well-known dielectric property, the refractive index, which usually has a value greater than unity, can have a value less than unity in an artificial dielectric. For our lens, the artificial-dielectric medium is made up of a parallel stack of 100 μm thick metal plates that form an array of parallel-plate waveguides. The convergent lens has a plano-concave geometry, in contrast to conventional dielectric lenses. Our results demonstrate that this lens is capable of focusing a 2 cm diameter beam to a spot size of 4 mm, at the design frequency of 0.17 THz. The results further demonstrate that the overall power transmission of the lens can be better than certain conventional dielectric lenses commonly used in the THz regime. Intriguingly, we also observe that under certain conditions, the lens boundary demarcated by the discontinuous plate edges actually resembles a smooth continuous surface. These results highlight the importance of this artificial-dielectric technology for the development of future THz-wave devices.

  11. Artificial Intelligence Project

    DTIC Science & Technology

    1990-01-01

    Computer Science, New Delhi, India , December 1986. (Also University of Texas, Artificial Intelligence Laboratory AITR-41, August 1987). Kumar, V. and...the Tenth ICAI ) A187-55 Expert Systems for Monitoring and Control, D. Dvorak, May 1987. Many large-scale industrial processes and services are

  12. Artificial intelligence and psychiatry.

    PubMed

    Servan-Schreiber, D

    1986-04-01

    This paper provides a brief historical introduction to the new field of artificial intelligence and describes some applications to psychiatry. It focuses on two successful programs: a model of paranoid processes and an expert system for the pharmacological management of depressive disorders. Finally, it reviews evidence in favor of computerized psychotherapy and offers speculations on the future development of research in this area.

  13. Artificial limb connection

    NASA Technical Reports Server (NTRS)

    Owens, L. J.

    1974-01-01

    Connection simplifies and eases donning and removing artificial limb; eliminates harnesses and clamps; and reduces skin pressures by allowing bone to carry all tensile and part of compressive loads between prosthesis and stump. Because connection is modular, it is easily modified to suit individual needs.

  14. Micromachined Artificial Haircell

    NASA Technical Reports Server (NTRS)

    Liu, Chang (Inventor); Engel, Jonathan (Inventor); Chen, Nannan (Inventor); Chen, Jack (Inventor)

    2010-01-01

    A micromachined artificial sensor comprises a support coupled to and movable with respect to a substrate. A polymer, high-aspect ratio cilia-like structure is disposed on and extends out-of-plane from the support. A strain detector is disposed with respect to the support to detect movement of the support.

  15. Artificial intelligence within AFSC

    NASA Technical Reports Server (NTRS)

    Gersh, Mark A.

    1990-01-01

    Information on artificial intelligence research in the Air Force Systems Command is given in viewgraph form. Specific research that is being conducted at the Rome Air Development Center, the Space Technology Center, the Human Resources Laboratory, the Armstrong Aerospace Medical Research Laboratory, the Armamant Laboratory, and the Wright Research and Development Center is noted.

  16. Principles of Calcite Dissolution in Human and Artificial Otoconia

    PubMed Central

    Walther, Leif Erik; Blödow, Alexander; Buder, Jana; Kniep, Rüdiger

    2014-01-01

    Human otoconia provide mechanical stimuli to deflect hair cells of the vestibular sensory epithelium for purposes of detecting linear acceleration and head tilts. During lifetime, the volume and number of otoconia are gradually reduced. In a process of degeneration morphological changes occur. Structural changes in human otoconia are assumed to cause vertigo and balance disorders such as benign paroxysmal positional vertigo (BPPV). The aim of this study was to investigate the main principles of morphological changes in human otoconia in dissolution experiments by exposure to hydrochloric acid, EDTA, demineralized water and completely purified water respectively. For comparison reasons artificial (biomimetic) otoconia (calcite gelatin nanocomposits) and natural calcite were used. Morphological changes were detected in time steps by the use of environmental scanning electron microscopy (ESEM). Under in vitro conditions three main dissolution mechanisms were identified as causing characteristic morphological changes of the specimen under consideration: pH drops in the acidic range, complex formation with calcium ions and changes of ion concentrations in the vicinity of otoconia. Shifts in pH cause a more uniform reduction of otoconia size (isotropic dissolution) whereas complexation reactions and changes of the ionic concentrations within the surrounding medium bring about preferred attacks at specific areas (anisotropic dissolution) of human and artificial otoconia. Owing to successive reduction of material, all the dissolution mechanisms finally produce fragments and remnants of otoconia. It can be assumed that the organic component of otoconia is not significantly attacked under the given conditions. Artificial otoconia serve as a suitable model system mimicking chemical attacks on biogenic specimens. The underlying principles of calcite dissolution under in vitro conditions may play a role in otoconia degeneration processes such as BPPV. PMID:25048115

  17. Researchers Create Artificial Mouse 'Embryo'

    MedlinePlus

    ... news/fullstory_163881.html Researchers Create Artificial Mouse 'Embryo' Experiment used two types of gene-modified stem ... they've created a kind of artificial mouse embryo using stem cells, which can be coaxed to ...

  18. A synthetic leaf: the biomimetic potential of graphene oxide

    NASA Astrophysics Data System (ADS)

    Lamb, Marilla; Koch, George W.; Morgan, Eric R.; Shafer, Michael W.

    2015-03-01

    Emerging materials such as graphene oxide (GO) have micro and nano features that are functionally similar to those in plant cell walls involved in water transport. Therefore, it may now be possible to design and build biomimetic trees to lift water via mechanisms similar to those employed by trees, allowing for potential applications such as passive water pumping, filtering, and evaporative cooling. The tallest trees can raise large volumes of water to over 100 meters using only the vapor pressure gradient between their leaves and the atmosphere. This phenomenon occurs in all terrestrial plants when capillary forces generated in the microscopic pores in the cell walls of leaves are collectively applied to large diameter xylem conduits. The design of a synthetic tree that mimics these mechanisms will allow water to be moved to heights greater than is currently possible by any engineered system that does not require the use of a positive pressure pump. We are testing the suitability of membranous GO as the leaf of a synthetic tree and present an analysis in support of this design. In addition, we include results from a preliminary design using ceramics.

  19. Mechanics of tunable helices and geometric frustration in biomimetic seashells

    NASA Astrophysics Data System (ADS)

    Guo, Qiaohang; Chen, Zi; Li, Wei; Dai, Pinqiang; Ren, Kun; Lin, Junjie; Taber, Larry A.; Chen, Wenzhe

    2014-03-01

    Helical structures are ubiquitous in nature and engineering, ranging from DNA molecules to plant tendrils, from sea snail shells to nanoribbons. While the helical shapes in natural and engineered systems often exhibit nearly uniform radius and pitch, helical shell structures with changing radius and pitch, such as seashells and some plant tendrils, add to the variety of this family of aesthetic beauty. Here we develop a comprehensive theoretical framework for tunable helical morphologies, and report the first biomimetic seashell-like structure resulting from mechanics of geometric frustration. In previous studies, the total potential energy is everywhere minimized when the system achieves equilibrium. In this work, however, the local energy minimization cannot be realized because of the geometric incompatibility, and hence the whole system deforms into a shape with a global energy minimum whereby the energy in each segment may not necessarily be locally optimized. This novel approach can be applied to develop materials and devices of tunable geometries with a range of applications in nano/biotechnology.

  20. Biomimetic 3D tissue printing for soft tissue regeneration.

    PubMed

    Pati, Falguni; Ha, Dong-Heon; Jang, Jinah; Han, Hyun Ho; Rhie, Jong-Won; Cho, Dong-Woo

    2015-09-01

    Engineered adipose tissue constructs that are capable of reconstructing soft tissue with adequate volume would be worthwhile in plastic and reconstructive surgery. Tissue printing offers the possibility of fabricating anatomically relevant tissue constructs by delivering suitable matrix materials and living cells. Here, we devise a biomimetic approach for printing adipose tissue constructs employing decellularized adipose tissue (DAT) matrix bioink encapsulating human adipose tissue-derived mesenchymal stem cells (hASCs). We designed and printed precisely-defined and flexible dome-shaped structures with engineered porosity using DAT bioink that facilitated high cell viability over 2 weeks and induced expression of standard adipogenic genes without any supplemented adipogenic factors. The printed DAT constructs expressed adipogenic genes more intensely than did non-printed DAT gel. To evaluate the efficacy of our printed tissue constructs for adipose tissue regeneration, we implanted them subcutaneously in mice. The constructs did not induce chronic inflammation or cytotoxicity postimplantation, but supported positive tissue infiltration, constructive tissue remodeling, and adipose tissue formation. This study demonstrates that direct printing of spatially on-demand customized tissue analogs is a promising approach to soft tissue regeneration.

  1. Biomimetic smart sensors for autonomous robotic behavior II: vestibular processing

    NASA Astrophysics Data System (ADS)

    Xue, Shuwan; Deligeorges, Socrates; Soloway, Aaron; Lichtenstein, Lee; Gore, Tyler; Hubbard, Allyn

    2009-05-01

    Limited autonomous behaviors are fast becoming a critical capability in the field of robotics as robotic applications are used in more complicated and interactive environments. As additional sensory capabilities are added to robotic platforms, sensor fusion to enhance and facilitate autonomous behavior becomes increasingly important. Using biology as a model, the equivalent of a vestibular system needs to be created in order to orient the system within its environment and allow multi-modal sensor fusion. In mammals, the vestibular system plays a central role in physiological homeostasis and sensory information integration (Fuller et al, Neuroscience 129 (2004) 461-471). At the level of the Superior Colliculus in the brain, there is multimodal sensory integration across visual, auditory, somatosensory, and vestibular inputs (Wallace et al, J Neurophysiol 80 (1998) 1006-1010), with the vestibular component contributing a strong reference frame gating input. Using a simple model for the deep layers of the Superior Colliculus, an off-the-shelf 3-axis solid state gyroscope and accelerometer was used as the equivalent representation of the vestibular system. The acceleration and rotational measurements are used to determine the relationship between a local reference frame of a robotic platform (an iRobot Packbot®) and the inertial reference frame (the outside world), with the simulated vestibular input tightly coupled with the acoustic and optical inputs. Field testing of the robotic platform using acoustics to cue optical sensors coupled through a biomimetic vestibular model for "slew to cue" gunfire detection have shown great promise.

  2. Role of magnesium on the biomimetic deposition of calcium phosphate

    NASA Astrophysics Data System (ADS)

    Sarma, Bimal K.; Sarma, Bikash

    2016-10-01

    Biomimetic depositions of calcium phosphate (CaP) are carried out using simulated body fluid (SBF), calcifying solution and newly developed magnesium containing calcifying solution. Calcium phosphate has a rich phase diagram and is well known for its excellent biocompatibility and bioactivity. The most common phase is hydroxyapatite (HAp), an integral component of human bone and tooth, widely used in orthopedic and dental applications. In addition, calcium phosphate nanoparticles show promise for the targeted drug delivery. The doping of calcium phosphate by magnesium, zinc, strontium etc. can change the protein uptake by CaP nanocrystals. This work describes the role of magnesium on the nucleation and growth of CaP on Ti and its oxide substrates. X-ray diffraction studies confirm formation of HAp nanocrystals which closely resemble the structure of bone apatite when grown using SBF and calcifying solution. It has been observed that magnesium plays crucial role in the nucleation and growth of calcium phosphate. A low magnesium level enhances the crystallinity of HAp while higher magnesium content leads to the formation of amorphous calcium phosphate (ACP) phase. Interestingly, the deposition of ACP phase is rapid when magnesium ion concentration in the solution is 40% of calcium plus magnesium ions concentration. Moreover, high magnesium content alters the morphology of CaP films.

  3. Biomimetic Hybrid Feedback Feedforward Neural-Network Learning Control.

    PubMed

    Pan, Yongping; Yu, Haoyong

    2016-03-30

    This brief presents a biomimetic hybrid feedback feedforward neural-network learning control (NNLC) strategy inspired by the human motor learning control mechanism for a class of uncertain nonlinear systems. The control structure includes a proportional-derivative controller acting as a feedback servo machine and a radial-basis-function (RBF) NN acting as a feedforward predictive machine. Under the sufficient constraints on control parameters, the closed-loop system achieves semiglobal practical exponential stability, such that an accurate NN approximation is guaranteed in a local region along recurrent reference traj- ectories. Compared with the existing NNLC methods, the novelties of the proposed method include: 1) the implementation of an adaptive NN control to guarantee plant states being recurrent is not needed, since recurrent reference signals rather than plant states are utilized as NN inputs, which greatly simplifies the analysis and synthesis of the NNLC and 2) the domain of NN approximation can be determined a priori by the given reference signals, which leads to an easy construction of the RBF-NNs. Simulation results have verified the effectiveness of this approach.

  4. Biomimetic and bio-inspired uses of mollusc shells.

    PubMed

    Morris, J P; Wang, Y; Backeljau, T; Chapelle, G

    2016-06-01

    Climate change and ocean acidification are likely to have a profound effect on marine molluscs, which are of great ecological and economic importance. One process particularly sensitive to climate change is the formation of biominerals in mollusc shells. Fundamental research is broadening our understanding of the biomineralization process, as well as providing more informed predictions on the effects of climate change on marine molluscs. Such studies are important in their own right, but their value also extends to applied sciences. Biominerals, organic/inorganic hybrid materials with many remarkable physical and chemical properties, have been studied for decades, and the possibilities for future improved use of such materials for society are widely recognised. This article highlights the potential use of our understanding of the shell biomineralization process in novel bio-inspired and biomimetic applications. It also highlights the potential for the valorisation of shells produced as a by-product of the aquaculture industry. Studying shells and the formation of biominerals will inspire novel functional hybrid materials. It may also provide sustainable, ecologically- and economically-viable solutions to some of the problems created by current human resource exploitation.

  5. Biomimetic surface structuring using cylindrical vector femtosecond laser beams.

    PubMed

    Skoulas, Evangelos; Manousaki, Alexandra; Fotakis, Costas; Stratakis, Emmanuel

    2017-03-22

    We report on a new, single-step and scalable method to fabricate highly ordered, multi-directional and complex surface structures that mimic the unique morphological features of certain species found in nature. Biomimetic surface structuring was realized by exploiting the unique and versatile angular profile and the electric field symmetry of cylindrical vector (CV) femtosecond (fs) laser beams. It is shown that, highly controllable, periodic structures exhibiting sizes at nano-, micro- and dual- micro/nano scales can be directly written on Ni upon line and large area scanning with radial and azimuthal polarization beams. Depending on the irradiation conditions, new complex multi-directional nanostructures, inspired by the Shark's skin morphology, as well as superhydrophobic dual-scale structures mimicking the Lotus' leaf water repellent properties can be attained. It is concluded that the versatility and features variations of structures formed is by far superior to those obtained via laser processing with linearly polarized beams. More important, by exploiting the capabilities offered by fs CV fields, the present technique can be further extended to fabricate even more complex and unconventional structures. We believe that our approach provides a new concept in laser materials processing, which can be further exploited for expanding the breadth and novelty of applications.

  6. Biomimetically enhanced demineralized bone matrix for bone regenerative applications

    PubMed Central

    Ravindran, Sriram; Huang, Chun-Chieh; Gajendrareddy, Praveen; Narayanan, Raghuvaran

    2015-01-01

    Demineralized bone matrix (DBM) is one of the most widely used bone graft materials in dentistry. However, the ability of DBM to reliably and predictably induce bone regeneration has always been a cause for concern. The quality of DBM varies greatly depending on several donor dependent factors and also manufacturing techniques. In order to standardize the quality and to enable reliable and predictable bone regeneration, we have generated a biomimetically-enhanced version of DBM (BE-DBM) using clinical grade commercial DBM as a control. We have generated the BE-DBM by incorporating a cell-derived pro-osteogenic extracellular matrix (ECM) within clinical grade DBM. In the present study, we have characterized the BE-DBM and evaluated its ability to induce osteogenic differentiation of human marrow derived stromal cells (HMSCs) with respect to clinical grade commercial DBM. Our results indicate that the BE-DBM contains significantly more pro-osteogenic factors than DBM and enhances HMSC differentiation and mineralized matrix formation in vitro and in vivo. Based on our results, we envision that the BE-DBM has the potential to replace DBM as the bone graft material of choice. PMID:26557093

  7. Scalable manufacturing of biomimetic moldable hydrogels for industrial applications

    NASA Astrophysics Data System (ADS)

    Yu, Anthony C.; Chen, Haoxuan; Chan, Doreen; Agmon, Gillie; Stapleton, Lyndsay M.; Sevit, Alex M.; Tibbitt, Mark W.; Acosta, Jesse D.; Zhang, Tony; Franzia, Paul W.; Langer, Robert; Appel, Eric A.

    2016-12-01

    Hydrogels are a class of soft material that is exploited in many, often completely disparate, industrial applications, on account of their unique and tunable properties. Advances in soft material design are yielding next-generation moldable hydrogels that address engineering criteria in several industrial settings such as complex viscosity modifiers, hydraulic or injection fluids, and sprayable carriers. Industrial implementation of these viscoelastic materials requires extreme volumes of material, upwards of several hundred million gallons per year. Here, we demonstrate a paradigm for the scalable fabrication of self-assembled moldable hydrogels using rationally engineered, biomimetic polymer–nanoparticle interactions. Cellulose derivatives are linked together by selective adsorption to silica nanoparticles via dynamic and multivalent interactions. We show that the self-assembly process for gel formation is easily scaled in a linear fashion from 0.5 mL to over 15 L without alteration of the mechanical properties of the resultant materials. The facile and scalable preparation of these materials leveraging self-assembly of inexpensive, renewable, and environmentally benign starting materials, coupled with the tunability of their properties, make them amenable to a range of industrial applications. In particular, we demonstrate their utility as injectable materials for pipeline maintenance and product recovery in industrial food manufacturing as well as their use as sprayable carriers for robust application of fire retardants in preventing wildland fires.

  8. Biomimetic antimicrobial cloak by graphene-oxide agar hydrogel.

    PubMed

    Papi, Massimiliano; Palmieri, Valentina; Bugli, Francesca; De Spirito, Marco; Sanguinetti, Maurizio; Ciancico, Carlotta; Braidotti, Maria Chiara; Gentilini, Silvia; Angelani, Luca; Conti, Claudio

    2016-12-01

    Antibacterial surfaces have an enormous economic and social impact on the worldwide technological fight against diseases. However, bacteria develop resistance and coatings are often not uniform and not stable in time. The challenge is finding an antibacterial coating that is biocompatible, cost-effective, not toxic, and spreadable over large and irregular surfaces. Here we demonstrate an antibacterial cloak by laser printing of graphene oxide hydrogels mimicking the Cancer Pagurus carapace. We observe up to 90% reduction of bacteria cells. This cloak exploits natural surface patterns evolved to resist to microorganisms infection, and the antimicrobial efficacy of graphene oxide. Cell integrity analysis by scanning electron microscopy and nucleic acids release show bacteriostatic and bactericidal effect. Nucleic acids release demonstrates microorganism cutting, and microscopy reveals cells wrapped by the laser treated gel. A theoretical active matter model confirms our findings. The employment of biomimetic graphene oxide gels opens unique possibilities to decrease infections in biomedical applications and chirurgical equipment; our antibiotic-free approach, based on the geometric reduction of microbial adhesion and the mechanical action of Graphene Oxide sheets, is potentially not affected by bacterial resistance.

  9. Piezoelectric Templates - New Views on Biomineralization and Biomimetics.

    PubMed

    Stitz, Nina; Eiben, Sabine; Atanasova, Petia; Domingo, Neus; Leineweber, Andreas; Burghard, Zaklina; Bill, Joachim

    2016-05-23

    Biomineralization in general is based on electrostatic interactions and molecular recognition of organic and inorganic phases. These principles of biomineralization have also been utilized and transferred to bio-inspired synthesis of functional materials during the past decades. Proteins involved in both, biomineralization and bio-inspired processes, are often piezoelectric due to their dipolar character hinting to the impact of a template's piezoelectricity on mineralization processes. However, the piezoelectric contribution on the mineralization process and especially the interaction of organic and inorganic phases is hardly considered so far. We herein report the successful use of the intrinsic piezoelectric properties of tobacco mosaic virus (TMV) to synthesize piezoelectric ZnO. Such films show a two-fold increase of the piezoelectric coefficient up to 7.2 pm V(-1) compared to films synthesized on non-piezoelectric templates. By utilizing the intrinsic piezoelectricity of a biotemplate, we thus established a novel synthesis pathway towards functional materials, which sheds light on the whole field of biomimetics. The obtained results are of even broader and general interest since they are providing a new, more comprehensive insight into the mechanisms involved into biomineralization in living nature.

  10. Biomimetic MEMS sensor array for navigation and water detection

    NASA Astrophysics Data System (ADS)

    Futterknecht, Oliver; Macqueen, Mark O.; Karman, Salmah; Diah, S. Zaleha M.; Gebeshuber, Ille C.

    2013-05-01

    The focus of this study is biomimetic concept development for a MEMS sensor array for navigation and water detection. The MEMS sensor array is inspired by abstractions of the respective biological functions: polarized skylight-based navigation sensors in honeybees (Apis mellifera) and the ability of African elephants (Loxodonta africana) to detect water. The focus lies on how to navigate to and how to detect water sources in desert-like or remote areas. The goal is to develop a sensor that can provide both, navigation clues and help in detecting nearby water sources. We basically use the information provided by the natural polarization pattern produced by the sunbeams scattered within the atmosphere combined with the capability of the honeybee's compound eye to extrapolate the navigation information. The detection device uses light beam reactive MEMS, which are capable to detect the skylight polarization based on the Rayleigh sky model. For water detection we present various possible approaches to realize the sensor. In the first approach, polarization is used: moisture saturated areas near ground have a small but distinctively different effect on scattering and polarizing light than less moist ones. Modified skylight polarization sensors (Karman, Diah and Gebeshuber, 2012) are used to visualize this small change in scattering. The second approach is inspired by the ability of elephants to detect infrasound produced by underground water reservoirs, and shall be used to determine the location of underground rivers and visualize their exact routes.

  11. Advances in biomimetic regeneration of elastic matrix structures

    PubMed Central

    Sivaraman, Balakrishnan; Bashur, Chris A.

    2012-01-01

    Elastin is a vital component of the extracellular matrix, providing soft connective tissues with the property of elastic recoil following deformation and regulating the cellular response via biomechanical transduction to maintain tissue homeostasis. The limited ability of most adult cells to synthesize elastin precursors and assemble them into mature crosslinked structures has hindered the development of functional tissue-engineered constructs that exhibit the structure and biomechanics of normal native elastic tissues in the body. In diseased tissues, the chronic overexpression of proteolytic enzymes can cause significant matrix degradation, to further limit the accumulation and quality (e.g., fiber formation) of newly deposited elastic matrix. This review provides an overview of the role and importance of elastin and elastic matrix in soft tissues, the challenges to elastic matrix generation in vitro and to regenerative elastic matrix repair in vivo, current biomolecular strategies to enhance elastin deposition and matrix assembly, and the need to concurrently inhibit proteolytic matrix disruption for improving the quantity and quality of elastogenesis. The review further presents biomaterial-based options using scaffolds and nanocarriers for spatio-temporal control over the presentation and release of these biomolecules, to enable biomimetic assembly of clinically relevant native elastic matrix-like superstructures. Finally, this review provides an overview of recent advances and prospects for the application of these strategies to regenerating tissue-type specific elastic matrix structures and superstructures. PMID:23355960

  12. Conducting IPN actuator/sensor for biomimetic vibrissa system

    NASA Astrophysics Data System (ADS)

    Festin, N.; Plesse, C.; Pirim, P.; Chevrot, C.; Vidal, F.

    2014-03-01

    Electroactive polymers, or EAPs, are polymers that exhibit a change in size or shape when stimulated by an electric field. The most common applications of this type of material are in actuators and sensors. One promising technology is the elaboration of electronic conducting polymers based actuators with Interpenetrating Polymer Networks (IPNs) architecture. Their many advantageous properties as low working voltage, light weight and high lifetime make them very attractive for various applications including robotics. Conducting IPNs were fabricated by oxidative polymerization of 3,4-ethylenedioxythiophene within a flexible Solid Polymer Electrolytes (SPE) combining poly(ethylene oxide) and Nitrile Butadiene Rubber. SPE mechanical properties and ionic conductivities in the presence of 1-ethyl-3- methylimidazolium bis-(trifluoromethylsulfonyl)-imide (EMITFSI) have been characterized. The presence of the elastomer within the SPE greatly improves the actuator performances. The free strain as well as the blocking force was characterized as a function of the actuator length. The sensing properties of those conducting IPNs allow their integration into a biomimetic perception prototype: a system mimicking the tactile perception of rat vibrissae.

  13. MIPs and Aptamers for Recognition of Proteins in Biomimetic Sensing

    PubMed Central

    Menger, Marcus; Yarman, Aysu; Erdőssy, Júlia; Yildiz, Huseyin Bekir; Gyurcsányi, Róbert E.; Scheller, Frieder W.

    2016-01-01

    Biomimetic binders and catalysts have been generated in order to substitute the biological pendants in separation techniques and bioanalysis. The two major approaches use either “evolution in the test tube” of nucleotides for the preparation of aptamers or total chemical synthesis for molecularly imprinted polymers (MIPs). The reproducible production of aptamers is a clear advantage, whilst the preparation of MIPs typically leads to a population of polymers with different binding sites. The realization of binding sites in the total bulk of the MIPs results in a higher binding capacity, however, on the expense of the accessibility and exchange rate. Furthermore, the readout of the bound analyte is easier for aptamers since the integration of signal generating labels is well established. On the other hand, the overall negative charge of the nucleotides makes aptamers prone to non-specific adsorption of positively charged constituents of the sample and the “biological” degradation of non-modified aptamers and ionic strength-dependent changes of conformation may be challenging in some application. PMID:27438862

  14. Measuring shear force transmission across a biomimetic glycocalyx

    NASA Astrophysics Data System (ADS)

    Bray, Isabel; Young, Dylan; Scrimgeour, Jan

    Human blood vessels are lined with a low-density polymer brush known as the glycocalyx. This brush plays an active role in defining the mechanical and biochemical environment of the endothelial cell in the blood vessel wall. In addition, it is involved in the detection of mechanical stimuli, such as the shear stress from blood flowing in the vessel. In this work, we construct a biomimetic version of the glycocalyx on top of a soft deformable substrate in order to measure its ability to modulate the effects of shear stress at the endothelial cell surface. The soft substrate is stamped on to a glass substrate and then enclosed inside a microfluidic device that generates a controlled flow over the substrate. The hydrogel chemistry has been optimized so that it reliably stamps into a defined shape and has consistent mechanical properties. Fluorescent microbeads embedded in the gel allow measurement of the surface deformation, and subsequently, calculation of the shear force at the surface of the soft substrate. We investigate the effect of the major structural elements of the glycocalyx, hyaluronic acid and charged proteoglycans, on the magnitude of the shear force transmitted to the surface of the hydrogel.

  15. Radiation damage in biomimetic dye molecules for solar cells.

    PubMed

    Cook, Peter L; Johnson, Phillip S; Liu, Xiaosong; Chin, An-Li; Himpsel, F J

    2009-12-07

    A significant obstacle to organic photovoltaics is radiation damage, either directly by photochemical reactions or indirectly via hot electrons. Such effects are investigated for biomimetic dye molecules for solar cells (phthalocyanines) and for a biological analog (the charge transfer protein cytochrome c). Both feature a central transition metal atom (or H(2)) surrounded by nitrogen atoms. Soft x-ray absorption spectroscopy and photoelectron spectroscopy are used to identify three types of radiation-induced changes in the electronic structure of these molecules. (1) The peptide bonds along the backbone of the protein are readily broken, while the nitrogen cage remains rather stable in phthalocyanines. This finding suggests minimizing peptide attachments to biologically inspired molecules for photovoltaic applications. (2) The metal atom in the protein changes its 3d electron configuration under irradiation. (3) The Fermi level E(F) shifts relative to the band gap in phthalocyanine films due to radiation-induced gap states. This effect has little influence on the optical absorption, but it changes the lineup between the energy levels of the absorbing dye and the acceptor/donor electrodes that collect the charge carriers in a solar cell.

  16. Design of a biomimetic polymer-composite hip prosthesis.

    PubMed

    Bougherara, Habiba; Bureau, Martin; Campbell, Melissa; Vadean, Aurelian; Yahia, L'Hocine

    2007-07-01

    A new biomimetic composite hip prosthesis (stem) was designed to obtain properties similar to those of the contiguous bone, in particular stiffness, to allow normal loading of the surrounding femoral bone. This normal loading would reduce excessive stress shielding, known to result in bone loss, and micromotions at the bone-implant interface, leading to aseptic prosthetic loosening. The design proposed is based on a hollow substructure made of hydroxyapatite-coated, continuous carbon fiber (CF) reinforced polyamide 12 (PA12) composite with an internal soft polymer-based core. Different composite configurations were studied to match the properties of host tissue. Nonlinear three-dimensional analysis of the hip prosthesis was carried out using a three-dimensional finite element bone model based on the composite femur. The performance of composite-based hip and titanium alloy-based (Ti-6Al-4V) stems embedded into femoral bone was compared. The effect of core stiffness and ply configuration was also analyzed. Results show that stresses in composite stem are lower than those in Ti stem, and that the femoral bone implanted with composite structure sustains more load than the one implanted with Ti stem. Micromotions in the composite stem are significantly smaller than those in Ti stem over the entire bone-implant surface because of the favorable interfacial stress distribution.

  17. Biomimetic surface structuring using cylindrical vector femtosecond laser beams

    PubMed Central

    Skoulas, Evangelos; Manousaki, Alexandra; Fotakis, Costas; Stratakis, Emmanuel

    2017-01-01

    We report on a new, single-step and scalable method to fabricate highly ordered, multi-directional and complex surface structures that mimic the unique morphological features of certain species found in nature. Biomimetic surface structuring was realized by exploiting the unique and versatile angular profile and the electric field symmetry of cylindrical vector (CV) femtosecond (fs) laser beams. It is shown that, highly controllable, periodic structures exhibiting sizes at nano-, micro- and dual- micro/nano scales can be directly written on Ni upon line and large area scanning with radial and azimuthal polarization beams. Depending on the irradiation conditions, new complex multi-directional nanostructures, inspired by the Shark’s skin morphology, as well as superhydrophobic dual-scale structures mimicking the Lotus’ leaf water repellent properties can be attained. It is concluded that the versatility and features variations of structures formed is by far superior to those obtained via laser processing with linearly polarized beams. More important, by exploiting the capabilities offered by fs CV fields, the present technique can be further extended to fabricate even more complex and unconventional structures. We believe that our approach provides a new concept in laser materials processing, which can be further exploited for expanding the breadth and novelty of applications. PMID:28327611

  18. On the need for a biomimetic breast device

    NASA Astrophysics Data System (ADS)

    Danos, Nicole; German, Rebecca

    2016-11-01

    The function of the mammary gland, a key anatomical innovation that led to the rise of mammals, is governed by solid-fluid mechanics. There is strong evidence that these mechanical interactions regulate the production of milk and the transport of milk through the lactiferous ducts and into the infant's mouth. Solid-fluid mechanics determine the rate of milk flow and therefore may affect the safe coordination of sucking, swallowing and breathing in the infant. Additionally, links between breastfeeding, the material properties of the gland and breast cancer have been shown repeatedly. However, there is to date no direct way of characterizing breast mechanics during the physiological function for which it has evolved: infant feeding. We are developing an engineered biomimetic breast in which we can experimentally manipulate both structural and material properties of the gland. The device will be tested with an animal model of infant feeding, the pig, to measure the direct effect of gland mechanics on infant feeding. Data from these studies may lead to better designed feeding bottles for infants, milk pumps for both humans and agricultural mammals, and will provide the control mechanical environmental for studies of breast cancer mechanobiology.

  19. Biomimetic and bioactive nanofibrous scaffolds from electrospun composite nanofibers

    PubMed Central

    Zhang, YZ; Su, B; Venugopal, J; Ramakrishna, S; Lim, CT

    2007-01-01

    Electrospinning is an enabling technology that can architecturally (in terms of geometry, morphology or topography) and biochemically fabricate engineered cellular scaffolds that mimic the native extracellular matrix (ECM). This is especially important and forms one of the essential paradigms in the area of tissue engineering. While biomimesis of the physical dimensions of native ECM’s major constituents (eg, collagen) is no longer a fabrication-related challenge in tissue engineering research, conveying bioactivity to electrospun nanofibrous structures will determine the efficiency of utilizing electrospun nanofibers for regenerating biologically functional tissues. This can certainly be achieved through developing composite nanofibers. This article gives a brief overview on the current development and application status of employing electrospun composite nanofibers for constructing biomimetic and bioactive tissue scaffolds. Considering that composites consist of at least two material components and phases, this review details three different configurations of nanofibrous composite structures by using hybridizing basic binary material systems as example. These are components blended composite nanofiber, core-shell structured composite nanofiber, and nanofibrous mingled structure. PMID:18203429

  20. Plasmonic nanoparticles tuned thermal sensitive photonic polymer for biomimetic chameleon

    PubMed Central

    Yan, Yang; Liu, Lin; Cai, Zihe; Xu, Jiwen; Xu, Zhou; Zhang, Di; Hu, Xiaobin

    2016-01-01

    Among many thermo-photochromic materials, the color-changing behavior caused by temperature and light is usually lack of a full color response. And the study on visible light-stimuli chromic response is rarely reported. Here, we proposed a strategy to design a thermo-photochromic chameleon biomimetic material consisting of photonic poly(N-isopropylacrylamide-co-methacrylic acid) copolymer and plasmonic nanoparticles which has a vivid color change triggered by temperature and light like chameleons. We make use of the plasmonic nanoparticles like gold nanoparticles and silver nanoparticles to increase the sensitivity of the responsive behavior and control the lower critical solution temperature of the thermosensitive films by tuning the polymer chain conformation transition. Finally, it is possible that this film would have colorimetric responses to the entire VIS spectrum by the addition of different plasmonic nanoparticles to tune the plasmonic excitation wavelength. As a result, this method provides a potential use in new biosensors, military and many other aspects. PMID:27502454

  1. Molecular biomimetics: nanotechnology and bionanotechnology using genetically engineered peptides.

    PubMed

    Tamerler, Candan; Sarikaya, Mehmet

    2009-05-13

    Nature provides inspiration for designing materials and systems that derive their functions from highly organized structures. Biological hard tissues are hybrid materials having inorganics within a complex organic matrix, the molecular scaffold controlling the inorganic structures. Biocomposites incorporate both biomacromolecules such as proteins, lipids and polysaccharides, and inorganic materials, such as hydroxyapatite, silica, magnetite and calcite. The ordered organization of hierarchical structures in organisms begins via the molecular recognition of inorganics by proteins that control interactions and is followed by the highly efficient self-assembly across scales. Following the molecular biological principle, proteins could also be used in controlling materials formation in practical engineering via self-assembled, hybrid, functional materials structures. In molecular biomimetics, material-specific peptides could be the key in the molecular engineering of biology-inspired materials. With the recent developments of nanoscale engineering in physical sciences and the advances in molecular biology, we now combine genetic tools with synthetic nanoscale constructs to create a novel methodology. We first genetically select and/or design peptides with specific binding to functional solids, tailor their binding and assembly characteristics, develop bifunctional peptide/protein genetic constructs with both material binding and biological activity, and use these as molecular synthesizers, erectors and assemblers. Here, we give an overview of solid-binding peptides as novel molecular agents coupling bio- and nanotechnology.

  2. Biomimetic surface structuring using cylindrical vector femtosecond laser beams

    NASA Astrophysics Data System (ADS)

    Skoulas, Evangelos; Manousaki, Alexandra; Fotakis, Costas; Stratakis, Emmanuel

    2017-03-01

    We report on a new, single-step and scalable method to fabricate highly ordered, multi-directional and complex surface structures that mimic the unique morphological features of certain species found in nature. Biomimetic surface structuring was realized by exploiting the unique and versatile angular profile and the electric field symmetry of cylindrical vector (CV) femtosecond (fs) laser beams. It is shown that, highly controllable, periodic structures exhibiting sizes at nano-, micro- and dual- micro/nano scales can be directly written on Ni upon line and large area scanning with radial and azimuthal polarization beams. Depending on the irradiation conditions, new complex multi-directional nanostructures, inspired by the Shark’s skin morphology, as well as superhydrophobic dual-scale structures mimicking the Lotus’ leaf water repellent properties can be attained. It is concluded that the versatility and features variations of structures formed is by far superior to those obtained via laser processing with linearly polarized beams. More important, by exploiting the capabilities offered by fs CV fields, the present technique can be further extended to fabricate even more complex and unconventional structures. We believe that our approach provides a new concept in laser materials processing, which can be further exploited for expanding the breadth and novelty of applications.

  3. Biomimetic Materials to Characterize Bacteria-host Interactions

    PubMed Central

    Vaz, Diana; Perez-Soto, Nicolas; Krachler, Anne M.

    2015-01-01

    Bacterial attachment to host cells is one of the earliest events during bacterial colonization of host tissues and thus a key step during infection. The biochemical and functional characterization of adhesins mediating these initial bacteria-host interactions is often compromised by the presence of other bacterial factors, such as cell wall components or secreted molecules, which interfere with the analysis. This protocol describes the production and use of biomimetic materials, consisting of pure recombinant adhesins chemically coupled to commercially available, functionalized polystyrene beads, which have been used successfully to dissect the biochemical and functional interactions between individual bacterial adhesins and host cell receptors. Protocols for different coupling chemistries, allowing directional immobilization of recombinant adhesins on polymer scaffolds, and for assessment of the coupling efficiency of the resulting “bacteriomimetic” materials are also discussed. We further describe how these materials can be used as a tool to inhibit pathogen mediated cytotoxicity and discuss scope, limitations and further applications of this approach in studying bacterial - host interactions. PMID:26650964

  4. Silaffins in Silica Biomineralization and Biomimetic Silica Precipitation

    PubMed Central

    Lechner, Carolin C.; Becker, Christian F. W.

    2015-01-01

    Biomineralization processes leading to complex solid structures of inorganic material in biological systems are constantly gaining attention in biotechnology and biomedical research. An outstanding example for biomineral morphogenesis is the formation of highly elaborate, nano-patterned silica shells by diatoms. Among the organic macromolecules that have been closely linked to the tightly controlled precipitation of silica in diatoms, silaffins play an extraordinary role. These peptides typically occur as complex posttranslationally modified variants and are directly involved in the silica deposition process in diatoms. However, even in vitro silaffin-based peptides alone, with and without posttranslational modifications, can efficiently mediate biomimetic silica precipitation leading to silica material with different properties as well as with encapsulated cargo molecules of a large size range. In this review, the biomineralization process of silica in diatoms is summarized with a specific focus on silaffins and their in vitro silica precipitation properties. Applications in the area of bio- and nanotechnology as well as in diagnostics and therapy are discussed. PMID:26295401

  5. Nanofibrous structured biomimetic strategies for skin tissue regeneration.

    PubMed

    Jayarama Reddy, Venugopal; Radhakrishnan, Sridhar; Ravichandran, Rajeswari; Mukherjee, Shayanti; Balamurugan, Ramalingam; Sundarrajan, Subramanian; Ramakrishna, Seeram

    2013-01-01

    Mimicking porous topography of natural extracellular matrix is advantageous for successful regeneration of damaged tissues or organs. Nanotechnology being one of the most promising and growing technology today shows an extremely huge potential in the field of tissue engineering. Nanofibrous structures that mimic the native extracellular matrix and promote the adhesion of various cells are being developed as tissue-engineered scaffolds for skin, bone, vasculature, heart, cornea, nervous system, and other tissues. A range of novel biocomposite materials has been developed to enhance the bioactive or therapeutic properties of these nanofibrous scaffolds via surface modifications, including the immobilization of functional cell-adhesive ligands and bioactive molecules such as drugs, enzymes, and cytokines. In skin tissue engineering, usage of allogeneic skin is avoided to reestablish physiological continuity and also to address the challenge of curing acute and chronic wounds, which remains as the area of exploration with various biomimetic approaches. Two-dimensional, three-dimensional scaffolds and stem cells are presently used as dermal regeneration templates for the treatment of full-thickness skin defects resulting from injuries and severe burns. The present review elaborates specifically on the fabrication of nanofibrous structured strategies for wound dressings, wound healing, and controlled release of growth factors for skin tissue regeneration.

  6. Dopamine-melanin nanofilms for biomimetic structural coloration.

    PubMed

    Wu, Tong-Fei; Hong, Jong-Dal

    2015-02-09

    This article describes the formation of dopamine-melanin thin films (50-200 nm thick) at an air/dopamine solution interface under static conditions. Beneath these films, spherical melanin granules formed in bulk liquid phase. The thickness of dopamine-melanin films at the interface relied mainly on the concentration of dopamine solution and the reaction time. A plausible mechanism underlining dopamine-melanin thin film formation was proposed based on the hydrophobicity of dopamine-melanin aggregates and the mass transport of the aggregates to the air/solution interface as a result of convective flow. The thickness of the interfacial films increased linearly with the dopamine concentration and the reaction time. The dopamine-melanin thin film and granules (formed in bulk liquid phase) with a double-layered structure were transferred onto a solid substrate to mimic the (keratin layer)/(melanin granules) structure present in bird plumage, thereby preparing full dopamine-melanin thin-film reflectors. The reflected color of the thin-film reflectors depended on the film thickness, which could be adjusted according to the dopamine concentration. The reflectance of the resulted reflectors exhibited a maximal reflectance value of 8-11%, comparable to that of bird plumage (∼11%). This study provides a useful, simple, and low-cost approach to the fabrication of biomimetic thin-film reflectors using full dopamine-melanin materials.

  7. Development of a biomimetic robotic fish and its control algorithm.

    PubMed

    Yu, Junzhi; Tan, Min; Wang, Shuo; Chen, Erkui

    2004-08-01

    This paper is concerned with the design of a robotic fish and its motion control algorithms. A radio-controlled, four-link biomimetic robotic fish is developed using a flexible posterior body and an oscillating foil as a propeller. The swimming speed of the robotic fish is adjusted by modulating joint's oscillating frequency, and its orientation is tuned by different joint's deflections. Since the motion control of a robotic fish involves both hydrodynamics of the fluid environment and dynamics of the robot, it is very difficult to establish a precise mathematical model employing purely analytical methods. Therefore, the fish's motion control task is decomposed into two control systems. The online speed control implements a hybrid control strategy and a proportional-integral-derivative (PID) control algorithm. The orientation control system is based on a fuzzy logic controller. In our experiments, a point-to-point (PTP) control algorithm is implemented and an overhead vision system is adopted to provide real-time visual feedback. The experimental results confirm the effectiveness of the proposed algorithms.

  8. Biomechanics and biomimetics in insect-inspired flight systems

    PubMed Central

    Liu, Hao; Ravi, Sridhar; Kolomenskiy, Dmitry; Tanaka, Hiroto

    2016-01-01

    Insect- and bird-size drones—micro air vehicles (MAV) that can perform autonomous flight in natural and man-made environments are now an active and well-integrated research area. MAVs normally operate at a low speed in a Reynolds number regime of 104–105 or lower, in which most flying animals of insects, birds and bats fly, and encounter unconventional challenges in generating sufficient aerodynamic forces to stay airborne and in controlling flight autonomy to achieve complex manoeuvres. Flying insects that power and control flight by flapping wings are capable of sophisticated aerodynamic force production and precise, agile manoeuvring, through an integrated system consisting of wings to generate aerodynamic force, muscles to move the wings and a control system to modulate power output from the muscles. In this article, we give a selective review on the state of the art of biomechanics in bioinspired flight systems in terms of flapping and flexible wing aerodynamics, flight dynamics and stability, passive and active mechanisms in stabilization and control, as well as flapping flight in unsteady environments. We further highlight recent advances in biomimetics of flapping-wing MAVs with a specific focus on insect-inspired wing design and fabrication, as well as sensing systems. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’. PMID:27528780

  9. Nanoviscosity Measurements Revealing Domain Formation in Biomimetic Membranes.

    PubMed

    Hasan, Imad Younus; Mechler, Adam

    2017-02-07

    Partitioning of lipid molecules in biomimetic membranes is a model system for the study of naturally occurring domains, such as rafts, in biological membranes. The existence of nanometer scale membrane domains in binary lipid mixtures has been shown with microscopy methods; however, the nature of these domains has not been established unequivocally. A common notion is to ascribe domain separation to thermodynamic phase equilibria. However, characterizing thermodynamic phases of single bilayer membranes has not been possible due to their extreme dimensions: the size of the domains falls to the order of tens to hundreds of nanometers whereas the membrane thickness is only a few nanometers. Here, we present direct measurements of phase transitions in single bilayers of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)/1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) phospholipid mixtures using quartz crystal microbalance-based nanoviscosity measurements. Coexisting thermodynamic phases have been successfully identified, and a phase diagram was constructed for the single bilayer binary lipid system. It was demonstrated that domain separation only takes place in planar membranes, and thus, it is absent in liposomes and not detectable in calorimetric measurements on liposome suspensions. On the basis of energetic analysis, the main transition was identified as the breaking of van der Waals interactions between the acyl chains.

  10. Biomechanics and biomimetics in insect-inspired flight systems.

    PubMed

    Liu, Hao; Ravi, Sridhar; Kolomenskiy, Dmitry; Tanaka, Hiroto

    2016-09-26

    Insect- and bird-size drones-micro air vehicles (MAV) that can perform autonomous flight in natural and man-made environments are now an active and well-integrated research area. MAVs normally operate at a low speed in a Reynolds number regime of 10(4)-10(5) or lower, in which most flying animals of insects, birds and bats fly, and encounter unconventional challenges in generating sufficient aerodynamic forces to stay airborne and in controlling flight autonomy to achieve complex manoeuvres. Flying insects that power and control flight by flapping wings are capable of sophisticated aerodynamic force production and precise, agile manoeuvring, through an integrated system consisting of wings to generate aerodynamic force, muscles to move the wings and a control system to modulate power output from the muscles. In this article, we give a selective review on the state of the art of biomechanics in bioinspired flight systems in terms of flapping and flexible wing aerodynamics, flight dynamics and stability, passive and active mechanisms in stabilization and control, as well as flapping flight in unsteady environments. We further highlight recent advances in biomimetics of flapping-wing MAVs with a specific focus on insect-inspired wing design and fabrication, as well as sensing systems.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'.

  11. Scalable manufacturing of biomimetic moldable hydrogels for industrial applications.

    PubMed

    Yu, Anthony C; Chen, Haoxuan; Chan, Doreen; Agmon, Gillie; Stapleton, Lyndsay M; Sevit, Alex M; Tibbitt, Mark W; Acosta, Jesse D; Zhang, Tony; Franzia, Paul W; Langer, Robert; Appel, Eric A

    2016-12-13

    Hydrogels are a class of soft material that is exploited in many, often completely disparate, industrial applications, on account of their unique and tunable properties. Advances in soft material design are yielding next-generation moldable hydrogels that address engineering criteria in several industrial settings such as complex viscosity modifiers, hydraulic or injection fluids, and sprayable carriers. Industrial implementation of these viscoelastic materials requires extreme volumes of material, upwards of several hundred million gallons per year. Here, we demonstrate a paradigm for the scalable fabrication of self-assembled moldable hydrogels using rationally engineered, biomimetic polymer-nanoparticle interactions. Cellulose derivatives are linked together by selective adsorption to silica nanoparticles via dynamic and multivalent interactions. We show that the self-assembly process for gel formation is easily scaled in a linear fashion from 0.5 mL to over 15 L without alteration of the mechanical properties of the resultant materials. The facile and scalable preparation of these materials leveraging self-assembly of inexpensive, renewable, and environmentally benign starting materials, coupled with the tunability of their properties, make them amenable to a range of industrial applications. In particular, we demonstrate their utility as injectable materials for pipeline maintenance and product recovery in industrial food manufacturing as well as their use as sprayable carriers for robust application of fire retardants in preventing wildland fires.

  12. Biomimetic scaffold design for functional and integrative tendon repair.

    PubMed

    Zhang, Xinzhi; Bogdanowicz, Danielle; Erisken, Cevat; Lee, Nancy M; Lu, Helen H

    2012-02-01

    Rotator cuff tears represent the most common shoulder injuries in the United States. The debilitating effect of this degenerative condition coupled with the high incidence of failure associated with existing graft choices underscores the clinical need for alternative grafting solutions. The 2 critical design criteria for the ideal tendon graft would require the graft to not only exhibit physiologically relevant mechanical properties but also be able to facilitate functional graft integration by promoting the regeneration of the native tendon-to-bone interface. Centered on these design goals, this review will highlight current approaches to functional and integrative tendon repair. In particular, the application of biomimetic design principles through the use of nanofiber- and nanocomposite-based scaffolds for tendon tissue engineering will be discussed. This review will begin with nanofiber-based approaches to functional tendon repair, followed by a section highlighting the exciting research on tendon-to-bone interface regeneration, with an emphasis on implementation of strategic biomimicry in nanofiber scaffold design and the concomitant formation of graded multi-tissue systems for integrative soft-tissue repair. This review will conclude with a summary and discussion of future directions.

  13. Nanoscale biomimetics studies of Salvinia molesta for micropattern fabrication.

    PubMed

    Hunt, James; Bhushan, Bharat

    2011-11-01

    The emerging field of biomimetics allows one to take inspiration from nature and mimic it in order to create various products, devices and structures. There are a large number of objects, including bacteria, plants, land and aquatic animals and seashells, with properties of commercial interest. The subject of interest for this research is the water fern Salvinia molesta because of its ability to trap air. Air-retaining surfaces are of technological interest due to their ability to reduce drag when used for fluid transport, ship coatings and other submersible industrial products in which drag is a concern. The purpose of this research is to mimic the air trapping ability of S. molesta in order to prove that a structure can be created in the lab that can mimic the behavior of the fern as well as demonstrate microfabrication techniques that can be utilized in industry to produce such materials. In this work, a novel methodology for the fabrication of microstructures that mimic the water-pinning and air-trapping ability of S. molesta is introduced. Water contact angle, water roll angle and adhesive force of the new microstructure and water fern are investigated.

  14. Clinical Performance of a New Biomimetic Double Network Material

    PubMed Central

    Dirxen, Christine; Blunck, Uwe; Preissner, Saskia

    2013-01-01

    Background: The development of ceramics during the last years was overwhelming. However, the focus was laid on the hardness and the strength of the restorative materials, resulting in high antagonistic tooth wear. This is critical for patients with bruxism. Objectives: The purpose of this study was to evaluate the clinical performance of the new double hybrid material for non-invasive treatment approaches. Material and Methods: The new approach of the material tested, was to modify ceramics to create a biomimetic material that has similar physical properties like dentin and enamel and is still as strong as conventional ceramics. Results: The produced crowns had a thickness ranging from 0.5 to 1.5 mm. To evaluate the clinical performance and durability of the crowns, the patient was examined half a year later. The crowns were still intact and soft tissues appeared healthy and this was achieved without any loss of tooth structure. Conclusions: The material can be milled to thin layers, but is still strong enough to prevent cracks which are stopped by the interpenetrating polymer within the network. Depending on the clinical situation, minimally- up to non-invasive restorations can be milled. Clinical Relevance: Dentistry aims in preservation of tooth structure. Patients suffering from loss of tooth structure (dental erosion, Amelogenesis imperfecta) or even young patients could benefit from minimally-invasive crowns. Due to a Vickers hardness between dentin and enamel, antagonistic tooth wear is very low. This might be interesting for treating patients with bruxism. PMID:24167534

  15. Laminin Functionalized Biomimetic Nanofibers For Nerve Tissue Engineering

    PubMed Central

    Junka, Radoslaw; Valmikinathan, Chandra M; Kalyon, Dilhan M; Yu, Xiaojun

    2013-01-01

    Large-gap peripheral nerve injuries present a significant challenge for nerve regeneration due to lack of suitable grafts, insufficient cell penetration, and repair. Biomimetic nanofibrous scaffolds, functionalized on the surface with extracellular matrix proteins, can lead to novel therapies for repair and regeneration of damaged peripheral nerves. Here, nanofibrous scaffolds electrospun from blends of poly(caprolactone) (PCL) and chitosan were fabricated. Taking advantage of the amine groups on the chitosan, the surface of the scaffolds were functionalized with laminin by carbodiimide based crosslinking. Crosslinking allowed laminin to be attached to the surfaces of the PCL-chitosan nanofibers at relatively high concentrations that were not possible using conventional adsorption methods. The nanofibrous meshes were tested for wettability, mechanical properties and cell attachment and proliferation. Blending of chitosan with PCL provided more favorable surfaces for attachment of Schwann cells due to the reduction of the contact angle in comparison to neat PCL. Proliferation rates of Schwann cells grown on PCL-chitosan scaffolds with crosslinked laminin were significantly higher than the rates for PCL-chitosan nanofibrous matrices with adsorbed laminin. PCL-chitosan scaffolds with modified surfaces via crosslinking of laminin could potentially serves as versatile substrates with excellent mechanical and surface properties for in vivo cell delivery for nerve tissue engineering applications. PMID:24083073

  16. Bio-mimetic optical sensor for structural deflection measurement

    NASA Astrophysics Data System (ADS)

    Frost, Susan A.; Wright, Cameron H. G.; Streeter, Robert W.; Khan, Md. A.; Barrett, Steven F.

    2014-03-01

    Reducing the environmental impact of aviation is a primary goal of NASA aeronautics research. One approach to achieve this goal is to build lighter weight aircraft, which presents complex challenges due to a corresponding increase in structural flexibility. Wing flexibility can adversely affect aircraft performance from the perspective of aerodynamic efficiency and safety. Knowledge of the wing position during flight can aid active control methods designed to mitigate problems due to increased wing flexibility. Current approaches to measuring wing deflection, including strain measurement devices, accelerometers, or GPS solutions, and new technologies such as fiber optic strain sensors, have limitations for their practical application to flexible aircraft control. Hence, it was proposed to use a bio-mimetic optical sensor based on the fly-eye to track wing deflection in real-time. The fly-eye sensor has several advantages over conventional sensors used for this application, including light weight, low power requirements, fast computation, and a small form factor. This paper reports on the fly-eye sensor development and its application to real-time wing deflection measurement.

  17. Nanoparticle-based biomimetic functional materials (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Ijiro, Kuniharu

    2015-09-01

    Self-assembly originated from molecules, is ubiquitous from nature to unnature systems. The formation of double-stranded structure of DNA, virus, molecular crystals, liposomes etc. are all instances of molecular self-assembly. In the biological system, for example, virus is an impressive feat of molecular engineering by assembly of hundreds of proteins through the weak hydrophobic effect. We propose a robust strategy for the size-controllable fabrication of gold nanoparticle vesicles(AuNVs) which are biomimetic nanostructures of virus consisted of gold nanoparticles instead of proteins by using carbohydrate terminated fluorinated surface ligand self-assembly with 5~40nm AuNPs, indicating that carbohydrate can act as stronger molecular glue than oligo(ethylene glycol). Carbohydrate was introduced to tune the hydrophilic effect of the ligand by varying the number of glucose (namely, glucose, maltose, and maltotriose). AuNVs size could be efficiently controlled by varying surface ligands, water content in dioxane, and AuNPs size. We find some similarities between VLPs and AuNVs composed of 30nm gold nanoparticles. Photonic properties of not only AuNVs but also other self-assemblies of nanoparticles were measured. Strong surface-enhanced Raman scattering (SERS) of molecules were detected from the AuNVs and self-assembled gold nanoparticles.

  18. Research on biomimetic underwater vehicles for underwater ISR

    NASA Astrophysics Data System (ADS)

    Szymak, Piotr; Praczyk, Tomasz; Naus, Krzysztof; Szturomski, Bogdan; Malec, Marcin; Morawski, Marcin

    2016-05-01

    Autonomous Biomimetic Underwater Vehicles BUVs driven by an undulating propulsion are a new branch in an area of an underwater robotics. They imitate both the construction and kinematics of a motion of underwater living organisms, e.g. fishes. Such vehicles have several features crucial from the point of view of military applications, e.g. larger secrecy and potential range of operation. The paper presents results of the research on BUVs carried out within two (Polish and EDA) projects both led by Polish Naval Academy. At the beginning, the initial efforts in building Polish BUV called CyberFish are included. Then, selected results of the tests of subsystems, e.g. navigational and 3D model of BUV built within national project are described. Next, the initial research achieved in the international project are showed. At the end, the schedule of the research planned to carry out within both projects is inserted. The paper is mainly focused on the hardware development of the BUVs.

  19. MIPs and Aptamers for Recognition of Proteins in Biomimetic Sensing.

    PubMed

    Menger, Marcus; Yarman, Aysu; Erdőssy, Júlia; Yildiz, Huseyin Bekir; Gyurcsányi, Róbert E; Scheller, Frieder W

    2016-07-18

    Biomimetic binders and catalysts have been generated in order to substitute the biological pendants in separation techniques and bioanalysis. The two major approaches use either "evolution in the test tube" of nucleotides for the preparation of aptamers or total chemical synthesis for molecularly imprinted polymers (MIPs). The reproducible production of aptamers is a clear advantage, whilst the preparation of MIPs typically leads to a population of polymers with different binding sites. The realization of binding sites in the total bulk of the MIPs results in a higher binding capacity, however, on the expense of the accessibility and exchange rate. Furthermore, the readout of the bound analyte is easier for aptamers since the integration of signal generating labels is well established. On the other hand, the overall negative charge of the nucleotides makes aptamers prone to non-specific adsorption of positively charged constituents of the sample and the "biological" degradation of non-modified aptamers and ionic strength-dependent changes of conformation may be challenging in some application.

  20. Biomimetic polymers of plant cutin: an approach from molecular modeling.

    PubMed

    San-Miguel, Miguel A; Oviedo, Jaime; Heredia-Guerrero, Jose Alejandro; Heredia, Antonio; Benitez, Jose Jesus

    2014-07-01

    Biomimetics of materials is based on adopting and reproducing a model in nature with a well-defined functionality optimized through evolution. An example is barrier polymers that protect living tissues from the environment. The protecting layer of fruits, leaves, and non-lignified stems is the plant cuticle. The cuticle is a complex system in which the cutin is the main component. Cutin is a biopolyester made of polyhydroxylated carboxylic acids of 16 and 18 carbon atoms. The biosynthesis of cutin in plants is not well understood yet, but a direct chemical route involving the self-assembly of either molecules or molecular aggregates has been proposed. In this work, we present a combined study using experimental and simulation techniques on self-assembled layers of monomers selectively functionalized with hydroxyl groups. Our results demonstrate that the number and position of the hydroxyl groups are critical for the interaction between single molecules and the further rearrangement. Also, the presence of lateral hydroxyl groups reinforces lateral interactions and favors the bi-dimensional growth (2D), while terminal hydroxyl groups facilitate the formation of a second layer caused by head-tail interactions. The balance of 2D/3D growth is fundamental for the plant to create a protecting layer both large enough in 2D and thick enough in 3D.

  1. Lactoferrin Adsorbed onto Biomimetic Hydroxyapatite Nanocrystals Controlling - In Vivo - the Helicobacter pylori Infection

    PubMed Central

    Fulgione, Andrea; Nocerino, Nunzia; Iannaccone, Marco; Roperto, Sante; Capuano, Federico; Roveri, Norberto; Lelli, Marco; Crasto, Antonio; Calogero, Armando; Pilloni, Argenia Paola; Capparelli, Rosanna

    2016-01-01

    Background The resistance of Helicobacter pylori to the antibiotic therapy poses the problem to discover new therapeutic approaches. Recently it has been stated that antibacterial, immunomodulatory, and antioxidant properties of lactoferrin are increased when this protein is surface-linked to biomimetic hydroxyapatite nanocrystals. Objective Based on these knowledge, the aim of the study was to investigate the efficacy of lactoferrin delivered by biomimetic hydroxyapatite nanoparticles with cell free supernatant from probiotic Lactobacillus paracasei as an alternative therapy against Helicobacter pylori infection. Methods Antibacterial and antinflammatory properties, humoral antibody induction, histopathological analysis and absence of side effects were evaluated in both in vitro and in vivo studies. Results The tests carried out have been demonstrated better performance of lactoferrin delivered by biomimetic hydroxyapatite nanoparticles combined with cell free supernatant from probiotic Lactobacillus paracasei compared to both lactoferrin and probiotic alone or pooled. Conclusion These findings indicate the effectiveness and safety of our proposed therapy as alternative treatment for Helicobacter pylori infection. PMID:27384186

  2. Caseoperoxidase, Mixed β-Casein-SDS-Hemin-Imidazole Complex: A Nano Artificial Enzyme

    PubMed Central

    Moosavi-Movahedi, Zainab; Gharibi, Hussein; Hadi-Alijanvand, Hamid; Akbarzadeh, Mohammad; Esmaili, Mansoore; Atri, Maliheh S.; Sefidbakht, Yahya; Bohlooli, Mousa; Nazari, Khodadad; Javadian, Soheila; Hong, Jun; Saboury, Ali A.; Sheibani, Nader; Moosavi-Movahedi, Ali A.

    2016-01-01

    A novel peroxidase-like artificial enzyme, named “caseoperoxidase”, was biomimetically designed using a nano artificial amino acid apo-protein hydrophobic pocket. This four-component nano artificial enzyme containing heme-imidazole-β-casein-SDS exhibited high activity growth and kcat performance towards the native horseradish peroxidase (HRP) demonstrated by the steady state kinetics using UV-Vis spectrophotometry. The hydrophobicity and secondary structure of the caseoperoxidase were studied by ANS fluorescence and circular dichroism spectroscopy. Camel β-casein (Cβ-casein), with a flexible structure and exalted hydrophobicity, was selected as an appropriate apo-protein for the heme active site using a homology modeling method. Heme docking into the newly obtained Cβ-casein structure indicated one heme was mainly incorporated with Cβ-casein. The presence of a main electrostatic site for the active site in the Cβ-casein was also confirmed by experimental methods through Wyman binding potential and isothermal titration calorimetry. The existence of Cβ-casein protein in this biocatalyst lowered the suicide inactivation, and indicated that the obtained structure has a good protective role for the heme active-site. Additional further experiments confirmed the retention of caseoperoxidase structure and function as an artificial enzyme. PMID:25562503

  3. Caseoperoxidase, mixed β-casein-SDS-hemin-imidazole complex: a nano artificial enzyme.

    PubMed

    Moosavi-Movahedi, Zainab; Gharibi, Hussein; Hadi-Alijanvand, Hamid; Akbarzadeh, Mohammad; Esmaili, Mansoore; Atri, Maliheh S; Sefidbakht, Yahya; Bohlooli, Mousa; Nazari, Khodadad; Javadian, Soheila; Hong, Jun; Saboury, Ali A; Sheibani, Nader; Moosavi-Movahedi, Ali A

    2015-01-01

    A novel peroxidase-like artificial enzyme, named "caseoperoxidase", was biomimetically designed using a nano artificial amino acid apo-protein hydrophobic pocket. This four-component nano artificial enzyme containing heme-imidazole-β-casein-SDS exhibited high activity growth and k(cat) performance toward the native horseradish peroxidase demonstrated by the steady state kinetics using UV-vis spectrophotometry. The hydrophobicity and secondary structure of the caseoperoxidase were studied by ANS fluorescence and circular dichroism spectroscopy. Camel β-casein (Cβ-casein) was selected as an appropriate apo-protein for the heme active site because of its innate flexibility and exalted hydrophobicity. This selection was confirmed by homology modeling method. Heme docking into the newly obtained Cβ-casein structure indicated one heme was mainly incorporated with Cβ-casein. The presence of a main electrostatic site for the active site in the Cβ-casein was also confirmed by experimental methods through Wyman binding potential and isothermal titration calorimetry. The existence of Cβ-casein protein in this biocatalyst lowered the suicide inactivation and provided a suitable protective role for the heme active-site. Additional experiments confirmed the retention of caseoperoxidase structure and function as an artificial enzyme.

  4. Squalyl Crown Ether Self-Assembled Conjugates: An Example of Highly Selective Artificial K(+) Channels.

    PubMed

    Sun, Zhanhu; Gilles, Arnaud; Kocsis, Istvan; Legrand, Yves-Marie; Petit, Eddy; Barboiu, Mihail

    2016-02-01

    The natural KcsA K(+) channel, one of the best-characterized biological pore structures, conducts K(+) cations at high rates while excluding Na(+) cations. The KcsA K(+) channel is of primordial inspiration for the design of artificial channels. Important progress in improving conduction activity and K(+) /Na(+) selectivity has been achieved with artificial ion-channel systems. However, simple artificial systems exhibiting K(+) /Na(+) selectivity and mimicking the biofunctions of the KcsA K(+) channel are unknown. Herein, an artificial ion channel formed by H-bonded stacks of squalyl crown ethers, in which K(+) conduction is highly preferred to Na(+) conduction, is reported. The K(+) -channel behavior is interpreted as arising from discreet stacks of dimers resulting in the formation of oligomeric channels, in which transport of cations occurs through macrocycles mixed with dimeric carriers undergoing dynamic exchange within the bilayer membrane. The present highly K(+) -selective macrocyclic channel can be regarded as a biomimetic alternative to the KcsA channel.

  5. Biomimetic TiO2 formation from interfacial sol-gel chemistry leading to new photocatalysts

    NASA Astrophysics Data System (ADS)

    Jaffer Al-Timimi, Iman A.; Onwukwe, Uche K.; Worsley, Myles P.; Sermon, Paul A.

    2016-09-01

    The surfaces of Portobello mushroom spores (PMS) have been used to produce Au and Ag nanoparticles, which are held thereon. They have then been overcoated with TiOx. These adsorbed more methyl orange (MO) pollutant from water than commercial P25 TiO2. After calcination they form biomimetic TiO2 (PMS) and removal of the biotemplate, they catalyse faster rates of MO from water (molecules/mg/s) than P25 anataserutile. Other biotemplates are now anticipated that will yield biomimetic photocatalysts with higher turnover number (s-1) removal of endocrine disrupters from water.

  6. Industrial-scale spray layer-by-layer assembly for production of biomimetic photonic systems.

    PubMed

    Krogman, K C; Cohen, R E; Hammond, P T; Rubner, M F; Wang, B N

    2013-12-01

    Layer-by-layer assembly is a powerful and flexible thin film process that has successfully reproduced biomimetic photonic systems such as structural colour. While most of the seminal work has been carried out using slow and ultimately unscalable immersion assembly, recent developments using spray layer-by-layer assembly provide a platform for addressing challenges to scale-up and manufacturability. A series of manufacturing systems has been developed to increase production throughput by orders of magnitude, making commercialized structural colour possible. Inspired by biomimetic photonic structures we developed and demonstrated a heat management system that relies on constructive reflection of near infrared radiation to bring about dramatic reductions in heat content.

  7. A novel biomimetic sonarhead using beamforming technology to mimic bat echolocation.

    PubMed

    Steckel, Jan; Peremans, Herbert

    2012-07-01

    A novel biomimetic sonarhead has been developed to allow researchers of bat echolocation behavior and biomimetic sonar to perform experiments with a system similar to the bat¿s sensory system. The bat's echolocation-related transfer function (ERTF) is implemented using an array of receivers to implement the head-related transfer function (HRTF), and an array of emitters mounted on a cylindrical manifold to implement the emission pattern of the bat. The complete system is controlled by a field-programmable gate array (FPGA) based embedded system connected through a USB interface.

  8. Biomimetic synthesis of shaped and chiral silica entities templated by organic objective materials.

    PubMed

    Jin, Ren-Hua; Yao, Dong-Dong; Levi, Rumi Tamoto

    2014-06-10

    Organic molecules with accompanying self-organization have been a great subject in chemistry, material science and nanotechnology in the past two decades. One of the most important roles of organized organic molecules is the capability of templating complexly structured inorganic materials. The focus of this Minireview is on nanostructured silica with divergent morphologies and/or integrated chirality directed by organic templates of self-assembled polyamine/polypeptides/block copolymers, chiral organogels, self-organized chiral amphiphiles and chiral crystalline complexes, etc., by biomimetic silicification and conventional sol-gel reaction. Among them, biosilica (diatoms and sponges)-inspired biomimetic silicifications are particularly highlighted.

  9. COST Action CM1201 "Biomimetic Radical Chemistry": free radical chemistry successfully meets many disciplines.

    PubMed

    Ferreri, Carla; Golding, Bernard T; Jahn, Ullrich; Ravanat, Jean-Luc

    2016-11-01

    The COST Action CM1201 "Biomimetic Radical Chemistry" has been active since December 2012 for 4 years, developing research topics organized into four working groups: WG1 - Radical Enzymes, WG2 - Models of DNA damage and consequences, WG3 - Membrane stress, signalling and defenses, and WG4 - Bio-inspired synthetic strategies. International collaborations have been established among the participating 80 research groups with brilliant interdisciplinary achievements. Free radical research with a biomimetic approach has been realized in the COST Action and are summarized in this overview by the four WG leaders.

  10. Artificial structures on Mars

    NASA Astrophysics Data System (ADS)

    Van Flandern, T.

    2002-05-01

    Approximately 70,000 images of the surface of Mars at a resolution of up to 1.4 meters per pixel, taken by the Mars Global Surveyor spacecraft, are now in public archives. Approximately 1% of those images show features that can be broadly described as `special shapes', `tracks, trails, and possible vegetation', `spots, stripes, and tubes', `artistic imagery', and `patterns and symbols'. Rather than optical illusions and tricks of light and shadow, most of these have the character that, if photographed on Earth, no one would doubt that they were the products of large biology and intelligence. In a few cases, relationships, context, and fulfillment of a priori predictions provide objective evidence of artificiality that is exempt from the influence of experimenter biases. Only controlled test results can be trusted because biases are strong and operate both for and against artificiality.

  11. Wide Band Artificial Pulsar

    NASA Astrophysics Data System (ADS)

    Parsons, Zackary

    2017-01-01

    The Wide Band Artificial Pulsar (WBAP) is an instrument verification device designed and built by the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virgina. The site currently operates the Green Bank Ultimate Pulsar Processing Instrument (GUPPI) and the Versatile Green Bank Astronomical Spectrometer (VEGAS) digital backends for their radio telescopes. The commissioning and continued support for these sophisticated backends has demonstrated a need for a device capable of producing an accurate artificial pulsar signal. The WBAP is designed to provide a very close approximation to an actual pulsar signal. This presentation is intended to provide an overview of the current hardware and software implementations and to also share the current results from testing using the WBAP.

  12. Artificially structured magnetic materials

    SciTech Connect

    Falco, C.M.

    1990-09-28

    This document reports the progress made during the first six months of the current three-year DOE grant on Artificially Structured Magnetic Materials.'' However, because some of the results of our previous three-year DOE grant on Artificially Structured Superconductors'' continue to emerge, both topics are addressed in this Progress Report. This report describes progress with DOE funding during the current calendar year; description of the research to be conducted during the remaining six months of the current grant year; a description of the status of the graduate students working on this research; lists of the invited talks, seminars and colloquia, of other recognition of our research, and of the publications crediting DOE sponsorship; and a summary of current and pending federal support. Since the research proposed to be conducted during the next 2 1/2 years is described in detail in our DOE proposal, it is only briefly reviewed here.

  13. Whither Artificial Reproduction?

    PubMed Central

    Percival-Smith, Robin

    1985-01-01

    Artificial reproduction now offers sub fertile couples a number of options which raise scientific and ethical questions. This article discusses the Canadian and British experiences in formulating regulations and legislation in this important field. Current work on mammalian embryo research foretells the direction which human research will take. This article stresses the need for family physicians' participation in the ethical decisions that accompany these new developments. PMID:21274181

  14. Artificial perception and consciousness

    NASA Astrophysics Data System (ADS)

    Caulfield, H. John; Johnson, John L.

    2000-06-01

    Perception has both unconscious and conscious aspects. In all cases, however, what we perceive is a model of reality. By brain construction through evolution, we divide the world into two parts--our body and the outside world. But the process is the same in both cases. We perceive a construct usually governed by sensed data but always involving memory, goals, fears, expectations, etc. As a first step toward Artificial Perception in man-made systems, we examine perception in general here.

  15. Artificial intelligence: Human effects

    SciTech Connect

    Yazdani, M.; Narayanan, A.

    1984-01-01

    This book presents an up-to-date study of the interaction between the fast-growing discipline of artificial intelligence and other human endeavors. The volume explores the scope and limitations of computing, and presents a history of the debate on the possibility of machines achieving intelligence. The authors offer a state-of-the-art survey of Al, concentrating on the ''mind'' (language understanding) and the ''body'' (robotics) of intelligent computing systems.

  16. Introducing artificial intelligence

    SciTech Connect

    Simons, G.L.

    1985-01-01

    This book is an introduction to the field of artificial intelligence. The volume sets Al in a broad context of historical attitudes, imaginative insights, and ideas about intelligence in general. The author offers a wide-ranging survey of Al concerns, including cognition, knowledge engineering, problem inference, speech understanding, and perception. He also discusses expert systems, LISP, smart robots, and other Al products, and provides a listing of all major Al systems.

  17. Biomimetic calcium phosphate coatings on Polyactive 1000/70/30.

    PubMed

    Du, C; Klasens, P; Haan, R E; Bezemer, J; Cui, F Z; de Groot, K; Layrolle, P

    2002-03-05

    Precalcification of Polyactive 1000/70/30 with a biomimetic calcium phosphate coating is expected to enhance the bioactivity of this biodegradable polymer for the application as bone filler or scaffold of bone tissue engineering. This study presents a 1-day one-step incubation method to obtain either amorphous or bone-like apatitic calcium phosphate coating on Polyactive 1000/70/30. Either dense plates or three-dimensional porous blocks of the polymer were incubated in a simplified but concentrated simulated body fluid-derived solution at 37 degrees C. By bubbling CO2 gas, a solution was prepared with calcium and phosphate ion concentrations five times of that of regular simulated body fluid. With controlled stirring, the CO2 was released out of the solution and exchanged by air. The pH of the solution increased to induce coating formation. Adjusting stirring rate and CO2/air exchange rate controlled the process kinetics. The reaction kinetics had little influence on the crystallographic structure of the final coating mineral for a given solution composition as shown by Fourier transform infrared spectroscopy and X-ray diffraction. However, the interface structure between the coating and substrate was kinetics-dependent. A fast precipitation condition resulted in a uniform but superficial calcification pattern at the surface of polymer. A slow process by selecting either a slow stirring or a slow CO2/air exchange, on the contrary, induced a localized but deep inside calcification pattern. A tensile test showed no statistically significant difference in the mechanical properties among uncoated and coated polymers. The cracking behavior of coatings from different kinetics, however, exhibited different manners, as can be attributed to different interface structures and interfacial strengths.

  18. Mechanics of Biomimetic Liposomes Encapsulating an Actin Shell.

    PubMed

    Guevorkian, Karine; Manzi, John; Pontani, Léa-Lætitia; Brochard-Wyart, Françoise; Sykes, Cécile

    2015-12-15

    Cell-shape changes are insured by a thin, dynamic, cortical layer of cytoskeleton underneath the plasma membrane. How this thin cortical structure impacts the mechanical properties of the whole cell is not fully understood. Here, we study the mechanics of liposomes or giant unilamellar vesicles, when a biomimetic actin cortex is grown at the inner layer of the lipid membrane via actin-nucleation-promoting factors. Using a hydrodynamic tube-pulling technique, we show that tube dynamics is clearly affected by the presence of an actin shell anchored to the lipid bilayer. The same force pulls much shorter tubes in the presence of the actin shell compared to bare membranes. However, in both cases, we observe that the dynamics of tube extrusion has two distinct features characteristic of viscoelastic materials: rapid elastic elongation, followed by a slower elongation phase at a constant rate. We interpret the initial elastic regime by an increase of membrane tension due to the loss of lipids into the tube. Tube length is considerably shorter for cortex liposomes at comparable pulling forces, resulting in a higher spring constant. The presence of the actin shell seems to restrict lipid mobility, as is observed in the corral effect in cells. The viscous regime for bare liposomes corresponds to a leakout of the internal liquid at constant membrane tension. The presence of the actin shell leads to a larger friction coefficient. As the tube is pulled from a patchy surface, membrane tension increases locally, leading to a Marangoni flow of lipids. As a conclusion, the presence of an actin shell is revealed by its action that alters membrane mechanics.

  19. Synthesis and characterization of biomimetic citrate-based biodegradable composites.

    PubMed

    Tran, Richard T; Wang, Liang; Zhang, Chang; Huang, Minjun; Tang, Wanjin; Zhang, Chi; Zhang, Zhongmin; Jin, Dadi; Banik, Brittany; Brown, Justin L; Xie, Zhiwei; Bai, Xiaochun; Yang, Jian

    2014-08-01

    Natural bone apatite crystals, which mediate the development and regulate the load-bearing function of bone, have recently been associated with strongly bound citrate molecules. However, such understanding has not been translated into bone biomaterial design and osteoblast cell culture. In this work, we have developed a new class of biodegradable, mechanically strong, and biocompatible citrate-based polymer blends (CBPBs), which offer enhanced hydroxyapatite binding to produce more biomimetic composites (CBPBHAs) for orthopedic applications. CBPBHAs consist of the newly developed osteoconductive citrate-presenting biodegradable polymers, crosslinked urethane-doped polyester and poly (octanediol citrate), which can be composited with up to 65 wt % hydroxyapatite. CBPBHA networks produced materials with a compressive strength of 116.23 ± 5.37 MPa comparable to human cortical bone (100-230 MPa), and increased C2C12 osterix gene and alkaline phosphatase gene expression in vitro. The promising results above prompted an investigation on the role of citrate supplementation in culture medium for osteoblast culture, which showed that exogenous citrate supplemented into media accelerated the in vitro phenotype progression of MG-63 osteoblasts. After 6 weeks of implantation in a rabbit lateral femoral condyle defect model, CBPBHA composites elicited minimal fibrous tissue encapsulation and were well integrated with the surrounding bone tissues. The development of citrate-presenting CBPBHA biomaterials and preliminary studies revealing the effects of free exogenous citrate on osteoblast culture shows the potential of citrate biomaterials to bridge the gap in orthopedic biomaterial design and osteoblast cell culture in that the role of citrate molecules has previously been overlooked.

  20. Mechanics of Biomimetic Liposomes Encapsulating an Actin Shell

    PubMed Central

    Guevorkian, Karine; Manzi, John; Pontani, Léa-Lætitia; Brochard-Wyart, Françoise; Sykes, Cécile

    2015-01-01

    Cell-shape changes are insured by a thin, dynamic, cortical layer of cytoskeleton underneath the plasma membrane. How this thin cortical structure impacts the mechanical properties of the whole cell is not fully understood. Here, we study the mechanics of liposomes or giant unilamellar vesicles, when a biomimetic actin cortex is grown at the inner layer of the lipid membrane via actin-nucleation-promoting factors. Using a hydrodynamic tube-pulling technique, we show that tube dynamics is clearly affected by the presence of an actin shell anchored to the lipid bilayer. The same force pulls much shorter tubes in the presence of the actin shell compared to bare membranes. However, in both cases, we observe that the dynamics of tube extrusion has two distinct features characteristic of viscoelastic materials: rapid elastic elongation, followed by a slower elongation phase at a constant rate. We interpret the initial elastic regime by an increase of membrane tension due to the loss of lipids into the tube. Tube length is considerably shorter for cortex liposomes at comparable pulling forces, resulting in a higher spring constant. The presence of the actin shell seems to restrict lipid mobility, as is observed in the corral effect in cells. The viscous regime for bare liposomes corresponds to a leakout of the internal liquid at constant membrane tension. The presence of the actin shell leads to a larger friction coefficient. As the tube is pulled from a patchy surface, membrane tension increases locally, leading to a Marangoni flow of lipids. As a conclusion, the presence of an actin shell is revealed by its action that alters membrane mechanics. PMID:26682806

  1. Cell surface receptor targeted biomimetic apatite nanocrystals for cancer therapy.

    PubMed

    Iafisco, Michele; Delgado-Lopez, Josè Manuel; Varoni, Elena Maria; Tampieri, Anna; Rimondini, Lia; Gomez-Morales, Jaime; Prat, Maria

    2013-11-25

    Nanosized drug carriers functionalized with moieties specifically targeting tumor cells are promising tools in cancer therapy, due to their ability to circulate in the bloodstream for longer periods and their selectivity for tumor cells, enabling the sparing of healthy tissues. Because of its biocompatibility, high bioresorbability, and responsiveness to pH changes, synthetic biomimetic nanocrystalline apatites are used as nanocarriers to produce multifunctional nanoparticles, by coupling them with the chemotherapeutic drug doxorubicin (DOXO) and the DO-24 monoclonal antibody (mAb) directed against the Met/Hepatocyte Growth Factor receptor (Met/HGFR), which is over-expressed on different types of carcinomas and thus represents a useful tumor target. The chemical-physical features of the nanoparticles are fully investigated and their interaction with cells expressing (GTL-16 gastric carcinoma line) or not expressing (NIH-3T3 fibroblasts) the Met/HGFR is analyzed. Functionalized nanoparticles specifically bind to and are internalized in cells expressing the receptor (GTL-16) but not in the ones that do not express it (NIH-3T3). Moreover they discharge DOXO in the targeted GTL-16 cells that reach the nucleus and display cytotoxicity as assessed in an MTT assay. Two different types of ternary nanoparticles are prepared, differing for the sequence of the functionalization steps (adsorption of DOXO first and then mAb or vice versa), and it is found that the ones in which mAb is adsorbed first are more efficient under all the examined aspects (binding, internalization, cytotoxicity), possibly because of a better mAb orientation on the nanoparticle surface. These multifunctional nanoparticles could thus be useful instruments for targeted local or systemic drug delivery, allowing a reduction in the therapeutic dose of the drug and thus adverse side effects. Moreover, this work opens new perspectives in the use of nanocrystalline apatites as a new platform for theranostic

  2. Biomimetic collagenous scaffold to tune inflammation by targeting macrophages

    PubMed Central

    Taraballi, Francesca; Corradetti, Bruna; Minardi, Silvia; Powel, Sebastian; Cabrera, Fernando; Van Eps, Jeff L.; Weiner, Bradley K; Tasciotti, Ennio

    2016-01-01

    The inflammatory response following implantation of a biomaterial is one of the major regulatory aspects of the overall regenerative process. The progress of inflammation determines whether functional tissue is restored or if nonfunctional fibrotic tissue is formed. This delicate balance is directed by the activity of different cells. Among these, macrophages and their different phenotypes, the inflammatory M1 to anti-inflammatory M2, are considered key players in the process. Recent approaches exploit macrophage’s regenerative potential in tissue engineering. Here, we propose a collagen scaffold functionalized with chondroitin sulfate (CSCL), a glycosaminoglycan known to be able to tune inflammation. We studied CSCL effects on bone-marrow-derived macrophages in physiological, and lipopolysaccharides-inflamed, conditions in vitro. Our data demonstrate that CSCL is able to modulate macrophage phenotype by inhibiting the LPS/CD44/NF-kB cascade. As a consequence, an upregulation of anti-inflammatory markers (TGF-β, Arg, MRC1, and IL-10) was found concomitantly with a decrease in the expression of pro-inflammatory markers (iNOS, TNF-α, IL-1β, IL-12β). We then implanted CSCL subcutaneously in a rat model to test whether the same molecular mechanism could be maintained in an in vivo environment. In vivo data confirmed the in vitro studies. A significant reduction in the number of infiltrating cells around and within the implants was observed at 72 h, with a significant downregulation of pro-inflammatory genes expression. The present work provides indications regarding the immunomodulatory potential of molecules used for the development of biomimetic materials and suggests their use to direct macrophage immune modulation for tissue repair. PMID:26977285

  3. Biomimetic Enamel Regeneration Mediated by Leucine-Rich Amelogenin Peptide.

    PubMed

    Kwak, S Y; Litman, A; Margolis, H C; Yamakoshi, Y; Simmer, J P

    2017-01-01

    We report here a novel biomimetic approach to the regeneration of human enamel. The approach combines the use of inorganic pyrophosphate (PPi) to control the onset and rate of enamel regeneration and the use of leucine-rich amelogenin peptide (LRAP), a nonphosphorylated 56-amino acid alternative splice product of amelogenin, to regulate the shape and orientation of growing enamel crystals. This study builds on our previous findings that show LRAP can effectively guide the formation of ordered arrays of needle-like hydroxyapatite (HA) crystals in vitro and on the known role mineralization inhibitors, like PPi, play in the regulation of mineralized tissue formation. Acid-etched enamel surfaces of extracted human molars, cut perpendicular or parallel to the direction of the enamel rods, were exposed to a PPi-stabilized supersaturated calcium phosphate (CaP) solution containing 0 to 0.06 mg/mL LRAP for 20 h. In the absence of LRAP, PPi inhibition was reversed by the presence of etched enamel surfaces and led to the formation of large, randomly distributed plate-like HA crystals that were weakly attached, regardless of rod orientation. In the presence of 0.04 mg/mL LRAP, however, densely packed mineral layers, comprising bundles of small needle-like HA crystals, formed on etched surfaces that were cut perpendicular to the enamel rods. These crystals were strongly attached, and their arrangement reflected to a significant degree the underlying enamel prism pattern. In contrast, under the same conditions with LRAP, little to no crystal formation was found on enamel surfaces that were cut parallel to the direction of the enamel rods. These results suggest that LRAP preferentially interacts with ab surfaces of mature enamel crystals, inhibiting their directional growth, thus selectively promoting linear growth along the c-axis of enamel crystals. The present findings demonstrate a potential for the development of a new approach to regenerate enamel structure and properties.

  4. Robust biomimetic-structural superhydrophobic surface on aluminum alloy.

    PubMed

    Li, Lingjie; Huang, Tao; Lei, Jinglei; He, Jianxin; Qu, Linfeng; Huang, Peiling; Zhou, Wei; Li, Nianbing; Pan, Fusheng

    2015-01-28

    The following facile approach has been developed to prepare a biomimetic-structural superhydrophobic surface with high stabilities and strong resistances on 2024 Al alloy that are robust to harsh environments. First, a simple hydrothermal treatment in a La(NO3)3 aqueous solution was used to fabricate ginkgo-leaf like nanostructures, resulting in a superhydrophilic surface on 2024 Al. Then a low-surface-energy compound, dodecafluoroheptyl-propyl-trimethoxylsilane (Actyflon-G502), was used to modify the superhydrophilic 2024 Al, changing the surface character from superhydrophilicity to superhydrophobicity. The water contact angle (WCA) of such a superhydrophobic surface reaches up to 160°, demonstrating excellent superhydrophobicity. Moreover, the as-prepared superhydrophobic surface shows high stabilities in air-storage, chemical and thermal environments, and has strong resistances to UV irradiation, corrosion, and abrasion. The WCAs of such a surface almost remain unchanged (160°) after storage in air for 80 days, exposure in 250 °C atmosphere for 24 h, and being exposed under UV irradiation for 24 h, are more than 144° whether in acidic or alkali medium, and are more than 150° after 48 h corrosion and after abrasion under 0.98 kPa for 1000 mm length. The remarkable durability of the as-prepared superhydrophobic surface can be attributed to its stable structure and composition, which are due to the existence of lanthanum (hydr)oxides in surface layer. The robustness of the as-prepared superhydrophobic surface to harsh environments will open their much wider applications. The fabricating approach for such robust superhydrophobic surface can be easily extended to other metals and alloys.

  5. Depletion of albumin and immunoglobulin G from human serum using epitope-imprinted polymers as artificial antibodies.

    PubMed

    Yang, Hsueh-Hui; Lu, Kuo-Hao; Lin, Yee-Fung; Tsai, Sheng-Hung; Chakraborty, Subrata; Zhai, Wei-Jun; Tai, Dar-Fu

    2013-07-01

    Serum is a readily available source for noninvasive studies in clinical research, but it contains abundant proteins such as albumin and immunoglobulin G that can hinder the presence of low-abundant proteins as well as decrease sample loading capacity of analytical methods. Therefore, depletion of these two proteins is required to observe low-abundance serum proteins. Molecularly imprinted polymers are template-induced artificial antibodies with the ability to recognize and selectively bind the target molecule. In this study, artificial albumin and immunoglobulin G antibodies were developed by using two epitopes of human serum albumin and immunoglobulin G as templates. Acrylic acid, acrylamide, and N-acryl tyramine were the corresponding monomers; N,N'-ethylene bisacrylamide served as a cross-linker, and cellulosic fibers were used as a supporting matrix. The adsorption capacity of these artificial antibodies was 15.2 mg, 10 mg, and 15 μL per gram for human serum albumin, immunoglobulin G, and human serum, respectively. The dissociation constant (Kd ) of these artificial antibodies toward the human serum albumin and immunoglobulin G was 1 μM and 0.6 μM, respectively. The biomimetic properties of these artificial antibodies, coupled with their economical and rapid production, high specificity and their reusability, make them attractive for protein separation and analysis.

  6. Biomimetics for NASA Langley Research Center: Year 2000 Report of Findings From a Six-Month Survey

    NASA Technical Reports Server (NTRS)

    Siochi, Emilie J.; Anders, John B., Jr.; Cox, David E.; Jegley, Dawn C.; Fox, Robert L.; Katzberg, Stephen J.

    2002-01-01

    This report represents an attempt to see if some of the techniques biological systems use to maximize their efficiency can be applied to the problems NASA faces in aeronautics and space exploration. It includes an internal survey of resources available at NASA Langley Research Center for biomimetics research efforts, an external survey of state of the art in biomimetics covering the Materials, Structures, Aerodynamics, Guidance and Controls areas. The Biomimetics Planning team also included ideas for potential research areas, as well as recommendations on how to implement this new program. This six-month survey was conducted in the second half of 1999.

  7. Nanolayered manganese oxide/poly(4-vinylpyridine) as a biomimetic and very efficient water oxidizing catalyst: toward an artificial enzyme in artificial photosynthesis.

    PubMed

    Najafpour, Mohammad Mahdi; Haghighi, Behzad; Ghobadi, Mohadeseh Zarei; Sedigh, Davood Jafarian

    2013-10-09

    Nanolayered Mn oxide/poly(4-vinylpyridine) as a model for Mn cluster in photosystem II was synthesized and characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR) and UV-Visible spectroscopy (UV-Vis). The compound is a very efficient water oxidizing catalyst, and sizable oxygen evolution was detected at 50 mV overpotential at near neutral pH. The number is as low as the overpotential is used by nature in photosystem II of cyanobacteria, algae and green plants for similar reactions.

  8. Biomimetic receptors for bioanalyte detection by quartz crystal microbalances - from molecules to cells.

    PubMed

    Latif, Usman; Qian, Jianjin; Can, Serpil; Dickert, Franz L

    2014-12-05

    A universal label-free detection of bioanalytes can be performed with biomimetic quartz crystal microbalance (QCM) coatings prepared by imprinting strategies. Bulk imprinting was used to detect the endocrine disrupting chemicals (EDCs) known as estradiols. The estrogen 17β-estradiol is one of the most potent EDCs, even at very low concentrations. A highly sensitive, selective and robust QCM sensor was fabricated for real time monitoring of 17β-estradiol in water samples by using molecular imprinted polyurethane. Optimization of porogen (pyrene) and cross-linker (phloroglucinol) levels leads to improved sensitivity, selectivity and response time of the estradiol sensor. Surface imprinting of polyurethane as sensor coating also allowed us to generate interaction sites for the selective recognition of bacteria, even in a very complex mixture of interfering compounds, while they were growing from their spores in nutrient solution. A double molecular imprinting approach was followed to transfer the geometrical features of natural bacteria onto the synthetic polymer to generate biomimetic bacteria. The use of biomimetic bacteria as template makes it possible to prepare multiple sensor coatings with similar sensitivity and selectivity. Thus, cell typing, e.g., differentiation of bacteria strains, bacteria growth profile and extent of their nutrition, can be monitored by biomimetic mass sensors. Obviously, this leads to controlled cell growth in bioreactors.

  9. A Novel General Chemistry Laboratory: Creation of Biomimetic Superhydrophobic Surfaces through Replica Molding

    ERIC Educational Resources Information Center

    Verbanic, Samuel; Brady, Owen; Sanda, Ahmed; Gustafson, Carolina; Donhauser, Zachary J.

    2014-01-01

    Biomimetic replicas of superhydrophobic lotus and taro leaf surfaces can be made using polydimethylsiloxane. These replicas faithfully reproduce the microstructures of the leaves' surface and can be analyzed using contact angle goniometry, self-cleaning experiments, and optical microscopy. These simple and adaptable experiments were used to…

  10. A New Absorbable Synthetic Substitute With Biomimetic Design for Dural Tissue Repair.

    PubMed

    Shi, Zhidong; Xu, Tao; Yuan, Yuyu; Deng, Kunxue; Liu, Man; Ke, Yiquan; Luo, Chengyi; Yuan, Tun; Ayyad, Ali

    2016-04-01

    Dural repair products are evolving from animal tissue-derived materials to synthetic materials as well as from inert to absorbable features; most of them lack functional and structural characteristics compared with the natural dura mater. In the present study, we evaluated the properties and tissue repair performance of a new dural repair product with biomimetic design. The biomimetic patch exhibits unique three-dimensional nonwoven microfiber structure with good mechanical strength and biocompatibility. The animal study showed that the biomimetic patch and commercially synthetic material group presented new subdural regeneration at 90 days, with low level inflammatory response and minimal to no adhesion formation detected at each stage. In the biological material group, no new subdural regeneration was observed and severe adhesion between the implant and the cortex occurred at each stage. In clinical case study, there was no cerebrospinal fluid leakage, and all the postoperation observations were normal. The biomimetic structure and proper rate of degradation of the new absorbable dura substitute can guide the meaningful reconstruction of the dura mater, which may provide a novel approach for dural defect repair.

  11. Smart Muscle-Driven Self-Cleaning of Biomimetic Microstructures from Liquid Crystal Elastomers.

    PubMed

    Shahsavan, Hamed; Salili, Seyyed Muhammad; Jákli, Antal; Zhao, Boxin

    2015-11-18

    Muscle-driven actuation of biomimetic microfibrillar structures is achieved using integrative soft-lithography on a backing splayed liquid-crystal elastomer (LCE). Variation in the backing LCE layer thickness yields different modes of thermal deformation from a pure bend to a twist-bend. Muscular motion and dynamic self-cleaning of gecko toe pads are mimicked via this mechanism.

  12. Preparation and properties of polyurethane/silicone materials for biomimetic gecko setae

    NASA Astrophysics Data System (ADS)

    Yu, Min; Dai, Zhendong; Yang, Shengrong

    2014-03-01

    In the biomimetic design of gecko setae, it is necessary to select materials with appropriate adhesive properties and to understand the effects of materials on normal and tangential adhesive forces. To meet the adhesion performance requirements of the biomimetic gecko robot foot, in this study, performance-improved polyurethane/silicone polymer materials were designed and synthesized, and the normal adhesion and tangential adhesion were measured using an adhesive friction comprehensive tester. The results show that normal adhesion increased with an increase in load when the normal load is small; when the normal load exceeds a critical value, the increase in normal adhesion slows and adhesion saturates. Under the condition of an adhesive state, the tangential adhesive force was larger for a smaller negative normal force, and a relatively large tangential adhesive force could be generated with a very small negative normal force. The elastic modulus of the synthetic polyurethane/silicone material varied with varying ratios of components, and it increased with increasing urethane content. Polyurethane/silicone material with about 30% polyurethane provided greater adhesion than other materials with different contents of polyurethane. The results provide a basis for the choice of biomimetic materials of the biomimetic gecko robot foot.

  13. Biomimetic 'Green' Synthesis of Nanomaterials Using Antioxidants-Vitamins, Glutathione and Polyphenols from Tea and Wine

    EPA Science Inventory

    The presentation summarizes our recent activity in chemical synthesis of nanomaterials via benign biomimetic ‘greener’ alternatives,1 such as the use antioxidants present in a variety of natural products, and ubiquitous glutathione in aqueous media.2 Vitamins B1, B2, C, and tea ...

  14. Role of the Conformational Rigidity in the Design of Biomimetic Antimicrobial Compounds

    SciTech Connect

    Ivankin, Andrey; Livne, Liran; Mor, Amram; Caputo, Gregory A.; DeGrado, William F.; Meron, Mati; Lin, Binhua; Gidalevitz, David

    2011-08-16

    A link between structural flexibility of biomimetic antimicrobials and their ability to penetrate into the hydrophobic core and disrupt the integrity of bacterial lipid model membranes has been established using liquid surface X-ray scattering techniques. Results indicate that the modes of interaction of flexible and conformationally restrained antimicrobials with the bacterial membranes are different.

  15. Fish and robots swimming together: attraction towards the robot demands biomimetic locomotion.

    PubMed

    Marras, Stefano; Porfiri, Maurizio

    2012-08-07

    The integration of biomimetic robots in a fish school may enable a better understanding of collective behaviour, offering a new experimental method to test group feedback in response to behavioural modulations of its 'engineered' member. Here, we analyse a robotic fish and individual golden shiners (Notemigonus crysoleucas) swimming together in a water tunnel at different flow velocities. We determine the positional preference of fish with respect to the robot, and we study the flow structure using a digital particle image velocimetry system. We find that biomimetic locomotion is a determinant of fish preference as fish are more attracted towards the robot when its tail is beating rather than when it is statically immersed in the water as a 'dummy'. At specific conditions, the fish hold station behind the robot, which may be due to the hydrodynamic advantage obtained by swimming in the robot's wake. This work makes a compelling case for the need of biomimetic locomotion in promoting robot-animal interactions and it strengthens the hypothesis that biomimetic robots can be used to study and modulate collective animal behaviour.

  16. Biomimetic patterned surfaces for controllable friction in micro- and nanoscale devices

    NASA Astrophysics Data System (ADS)

    Singh, Arvind; Suh, Kahp-Yang

    2013-12-01

    Biomimetics is the study and simulation of biological systems for desired functional properties. It involves the transformation of underlying principles discovered in nature into man-made technologies. In this context, natural surfaces have significantly inspired and motivated new solutions for micro- and nano-scale devices (e.g., Micro/Nano-Electro-Mechanical Systems, MEMS/NEMS) towards controllable friction, during their operation. As a generic solution to reduce friction at small scale, various thin films/coatings have been employed in the last few decades. In recent years, inspiration from `Lotus Effect' has initiated a new research direction for controllable friction with biomimetic patterned surfaces. By exploiting the intrinsic hydrophobicity and ability to reduce contact area, such micro- or nano-patterned surfaces have demonstrated great strength and potential for applications in MEMS/NEMS devices. This review highlights recent advancements on the design, development and performance of these biomimetic patterned surfaces. Also, we present some hybrid approaches to tackle current challenges in biomimetic tribological applications for MEMS/NEMS devices.

  17. Biomimetic synthesis and antiproliferative properties of racemic natural(-) and unnnatural(+) glyceollin I

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 14-step biomimetic synthetic route to glyceollin I in ca. 1.5% overall yield has been developed. In addition to being useful for the elaboration of analogs that can contribute to SAR, this route provides practical access to analytical standards that may be used for quality control purposes when gl...

  18. Biomimetic membrane platform containing hERG potassium channel and its application to drug screening.

    PubMed

    Arslan Yildiz, Ahu; Kang, CongBao; Sinner, Eva-Kathrin

    2013-04-07

    The hERG (human ether-à-go-go-related gene) potassium channel has been extensively studied by both academia and industry because of its relation to inherited or drug-induced long QT syndrome (LQTS). Unpredicted hERG and drug interaction affecting channel activity is of main concern for drug discovery. Although there are several methods to test hERG and drug interaction, it is still necessary to develop some efficient and economic ways to probe hERG and drug interactions. To contribute this aim, we have developed a biomimetic lipid membrane platform into which the hERG channel can be folded. Expression and integration of the hERG channel was achieved using a cell-free (CF) expression system. The folding of hERG in the biomimetic membrane system was investigated using Surface Plasmon Enhanced Fluorescence Spectroscopy (SPFS) and Imaging Surface Plasmon Resonance (iSPR). In addition, the hERG channel folded into our biomimetic membrane platform was used for probing the channel and drug interactions through fluorescence polarization (FP) assay. Our results suggest that the biomimetic system employed is capable of detecting the interaction between hERG and different channel blockers at varied concentrations. We believe that our current approach could be applied to other membrane proteins for drug screening or other protein-related interactions.

  19. Can Stabilization and Inhibition of Aquaporins Contribute to Future Development of Biomimetic Membranes?

    PubMed Central

    To, Janet; Torres, Jaume

    2015-01-01

    In recent years, the use of biomimetic membranes that incorporate membrane proteins, i.e., biomimetic-hybrid membranes, has increased almost exponentially. Key membrane proteins in these systems have been aquaporins, which selectively permeabilize cellular membranes to water. Aquaporins may be incorporated into synthetic lipid bilayers or to more stable structures made of block copolymers or solid-state nanopores. However, translocation of aquaporins to these alien environments has adverse consequences in terms of performance and stability. Aquaporins incorporated in biomimetic membranes for use in water purification and desalination should also withstand the harsh environment that may prevail in these conditions, such as high pressure, and presence of salt or other chemicals. In this respect, modified aquaporins that can be adapted to these new environments should be developed. Another challenge is that biomimetic membranes that incorporate high densities of aquaporin should be defect-free, and this can only be efficiently ascertained with the availability of completely inactive mutants that behave otherwise like the wild type aquaporin, or with effective non-toxic water channel inhibitors that are so far inexistent. In this review, we describe approaches that can potentially be used to overcome these challenges. PMID:26266425

  20. Biomimetic Receptors for Bioanalyte Detection by Quartz Crystal Microbalances — From Molecules to Cells †

    PubMed Central

    Latif, Usman; Qian, Jianjin; Can, Serpil; Dickert, Franz L.

    2014-01-01

    A universal label-free detection of bioanalytes can be performed with biomimetic quartz crystal microbalance (QCM) coatings prepared by imprinting strategies. Bulk imprinting was used to detect the endocrine disrupting chemicals (EDCs) known as estradiols. The estrogen 17β-estradiol is one of the most potent EDCs, even at very low concentrations. A highly sensitive, selective and robust QCM sensor was fabricated for real time monitoring of 17β-estradiol in water samples by using molecular imprinted polyurethane. Optimization of porogen (pyrene) and cross-linker (phloroglucinol) levels leads to improved sensitivity, selectivity and response time of the estradiol sensor. Surface imprinting of polyurethane as sensor coating also allowed us to generate interaction sites for the selective recognition of bacteria, even in a very complex mixture of interfering compounds, while they were growing from their spores in nutrient solution. A double molecular imprinting approach was followed to transfer the geometrical features of natural bacteria onto the synthetic polymer to generate biomimetic bacteria. The use of biomimetic bacteria as template makes it possible to prepare multiple sensor coatings with similar sensitivity and selectivity. Thus, cell typing, e.g., differentiation of bacteria strains, bacteria growth profile and extent of their nutrition, can be monitored by biomimetic mass sensors. Obviously, this leads to controlled cell growth in bioreactors. PMID:25490598

  1. Artificial intelligence in hematology.

    PubMed

    Zini, Gina

    2005-10-01

    Artificial intelligence (AI) is a computer based science which aims to simulate human brain faculties using a computational system. A brief history of this new science goes from the creation of the first artificial neuron in 1943 to the first artificial neural network application to genetic algorithms. The potential for a similar technology in medicine has immediately been identified by scientists and researchers. The possibility to store and process all medical knowledge has made this technology very attractive to assist or even surpass clinicians in reaching a diagnosis. Applications of AI in medicine include devices applied to clinical diagnosis in neurology and cardiopulmonary diseases, as well as the use of expert or knowledge-based systems in routine clinical use for diagnosis, therapeutic management and for prognostic evaluation. Biological applications include genome sequencing or DNA gene expression microarrays, modeling gene networks, analysis and clustering of gene expression data, pattern recognition in DNA and proteins, protein structure prediction. In the field of hematology the first devices based on AI have been applied to the routine laboratory data management. New tools concern the differential diagnosis in specific diseases such as anemias, thalassemias and leukemias, based on neural networks trained with data from peripheral blood analysis. A revolution in cancer diagnosis, including the diagnosis of hematological malignancies, has been the introduction of the first microarray based and bioinformatic approach for molecular diagnosis: a systematic approach based on the monitoring of simultaneous expression of thousands of genes using DNA microarray, independently of previous biological knowledge, analysed using AI devices. Using gene profiling, the traditional diagnostic pathways move from clinical to molecular based diagnostic systems.

  2. Artificial mismatch hybridization

    DOEpatents

    Guo, Zhen; Smith, Lloyd M.

    1998-01-01

    An improved nucleic acid hybridization process is provided which employs a modified oligonucleotide and improves the ability to discriminate a control nucleic acid target from a variant nucleic acid target containing a sequence variation. The modified probe contains at least one artificial mismatch relative to the control nucleic acid target in addition to any mismatch(es) arising from the sequence variation. The invention has direct and advantageous application to numerous existing hybridization methods, including, applications that employ, for example, the Polymerase Chain Reaction, allele-specific nucleic acid sequencing methods, and diagnostic hybridization methods.

  3. Artificial cell division.

    PubMed

    Mange, Daniel; Stauffer, André; Petraglio, Enrico; Tempesti, Gianluca

    2004-01-01

    After a survey of the theory and some realizations of self-replicating machines, this paper presents a novel self-replicating loop endowed with universal construction and computation properties. Based on the hardware implementation of the so-called Tom Thumb algorithm, the design of this loop leads to a new kind of cellular automaton made of a processing and a control units. The self-replication of the Swiss flag serves as an artificial cell division example of the loop which, according to autopoietic evaluation criteria, corresponds to a cell showing the phenomenology of a living system.

  4. Templated nanocrystal assembly on biodynamic artificial microtubule asters.

    PubMed

    Spoerke, Erik D; Boal, Andrew K; Bachand, George D; Bunker, Bruce C

    2013-03-26

    Microtubules (MTs) and the MT-associated proteins (MAPs) are critical cooperative agents involved in complex nanoassembly processes in biological systems. These biological materials and processes serve as important inspiration in developing new strategies for the assembly of synthetic nanomaterials in emerging techologies. Here, we explore a dynamic biofabrication process, modeled after the form and function of natural aster-like MT assemblies such as centrosomes. Specifically, we exploit the cooperative assembly of MTs and MAPs to form artificial microtubule asters and demonstrate that (1) these three-dimensional biomimetic microtubule asters can be controllably, reversibly assembled and (2) they serve as unique, dynamic biotemplates for the organization of secondary nanomaterials. We describe the MAP-mediated assembly and growth of functionalized MTs onto synthetic particles, the dynamic character of the assembled asters, and the application of these structures as templates for three-dimensional nanocrystal organization across multiple length scales. This biomediated nanomaterials assembly strategy illuminates a promising new pathway toward next-generation nanocomposite development.

  5. Superior Performance of Artificial Nacre Based on Graphene Oxide Nanosheets.

    PubMed

    Wang, Yang; Yuan, Hao; Ma, Piming; Bai, Huiyu; Chen, Mingqing; Dong, Weifu; Xie, Yi; Deshmukh, Yogesh S

    2017-02-01

    Natural nacre is well-known by its unique properties due to the well-recognized "bricks-and-mortar" structure. Inspired by the natural nacre, graphene oxide (GO) was reduced by dopamine with simultaneous coating by polydopamine (PDA) in aqueous solution to yield polydopamine-capped reduce GO (PDG). The artificial nacre nanocomposite materials of poly(vinyl alcohol) (PVA) and PDG presenting layered structure had been successfully constructed via a vacuum-assisted assembly process, in which PDG and PVA served as "bricks" and "mortar", respectively. A combination of hydrogen bonding, strong adhesion and friction between PDG nanosheets and PVA chains resulted in enhancements for mechanical properties. The tensile strength, elongation at break, and toughness of PDG-PVA nanocomposite reached to 327 ± 19.3 MPa, 8 ± 0.2%, and 13.0 ± 0.7 MJ m(-3), which is simultaneously 2.4, 8, and 7 times higher than that of nature nacre with 80-135 MPa, ∼1%, and ∼1.8 MJ m(-3), respectively. More interestingly, the obtained nanocomposites demonstrated a high anisotropy of thermal conductivity (k∥/k⊥ ≈ 380). Combined with superior mechanical properties and high anisotropy of thermal conductivity make these biomimetic materials promising candidates in aerospace, tissue engineering, and thermal management applications.

  6. Engineering vascularized bone grafts by integrating a biomimetic periosteum and β-TCP scaffold.

    PubMed

    Kang, Yunqing; Ren, Liling; Yang, Yunzhi

    2014-06-25

    Treatment of large bone defects using synthetic scaffolds remain a challenge mainly due to insufficient vascularization. This study is to engineer a vascularized bone graft by integrating a vascularized biomimetic cell-sheet-engineered periosteum (CSEP) and a biodegradable macroporous beta-tricalcium phosphate (β-TCP) scaffold. We first cultured human mesenchymal stem cells (hMSCs) to form cell sheet and human umbilical vascular endothelial cells (HUVECs) were then seeded on the undifferentiated hMSCs sheet to form vascularized cell sheet for mimicking the fibrous layer of native periosteum. A mineralized hMSCs sheet was cultured to mimic the cambium layer of native periosteum. This mineralized hMSCs sheet was first wrapped onto a cylindrical β-TCP scaffold followed by wrapping the vascularized HUVEC/hMSC sheet, thus generating a biomimetic CSEP on the β-TCP scaffold. A nonperiosteum structural cell sheets-covered β-TCP and plain β-TCP were used as controls. In vitro studies indicate that the undifferentiated hMSCs sheet facilitated HUVECs to form rich capillary-like networks. In vivo studies indicate that the biomimetic CSEP enhanced angiogenesis and functional anastomosis between the in vitro preformed human capillary networks and the mouse host vasculature. MicroCT analysis and osteocalcin staining show that the biomimetic CSEP/β-TCP graft formed more bone matrix compared to the other groups. These results suggest that the CSEP that mimics the cellular components and spatial configuration of periosteum plays a critical role in vascularization and osteogenesis. Our studies suggest that a biomimetic periosteum-covered β-TCP graft is a promising approach for bone regeneration.

  7. Biomimetic ceramics for periodontal regeneration in infrabony defects: A systematic review

    PubMed Central

    Rai, Jasuma Jagdish; Kalantharakath, Thanveer

    2014-01-01

    Biomimetic materials are widely used in the treatment of osseous defects as an alternative to autogenous bone graft. The aim of this article was to review the literature and compare the quality of published articles on biomimetic ceramic material used for periodontal regeneration in the treatment of infrabony defects and to discuss the future direction of research. The bibliographic databases PubMed, Ebsco, and Google Scholar were searched from January 2000 to March 2014 for randomized control trials in which biomimetic ceramic graft material was compared with open flap debridement or in combination with any other regenerative material. To avoid the variability of the search terms, the thesaurus Mesh was used. The primary outcome variable assessed was clinical attachment level (CAL). The screening of eligible studies, assessment of the methodological quality of the trials, and data extraction were performed by two observers independently. Twenty-six articles were identified and included in this systematic review. The primary outcome was CAL. Out of the 26 studies, 24 showed more than 2 mm of CAL gain. The difference in CAL change between test and control groups varied from 1.2 mm to 5.88 mm with respect to different biomaterials/biomimetic materials, which was clinically and statistically significant. Meta-analysis was not done due to heterogeneity in results between studies. Overall, biomaterials were found to be more effective than open flap debridement in improving the attachment levels in intraosseous defects. Future research should aim at increasing the osteoinductive capacity of these biomimetic graft materials. PMID:25558455

  8. Artificial Intelligence in Space Platforms.

    DTIC Science & Technology

    1984-12-01

    computer algorithms, there still appears to be a need for Artificial Inteligence techniques in the navigation area. The reason is that navigaion, in...RD-RI32 679 ARTIFICIAL INTELLIGENCE IN SPACE PLRTFORNSMU AIR FORCE 1/𔃼 INST OF TECH WRIGHT-PRTTERSON AFB OH SCHOOL OF ENGINEERING M A WRIGHT DEC 94...i4 Preface The purpose of this study was to analyze the feasibility of implementing Artificial Intelligence techniques to increase autonomy for

  9. Trimaran Resistance Artificial Neural Network

    DTIC Science & Technology

    2011-01-01

    11th International Conference on Fast Sea Transportation FAST 2011, Honolulu, Hawaii, USA, September 2011 Trimaran Resistance Artificial Neural Network Richard...Trimaran Resistance Artificial Neural Network 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e... Artificial Neural Network and is restricted to the center and side-hull configurations tested. The value in the parametric model is that it is able to

  10. Artificial hydrogenases: biohybrid and supramolecular systems for catalytic hydrogen production or uptake.

    PubMed

    Caserta, Giorgio; Roy, Souvik; Atta, Mohamed; Artero, Vincent; Fontecave, Marc

    2015-04-01

    There is an urgent need for cheap, abundant and efficient catalysts as an alternative to platinum for hydrogen production and oxidation in (photo)electrolyzers and fuel cells. Hydrogenases are attractive solutions. These enzymes use exclusively nickel and iron in their active sites and function with high catalytic rates at the thermodynamic equilibrium. As an alternative, a number of biomimetic and bioinspired catalysts for H2 production and/or uptake, based on Ni, Fe and Co, have been developed and shown to display encouraging performances. In this review we discuss specifically recent approaches aiming at incorporating these compounds within oligomeric and polymeric hosts. The latter are most often biological compounds (peptides, proteins, polysaccharides, etc.) but we also discuss non-biological scaffolds (synthetic polymers, Metal-organic-Frameworks, etc.) which can provide the appropriate environment to tune the activity and stability of the synthetic catalysts. These supramolecular catalytic systems thus define a class of original compounds so-called artificial hydrogenases.

  11. Computational Research Needs for Renewable and Alternative Energy: Studies of Natural and Artificial Photosynthesis

    NASA Astrophysics Data System (ADS)

    Batista, Victor

    2009-03-01

    The atomspheric oxygen that sustains life on earth has been generated by plants during the light period of photosynthesis. At the molecular level, the reaction involves catalytic water splitting into dioxygen, protons and electrons in the subunit D1 of photosystem II (a transmembrane complex of about 20 proteins found in the thylakoid membranes of green plant chloroplasts). Both the reaction mechanism and the structure of the catalytic center responsible for this important reaction remain poorly understood. This talk will present recent advances in experimental and computational studies towards the development of rigorous models of the oxomangenese catalytic complex and the catalytic cycle responsible for oxygen evolution, as well as recent progress on studies of biomimetic systems for artificial photosynthesis.

  12. Artificial Bone and Teeth through Controlled Ice Growth in Colloidal Suspensions

    SciTech Connect

    Tomsia, Antoni P.; Saiz, Eduardo; Deville, Sylvain

    2007-06-14

    The formation of regular patterns is a common feature of many solidification processes involving cast materials. We describe here how regular patterns can be obtained in porous alumina and hydroxyapatite (HAP) by controlling the freezing of ceramic slurries followed by subsequent ice sublimation and sintering, leading to multilayered porous ceramic structures with homogeneous and well-defined architecture. These porous materials can be infiltrated with a second phase of choice to yield biomimetic nacre-like composites with improved mechanical properties, which could be used for artificial bone and teeth applications. Proper control of the solidification patterns provides powerful means of control over the final functional properties. We discuss the relationships between the experimental results, ice growth fundamentals, the physics of ice and the interaction between inert particles and the solidification front during directional freezing.

  13. THRESHOLD LOGIC IN ARTIFICIAL INTELLIGENCE

    DTIC Science & Technology

    COMPUTER LOGIC, ARTIFICIAL INTELLIGENCE , BIONICS, GEOMETRY, INPUT OUTPUT DEVICES, LINEAR PROGRAMMING, MATHEMATICAL LOGIC, MATHEMATICAL PREDICTION, NETWORKS, PATTERN RECOGNITION, PROBABILITY, SWITCHING CIRCUITS, SYNTHESIS

  14. [Artificial neural networks in Neurosciences].

    PubMed

    Porras Chavarino, Carmen; Salinas Martínez de Lecea, José María

    2011-11-01

    This article shows that artificial neural networks are used for confirming the relationships between physiological and cognitive changes. Specifically, we explore the influence of a decrease of neurotransmitters on the behaviour of old people in recognition tasks. This artificial neural network recognizes learned patterns. When we change the threshold of activation in some units, the artificial neural network simulates the experimental results of old people in recognition tasks. However, the main contributions of this paper are the design of an artificial neural network and its operation inspired by the nervous system and the way the inputs are coded and the process of orthogonalization of patterns.

  15. Microscopic artificial swimmers

    NASA Astrophysics Data System (ADS)

    Dreyfus, Rémi; Baudry, Jean; Roper, Marcus L.; Fermigier, Marc; Stone, Howard A.; Bibette, Jérôme

    2005-10-01

    Microorganisms such as bacteria and many eukaryotic cells propel themselves with hair-like structures known as flagella, which can exhibit a variety of structures and movement patterns. For example, bacterial flagella are helically shaped and driven at their bases by a reversible rotary engine, which rotates the attached flagellum to give a motion similar to that of a corkscrew. In contrast, eukaryotic cells use flagella that resemble elastic rods and exhibit a beating motion: internally generated stresses give rise to a series of bends that propagate towards the tip. In contrast to this variety of swimming strategies encountered in nature, a controlled swimming motion of artificial micrometre-sized structures has not yet been realized. Here we show that a linear chain of colloidal magnetic particles linked by DNA and attached to a red blood cell can act as a flexible artificial flagellum. The filament aligns with an external uniform magnetic field and is readily actuated by oscillating a transverse field. We find that the actuation induces a beating pattern that propels the structure, and that the external fields can be adjusted to control the velocity and the direction of motion.

  16. Development of artificial empathy.

    PubMed

    Asada, Minoru

    2015-01-01

    We have been advocating cognitive developmental robotics to obtain new insight into the development of human cognitive functions by utilizing synthetic and constructive approaches. Among the different emotional functions, empathy is difficult to model, but essential for robots to be social agents in our society. In my previous review on artificial empathy (Asada, 2014b), I proposed a conceptual model for empathy development beginning with emotional contagion to envy/schadenfreude along with self/other differentiation. In this article, the focus is on two aspects of this developmental process, emotional contagion in relation to motor mimicry, and cognitive/affective aspects of the empathy. It begins with a summary of the previous review (Asada, 2014b) and an introduction to affective developmental robotics as a part of cognitive developmental robotics focusing on the affective aspects. This is followed by a review and discussion on several approaches for two focused aspects of affective developmental robotics. Finally, future issues involved in the development of a more authentic form of artificial empathy are discussed.

  17. The total artificial heart.

    PubMed

    Cook, Jason A; Shah, Keyur B; Quader, Mohammed A; Cooke, Richard H; Kasirajan, Vigneshwar; Rao, Kris K; Smallfield, Melissa C; Tchoukina, Inna; Tang, Daniel G

    2015-12-01

    The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient's native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review.

  18. The total artificial heart

    PubMed Central

    Cook, Jason A.; Shah, Keyur B.; Quader, Mohammed A.; Cooke, Richard H.; Kasirajan, Vigneshwar; Rao, Kris K.; Smallfield, Melissa C.; Tchoukina, Inna

    2015-01-01

    The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient’s native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review. PMID:26793338

  19. Artificial lung: current perspectives.

    PubMed

    Go, T; Macchiarini, P

    2008-10-01

    While the number of the patients suffering from end-stage pulmonary disease has been increasing, the most common treatment for this entity remains mechanical ventilation that entails the risks of lung damage by itself. Although the lung protective strategy for the prevention of further damage to the lung tissue has been elucidated and performed, mechanical ventilation alone as the management tactic coping with the patients of acute respiratory distress syndrome, chronic respiratory failure and lung transplantations has been a frustrated scenario. Extracorporeal membrane oxygenation or extracorporeal lung assist have been applied to these patients with occasional success, but it always accompanies difficulties such as multiple blood transfusion, labor intensity, technically complexity and tendency to infection. In contrast to advances in the development of cardiac or renal support systems for adults, the development of extra-, para- and intracorporeal mechanical systems for acute or chronic lung respiratory failure has logged far behind. It has been mostly due to the lack of the capable technologies. Entering 21st century with advent of new technology especially invention of the low resistance oxygenator, the developments of artificial lungs have entered the new stage. In this report current status of the artificial lungs will be reviewed.

  20. Microscopic artificial swimmers.

    PubMed

    Dreyfus, Rémi; Baudry, Jean; Roper, Marcus L; Fermigier, Marc; Stone, Howard A; Bibette, Jérôme

    2005-10-06

    Microorganisms such as bacteria and many eukaryotic cells propel themselves with hair-like structures known as flagella, which can exhibit a variety of structures and movement patterns. For example, bacterial flagella are helically shaped and driven at their bases by a reversible rotary engine, which rotates the attached flagellum to give a motion similar to that of a corkscrew. In contrast, eukaryotic cells use flagella that resemble elastic rods and exhibit a beating motion: internally generated stresses give rise to a series of bends that propagate towards the tip. In contrast to this variety of swimming strategies encountered in nature, a controlled swimming motion of artificial micrometre-sized structures has not yet been realized. Here we show that a linear chain of colloidal magnetic particles linked by DNA and attached to a red blood cell can act as a flexible artificial flagellum. The filament aligns with an external uniform magnetic field and is readily actuated by oscillating a transverse field. We find that the actuation induces a beating pattern that propels the structure, and that the external fields can be adjusted to control the velocity and the direction of motion.