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Sample records for fabricate 3d alginate

  1. 3D Cell Culture in Alginate Hydrogels

    PubMed Central

    Andersen, Therese; Auk-Emblem, Pia; Dornish, Michael

    2015-01-01

    This review compiles information regarding the use of alginate, and in particular alginate hydrogels, in culturing cells in 3D. Knowledge of alginate chemical structure and functionality are shown to be important parameters in design of alginate-based matrices for cell culture. Gel elasticity as well as hydrogel stability can be impacted by the type of alginate used, its concentration, the choice of gelation technique (ionic or covalent), and divalent cation chosen as the gel inducing ion. The use of peptide-coupled alginate can control cell–matrix interactions. Gelation of alginate with concomitant immobilization of cells can take various forms. Droplets or beads have been utilized since the 1980s for immobilizing cells. Newer matrices such as macroporous scaffolds are now entering the 3D cell culture product market. Finally, delayed gelling, injectable, alginate systems show utility in the translation of in vitro cell culture to in vivo tissue engineering applications. Alginate has a history and a future in 3D cell culture. Historically, cells were encapsulated in alginate droplets cross-linked with calcium for the development of artificial organs. Now, several commercial products based on alginate are being used as 3D cell culture systems that also demonstrate the possibility of replacing or regenerating tissue. PMID:27600217

  2. 3D Cell Culture in Alginate Hydrogels

    PubMed Central

    Andersen, Therese; Auk-Emblem, Pia; Dornish, Michael

    2015-01-01

    This review compiles information regarding the use of alginate, and in particular alginate hydrogels, in culturing cells in 3D. Knowledge of alginate chemical structure and functionality are shown to be important parameters in design of alginate-based matrices for cell culture. Gel elasticity as well as hydrogel stability can be impacted by the type of alginate used, its concentration, the choice of gelation technique (ionic or covalent), and divalent cation chosen as the gel inducing ion. The use of peptide-coupled alginate can control cell–matrix interactions. Gelation of alginate with concomitant immobilization of cells can take various forms. Droplets or beads have been utilized since the 1980s for immobilizing cells. Newer matrices such as macroporous scaffolds are now entering the 3D cell culture product market. Finally, delayed gelling, injectable, alginate systems show utility in the translation of in vitro cell culture to in vivo tissue engineering applications. Alginate has a history and a future in 3D cell culture. Historically, cells were encapsulated in alginate droplets cross-linked with calcium for the development of artificial organs. Now, several commercial products based on alginate are being used as 3D cell culture systems that also demonstrate the possibility of replacing or regenerating tissue.

  3. 3D Cell Culture in Alginate Hydrogels.

    PubMed

    Andersen, Therese; Auk-Emblem, Pia; Dornish, Michael

    2015-03-24

    This review compiles information regarding the use of alginate, and in particular alginate hydrogels, in culturing cells in 3D. Knowledge of alginate chemical structure and functionality are shown to be important parameters in design of alginate-based matrices for cell culture. Gel elasticity as well as hydrogel stability can be impacted by the type of alginate used, its concentration, the choice of gelation technique (ionic or covalent), and divalent cation chosen as the gel inducing ion. The use of peptide-coupled alginate can control cell-matrix interactions. Gelation of alginate with concomitant immobilization of cells can take various forms. Droplets or beads have been utilized since the 1980s for immobilizing cells. Newer matrices such as macroporous scaffolds are now entering the 3D cell culture product market. Finally, delayed gelling, injectable, alginate systems show utility in the translation of in vitro cell culture to in vivo tissue engineering applications. Alginate has a history and a future in 3D cell culture. Historically, cells were encapsulated in alginate droplets cross-linked with calcium for the development of artificial organs. Now, several commercial products based on alginate are being used as 3D cell culture systems that also demonstrate the possibility of replacing or regenerating tissue.

  4. Alginate/nanohydroxyapatite scaffolds with designed core/shell structures fabricated by 3D plotting and in situ mineralization for bone tissue engineering.

    PubMed

    Luo, Yongxiang; Lode, Anja; Wu, Chengtie; Chang, Jiang; Gelinsky, Michael

    2015-04-01

    Composite scaffolds, especially polymer/hydroxyapatite (HAP) composite scaffolds with predesigned structures, are promising materials for bone tissue engineering. Various methods including direct mixing of HAP powder with polymers or incubating polymer scaffolds in simulated body fluid for preparing polymer/HAP composite scaffolds are either uncontrolled or require long times of incubation. In this work, alginate/nano-HAP composite scaffolds with designed pore parameters and core/shell structures were fabricated using 3D plotting technique and in situ mineralization under mild conditions (at room temperature and without the use of any organic solvents). Light microscopy, scanning electron microscopy, microcomputer tomography, X-ray diffraction, and Fourier transform infrared spectroscopy were applied to characterize the fabricated scaffolds. Mechanical properties and protein delivery of the scaffolds were evaluated, as well as the cell response to the scaffolds by culturing human bone-marrow-derived mesenchymal stem cells (hBMSC). The obtained data indicate that this method is suitable to fabricate alginate/nano-HAP composite scaffolds with a layer of nano-HAP, coating the surface of the alginate strands homogeneously and completely. The surface mineralization enhanced the mechanical properties and improved the cell attachment and spreading, as well as supported sustaining protein release, compared to pure alginate scaffolds without nano-HAP shell layer. The results demonstrated that the method provides an interesting option for bone tissue engineering application.

  5. 3D printing facilitated scaffold-free tissue unit fabrication.

    PubMed

    Tan, Yu; Richards, Dylan J; Trusk, Thomas C; Visconti, Richard P; Yost, Michael J; Kindy, Mark S; Drake, Christopher J; Argraves, William Scott; Markwald, Roger R; Mei, Ying

    2014-06-01

    Tissue spheroids hold great potential in tissue engineering as building blocks to assemble into functional tissues. To date, agarose molds have been extensively used to facilitate fusion process of tissue spheroids. As a molding material, agarose typically requires low temperature plates for gelation and/or heated dispenser units. Here, we proposed and developed an alginate-based, direct 3D mold-printing technology: 3D printing microdroplets of alginate solution into biocompatible, bio-inert alginate hydrogel molds for the fabrication of scaffold-free tissue engineering constructs. Specifically, we developed a 3D printing technology to deposit microdroplets of alginate solution on calcium containing substrates in a layer-by-layer fashion to prepare ring-shaped 3D hydrogel molds. Tissue spheroids composed of 50% endothelial cells and 50% smooth muscle cells were robotically placed into the 3D printed alginate molds using a 3D printer, and were found to rapidly fuse into toroid-shaped tissue units. Histological and immunofluorescence analysis indicated that the cells secreted collagen type I playing a critical role in promoting cell-cell adhesion, tissue formation and maturation.

  6. 3D Printing Facilitated Scaffold-free Tissue Unit Fabrication

    PubMed Central

    Tan, Yu; Richards, Dylan J.; Trusk, Thomas C.; Visconti, Richard P.; Yost, Michael J.; Kindy, Mark S.; Drake, Christopher J.; Argraves, William Scott; Markwald, Roger R.; Mei, Ying

    2014-01-01

    Tissue spheroids hold great potential in tissue engineering as building blocks to assemble into functional tissues. To date, agarose molds have been extensively used to facilitate fusion process of tissue spheroids. As a molding material, agarose typically requires low temperature plates for gelation and/or heated dispenser units. Here, we proposed and developed an alginate-based, direct 3D mold-printing technology: 3D printing micro-droplets of alginate solution into biocompatible, bio-inert alginate hydrogel molds for the fabrication of scaffold-free tissue engineering constructs. Specifically, we developed a 3D printing technology to deposit micro-droplets of alginate solution on calcium containing substrates in a layer-by-layer fashion to prepare ring-shaped 3D hydrogel molds. Tissue spheroids composed of 50% endothelial cells and 50% smooth muscle cells were robotically placed into the 3D printed alginate molds using a 3D printer, and were found to rapidly fuse into toroid-shaped tissue units. Histological and immunofluorescence analysis indicated that the cells secreted collagen type I playing a critical role in promoting cell-cell adhesion, tissue formation and maturation. PMID:24717646

  7. 3D Bioprinting of Heterogeneous Aortic Valve Conduits with Alginate/Gelatin Hydrogels

    PubMed Central

    Duan, Bin; Hockaday, Laura A.; Kang, Kevin H.; Butcher, Jonathan T.

    2013-01-01

    Heart valve disease is a serious and growing public health problem for which prosthetic replacement is most commonly indicated. Current prosthetic devices are inadequate for younger adults and growing children. Tissue engineered living aortic valve conduits have potential for remodeling, regeneration, and growth, but fabricating natural anatomical complexity with cellular heterogeneity remain challenging. In the current study, we implement 3D bioprinting to fabricate living alginate/gelatin hydrogel valve conduits with anatomical architecture and direct incorporation of dual cell types in a regionally constrained manner. Encapsulated aortic root sinus smooth muscle cells (SMC) and aortic valve leaflet interstitial cells (VIC) were viable within alginate/gelatin hydrogel discs over 7 days in culture. Acellular 3D printed hydrogels exhibited reduced modulus, ultimate strength, and peak strain reducing slightly over 7-day culture, while the tensile biomechanics of cell-laden hydrogels were maintained. Aortic valve conduits were successfully bioprinted with direct encapsulation of SMC in the valve root and VIC in the leaflets. Both cell types were viable (81.4±3.4% for SMC and 83.2±4.0% for VIC) within 3D printed tissues. Encapsulated SMC expressed elevated alpha-smooth muscle actin when printed in stiff matrix, while VIC expressed elevated vimentin in soft matrix. These results demonstrate that anatomically complex, heterogeneously encapsulated aortic valve hydrogel conduits can be fabricated with 3D bioprinting. PMID:23015540

  8. Fabrication of 3D Silicon Sensors

    SciTech Connect

    Kok, A.; Hansen, T.E.; Hansen, T.A.; Lietaer, N.; Summanwar, A.; Kenney, C.; Hasi, J.; Da Via, C.; Parker, S.I.; /Hawaii U.

    2012-06-06

    Silicon sensors with a three-dimensional (3-D) architecture, in which the n and p electrodes penetrate through the entire substrate, have many advantages over planar silicon sensors including radiation hardness, fast time response, active edge and dual readout capabilities. The fabrication of 3D sensors is however rather complex. In recent years, there have been worldwide activities on 3D fabrication. SINTEF in collaboration with Stanford Nanofabrication Facility have successfully fabricated the original (single sided double column type) 3D detectors in two prototype runs and the third run is now on-going. This paper reports the status of this fabrication work and the resulted yield. The work of other groups such as the development of double sided 3D detectors is also briefly reported.

  9. Surface modified alginate microcapsules for 3D cell culture

    NASA Astrophysics Data System (ADS)

    Chen, Yi-Wen; Kuo, Chiung Wen; Chueh, Di-Yen; Chen, Peilin

    2016-06-01

    Culture as three dimensional cell aggregates or spheroids can offer an ideal platform for tissue engineering applications and for pharmaceutical screening. Such 3D culture models, however, may suffer from the problems such as immune response and ineffective and cumbersome culture. This paper describes a simple method for producing microcapsules with alginate cores and a thin shell of poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) to encapsulate mouse induced pluripotent stem (miPS) cells, generating a non-fouling surface as an effective immunoisolation barrier. We demonstrated the trapping of the alginate microcapsules in a microwell array for the continuous observation and culture of a large number of encapsulated miPS cells in parallel. miPS cells cultured in the microcapsules survived well and proliferated to form a single cell aggregate. Droplet formation of monodisperse microcapsules with controlled size combined with flow cytometry provided an efficient way to quantitatively analyze the growth of encapsulated cells in a high-throughput manner. The simple and cost-effective coating technique employed to produce the core-shell microcapsules could be used in the emerging field of cell therapy. The microwell array would provide a convenient, user friendly and high-throughput platform for long-term cell culture and monitoring.

  10. Fabricating 3D figurines with personalized faces.

    PubMed

    Tena, J Rafael; Mahler, Moshe; Beeler, Thabo; Grosse, Max; Hengchin Yeh; Matthews, Iain

    2013-01-01

    We present a semi-automated system for fabricating figurines with faces that are personalised to the individual likeness of the customer. The efficacy of the system has been demonstrated by commercial deployments at Walt Disney World Resort and Star Wars Celebration VI in Orlando Florida. Although the system is semi automated, human intervention is limited to a few simple tasks to maintain the high throughput and consistent quality required for commercial application. In contrast to existing systems that fabricate custom heads that are assembled to pre-fabricated plastic bodies, our system seamlessly integrates 3D facial data with a predefined figurine body into a unique and continuous object that is fabricated as a single piece. The combination of state-of-the-art 3D capture, modelling, and printing that are the core of our system provide the flexibility to fabricate figurines whose complexity is only limited by the creativity of the designer.

  11. Fabricating 3D figurines with personalized faces.

    PubMed

    Tena, J Rafael; Mahler, Moshe; Beeler, Thabo; Grosse, Max; Hengchin Yeh; Matthews, Iain

    2013-01-01

    We present a semi-automated system for fabricating figurines with faces that are personalised to the individual likeness of the customer. The efficacy of the system has been demonstrated by commercial deployments at Walt Disney World Resort and Star Wars Celebration VI in Orlando Florida. Although the system is semi automated, human intervention is limited to a few simple tasks to maintain the high throughput and consistent quality required for commercial application. In contrast to existing systems that fabricate custom heads that are assembled to pre-fabricated plastic bodies, our system seamlessly integrates 3D facial data with a predefined figurine body into a unique and continuous object that is fabricated as a single piece. The combination of state-of-the-art 3D capture, modelling, and printing that are the core of our system provide the flexibility to fabricate figurines whose complexity is only limited by the creativity of the designer. PMID:24808129

  12. Freeform drop-on-demand laser printing of 3D alginate and cellular constructs.

    PubMed

    Xiong, Ruitong; Zhang, Zhengyi; Chai, Wenxuan; Huang, Yong; Chrisey, Douglas B

    2015-01-01

    Laser printing is an orifice-free printing approach and has been investigated for the printing of two-dimensional patterns and simple three-dimensional (3D) constructs. To demonstrate the potential of laser printing as an effective bioprinting technique, both straight and Y-shaped tubes have been freeform printed using two different bioinks: 8% alginate solution and 2% alginate-based mouse fibroblast suspension. It has been demonstrated that 3D cellular tubes, including constructs with bifurcated overhang structures, can be adequately fabricated under optimal printing conditions. The post-printing cell viabilities immediately after printing as well as after 24 h incubation are above 60% for printed straight and Y-shaped fibroblast tubes. During fabrication, overhang and spanning structures can be printed using a dual-purpose crosslinking solution, which also functions as a support material. The advancement distance of gelation reaction front after a cycle time of the receiving platform downward motion should be estimated for experimental planning. The optimal downward movement step size of receiving platform should be chosen to be equal to the height of ungelled portion of a previously printed layer. PMID:26693735

  13. Freeform drop-on-demand laser printing of 3D alginate and cellular constructs.

    PubMed

    Xiong, Ruitong; Zhang, Zhengyi; Chai, Wenxuan; Huang, Yong; Chrisey, Douglas B

    2015-12-22

    Laser printing is an orifice-free printing approach and has been investigated for the printing of two-dimensional patterns and simple three-dimensional (3D) constructs. To demonstrate the potential of laser printing as an effective bioprinting technique, both straight and Y-shaped tubes have been freeform printed using two different bioinks: 8% alginate solution and 2% alginate-based mouse fibroblast suspension. It has been demonstrated that 3D cellular tubes, including constructs with bifurcated overhang structures, can be adequately fabricated under optimal printing conditions. The post-printing cell viabilities immediately after printing as well as after 24 h incubation are above 60% for printed straight and Y-shaped fibroblast tubes. During fabrication, overhang and spanning structures can be printed using a dual-purpose crosslinking solution, which also functions as a support material. The advancement distance of gelation reaction front after a cycle time of the receiving platform downward motion should be estimated for experimental planning. The optimal downward movement step size of receiving platform should be chosen to be equal to the height of ungelled portion of a previously printed layer.

  14. Mastoid obliteration using 3D PCL scaffold in combination with alginate and rhBMP-2.

    PubMed

    Jang, Chul Ho; Kim, Min Seong; Cho, Yong Beom; Jang, Yoon Seok; Kim, Geun Hyung

    2013-11-01

    Various materials, both biological and alloplastic, have been used for mastoid obliteration after canal wall-down mastoidectomy in chronic otitis media. The purpose of this study is to investigate the osteoinductive potential of PCL scaffolds in mastoid obliteration, and to test that osteoinductivity can be enhanced by coating PCL with alginate and rhBMP-2. The in vitro biocompatibilities of the scaffolds were examined using osteoblast-like cells (MG63). Cell-morphology and calcium deposition were assessed. Based on scanning electron microscope (SEM) images, the cells grew sporadically on the surfaces of the struts in the PCL scaffold, while the entire struts of the PCL/alginate/BMP-2 scaffold was covered with the cells. Furthermore, the PCL/alginate/BMP-2 scaffold showed significantly higher calcium deposition than the PCL/alginate scaffold. Micro-CT showed osteogenesis in the pores of the 3D PCL scaffold in the experimental group, compared to the control group. Confocal microscopic findings showed that the honeycomb appearance of the PCL structure remained in the control group (pure PCL), but significant amount of bone remodeling in the experimental group (PCL/alginate/BMP-2). Histomorphometric analysis showed that the experimental group demonstrated a significantly higher amount (p=0.014) of new bone formation with 50.2 ± 6.5% (mean ± SD), compared to 10.2 ± 3.5% for the control group. Based on these in vitro and in vivo results, the use of the PCL/alginate/BMP-2 scaffold seemed to be a promising technique for the mastoid obliteration.

  15. Fluid and cell behaviors along a 3D printed alginate/gelatin/fibrin channel.

    PubMed

    Xu, Yufan; Wang, Xiaohong

    2015-08-01

    Three-dimensional (3D) cell manipulation is available with the integration of microfluidic technology and rapid prototyping techniques. High-Fidelity (Hi-Fi) constructs hold enormous therapeutic potential for organ manufacturing and regenerative medicine. In the present paper we introduced a quasi-three-dimensional (Q3D) model with parallel biocompatible alginate/gelatin/fibrin hurdles. The behaviors of fluids and cells along the microfluidic channels with various widths were studied. Cells inside the newly designed microfluidic channels attached and grew well. Morphological changes of adipose-derived stem cells (ADSCs) in both two-dimensional (2D) and 3D milieu were found on the printed constructs. Endothelialization occurred with the co-cultures of ADSCs and hepatocytes. This study provides insights into the interactions among fluids, cells and biomaterials, the behaviors of fluids and cells along the microfluidic channels, and the applications of Q3D techniques.

  16. 3D Bioprinting Human Chondrocytes with Nanocellulose-Alginate Bioink for Cartilage Tissue Engineering Applications.

    PubMed

    Markstedt, Kajsa; Mantas, Athanasios; Tournier, Ivan; Martínez Ávila, Héctor; Hägg, Daniel; Gatenholm, Paul

    2015-05-11

    The introduction of 3D bioprinting is expected to revolutionize the field of tissue engineering and regenerative medicine. The 3D bioprinter is able to dispense materials while moving in X, Y, and Z directions, which enables the engineering of complex structures from the bottom up. In this study, a bioink that combines the outstanding shear thinning properties of nanofibrillated cellulose (NFC) with the fast cross-linking ability of alginate was formulated for the 3D bioprinting of living soft tissue with cells. Printability was evaluated with concern to printer parameters and shape fidelity. The shear thinning behavior of the tested bioinks enabled printing of both 2D gridlike structures as well as 3D constructs. Furthermore, anatomically shaped cartilage structures, such as a human ear and sheep meniscus, were 3D printed using MRI and CT images as blueprints. Human chondrocytes bioprinted in the noncytotoxic, nanocellulose-based bioink exhibited a cell viability of 73% and 86% after 1 and 7 days of 3D culture, respectively. On the basis of these results, we can conclude that the nanocellulose-based bioink is a suitable hydrogel for 3D bioprinting with living cells. This study demonstrates the potential use of nanocellulose for 3D bioprinting of living tissues and organs. PMID:25806996

  17. Focused electrojetting for nanoscale 3-D fabrication

    NASA Astrophysics Data System (ADS)

    Lee, Minhee; Kim, Ho-Young

    2012-11-01

    Although extreme miniaturization of components in integrated circuits and biochemical chips has driven the development of various nanofabrication technologies, three-dimensional fabrication of nanoscale objects is still in its infancy. Here we propose a novel method to fabricate a free-standing nanowall by the line-by-line deposition of electrospun polymer nanofibers. We show that the electrified nanojet, which tends to get unstable as traveling in free space due to the Coulombic repulsion, can be stably focused onto a narrow line of metal electrode. On the conducting line, the polymer nanojet is spontaneously folded successively to form a wall-like structure. We rationalize the period of spontaneous folding by balancing the tension in the polymer fiber with the electrostatic interaction of the fiber with the metal ground. This novel fabrication scheme can be applied for the development of three-dimensional bioscaffolds, nanofilters and nanorobots.

  18. Calcium signaling in response to fluid flow by chondrocytes in 3D alginate culture.

    PubMed

    Degala, Satish; Williams, Rebecca; Zipfel, Warren; Bonassar, Lawrence J

    2012-05-01

    Quantifying the effects of mechanical loading on the metabolic response of chondrocytes is difficult due to complicated structure of cartilage ECM and the coupled nature of the mechanical stimuli presented to the cells. In this study we describe the effects of fluid flow, particularly hydrostatic pressure and wall shear stress, on the Ca(2+) signaling response of bovine articular chondrocytes in 3D culture. Using well-established alginate hydrogel system to maintain spherical chondrocyte morphology, we altered solid volume fraction to change scaffold mechanics. Fluid velocities in the bulk of the scaffolds were directly measured via an optical technique and scaffold permeability and aggregate modulus was characterized to quantify the mechanical stimuli presented to cells. Ca(2+) signaling response to direct perfusion of chondrocyte-seeded scaffolds increased monotonically with flow rate and was found more directly dependent on fluid velocity rather than shear stress or hydrostatic pressure. Chondrocytes in alginate scaffolds responded to fluid flow at velocities and shear stresses 2-3 orders of magnitude lower than seen in previous monolayer studies. Our data suggest that flow-induced Ca(2+) signaling response of chondrocytes in alginate culture may be due to mechanical signaling pathways, which is influenced by the 3D nature of cell shape.

  19. Fabrication of 3-D Submicron Glass Structures by FIB

    NASA Astrophysics Data System (ADS)

    Chao, C. H.; Shen, S. C.; Wu, J. R.

    2009-10-01

    The fabrication characteristic of focused ion beam (FIB) for Pyrex glass was investigated. FIB has several advantages such as high resolution, high material removal rates, low forward scattering, and direct fabrication in selective area without any etching mask. In this study, FIB-etched Pyrex glass was used for fast fabrication of 3-D submicron structures. A glass structure with 0.39 μm in width was fabricated. The experimental results in terms of limiting beam size, ion dose (ion/cm2), and beam current are discussed. The influence of XeF2 gas on FIB glass fabrication was investigated.

  20. Optofluidic fabrication for 3D-shaped particles

    NASA Astrophysics Data System (ADS)

    Paulsen, Kevin S.; di Carlo, Dino; Chung, Aram J.

    2015-04-01

    Complex three-dimensional (3D)-shaped particles could play unique roles in biotechnology, structural mechanics and self-assembly. Current methods of fabricating 3D-shaped particles such as 3D printing, injection moulding or photolithography are limited because of low-resolution, low-throughput or complicated/expensive procedures. Here, we present a novel method called optofluidic fabrication for the generation of complex 3D-shaped polymer particles based on two coupled processes: inertial flow shaping and ultraviolet (UV) light polymerization. Pillars within fluidic platforms are used to deterministically deform photosensitive precursor fluid streams. The channels are then illuminated with patterned UV light to polymerize the photosensitive fluid, creating particles with multi-scale 3D geometries. The fundamental advantages of optofluidic fabrication include high-resolution, multi-scalability, dynamic tunability, simple operation and great potential for bulk fabrication with full automation. Through different combinations of pillar configurations, flow rates and UV light patterns, an infinite set of 3D-shaped particles is available, and a variety are demonstrated.

  1. Optofluidic fabrication for 3D-shaped particles

    PubMed Central

    Paulsen, Kevin S.; Di Carlo, Dino; Chung, Aram J.

    2015-01-01

    Complex three-dimensional (3D)-shaped particles could play unique roles in biotechnology, structural mechanics and self-assembly. Current methods of fabricating 3D-shaped particles such as 3D printing, injection moulding or photolithography are limited because of low-resolution, low-throughput or complicated/expensive procedures. Here, we present a novel method called optofluidic fabrication for the generation of complex 3D-shaped polymer particles based on two coupled processes: inertial flow shaping and ultraviolet (UV) light polymerization. Pillars within fluidic platforms are used to deterministically deform photosensitive precursor fluid streams. The channels are then illuminated with patterned UV light to polymerize the photosensitive fluid, creating particles with multi-scale 3D geometries. The fundamental advantages of optofluidic fabrication include high-resolution, multi-scalability, dynamic tunability, simple operation and great potential for bulk fabrication with full automation. Through different combinations of pillar configurations, flow rates and UV light patterns, an infinite set of 3D-shaped particles is available, and a variety are demonstrated. PMID:25904062

  2. Freestanding 3-D microvascular networks made of alginate hydrogel as a universal tool to create microchannels inside hydrogels.

    PubMed

    Hu, Chong; Sun, Han; Liu, Zhengzhi; Chen, Yin; Chen, Yangfan; Wu, Hongkai; Ren, Kangning

    2016-07-01

    The diffusion of molecules such as nutrients and oxygen through densely packed cells is impeded by blockage and consumption by cells, resulting in a limited depth of penetration. This has been a major hurdle to a bulk (3-D) culture. Great efforts have been made to develop methods for generating branched microchannels inside hydrogels to support mass exchange inside a bulk culture. These previous attempts faced a common obstacle: researchers tried to fabricate microchannels with gels already loaded with cells, but the fabrication procedures are often harmful to the embedded cells. Herein, we present a universal strategy to create microchannels in different types of hydrogels, which effectively avoids cell damage. This strategy is based on a freestanding alginate 3-D microvascular network prepared by in-situ generation of copper ions from a sacrificial copper template. This alginate network could be used as implants to create microchannels inside different types of hydrogels. This approach effectively addresses the issue of cell damage during microfabrication and made it possible to create microchannels inside different types of gels. The microvascular network produced with this method is (1) strong enough to allow handling, (2) biocompatible to allow cell culturing, and (3) appropriately permeable to allow diffusion of small molecules, while sufficiently dense to prevent blocking of channels when embedded in different types of gels. In addition, composite microtubules could be prepared by simply pre-loading other materials, e.g., particles and large biomolecules, in the hydrogel. Compared with other potential strategies to fabricate freestanding gel channel networks, our method is more rapid, low-cost and scalable due to parallel processing using an industrially mass-producible template. We demonstrated the use of such vascular networks in creating microchannels in different hydrogels and composite gels, as well as with a cell culture in a nutrition gradient based

  3. 3D nanostructures fabricated by advanced stencil lithography

    NASA Astrophysics Data System (ADS)

    Yesilkoy, F.; Flauraud, V.; Rüegg, M.; Kim, B. J.; Brugger, J.

    2016-02-01

    This letter reports on a novel fabrication method for 3D metal nanostructures using high-throughput nanostencil lithography. Aperture clogging, which occurs on the stencil membranes during physical vapor deposition, is leveraged to create complex topographies on the nanoscale. The precision of the 3D nanofabrication method is studied in terms of geometric parameters and material types. The versatility of the technique is demonstrated by various symmetric and chiral patterns made of Al and Au.

  4. 3D nanostructures fabricated by advanced stencil lithography.

    PubMed

    Yesilkoy, F; Flauraud, V; Rüegg, M; Kim, B J; Brugger, J

    2016-03-01

    This letter reports on a novel fabrication method for 3D metal nanostructures using high-throughput nanostencil lithography. Aperture clogging, which occurs on the stencil membranes during physical vapor deposition, is leveraged to create complex topographies on the nanoscale. The precision of the 3D nanofabrication method is studied in terms of geometric parameters and material types. The versatility of the technique is demonstrated by various symmetric and chiral patterns made of Al and Au. PMID:26884085

  5. Low intensity pulse ultrasound stimulate chondrocytes growth in a 3-D alginate scaffold through improved porosity and permeability.

    PubMed

    Guo, Gepu; Lu, Lu; Ji, Hongfei; Ma, Yong; Dong, Rui; Tu, Juan; Guo, Xiasheng; Qiu, Yuanyuan; Wu, Junru; Zhang, Dong

    2015-04-01

    A 3-D scaffold culture system has been used to promote in producing functional chondrocytes for repairing damaged cartilage. In the present study, the low intensity pulse ultrasound (LIPUS) (P(-)=0, 0.055, 0.085 and 0.11 MPa) was applied to improve the porosity and permeability of a 3-D alginate scaffold which was beneficial for the nutrition supply and metabolism during cell growth in 3-D alginate scaffold. The porosity and permeability of the scaffold was quantitatively analyzed based on scanning electron microscopy examination and fluorescence image observation. The results suggest that, for the scaffold exposed to LIPUS, its porosity and permeability could be significantly enhanced by the increasing LIPUS amplitude, which might be induced by the microstreaming shear stress generated by ultrasound-driven microbubble oscillations. Furthermore, the assessments of cell proliferation and collagen II expression confirmed that chondrocytes growth could be effectively promoted in 3-D alginate scaffolds treated by LIPUS, because of the improved scaffold porosity and permeability might benefit cell growth space and nutrition supply. It should also be noticed that appropriate LIPUS driving parameters should be adapted to achieve optimized chondrocytes culture effect in 3-D alginate scaffold. PMID:25543661

  6. Low intensity pulse ultrasound stimulate chondrocytes growth in a 3-D alginate scaffold through improved porosity and permeability.

    PubMed

    Guo, Gepu; Lu, Lu; Ji, Hongfei; Ma, Yong; Dong, Rui; Tu, Juan; Guo, Xiasheng; Qiu, Yuanyuan; Wu, Junru; Zhang, Dong

    2015-04-01

    A 3-D scaffold culture system has been used to promote in producing functional chondrocytes for repairing damaged cartilage. In the present study, the low intensity pulse ultrasound (LIPUS) (P(-)=0, 0.055, 0.085 and 0.11 MPa) was applied to improve the porosity and permeability of a 3-D alginate scaffold which was beneficial for the nutrition supply and metabolism during cell growth in 3-D alginate scaffold. The porosity and permeability of the scaffold was quantitatively analyzed based on scanning electron microscopy examination and fluorescence image observation. The results suggest that, for the scaffold exposed to LIPUS, its porosity and permeability could be significantly enhanced by the increasing LIPUS amplitude, which might be induced by the microstreaming shear stress generated by ultrasound-driven microbubble oscillations. Furthermore, the assessments of cell proliferation and collagen II expression confirmed that chondrocytes growth could be effectively promoted in 3-D alginate scaffolds treated by LIPUS, because of the improved scaffold porosity and permeability might benefit cell growth space and nutrition supply. It should also be noticed that appropriate LIPUS driving parameters should be adapted to achieve optimized chondrocytes culture effect in 3-D alginate scaffold.

  7. PCL/alginate composite scaffolds for hard tissue engineering: fabrication, characterization, and cellular activities.

    PubMed

    Kim, Yong Bok; Kim, Geun Hyung

    2015-02-01

    Alginates have been used widely in biomedical applications because of good biocompatibility, low cost, and rapid gelation in the presence of calcium ions. However, poor mechanical properties and fabrication-ability for three-dimensional shapes have been obstacles in hard-tissue engineering applications. To overcome these shortcomings of alginates, we suggest a new composite system, consisting of a synthetic polymer, poly(ε-caprolactone), and various weight fractions (10-40 wt %) of alginate. The fabricated composite scaffolds displayed a multilayered 3D structure, consisting of microsized composite struts, and they provided a 100% offset for each layer. To show the feasibility of the scaffold for hard tissue regeneration, the composite scaffolds fabricated were assessed not only for physical properties, including surface roughness, tensile strength, and water absorption and wetting, but also in vitro osteoblastic cellular responses (cell-seeding efficiency, cell viability, fluorescence analyses, alkaline phosphatase (ALP) activity, and mineralization) by culturing with preosteoblasts (MC3T3-E1). Due to the alginate components in the composites, the scaffolds showed significantly enhanced wetting behavior, water-absorption (∼12-fold), and meaningful biological activities (∼2.1-fold for cell-seeding efficiency, ∼2.5-fold for cell-viability at 7 days, ∼3.4-fold for calcium deposition), compared with a pure PCL scaffold.

  8. 3D printing of liquid metals as fugitive inks for fabrication of 3D microfluidic channels.

    PubMed

    Parekh, Dishit P; Ladd, Collin; Panich, Lazar; Moussa, Khalil; Dickey, Michael D

    2016-05-21

    This paper demonstrates a simple method to fabricate 3D microchannels and microvasculature at room temperature by direct-writing liquid metal as a sacrificial template. The formation of a surface oxide skin on the low-viscosity liquid metal stabilizes the shape of the printed metal for planar and out-of-plane structures. The printed structures can be embedded in a variety of soft (e.g. elastomeric) and rigid (e.g. thermoset) polymers. Both acid and electrochemical reduction are capable of removing the oxide skin that forms on the metal, which destabilizes the ink so that it withdraws from the encapsulating material due to capillary forces, resulting in nearly full recovery of the fugitive ink at room temperature. Whereas conventional fabrication procedures typically confine microchannels to 2D planes, the geometry of the printed microchannels can be varied from a simple 2D network to complex 3D architectures without using lithography. The method produces robust monolithic structures without the need for any bonding or assembling techniques that often limit the materials of construction of conventional microchannels. Removing select portions of the metal leaves behind 3D metal features that can be used as antennas, interconnects, or electrodes for interfacing with lab-on-a-chip devices. This paper describes the capabilities and limitations of this simple process. PMID:27025537

  9. 3D printing of liquid metals as fugitive inks for fabrication of 3D microfluidic channels.

    PubMed

    Parekh, Dishit P; Ladd, Collin; Panich, Lazar; Moussa, Khalil; Dickey, Michael D

    2016-05-21

    This paper demonstrates a simple method to fabricate 3D microchannels and microvasculature at room temperature by direct-writing liquid metal as a sacrificial template. The formation of a surface oxide skin on the low-viscosity liquid metal stabilizes the shape of the printed metal for planar and out-of-plane structures. The printed structures can be embedded in a variety of soft (e.g. elastomeric) and rigid (e.g. thermoset) polymers. Both acid and electrochemical reduction are capable of removing the oxide skin that forms on the metal, which destabilizes the ink so that it withdraws from the encapsulating material due to capillary forces, resulting in nearly full recovery of the fugitive ink at room temperature. Whereas conventional fabrication procedures typically confine microchannels to 2D planes, the geometry of the printed microchannels can be varied from a simple 2D network to complex 3D architectures without using lithography. The method produces robust monolithic structures without the need for any bonding or assembling techniques that often limit the materials of construction of conventional microchannels. Removing select portions of the metal leaves behind 3D metal features that can be used as antennas, interconnects, or electrodes for interfacing with lab-on-a-chip devices. This paper describes the capabilities and limitations of this simple process.

  10. 3D Stretchable Arch Ribbon Array Fabricated via Grayscale Lithography.

    PubMed

    Pang, Yu; Shu, Yi; Shavezipur, Mohammad; Wang, Xuefeng; Mohammad, Mohammad Ali; Yang, Yi; Zhao, Haiming; Deng, Ningqin; Maboudian, Roya; Ren, Tian-Ling

    2016-01-01

    Microstructures with flexible and stretchable properties display tremendous potential applications including integrated systems, wearable devices and bio-sensor electronics. Hence, it is essential to develop an effective method for fabricating curvilinear and flexural microstructures. Despite significant advances in 2D stretchable inorganic structures, large scale fabrication of unique 3D microstructures at a low cost remains challenging. Here, we demonstrate that the 3D microstructures can be achieved by grayscale lithography to produce a curved photoresist (PR) template, where the PR acts as sacrificial layer to form wavelike arched structures. Using plasma-enhanced chemical vapor deposition (PECVD) process at low temperature, the curved PR topography can be transferred to the silicon dioxide layer. Subsequently, plasma etching can be used to fabricate the arched stripe arrays. The wavelike silicon dioxide arch microstructure exhibits Young modulus and fracture strength of 52 GPa and 300 MPa, respectively. The model of stress distribution inside the microstructure was also established, which compares well with the experimental results. This approach of fabricating a wavelike arch structure may become a promising route to produce a variety of stretchable sensors, actuators and circuits, thus providing unique opportunities for emerging classes of robust 3D integrated systems.

  11. 3D Stretchable Arch Ribbon Array Fabricated via Grayscale Lithography

    PubMed Central

    Pang, Yu; Shu, Yi; Shavezipur, Mohammad; Wang, Xuefeng; Mohammad, Mohammad Ali; Yang, Yi; Zhao, Haiming; Deng, Ningqin; Maboudian, Roya; Ren, Tian-Ling

    2016-01-01

    Microstructures with flexible and stretchable properties display tremendous potential applications including integrated systems, wearable devices and bio-sensor electronics. Hence, it is essential to develop an effective method for fabricating curvilinear and flexural microstructures. Despite significant advances in 2D stretchable inorganic structures, large scale fabrication of unique 3D microstructures at a low cost remains challenging. Here, we demonstrate that the 3D microstructures can be achieved by grayscale lithography to produce a curved photoresist (PR) template, where the PR acts as sacrificial layer to form wavelike arched structures. Using plasma-enhanced chemical vapor deposition (PECVD) process at low temperature, the curved PR topography can be transferred to the silicon dioxide layer. Subsequently, plasma etching can be used to fabricate the arched stripe arrays. The wavelike silicon dioxide arch microstructure exhibits Young modulus and fracture strength of 52 GPa and 300 MPa, respectively. The model of stress distribution inside the microstructure was also established, which compares well with the experimental results. This approach of fabricating a wavelike arch structure may become a promising route to produce a variety of stretchable sensors, actuators and circuits, thus providing unique opportunities for emerging classes of robust 3D integrated systems. PMID:27345766

  12. 3D Stretchable Arch Ribbon Array Fabricated via Grayscale Lithography

    NASA Astrophysics Data System (ADS)

    Pang, Yu; Shu, Yi; Shavezipur, Mohammad; Wang, Xuefeng; Mohammad, Mohammad Ali; Yang, Yi; Zhao, Haiming; Deng, Ningqin; Maboudian, Roya; Ren, Tian-Ling

    2016-06-01

    Microstructures with flexible and stretchable properties display tremendous potential applications including integrated systems, wearable devices and bio-sensor electronics. Hence, it is essential to develop an effective method for fabricating curvilinear and flexural microstructures. Despite significant advances in 2D stretchable inorganic structures, large scale fabrication of unique 3D microstructures at a low cost remains challenging. Here, we demonstrate that the 3D microstructures can be achieved by grayscale lithography to produce a curved photoresist (PR) template, where the PR acts as sacrificial layer to form wavelike arched structures. Using plasma-enhanced chemical vapor deposition (PECVD) process at low temperature, the curved PR topography can be transferred to the silicon dioxide layer. Subsequently, plasma etching can be used to fabricate the arched stripe arrays. The wavelike silicon dioxide arch microstructure exhibits Young modulus and fracture strength of 52 GPa and 300 MPa, respectively. The model of stress distribution inside the microstructure was also established, which compares well with the experimental results. This approach of fabricating a wavelike arch structure may become a promising route to produce a variety of stretchable sensors, actuators and circuits, thus providing unique opportunities for emerging classes of robust 3D integrated systems.

  13. 3D Stretchable Arch Ribbon Array Fabricated via Grayscale Lithography.

    PubMed

    Pang, Yu; Shu, Yi; Shavezipur, Mohammad; Wang, Xuefeng; Mohammad, Mohammad Ali; Yang, Yi; Zhao, Haiming; Deng, Ningqin; Maboudian, Roya; Ren, Tian-Ling

    2016-01-01

    Microstructures with flexible and stretchable properties display tremendous potential applications including integrated systems, wearable devices and bio-sensor electronics. Hence, it is essential to develop an effective method for fabricating curvilinear and flexural microstructures. Despite significant advances in 2D stretchable inorganic structures, large scale fabrication of unique 3D microstructures at a low cost remains challenging. Here, we demonstrate that the 3D microstructures can be achieved by grayscale lithography to produce a curved photoresist (PR) template, where the PR acts as sacrificial layer to form wavelike arched structures. Using plasma-enhanced chemical vapor deposition (PECVD) process at low temperature, the curved PR topography can be transferred to the silicon dioxide layer. Subsequently, plasma etching can be used to fabricate the arched stripe arrays. The wavelike silicon dioxide arch microstructure exhibits Young modulus and fracture strength of 52 GPa and 300 MPa, respectively. The model of stress distribution inside the microstructure was also established, which compares well with the experimental results. This approach of fabricating a wavelike arch structure may become a promising route to produce a variety of stretchable sensors, actuators and circuits, thus providing unique opportunities for emerging classes of robust 3D integrated systems. PMID:27345766

  14. Single-step laser-based fabrication and patterning of cell-encapsulated alginate microbeads

    PubMed Central

    Kingsley, DM; Dias, AD; Chrisey, DB; Corr, DT

    2014-01-01

    Alginate can be used to encapsulate mammalian cells and for the slow release of small molecules. Packaging alginate as microbead structures allows customizable delivery for tissue engineering, drug release, or contrast agents for imaging. However, state-of-the-art microbead fabrication has limited range in achievable bead sizes, and poor control over bead placement, which may be desired to localize cellular signaling or delivery. Herein, we present a novel, laser-based method for single-step fabrication and precise planar placement of alginate microbeads. Our results show that bead size is controllable within 8%, and fabricated microbeads can remain immobilized within 2% of their target placement. Demonstration of this technique using human breast cancer cells shows that cells encapsulated within these microbeads survive at a rate of 89.6%, decreasing to 84.3% after five days in culture. Infusing rhodamine dye into microbeads prior to fluorescent microscopy shows their 3D spheroidal geometry and the ability to sequester small molecules. Microbead fabrication and patterning is compatible with conventional cellular transfer and patterning by laser direct-write, allowing location-based cellular studies. While this method can also be used to fabricate microbeads en masse for collection, the greatest value to tissue engineering and drug delivery studies and applications lies in the pattern registry of printed microbeads. PMID:24192221

  15. Micro stereo lithography and fabrication of 3D microdevices

    NASA Astrophysics Data System (ADS)

    Varadan, Vijay K.; Varadan, Vasundara V.

    1999-08-01

    Micro Stereo Lithography (MSL) is a poor man's LIGA for fabricating high aspect ratio MEMS devices in UV curable semiconducting polymers using either two computer-controlled low inertia galvanometric mirrors with the aid of focusing lens or an array of optical fibers. For 3D MEMS devices, the polymers need to have conductive and possibly piezoelectric or ferroelectric properties. Such polymers are being developed at Penn State resulting in microdevices for fluid and drug delivery. Applications may include implanted medical delivery systems, chemical and biological instruments, fluid delivery in engines, pump coolants and refrigerants for local cooling of electronic components. With the invention of organic thin film transistor, now it is possible to fabricate 3D polymeric MEMS devices with built-in-electronics similar to silicon based microelectronics. In this paper, a brief introduction of MSL system is presented followed by a detailed design and development of micro pumps using this approach.

  16. A method to fabricate disconnected silver nanostructures in 3D.

    PubMed

    Vora, Kevin; Kang, SeungYeon; Mazur, Eric

    2012-01-01

    The standard nanofabrication toolkit includes techniques primarily aimed at creating 2D patterns in dielectric media. Creating metal patterns on a submicron scale requires a combination of nanofabrication tools and several material processing steps. For example, steps to create planar metal structures using ultraviolet photolithography and electron-beam lithography can include sample exposure, sample development, metal deposition, and metal liftoff. To create 3D metal structures, the sequence is repeated multiple times. The complexity and difficulty of stacking and aligning multiple layers limits practical implementations of 3D metal structuring using standard nanofabrication tools. Femtosecond-laser direct-writing has emerged as a pre-eminent technique for 3D nanofabrication.(1,2) Femtosecond lasers are frequently used to create 3D patterns in polymers and glasses.(3-7) However, 3D metal direct-writing remains a challenge. Here, we describe a method to fabricate silver nanostructures embedded inside a polymer matrix using a femtosecond laser centered at 800 nm. The method enables the fabrication of patterns not feasible using other techniques, such as 3D arrays of disconnected silver voxels.(8) Disconnected 3D metal patterns are useful for metamaterials where unit cells are not in contact with each other,(9) such as coupled metal dot(10,11)or coupled metal rod(12,13) resonators. Potential applications include negative index metamaterials, invisibility cloaks, and perfect lenses. In femtosecond-laser direct-writing, the laser wavelength is chosen such that photons are not linearly absorbed in the target medium. When the laser pulse duration is compressed to the femtosecond time scale and the radiation is tightly focused inside the target, the extremely high intensity induces nonlinear absorption. Multiple photons are absorbed simultaneously to cause electronic transitions that lead to material modification within the focused region. Using this approach, one can

  17. Electroactive Film of Myoglobin Incorporated in a 3D-porous Calcium Alginate Film with Polyvinyl Alcohol, Glycerin and Gelatin.

    PubMed

    Zheng, Xueqin; Sun, Hong; Hou, Shifeng

    2015-01-01

    In this work, an electroactive porous Mb-CA's composite film was fabricated by incorporating myoglobin (Mb) in a three-dimension (3D) porous calcium alginate (CA) film with polyvinyl alcohol, glycerol, and gelatin. The porous Mb-CA's film modified electrodes exhibited a pair of well-defined, quasi-reversible cyclic voltammetric (CV) peaks at about -0.37 V vs. SCE in pH 7.0 buffers, characteristic of Mb heme Fe((III))/Fe((II)) redox couples. The electrochemical parameters, such as formal potentials (E(o')) and apparent heterogeneous electron-transfer rate constants (ks), were estimated by square-wave voltammetry with nonlinear regression analysis. The porous CA's composite film could form hydrogel in aqueous solution. The positions of the Soret absorbance band suggest that Mb in the CA's composite film kept its native states in the medium pH range. Hydrogen peroxide, oxygen, and nitrite were electrochemically catalyzed by the Mb-CA's composite film with significant lowering of the reduction overpotential.

  18. Laser-assisted fabrication of highly viscous alginate microsphere

    NASA Astrophysics Data System (ADS)

    Lin, Yafu; Huang, Yong

    2011-04-01

    Encapsulated microspheres have been widely used in various biomedical applications. However, fabrication of encapsulated microspheres from highly viscous materials has always been a manufacturing challenge. The objective of this study is to explore a novel metallic foil-assisted laser-induced forward transfer (LIFT), a laser-assisted fabrication technique, to make encapsulated microspheres using high sodium alginate concentration solutions. The proposed four-layer approach includes a quartz disk, a sacrificial and adhesive layer, a metallic foil, and a transferred suspension layer. It is found that the proposed four-layer modified LIFT approach provides a promising fabrication technology for making of bead-encapsulated microspheres from highly viscous solutions. During the process, the microsphere only can be formed if the direct-writing height is larger than the critical direct-writing height; otherwise, tail structured droplets are formed; and the encapsulated microsphere diameter linearly increases with the laser fluence and decreases with the sodium alginate concentration.

  19. 3D ultrasound imaging for prosthesis fabrication and diagnostic imaging

    SciTech Connect

    Morimoto, A.K.; Bow, W.J.; Strong, D.S.

    1995-06-01

    The fabrication of a prosthetic socket for a below-the-knee amputee requires knowledge of the underlying bone structure in order to provide pressure relief for sensitive areas and support for load bearing areas. The goal is to enable the residual limb to bear pressure with greater ease and utility. Conventional methods of prosthesis fabrication are based on limited knowledge about the patient`s underlying bone structure. A 3D ultrasound imaging system was developed at Sandia National Laboratories. The imaging system provides information about the location of the bones in the residual limb along with the shape of the skin surface. Computer assisted design (CAD) software can use this data to design prosthetic sockets for amputees. Ultrasound was selected as the imaging modality. A computer model was developed to analyze the effect of the various scanning parameters and to assist in the design of the overall system. The 3D ultrasound imaging system combines off-the-shelf technology for image capturing, custom hardware, and control and image processing software to generate two types of image data -- volumetric and planar. Both volumetric and planar images reveal definition of skin and bone geometry with planar images providing details on muscle fascial planes, muscle/fat interfaces, and blood vessel definition. The 3D ultrasound imaging system was tested on 9 unilateral below-the- knee amputees. Image data was acquired from both the sound limb and the residual limb. The imaging system was operated in both volumetric and planar formats. An x-ray CT (Computed Tomography) scan was performed on each amputee for comparison. Results of the test indicate beneficial use of ultrasound to generate databases for fabrication of prostheses at a lower cost and with better initial fit as compared to manually fabricated prostheses.

  20. 3D lithographically fabricated nanoliter containers for drug delivery.

    PubMed

    Randall, Christina L; Leong, Timothy G; Bassik, Noy; Gracias, David H

    2007-12-22

    Lithographic patterning offers the possibility for precise structuring of drug delivery devices. The fabrication process can also facilitate the incorporation of advanced functionality for imaging, sensing, telemetry and actuation. However, a major limitation of present day lithographic fabrication is the inherent two-dimensionality of the patterning process. We review a new approach to construct three dimensional (3D) patterned containers by lithographically patterning two dimensional (2D) templates with liquefiable hinges that spontaneously fold upon heating into hollow polyhedral containers. The containers have finite encapsulation volumes, can be made small enough to pass through a hypodermic needle, and the 3D profile of the containers facilitates enhanced diffusion with the surrounding medium as compared to reservoir systems fabricated in planar substrates. We compare the features of the containers to those of present day drug delivery systems. These features include ease of manufacture, versatility in size and shape, monodisperse porosity, ability for spatial manipulation and remote triggering to release drugs on-demand, the incorporation of electronic modules, cell encapsulation, biocompatibility and stability. We also review possible applications in drug delivery and cell encapsulation therapy (CET). The results summarized in this review suggest a new strategy to enable construction of "smart", three dimensional drug delivery systems using lithography.

  1. Formulation and stability evaluation of 3D alginate beads potentially useful for cumulus-oocyte complexes culture.

    PubMed

    Dorati, Rossella; Genta, Ida; Ferrari, Michela; Vigone, Giulia; Merico, Valeria; Garagna, Silvia; Zuccotti, Maurizio; Conti, Bice

    2016-01-01

    Ovarian follicle encapsulation in synthetic or natural matrixes based on biopolymers is potentially a promising approach to in vitro maturation (IVM) process, since it maintains follicle 3D organisation by preventing its flattening and consequent disruption of gap junctions, preserving the functional relationship between oocyte and companion follicle cells. The aim of the work was to optimise physico-chemical parameters of alginate microcapsules for perspective IVM under 3D environments. On this purpose alginate and cross-linking agent concentrations were investigated. Alginate concentration between 0.75% and 0.125% w/w and Mg(2+), Ba(2+), Ca(2+ )at concentration between 100 and 20 mM were tested. Follicle encapsulation was obtained by on purpose modified diffusion setting gelation technique, and evaluated together with beads, chemical and mechanical stability in standard and stressing conditions. Beads permeability was tested towards albumin, fetuin, pyruvate, glucose, pullulan. Results demonstrated that 0.25% alginate cross-linked in 100 mM CaCl2 beads is suitable to follicle encapsulation. PMID:26791322

  2. Solid organ fabrication: comparison of decellularization to 3D bioprinting.

    PubMed

    Jung, Jangwook P; Bhuiyan, Didarul B; Ogle, Brenda M

    2016-01-01

    Solid organ fabrication is an ultimate goal of Regenerative Medicine. Since the introduction of Tissue Engineering in 1993, functional biomaterials, stem cells, tunable microenvironments, and high-resolution imaging technologies have significantly advanced efforts to regenerate in vitro culture or tissue platforms. Relatively simple flat or tubular organs are already in (pre)clinical trials and a few commercial products are in market. The road to more complex, high demand, solid organs including heart, kidney and lung will require substantive technical advancement. Here, we consider two emerging technologies for solid organ fabrication. One is decellularization of cadaveric organs followed by repopulation with terminally differentiated or progenitor cells. The other is 3D bioprinting to deposit cell-laden bio-inks to attain complex tissue architecture. We reviewed the development and evolution of the two technologies and evaluated relative strengths needed to produce solid organs, with special emphasis on the heart and other tissues of the cardiovascular system. PMID:27583168

  3. Solid organ fabrication: comparison of decellularization to 3D bioprinting.

    PubMed

    Jung, Jangwook P; Bhuiyan, Didarul B; Ogle, Brenda M

    2016-01-01

    Solid organ fabrication is an ultimate goal of Regenerative Medicine. Since the introduction of Tissue Engineering in 1993, functional biomaterials, stem cells, tunable microenvironments, and high-resolution imaging technologies have significantly advanced efforts to regenerate in vitro culture or tissue platforms. Relatively simple flat or tubular organs are already in (pre)clinical trials and a few commercial products are in market. The road to more complex, high demand, solid organs including heart, kidney and lung will require substantive technical advancement. Here, we consider two emerging technologies for solid organ fabrication. One is decellularization of cadaveric organs followed by repopulation with terminally differentiated or progenitor cells. The other is 3D bioprinting to deposit cell-laden bio-inks to attain complex tissue architecture. We reviewed the development and evolution of the two technologies and evaluated relative strengths needed to produce solid organs, with special emphasis on the heart and other tissues of the cardiovascular system.

  4. Simple and Versatile 3D Printed Microfluidics Using Fused Filament Fabrication.

    PubMed

    Morgan, Alex J L; Hidalgo San Jose, Lorena; Jamieson, William D; Wymant, Jennifer M; Song, Bing; Stephens, Phil; Barrow, David A; Castell, Oliver K

    2016-01-01

    The uptake of microfluidics by the wider scientific community has been limited by the fabrication barrier created by the skills and equipment required for the production of traditional microfluidic devices. Here we present simple 3D printed microfluidic devices using an inexpensive and readily accessible printer with commercially available printer materials. We demonstrate that previously reported limitations of transparency and fidelity have been overcome, whilst devices capable of operating at pressures in excess of 2000 kPa illustrate that leakage issues have also been resolved. The utility of the 3D printed microfluidic devices is illustrated by encapsulating dental pulp stem cells within alginate droplets; cell viability assays show the vast majority of cells remain live, and device transparency is sufficient for single cell imaging. The accessibility of these devices is further enhanced through fabrication of integrated ports and by the introduction of a Lego®-like modular system facilitating rapid prototyping whilst offering the potential for novices to build microfluidic systems from a database of microfluidic components. PMID:27050661

  5. Simple and Versatile 3D Printed Microfluidics Using Fused Filament Fabrication

    PubMed Central

    Morgan, Alex J. L.; Hidalgo San Jose, Lorena; Jamieson, William D.; Wymant, Jennifer M.; Song, Bing; Stephens, Phil

    2016-01-01

    The uptake of microfluidics by the wider scientific community has been limited by the fabrication barrier created by the skills and equipment required for the production of traditional microfluidic devices. Here we present simple 3D printed microfluidic devices using an inexpensive and readily accessible printer with commercially available printer materials. We demonstrate that previously reported limitations of transparency and fidelity have been overcome, whilst devices capable of operating at pressures in excess of 2000 kPa illustrate that leakage issues have also been resolved. The utility of the 3D printed microfluidic devices is illustrated by encapsulating dental pulp stem cells within alginate droplets; cell viability assays show the vast majority of cells remain live, and device transparency is sufficient for single cell imaging. The accessibility of these devices is further enhanced through fabrication of integrated ports and by the introduction of a Lego®-like modular system facilitating rapid prototyping whilst offering the potential for novices to build microfluidic systems from a database of microfluidic components. PMID:27050661

  6. Simple and Versatile 3D Printed Microfluidics Using Fused Filament Fabrication.

    PubMed

    Morgan, Alex J L; Hidalgo San Jose, Lorena; Jamieson, William D; Wymant, Jennifer M; Song, Bing; Stephens, Phil; Barrow, David A; Castell, Oliver K

    2016-01-01

    The uptake of microfluidics by the wider scientific community has been limited by the fabrication barrier created by the skills and equipment required for the production of traditional microfluidic devices. Here we present simple 3D printed microfluidic devices using an inexpensive and readily accessible printer with commercially available printer materials. We demonstrate that previously reported limitations of transparency and fidelity have been overcome, whilst devices capable of operating at pressures in excess of 2000 kPa illustrate that leakage issues have also been resolved. The utility of the 3D printed microfluidic devices is illustrated by encapsulating dental pulp stem cells within alginate droplets; cell viability assays show the vast majority of cells remain live, and device transparency is sufficient for single cell imaging. The accessibility of these devices is further enhanced through fabrication of integrated ports and by the introduction of a Lego®-like modular system facilitating rapid prototyping whilst offering the potential for novices to build microfluidic systems from a database of microfluidic components.

  7. Fabrication of novel core-shell hybrid alginate hydrogel beads.

    PubMed

    Liu, Hongxia; Wang, Chaoyang; Gao, Quanxing; Liu, Xinxing; Tong, Zhen

    2008-03-01

    Novel hybrid alginate hydrogel beads with shells of porous CaCO3 microparticles were fabricated by templating water-in-oil emulsion and subsequent in situ gelation. Porous CaCO3 microparticles were self-assembled at interfaces of water-in-oil emulsion. Water droplets containing alginate in the emulsion were subsequently in situ gelated by Ca2+ released from CaCO3 through decreasing pH with slow hydrolysis of d-glucono-delta-lactone (GDL). The resulting hybrid beads with alginate gel cores and shells of porous CaCO3 microparticles were called colloidosomes. The packed density of CaCO3 microparticles in the shell increased with increasing the ratio of the CaCO3 microparticle weight to the water phase volume Mp/Vw and decreased with addition of NaCl into water. The size of the produced colloidosome beads was independent of Mp/Vw. Increasing the volume fraction of water Phi w to 0.5, some colloidosome beads deformed to nonspheral shape and even broken. Brilliant blue (BB) as a drug model was loaded into the colloidosome beads by being dissolved in the alginate aqueous solution before gelation. The BB release from the colloidosome beads was slowed down because of the formation of the shells of CaCO3 microparticles. The colloidosome beads may find applications as delivery vehicles for drugs, cosmetics, food supplements and living cell.

  8. Fabrication of cross-linked alginate beads using electrospraying for adenovirus delivery.

    PubMed

    Park, Hongkwan; Kim, Pyung-Hwan; Hwang, Taewon; Kwon, Oh-Joon; Park, Tae-Joon; Choi, Sung-Wook; Yun, Chae-Ok; Kim, Jung Hyun

    2012-05-10

    Cross-linked alginate beads containing adenovirus (Ad) were successfully fabricated using an electrospraying method to achieve the protection and release of Ad in a controlled manner. An aqueous alginate solution containing Ad was electrosprayed into an aqueous phase containing a cross-linking agent (calcium chloride) at different process variables (voltages, alginate concentrations, and flow rates). Alginate beads containing Ad were used for transduction of U343 glioma cells and the transduction efficiency of the alginate beads was measured by quantification of gene expression using a fluorescence-activated cell sorter at different time points. In vitro results of gene expression revealed that the Ad encapsulated in the alginate beads with 0.5 wt% of alginate concentration exhibited a high activity for a long period (over 7 days) and was released in a sustained manner from the alginate beads. The Ad-encapsulating alginate beads could be promising materials for local delivery of Ad at a high concentration into target sites.

  9. Fabrication of cationic chitin nanofiber/alginate composite materials.

    PubMed

    Sato, Koki; Tanaka, Kohei; Takata, Yusei; Yamamoto, Kazuya; Kadokawa, Jun-Ichi

    2016-10-01

    We have already found that an amidinated chitin, which was prepared by the reaction of a partially deacetylated chitin with N,N-dimethylacetamide dimethyl acetal, was converted into an amidinium chitin bicarbonate with nanofiber morphology by CO2 gas bubbling and ultrasonic treatments in water. In this study, we performed the fabrication of composite materials of such cationic chitin nanofibers with an anionic polysaccharide, sodium alginate, by ion exchange. When the amidinium chitin bicarbonate nanofiber aqueous dispersion was added to an aqueous solution of sodium alginate, the composite material was agglomerated, which was isolated by centrifugation, filtration, and lyophilization, to form a manipulatable sheet. The morphology of the resulting sheet at nano-scale was evaluated by SEM measurement. PMID:27288700

  10. Biomedical-grade, high mannuronic acid content (BioMVM) alginate enhances the proteoglycan production of primary human meniscal fibrochondrocytes in a 3-D microenvironment

    PubMed Central

    Rey-Rico, Ana; Klich, Angelique; Cucchiarini, Magali; Madry, Henning

    2016-01-01

    Alginates are important hydrogels for meniscus tissue engineering as they support the meniscal fibrochondrocyte phenotype and proteoglycan production, the extracellular matrix (ECM) component chiefly responsible for its viscoelastic properties. Here, we systematically evaluated four biomedical- and two nonbiomedical-grade alginates for their capacity to provide the best three-dimensional (3-D) microenvironment and to support proteoglycan synthesis of encapsulated human meniscal fibrochondrocytes in vitro. Biomedical-grade, high mannuronic acid alginate spheres (BioLVM, BioMVM) were the most uniform in size, indicating an effect of the purity of alginate on the shape of the spheres. Interestingly, the purity of alginates did not affect cell viability. Of note, only fibrochondrocytes encapsulated in BioMVM alginate produced and retained significant amounts of proteoglycans. Following transplantation in an explant culture model, the alginate spheres containing fibrochondrocytes remained in close proximity with the meniscal tissue adjacent to the defect. The results reveal a promising role of BioMVM alginate to enhance the proteoglycan production of primary human meniscal fibrochondrocytes in a 3-D hydrogel microenvironment. These findings have significant implications for cell-based translational studies aiming at restoring lost meniscal tissue in regions containing high amounts of proteoglycans. PMID:27302206

  11. Fabric defects identification based on on-line 3D measurement

    NASA Astrophysics Data System (ADS)

    Song, Limei; An, Hongwei; Dong, Xiaoxiao; Zhang, Chunbo

    2011-08-01

    This paper using on-line identification of three dimensions to solve some difficult problems of two dimensional defects identification. Different defects have different 3D structural features, thus to identify and classify defects based on 3D testing data. Compared with fabric defects processed by two-dimensional image, 3D identification can more exclude cloth wrinkles and the flying thick silk floss. So the 3D identification is of high accuracy and reliability to identify fabric defects.

  12. Development and characterization of novel porous 3D alginate-cockle shell powder nanobiocomposite bone scaffold.

    PubMed

    Bharatham, B Hemabarathy; Abu Bakar, Md Zuki; Perimal, Enoch Kumar; Yusof, Loqman Mohamed; Hamid, Muhajir

    2014-01-01

    A novel porous three-dimensional bone scaffold was developed using a natural polymer (alginate/Alg) in combination with a naturally obtained biomineral (nano cockle shell powder/nCP) through lyophilization techniques. The scaffold was developed in varying composition mixture of Alg-nCP and characterized using various evaluation techniques as well as preliminary in vitro studies on MG63 human osteoblast cells. Morphological observations using SEM revealed variations in structures with the use of different Alg-nCP composition ratios. All the developed scaffolds showed a porous structure with pore sizes ideal for facilitating new bone growth; however, not all combination mixtures showed subsequent favorable characteristics to be used for biological applications. Scaffolds produced using the combination mixture of 40% Alg and 60% nCP produced significantly promising results in terms of mechanical strength, degradation rate, and increased cell proliferation rates making it potentially the optimum composition mixture of Alg-nCP with future application prospects.

  13. Optical fabrication of lightweighted 3D printed mirrors

    NASA Astrophysics Data System (ADS)

    Herzog, Harrison; Segal, Jacob; Smith, Jeremy; Bates, Richard; Calis, Jacob; De La Torre, Alyssa; Kim, Dae Wook; Mici, Joni; Mireles, Jorge; Stubbs, David M.; Wicker, Ryan

    2015-09-01

    Direct Metal Laser Sintering (DMLS) and Electron Beam Melting (EBM) 3D printing technologies were utilized to create lightweight, optical grade mirrors out of AlSi10Mg aluminum and Ti6Al4V titanium alloys at the University of Arizona in Tucson. The mirror prototypes were polished to meet the λ/20 RMS and λ/4 P-V surface figure requirements. The intent of this project was to design topologically optimized mirrors that had a high specific stiffness and low surface displacement. Two models were designed using Altair Inspire software, and the mirrors had to endure the polishing process with the necessary stiffness to eliminate print-through. Mitigating porosity of the 3D printed mirror blanks was a challenge in the face of reconciling new printing technologies with traditional optical polishing methods. The prototypes underwent Hot Isostatic Press (HIP) and heat treatment to improve density, eliminate porosity, and relieve internal stresses. Metal 3D printing allows for nearly unlimited topological constraints on design and virtually eliminates the need for a machine shop when creating an optical quality mirror. This research can lead to an increase in mirror mounting support complexity in the manufacturing of lightweight mirrors and improve overall process efficiency. The project aspired to have many future applications of light weighted 3D printed mirrors, such as spaceflight. This paper covers the design/fab/polish/test of 3D printed mirrors, thermal/structural finite element analysis, and results.

  14. Proliferation and enrichment of CD133+ glioblastoma cancer stem cells on 3D chitosan-alginate scaffolds

    PubMed Central

    Kievit, Forrest M.; Florczyk, Stephen J.; Leung, Matthew C.; Wang, Kui; Wu, Jennifer D.; Silber, John R.; Ellenbogen, Richard G.; Lee, Jerry S.H.; Zhang, Miqin

    2014-01-01

    Emerging evidence implicates cancer stem cells (CSCs) as primary determinants of the clinical behavior of human cancers, representing an ideal target for next-generation anticancer therapies. However CSCs are difficult to propagate in vitro, severely limiting the study of CSC biology and drug development. Here we report that growing cells from glioblastoma (GBM) cell lines on three dimensional (3D) porous chitosan-alginate (CA) scaffolds dramatically promotes the proliferation and enrichment of cells possessing the hallmarks of CSCs. CA scaffold-grown cells were found more tumorigenic in nude mouse xenografts than cells grown from monolayers. Growing in CA scaffolds rapidly promoted expression of genes involved in the epithelial-to-mesenchymal transition that has been implicated in the genesis of CSCs. Our results indicate that CA scaffolds have utility as a simple and inexpensive means to cultivate CSCs in vitro in support of studies to understand CSC biology and develop more effective anti-cancer therapies. PMID:25109438

  15. Microfluidic Fabrication of Bio-Inspired Microfibers with Controllable Magnetic Spindle-Knots for 3D Assembly and Water Collection.

    PubMed

    He, Xiao-Heng; Wang, Wei; Liu, Ying-Mei; Jiang, Ming-Yue; Wu, Fang; Deng, Ke; Liu, Zhuang; Ju, Xiao-Jie; Xie, Rui; Chu, Liang-Yin

    2015-08-12

    A simple and flexible approach is developed for controllable fabrication of spider-silk-like microfibers with tunable magnetic spindle-knots from biocompatible calcium alginate for controlled 3D assembly and water collection. Liquid jet templates with volatile oil drops containing magnetic Fe3O4 nanoparticles are generated from microfluidics for fabricating spider-silk-like microfibers. The structure of jet templates can be precisely adjusted by simply changing the flow rates to tailor the structures of the resultant spider-silk-like microfibers. The microfibers can be well manipulated by external magnetic fields for controllably moving, and patterning and assembling into different 2D and 3D structures. Moreover, the dehydrated spider-silk-like microfibers, with magnetic spindle-knots for collecting water drops, can be controllably assembled into spider-web-like structures for excellent water collection. These spider-silk-like microfibers are promising as functional building blocks for engineering complex 3D scaffolds for water collection, cell culture, and tissue engineering.

  16. Microfluidic Fabrication of Bio-Inspired Microfibers with Controllable Magnetic Spindle-Knots for 3D Assembly and Water Collection.

    PubMed

    He, Xiao-Heng; Wang, Wei; Liu, Ying-Mei; Jiang, Ming-Yue; Wu, Fang; Deng, Ke; Liu, Zhuang; Ju, Xiao-Jie; Xie, Rui; Chu, Liang-Yin

    2015-08-12

    A simple and flexible approach is developed for controllable fabrication of spider-silk-like microfibers with tunable magnetic spindle-knots from biocompatible calcium alginate for controlled 3D assembly and water collection. Liquid jet templates with volatile oil drops containing magnetic Fe3O4 nanoparticles are generated from microfluidics for fabricating spider-silk-like microfibers. The structure of jet templates can be precisely adjusted by simply changing the flow rates to tailor the structures of the resultant spider-silk-like microfibers. The microfibers can be well manipulated by external magnetic fields for controllably moving, and patterning and assembling into different 2D and 3D structures. Moreover, the dehydrated spider-silk-like microfibers, with magnetic spindle-knots for collecting water drops, can be controllably assembled into spider-web-like structures for excellent water collection. These spider-silk-like microfibers are promising as functional building blocks for engineering complex 3D scaffolds for water collection, cell culture, and tissue engineering. PMID:26192108

  17. 3D printing technology using high viscous materials - Synthesis of functional materials and fabrication of 3D metal structure

    NASA Astrophysics Data System (ADS)

    Hong, Seongik

    In the 3D printing technology, the research for using various materials has been performing. In this research work, 3D printable high viscous materials are suggested as one of the solutions for problems in the traditional 3D printing technology. First, Cu-Ag coreshell was synthesized as a functional material. In terms of the reaction rate, reaction rate limiting step was defined as a fundamental research, and then prepared Cu-Ag coreshell was printed and analyzed. Second, the high viscous Cu paste was prepared and then metal 3D printed structure was fabricated by using new printing method. In the synthesis of Cu-Ag coreshell, different sizes of Cu particle, 2μm and 100nm were used, and when 2μm Cu was applied, the reaction rate was limited by film diffusion control. However, when 100nm Cu was applied, reaction rate was controlled by CuO film and the rate of the reaction, which includes removing CuO film in the solution, is limited by chemical reaction control. The shape of Cu-Ag particle is spherical in the 2μm Cu condition and dendrite shape in the 100nm Cu condition respectively. The conductivity of Cu-Ag coreshell paste increased as increasing content of coreshell particle in the paste and sintering temperature. In order to print high viscous metal paste, the high viscous Cu paste was printed by using screw extruder, and the viscosity of Cu paste was measured as a fundamental research. As increasing wt.% of Cu in the paste, the viscosity also increased. In addition, the shrinkage factor was reduced by increasing wt.% of Cu in the paste. An optimized printing condition for the high viscous material was obtained, and by using this condition, 3D metal structure was fabricated. The final product was heat treated and polished. Through these processes, a fine quality of metal 3D structure was printed.

  18. Fabrication of cubic micron-scale 3D metamaterial resonators.

    SciTech Connect

    Sinclair, Michael B.; Brener, Igal; Wendt, Joel Robert; Burckel, David Bruce; Ten Eyck, Gregory A.

    2010-06-01

    We present a new fabrication technique called Membrane Projection Lithography for the production of three-dimensional metamaterials at infrared wavelengths. Using this technique, multilayer infrared metamaterials that include both in-plane and out-of-plane resonators can be fabricated.

  19. Fabrication of Conductive 3D Gold-Containing Microstructures via Direct Laser Writing.

    PubMed

    Blasco, Eva; Müller, Jonathan; Müller, Patrick; Trouillet, Vanessa; Schön, Markus; Scherer, Torsten; Barner-Kowollik, Christopher; Wegener, Martin

    2016-05-01

    3D conductive microstructures containing gold are fabricated by simultaneous photopolymerization and photoreduction via direct laser writing. The photoresist employed consists of water-soluble polymers and a gold precursor. The fabricated microstructures show good conductivity and are successfully employed for 3D connections between gold pads. PMID:26953811

  20. Development and characterization of novel porous 3D alginate-cockle shell powder nanobiocomposite bone scaffold.

    PubMed

    Bharatham, B Hemabarathy; Abu Bakar, Md Zuki; Perimal, Enoch Kumar; Yusof, Loqman Mohamed; Hamid, Muhajir

    2014-01-01

    A novel porous three-dimensional bone scaffold was developed using a natural polymer (alginate/Alg) in combination with a naturally obtained biomineral (nano cockle shell powder/nCP) through lyophilization techniques. The scaffold was developed in varying composition mixture of Alg-nCP and characterized using various evaluation techniques as well as preliminary in vitro studies on MG63 human osteoblast cells. Morphological observations using SEM revealed variations in structures with the use of different Alg-nCP composition ratios. All the developed scaffolds showed a porous structure with pore sizes ideal for facilitating new bone growth; however, not all combination mixtures showed subsequent favorable characteristics to be used for biological applications. Scaffolds produced using the combination mixture of 40% Alg and 60% nCP produced significantly promising results in terms of mechanical strength, degradation rate, and increased cell proliferation rates making it potentially the optimum composition mixture of Alg-nCP with future application prospects. PMID:25110655

  1. Fabricating gradient hydrogel scaffolds for 3D cell culture.

    PubMed

    Chatterjee, Kaushik; Young, Marian F; Simon, Carl G

    2011-05-01

    Optimizing cell-material interactions is critical for maximizing regeneration in tissue engineering. Combinatorial and high-throughput (CHT) methods can be used to systematically screen tissue scaffolds to identify optimal biomaterial properties. Previous CHT platforms in tissue engineering have involved a two-dimensional (2D) cell culture format where cells were cultured on material surfaces. However, these platforms are inadequate to predict cellular response in a three-dimensional (3D) tissue scaffold. We have developed a simple CHT platform to screen cell-material interactions in 3D culture format that can be applied to screen hydrogel scaffolds. Herein we provide detailed instructions on a method to prepare gradients in elastic modulus of photopolymerizable hydrogels.

  2. Silicon-Embedding Approaches to 3-D Toroidal Inductor Fabrication

    SciTech Connect

    Yu, XH; Kim, M; Herrault, F; Ji, CH; Kim, J; Allen, MG

    2013-06-01

    This paper presents complementary-metal-oxide-semiconductor-compatible silicon-embedding techniques for on-chip integration of microelectromechanical-system devices with 3-D complex structures. By taking advantage of the "dead volume" within the bulk of the silicon wafer, functional devices with large profile can be embedded into the substrate without consuming valuable die area on the wafer surface or increasing the packaging complexity. Furthermore, through-wafer interconnects can be implemented to connect the device to the circuitry on the wafer surface. The key challenge of embedding structures within the wafer volume is processing inside deep trenches. To achieve this goal in an area-efficient manner, straight-sidewall trenches are desired, adding additional difficulty to the embedding process. Two approaches to achieve this goal are presented in this paper, i.e., a lithography-based process and a shadow-mask-based process. The lithography-based process utilizes a spray-coating technique and proximity lithography in combination with thick epoxy processing and laminated dry-film lithography. The shadow-mask-based process employs a specially designed 3-D silicon shadow mask to enable simultaneous metal patterning on both the vertical sidewall and the bottom surface of the trench during deposition, eliminating multiple lithography steps and reducing the process time. Both techniques have been demonstrated through the embedding of the topologically complex 3-D toroidal inductors into the silicon substrate for power supply on-chip (PwrSoC) applications. Embedded 3-D inductors that possess 25 turns and a diameter of 6 mm in a silicon trench of 300-mu m depth achieve overall inductances of 45-60 nH, dc resistances of 290-400 m Omega, and quality factors of 16-17.5 at 40-70 MHz.

  3. Fabrication and characterization of gels with integrated channels using 3D printing with microfluidic nozzle for tissue engineering applications.

    PubMed

    Attalla, R; Ling, C; Selvaganapathy, P

    2016-02-01

    The lack of a simple and effective method to integrate vascular network with engineered scaffolds and tissue constructs remains one of the biggest challenges in true 3D tissue engineering. Here, we detail the use of a commercially available, low-cost, open-source 3D printer modified with a microfluidic print-head in order to develop a method for the generation of instantly perfusable vascular network integrated with gel scaffolds seeded with cells. The print-head features an integrated coaxial nozzle that allows the fabrication of hollow, calcium-polymerized alginate tubes that can be easily patterned using 3D printing techniques. The diameter of the hollow channel can be precisely controlled and varied between 500 μm - 2 mm by changing applied flow rates or print-head speed. These channels are integrated into gel layers with a thickness of 800 μm - 2.5 mm. The structural rigidity of these constructs allows the fabrication of multi-layered structures without causing the collapse of hollow channels in lower layers. The 3D printing method was fully characterized at a range of operating speeds (0-40 m/min) and corresponding flow rates (1-30 mL/min) were identified to produce precise definition. This microfluidic design also allows the incorporation of a wide range of scaffold materials as well as biological constituents such as cells, growth factors, and ECM material. Media perfusion of the channels causes a significant viability increase in the bulk of cell-laden structures over the long-term. With this setup, gel constructs with embedded arrays of hollow channels can be created and used as a potential substitute for blood vessel networks. PMID:26842949

  4. Fabrication and characterization of gels with integrated channels using 3D printing with microfluidic nozzle for tissue engineering applications.

    PubMed

    Attalla, R; Ling, C; Selvaganapathy, P

    2016-02-01

    The lack of a simple and effective method to integrate vascular network with engineered scaffolds and tissue constructs remains one of the biggest challenges in true 3D tissue engineering. Here, we detail the use of a commercially available, low-cost, open-source 3D printer modified with a microfluidic print-head in order to develop a method for the generation of instantly perfusable vascular network integrated with gel scaffolds seeded with cells. The print-head features an integrated coaxial nozzle that allows the fabrication of hollow, calcium-polymerized alginate tubes that can be easily patterned using 3D printing techniques. The diameter of the hollow channel can be precisely controlled and varied between 500 μm - 2 mm by changing applied flow rates or print-head speed. These channels are integrated into gel layers with a thickness of 800 μm - 2.5 mm. The structural rigidity of these constructs allows the fabrication of multi-layered structures without causing the collapse of hollow channels in lower layers. The 3D printing method was fully characterized at a range of operating speeds (0-40 m/min) and corresponding flow rates (1-30 mL/min) were identified to produce precise definition. This microfluidic design also allows the incorporation of a wide range of scaffold materials as well as biological constituents such as cells, growth factors, and ECM material. Media perfusion of the channels causes a significant viability increase in the bulk of cell-laden structures over the long-term. With this setup, gel constructs with embedded arrays of hollow channels can be created and used as a potential substitute for blood vessel networks.

  5. Performance evaluation of bipolar and tripolar excitations during nozzle-jetting-based alginate microsphere fabrication

    NASA Astrophysics Data System (ADS)

    Herran, C. Leigh; Huang, Yong; Chai, Wenxuan

    2012-08-01

    Microspheres, small spherical (polymeric) particles with or without second phase materials embedded or encapsulated, are important for many biomedical applications such as drug delivery and organ printing. Scale-up fabrication with the ability to precisely control the microsphere size and morphology has always been of great manufacturing interest. The objective of this work is to experimentally study the performance differences of bipolar and tripolar excitation waveforms in using drop-on-demand (DOD)-based single nozzle jetting for alginate microsphere fabrication. The fabrication performance has been evaluated based on the formability of alginate microspheres as a function of materials properties (sodium alginate and calcium chloride concentrations) and operating conditions. The operating conditions for each excitation include voltage rise/fall times, dwell times and excitation voltage amplitudes. Overall, the bipolar excitation is more robust in making spherical, monodispersed alginate microspheres as good microspheres for its wide working range of material properties and operating conditions, especially during the fabrication of highly viscous materials such as the 2% sodium alginate solution. For both bipolar and tripolar excitations, the sodium alginate concentration and the voltage dwell times should be carefully selected to achieve good microsphere formability.

  6. Proliferation and enrichment of CD133(+) glioblastoma cancer stem cells on 3D chitosan-alginate scaffolds.

    PubMed

    Kievit, Forrest M; Florczyk, Stephen J; Leung, Matthew C; Wang, Kui; Wu, Jennifer D; Silber, John R; Ellenbogen, Richard G; Lee, Jerry S H; Zhang, Miqin

    2014-11-01

    Emerging evidence implicates cancer stem cells (CSCs) as primary determinants of the clinical behavior of human cancers, representing an ideal target for next-generation anti-cancer therapies. However CSCs are difficult to propagate in vitro, severely limiting the study of CSC biology and drug development. Here we report that growing cells from glioblastoma (GBM) cell lines on three dimensional (3D) porous chitosan-alginate (CA) scaffolds dramatically promotes the proliferation and enrichment of cells possessing the hallmarks of CSCs. CA scaffold-grown cells were found more tumorigenic in nude mouse xenografts than cells grown from monolayers. Growing in CA scaffolds rapidly promoted expression of genes involved in the epithelial-to-mesenchymal transition that has been implicated in the genesis of CSCs. Our results indicate that CA scaffolds have utility as a simple and inexpensive means to cultivate CSCs in vitro in support of studies to understand CSC biology and develop more effective anti-cancer therapies.

  7. Fabrication and characterization of freestanding 3D carbon microstructures using multi-exposures and resist pyrolysis

    NASA Astrophysics Data System (ADS)

    Lee, Jung A.; Lee, Seok Woo; Lee, Kwang-Cheol; Park, Se Il; Lee, Seung S.

    2008-03-01

    We present a fabrication method for freestanding complex 3D carbon microstructures utilizing a lithogaphy step and a heating step. We developed two fabrication methods for multi-level 3D SU-8 microstructures, which were used as polymer precursors in a carbonization process. In one method, multiple SU-8 layers were successively coated and cross-linked. In the other method, aligned partial exposures were used to control the thickness of the freestanding SU-8 layer. Freestyle, freestanding carbon microstructures were fabricated by heating 3D SU-8 microstructures below 1000 °C in a nitrogen atmosphere. Characterization of the pyrolysis process, through measurements such as dimensional changes, roughness, hardness, elastic modulus and resistivity, was performed for positive resists AZ5214 and AZ9260 as well as SU-8. 3D carbon microstructures fabricated using our methods can be utilized for various applications such as low cost resonating microsensors and microfluidics.

  8. The fabrication of 3-D nanostructures by a low- voltage EBL

    NASA Astrophysics Data System (ADS)

    Oh, Seung Hun; Kim, Jae Gu; Kim, Chang Seok; Choi, Doo Sun; Chang, Sunghwan; Jeong, Myung Yung

    2011-02-01

    Three-dimensional (3-D) structures are used in many applications, including the fabrication of opto-electronic and bio-MEMS devices. Among the various fabrication techniques available for 3-D structures, nano imprint lithography (NIL) is preferred for producing nanoscale 3-D patterns because of its simplicity, relatively short processing time, and high manufacturing precision. For efficient replication in NIL, a precise 3-D stamp must be used as an imprinting tool. Hence, we attempted the fabrication of original 3-D master molds by low-voltage electron beam lithography (EBL). We then fabricated polydimethylsiloxane (PDMS) stamps from the original 3-D mold via replica molding with ultrasonic vibration.First, we experimentally analyzed the characteristics of low-voltage EBL in terms of various parameters such as resist thickness, acceleration voltage, aperture size, and baking temperature. From these e-beam exposure experiments, we found that the exposure depth and width were almost saturated at 3 kV or lesser, even when the electron dosage was increased. This allowed for the fabrication of various stepped 3-D nanostructures at a low voltage. In addition, by using line-dose EBL, V-groove patterns could be fabricated on a cured electron resist (ER) at a low voltage and low baking temperature. Finally, the depth variation could be controlled to within 10 nm through superposition exposure at 1 kV. From these results, we determined the optimum electron beam exposure conditions for the fabrication of various 3-D structures on ERs by low-voltage EBL. We then fabricated PDMS stamps via the replica molding process.

  9. Enhancement of cell viability by fabrication of macroscopic 3D hydrogel scaffolds using an innovative cell-dispensing technique supplemented by preosteoblast-laden micro-beads.

    PubMed

    Lee, Hyeongjin; Ahn, Seunghyun; Chun, Wook; Kim, Geunhyung

    2014-04-15

    We propose a new cell-encapsulated dispensing method consisting of hydrogel struts, embedded with cell-laden micro-beads. To develop the scaffolds, we accommodated a three-axis robot dispensing system and aerosol spraying of a cross-linking agent to effect tentative surface gelation of hydrogel alginate struts. To show the feasibility of the method, we used pre-osteoblast (MC3T3-E1) cells. Using this technique, we obtained a reasonable cell viability (>90% after several culture periods) relative to that of a scaffold onto which cells were dispensed in the conventional manner, and successfully fabricated a realistic macroscopic pore-size in a controlled manner with 100% pore-interconnected 3D alginate hydrogel scaffolds of 20 mm × 20 mm × 6 mm.

  10. Fabrication of a 3D electrically small antenna using holographic photolithography

    NASA Astrophysics Data System (ADS)

    Toriz-Garcia, J. J.; Cowling, J. J.; Williams, G. L.; Bai, Q.; Seed, N. L.; Tennant, A.; McWilliam, R.; Purvis, A.; Soulard, F. B.; Ivey, P. A.

    2013-05-01

    We describe the novel fabrication of a 3D electrical small antenna and its subsequent characterization. The patterning of meander lines conformed onto a hemispherical substrate is achieved by 3D holographic photolithography, which uses time-division multiplexing of a series of iteratively optimized computer-generated holograms. The meander lines have a line width of 100 µm and line separation of 400 µm, with a line pitch of 500 µm and a total meander length of 145 mm. The working frequency is found to be 2.06 GHz, with an efficiency of 46%. This work demonstrates a new method for the fabrication of 3D conformal antennas.

  11. Laser fabrication of 2D and 3D metal nanoparticle structures and arrays.

    PubMed

    Kuznetsov, A I; Kiyan, R; Chichkov, B N

    2010-09-27

    A novel method for fabrication of 2D and 3D metal nanoparticle structures and arrays is proposed. This technique is based on laser-induced transfer of molten metal nanodroplets from thin metal films. Metal nanoparticles are produced by solidification of these nanodroplets. The size of the transferred nanoparticles can be controllably changed in the range from 180 nm to 1500 nm. Several examples of complex 2D and 3D microstructures generated form gold nanoparticles are demonstrated. PMID:20941016

  12. Fabrication of a customized bone scaffold using a homemade medical 3D printer for comminuted fractures

    NASA Astrophysics Data System (ADS)

    Yoon, Do-Kun; Jung, Joo-Young; Shin, Han-Back; Kim, Moo-Sub; Choe, Bo-Young; Kim, Sunmi; Suh, Tae Suk; Lee, Keum Sil; Xing, Lei

    2016-09-01

    The purpose of this study was to show a 3D printed reconstruction model of a bone destroyed by a comminuted fracture. After a thoracic limb of a cow with a comminuted fracture was scanned by using computed tomography, a scaffold was designed by using a 3D modeling tool for its reconstruction and fabricated by using a homemade medical 3D printer. The homemade medical 3D printer was designed for medical use. In order to reconstruct the geometry of the destroyed bone, we use the geometry of a similar section (reference geometry) of normal bone in the 3D modeling process. The missing part between the destroyed ridge and the reference geometry was filled with an effective space by using a manual interpolation. Inexpensive materials and free software were used to construct the medical 3D printer system. The fabrication of the scaffold progressed according to the design of reconstructed bone by using this medical 3D printer. The material of the scaffold was biodegradable material, and could be transplanted into the human body. The fabricated scaffold was correctly inserted into the fractured bone in place of the destroyed portion, with good agreement. According to physical stress test results, the performance of printing resolution was 0.1 mm. The average geometrical error of the scaffold was below 0.3 mm. The reconstructed bone by using the fabricated scaffold was able to support the weight of the human body. No process used to obtain the result was complex or required many resources. The methods and results in this study show several possible clinical applications in fields such as orthopedics or oncology without a need to purchase high-price instruments for 3D printing.

  13. Fabrication of 3D polypyrrole microstructures and their utilization as electrodes in supercapacitors

    NASA Astrophysics Data System (ADS)

    Ho, Vinh; Zhou, Cheng; Kulinsky, Lawrence; Madou, Marc

    2013-12-01

    We present a novel fabrication method for constructing three-dimensional (3D) conducting microstructures based on the controlled-growth of electrodeposited polypyrrole (PPy) within a lithographically patterned photoresist layer. PPy thin films, post arrays, suspended planes supported by post arrays and multi-layered PPy structures were fabricated. The performance of supercapacitors based on 3D PPy electrodes doped with dodecylbenzene sulfonate (DBS-) and perchlorate (ClO4-) anions was studied using cyclic voltammetry and galvanostatic charge/discharge tests. The highest specific capacitance obtained from the multi-layered PPy(ClO4) electrodes was 401 ± 18 mF cm-2, which is roughly twice as high as the highest specific capacitance of PPy-based supercapacitor reported thus far. The increase in capacitance is the result of higher surface area per unit footprint achieved through the fabrication of multi-layered 3D electrodes.

  14. 3D printed auxetic forms on knitted fabrics for adjustable permeability and mechanical properties

    NASA Astrophysics Data System (ADS)

    Grimmelsmann, N.; Meissner, H.; Ehrmann, A.

    2016-07-01

    The 3D printing technology can be applied into manufacturing primary shaping diverse products, from models dealing as examples for future products that will be produced with another technique, to useful objects. Since 3D printing is nowadays significantly slower than other possibilities to manufacture items, such as die casting, it is often used for small parts that are produced in small numbers or for products that cannot be created in another way. Combinations of 3D printing with other objects, adding novel functionalities to them, are thus favourable to a complete primary shaping process. Textile fabrics belong to the objects whose mechanical and other properties can notably be modified by adding 3D printed forms. This article mainly reports on a new possibility to change the permeability of textile fabrics by 3D printing auxetic forms, e.g. for utilising them in textile filters. In addition, auxetic forms 3D printed on knitted fabrics can bring about mechanical properties that are conducive to tensile constructions.

  15. Novel Target Fabrication Using 3D Printing Developed at University of Michigan

    NASA Astrophysics Data System (ADS)

    Klein, Sallee R.; Deininger, Michael; Gillespie, Robb S.; Di Stefano, Carlos A.; MacDonald, Michael J.; J-E Manuel, Mario; Young, Rachel P.; Kuranz, Carolyn C.; Keiter, Paul A.; Drake, R. Paul

    2016-04-01

    The University of Michigan has been fabricating targets for high-energy-density experiments for the past decade. We utilize the technique of machined acrylic bodies and mating components acting as constraints to build repeatable targets. Combining 3D printing with traditional machining, we are able to take advantage of the very best part of both aspects of manufacturing. Here we present several recent campaigns to act as showcase and introduction of our techniques and our experience with 3D printing, effecting how we utilize 3D printing in our target builds.

  16. A Review on Energy Harvesting Using 3D Printed Fabrics for Wearable Electronics

    NASA Astrophysics Data System (ADS)

    Gowthaman, Swaminathan; Chidambaram, Gowri Shankar; Rao, Dilli Babu Govardhana; Subramya, Hemakumar Vyudhayagiri; Chandrasekhar, Udhayagiri

    2016-06-01

    Embedding of energy harvesting systems into wearable health and environment monitoring systems, like integration of smart piezoelectric fibers into soldier fabric structures opens up avenues in generating electricity from natural mechanical movements for self-powering of wearable electronics. Emergence of multitudinous of materials and manufacturing technologies has enabled realization of various energy harvesting systems from mechanical movements. The materials and manufacturing related to 3D printing of energy harvesting fabrics are reviewed in this paper. State-of-the-art energy harvesting sources are briefly described following which an in-depth analysis on the materials and 3D printing techniques for energy harvesting fabrics are presented. While tremendous motivation and opportunity exists for wider-scale adoption of 3D printing for this niche area, the success depends on efficient design of three critical factors namely materials, process and structure. The present review discusses on the complex issues of materials selection, modelling and processing of 3D printed fabrics. The paper culminates by presenting a discussion on how future advancements in 3D printing technology might be useful for development of wearable electronics.

  17. Efficient fabrication method of nano-grating for 3D holographic display with full parallax views.

    PubMed

    Wan, Wenqiang; Qiao, Wen; Huang, Wenbin; Zhu, Ming; Fang, Zongbao; Pu, Donglin; Ye, Yan; Liu, Yanhua; Chen, Linsen

    2016-03-21

    Without any special glasses, multiview 3D displays based on the diffractive optics can present high resolution, full-parallax 3D images in an ultra-wide viewing angle. The enabling optical component, namely the phase plate, can produce arbitrarily distributed view zones by carefully designing the orientation and the period of each nano-grating pixel. However, such 3D display screen is restricted to a limited size due to the time-consuming fabricating process of nano-gratings on the phase plate. In this paper, we proposed and developed a lithography system that can fabricate the phase plate efficiently. Here we made two phase plates with full nano-grating pixel coverage at a speed of 20 mm2/mins, a 500 fold increment in the efficiency when compared to the method of E-beam lithography. One 2.5-inch phase plate generated 9-view 3D images with horizontal-parallax, while the other 6-inch phase plate produced 64-view 3D images with full-parallax. The angular divergence in horizontal axis and vertical axis was 1.5 degrees, and 1.25 degrees, respectively, slightly larger than the simulated value of 1.2 degrees by Finite Difference Time Domain (FDTD). The intensity variation was less than 10% for each viewpoint, in consistency with the simulation results. On top of each phase plate, a high-resolution binary masking pattern containing amplitude information of all viewing zone was well aligned. We achieved a resolution of 400 pixels/inch and a viewing angle of 40 degrees for 9-view 3D images with horizontal parallax. In another prototype, the resolution of each view was 160 pixels/inch and the view angle was 50 degrees for 64-view 3D images with full parallax. As demonstrated in the experiments, the homemade lithography system provided the key fabricating technology for multiview 3D holographic display.

  18. Alginate gel microwell arrays using electrodeposition for three-dimensional cell culture.

    PubMed

    Ozawa, Fumisato; Ino, Kosuke; Arai, Toshiharu; Ramón-Azcón, Javier; Takahashi, Yasufumi; Shiku, Hitoshi; Matsue, Tomokazu

    2013-08-01

    In this study, we developed a novel method for fabricating microwell arrays constructed from alginate gels, and the alginate gel microwells were used for three-dimensional (3D) cell culture. The alginate gel microwells were fabricated on a patterned ITO electrode using alginate gel electrodeposition. Embryonic stem (ES) cells or hepatocellular carcinoma cells (HepG2) were cultured in the alginate gel microwells containing 3T3 cells. During the culture, embryoid bodies (EBs) or HepG2 spheroids were successfully fabricated in the alginate gel microwells. The oxygen consumption of the EBs indicated that they were successfully cultured. Liver-specific gene expressions of the HepG2 spheroids apparently increased by performing 3D co-culture in the microwell arrays with 3T3 cells. These results show that the alginate gel microwells are a useful 3D culture system.

  19. Formation of Neural Networks in 3D Scaffolds Fabricated by Means of Laser Microstereolithography.

    PubMed

    Vedunova, M V; Timashev, P S; Mishchenko, T A; Mitroshina, E V; Koroleva, A V; Chichkov, B N; Panchenko, V Ya; Bagratashvili, V N; Mukhina, I V

    2016-08-01

    We developed and tested new 3D scaffolds for neurotransplantation. Scaffolds of predetermined architectonic were prepared using microstereolithography technique. Scaffolds were highly biocompatible with the nervous tissue cells. In vitro studies showed that the material of fabricated scaffolds is not toxic for dissociated brain cells and promotes the formation of functional neural networks in the matrix. These results demonstrate the possibility of fabrication of tissue-engineering constructs for neurotransplantation based on created scaffolds. PMID:27595153

  20. Facile fabrication of organic-inorganic hybrid beads by aminated alginate enabled gelation and biomimetic mineralization.

    PubMed

    Li, Jian; Wu, Hong; Liang, Yanpeng; Jiang, Zhongyi; Jiang, Yanjun; Zhang, Lei

    2013-01-01

    Inspired by biomineralization, design and preparation of biomimetic organic-inorganic composites have become a hot issue and a research frontier in many areas, including enzyme engineering. In this research, a unique and facile method for fabricating organic-inorganic hybrid beads is proposed. Modified alginate with a dual function of gelation and mineralization was synthesized for fabrication of hybrid carriers for enzyme immobilization. With the aid of EDC/NHS conjugation chemistry, the amine groups from diethylene triamine were grafted onto alginate in a controllable way. The resultant aminated alginate served manifold functions: forming a hydrogel via Ca(2+)-cross-linking, inducing the biomimetic silicification and manipulating the distribution of silica nanoparticles. Owing to the compact polymer network structure and the homogeneous silica nanoparticle dispersion, the as-prepared NH2-alginate/silica hybrid beads displayed superior swelling resistance and mechanical stability to pure alginate beads. The hybrid beads were subsequently utilized for encapsulation of yeast alcohol dehydrogenase (YADH). It was found that the thermal stability, pH tolerance and storage stability of the immobilized enzyme were all improved without significantly lowering the catalytic activity.

  1. A novel method for fabricating curved frequency selective surface via 3D printing technology

    NASA Astrophysics Data System (ADS)

    Liang, Fengchao; Gao, Jinsong

    2014-12-01

    A novel method for fabricating curved frequency selective surfaces with undevelopable curved shape using 3D printing technology was proposed in this paper. First, FSS composed of Y slotted elements that adapt to 0° ~ 70 ° incidences was designed. Then, the 3D model of the curved FSS was created in a 3D modeling software. Next, the 3D model was digitalized into stl format file and then the stl file was inputted into a stereo lithography 3D printer. Next, the prototype of the curved FSS was fabricated by the 3D printer layer by layer. Finally, a 10 μm thick aluminum film was coated on the outer surface of the prototype of the curved FSS by a vacuum coater. The transmission performance of the metallised curved FSS was tested using free space method. It was shown that frequency selection characteristic of the metallised curved FSS reached the requirements of simulation design. The pass-band was in the Ku-band and the transmission rate on center frequency was 63% for nose cone incident direction. This method provides a new way to apply the FSS to arbitrary curved electromagnetic window.

  2. Fabrication of 3D high aspect ratio PDMS microfluidic networks with a hybrid stamp.

    PubMed

    Kung, Yu-Chun; Huang, Kuo-Wei; Fan, Yu-Jui; Chiou, Pei-Yu

    2015-04-21

    We report a novel methodology for fabricating large-area, multilayer, thin-film, high aspect ratio, 3D microfluidic structures with through-layer vias and open channels that can be bonded between hard substrates. It is realized by utilizing a hybrid stamp with a thin plastic sheet embedded underneath a PDMS surface. This hybrid stamp solves an important edge protrusion issue during PDMS molding while maintaining necessary stamp elasticity to ensure the removal of PDMS residues at through-layer regions. Removing edge protrusion is a significant progress toward fabricating 3D structures since high aspect ratio PDMS structures with flat interfaces can be realized to facilitate multilayer stacking and bonding to hard substrates. Our method also allows for the fabrication of 3D deformable channels, which can lead to profound applications in electrokinetics, optofluidics, inertial microfluidics, and other fields where the shape of the channel cross section plays a key role in device physics. To demonstrate, as an example, we have fabricated a microfluidic channel by sandwiching two 20 μm wide, 80 μm tall PDMS membranes between two featureless ITO glass substrates. By applying electrical bias to the two ITO substrates and pressure to deform the thin membrane sidewalls, strong electric field enhancement can be generated in the center of a channel to enable 3D sheathless dielectrophoretic focusing of biological objects including mammalian cells and bacteria at a flow speed up to 14 cm s(-1).

  3. Formation and properties of 3D metamaterial composites fabricated using nanometer scale laser lithography (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Prokes, Sharka M.; Perkins, Frank K.; Glembocki, Orest J.

    2015-08-01

    Metamaterials designed for the visible or near IR wavelengths require patterning on the nanometer scale. To achieve this, e-beam lithography is used, but it is extremely difficult and can only produce 2D structures. A new alternative technique to produce 2D and 3D structures involves laser fabrication using the Nanoscribe 3D laser lithography system. This is a direct laser writing technique which can form arbitrary 3D nanostructures on the nanometer scale and is based on multi-photon polymerization. We are creating 2D and 3D metamaterials via this technique, and subsequently conformally coating them using Atomic Layer Deposition of oxides and Ag. We will discuss the optical properties of these novel composite structures and their potential for dual resonant metamaterials.

  4. Directionality in laser fabrication of 3D graphitic microwires in diamond

    NASA Astrophysics Data System (ADS)

    Sun, B.; Salter, P. S.; Booth, M. J.

    2016-03-01

    Graphitic wires embedded beneath the surface of single crystal diamond are promising for a variety of applications. Through a combination of ultra short (femtosecond) pulsed fabrication, high numerical aperture focusing and adaptive optics, graphitic wires can be written along any 3D path. Here, we demonstrate a non-reciprocal directional dependence to the graphitization process: the features are distinct when the fabrication direction is reversed. The non-reciprocal effects are significantly determined by the laser power, the fabrication speed, the light polarization and pulse front tilt. The influences of these factors are studied.

  5. Fabrication of low cost soft tissue prostheses with the desktop 3D printer

    PubMed Central

    He, Yong; Xue, Guang-huai; Fu, Jian-zhong

    2014-01-01

    Soft tissue prostheses such as artificial ear, eye and nose are widely used in the maxillofacial rehabilitation. In this report we demonstrate how to fabricate soft prostheses mold with a low cost desktop 3D printer. The fabrication method used is referred to as Scanning Printing Polishing Casting (SPPC). Firstly the anatomy is scanned with a 3D scanner, then a tissue casting mold is designed on computer and printed with a desktop 3D printer. Subsequently, a chemical polishing method is used to polish the casting mold by removing the staircase effect and acquiring a smooth surface. Finally, the last step is to cast medical grade silicone into the mold. After the silicone is cured, the fine soft prostheses can be removed from the mold. Utilizing the SPPC method, soft prostheses with smooth surface and complicated structure can be fabricated at a low cost. Accordingly, the total cost of fabricating ear prosthesis is about $30, which is much lower than the current soft prostheses fabrication methods. PMID:25427880

  6. Fabrication of low cost soft tissue prostheses with the desktop 3D printer

    NASA Astrophysics Data System (ADS)

    He, Yong; Xue, Guang-Huai; Fu, Jian-Zhong

    2014-11-01

    Soft tissue prostheses such as artificial ear, eye and nose are widely used in the maxillofacial rehabilitation. In this report we demonstrate how to fabricate soft prostheses mold with a low cost desktop 3D printer. The fabrication method used is referred to as Scanning Printing Polishing Casting (SPPC). Firstly the anatomy is scanned with a 3D scanner, then a tissue casting mold is designed on computer and printed with a desktop 3D printer. Subsequently, a chemical polishing method is used to polish the casting mold by removing the staircase effect and acquiring a smooth surface. Finally, the last step is to cast medical grade silicone into the mold. After the silicone is cured, the fine soft prostheses can be removed from the mold. Utilizing the SPPC method, soft prostheses with smooth surface and complicated structure can be fabricated at a low cost. Accordingly, the total cost of fabricating ear prosthesis is about $30, which is much lower than the current soft prostheses fabrication methods.

  7. Fabrication of low cost soft tissue prostheses with the desktop 3D printer.

    PubMed

    He, Yong; Xue, Guang-huai; Fu, Jian-zhong

    2014-01-01

    Soft tissue prostheses such as artificial ear, eye and nose are widely used in the maxillofacial rehabilitation. In this report we demonstrate how to fabricate soft prostheses mold with a low cost desktop 3D printer. The fabrication method used is referred to as Scanning Printing Polishing Casting (SPPC). Firstly the anatomy is scanned with a 3D scanner, then a tissue casting mold is designed on computer and printed with a desktop 3D printer. Subsequently, a chemical polishing method is used to polish the casting mold by removing the staircase effect and acquiring a smooth surface. Finally, the last step is to cast medical grade silicone into the mold. After the silicone is cured, the fine soft prostheses can be removed from the mold. Utilizing the SPPC method, soft prostheses with smooth surface and complicated structure can be fabricated at a low cost. Accordingly, the total cost of fabricating ear prosthesis is about $30, which is much lower than the current soft prostheses fabrication methods.

  8. Effect of Frictions on the Ballistic Performance of a 3D Warp Interlock Fabric: Numerical Analysis

    NASA Astrophysics Data System (ADS)

    Ha-Minh, Cuong; Boussu, François; Kanit, Toufik; Crépin, David; Imad, Abdellatif

    2012-06-01

    3D interlock woven fabrics are promising materials to replace the 2D structures in the field of ballistic protection. The structural complexity of this material caused many difficulties in numerical modeling. This paper presents a new tool that permits to generate a geometry model of any woven fabric, then, mesh this model in shell or solid elements, and apply the mechanical properties of yarns to them. The tool shows many advantages over existing software. It is very handy in use with an organization of the functions in menu and using a graphic interface. It can describe correctly the geometry of all textile woven fabrics. With this tool, the orientation of the local axes of finite elements following the yarn direction facilitates defining the yarn mechanical properties in a numerical model. This tool can be largely applied because it is compatible with popular finite element codes such as Abaqus, Ansys, Radioss etc. Thanks to this tool, a finite element model was carried out to describe a ballistic impact on a 3D warp interlock Kevlar KM2® fabric. This work focuses on studying the effect of friction onto the ballistic impact behavior of this textile interlock structure. Results showed that the friction among yarns affects considerably on the impact behavior of this fabric. The effect of the friction between projectile and yarn is less important. The friction plays an important role in keeping the fabric structural stability during the impact event. This phenomenon explained why the projectile is easier to penetrate this 3D warp interlock fabric in the no-friction case. This result also indicates that the ballistic performance of the interlock woven fabrics can be improved by using fibers with great friction coefficients.

  9. Using double-poured alginate impressions to fabricate bleaching trays.

    PubMed

    Haywood, V B; Powe, A

    1998-01-01

    Esthetic and diagnostic treatment often requires two casts of one arch, one for baseline and one for alterations (diagnostic wax-up, bleaching tray, occlusal analysis). The purpose of this study was to compare the accuracy of stone casts generated from a second pour of a properly handled alginate impression with first-poured casts. A maxillary dentoform was indexed with six reference spaces (#8-15, 9-2, 2-15, and incisal-to-gingival of #3, 9, 14). Irreversible hydrocolloid (Jeltrate) impressions were made in perforated steel trays by a single investigator. Impression material was spatulated for 1 minute. The seated impression and dentoform were wrapped in a damp paper towel to simulate intraoral conditions, and allowed to set for 2 minutes. Upon separation, the impression was stored in a damp towel for 5 minutes. The impression was poured in cast stone (Microstone) according to the manufacturer's instructions. The stone-filled impression was immediately rewrapped in a damp paper towel and allowed to set for 45 minutes at room temperature. Upon removal of the stone, the impression was rinsed with cold water, shaken dry, and repoured in the same manner. Ten impressions were made: the first five impressions were poured to make casts for Group A, then repoured as described above for casts for Group B. The remaining five impressions were poured once to make casts for Group C. The six spaces of each cast were measured three times in random order using a dial caliper and the space average calculated for the cast. At each space, analysis of variance showed no significant difference among Groups A, B, or C (P < 0.05). When alginate impressions that have been poured with cast stone are kept moist during stone setting and repoured within 45 minutes, two casts can be generated from one impression with the same degree of accuracy as two casts made from taking two separate impressions, providing the alginate does not tear during first cast removal.

  10. Facile 3D Metal Electrode Fabrication for Energy Applications via Inkjet Printing and Shape Memory Polymer

    NASA Astrophysics Data System (ADS)

    Roberts, R. C.; Wu, J.; Hau, N. Y.; Chang, Y. H.; Feng, S. P.; Li, D. C.

    2014-11-01

    This paper reports on a simple 3D metal electrode fabrication technique via inkjet printing onto a thermally contracting shape memory polymer (SMP) substrate. Inkjet printing allows for the direct patterning of structures from metal nanoparticle bearing liquid inks. After deposition, these inks require thermal curing steps to render a stable conductive film. By printing onto a SMP substrate, the metal nanoparticle ink can be cured and substrate shrunk simultaneously to create 3D metal microstructures, forming a large surface area topology well suited for energy applications. Polystyrene SMP shrinkage was characterized in a laboratory oven from 150-240°C, resulting in a size reduction of 1.97-2.58. Silver nanoparticle ink was patterned into electrodes, shrunk, and the topology characterized using scanning electron microscopy. Zinc-Silver Oxide microbatteries were fabricated to demonstrate the 3D electrodes compared to planar references. Characterization was performed using 10M potassium hydroxide electrolyte solution doped with zinc oxide (57g/L). After a 300s oxidation at 3Vdc, the 3D electrode battery demonstrated a 125% increased capacity over the reference cell. Reference cells degraded with longer oxidations, but the 3D electrodes were fully oxidized for 4 hours, and exhibited a capacity of 5.5mA-hr/cm2 with stable metal performance.

  11. Fabrication of 3D microfluidic structures inside glass by femtosecond laser micromachining

    NASA Astrophysics Data System (ADS)

    Sugioka, Koji; Cheng, Ya

    2014-01-01

    Femtosecond lasers have opened up new avenues in materials processing due to their unique characteristics of ultrashort pulse widths and extremely high peak intensities. One of the most important features of femtosecond laser processing is that a femtosecond laser beam can induce strong absorption in even transparent materials due to nonlinear multiphoton absorption. This makes it possible to directly create three-dimensional (3D) microfluidic structures in glass that are of great use for fabrication of biochips. For fabrication of the 3D microfluidic structures, two technical approaches are being attempted. One of them employs femtosecond laser-induced internal modification of glass followed by wet chemical etching using an acid solution (Femtosecond laser-assisted wet chemical etching), while the other one performs femtosecond laser 3D ablation of the glass in distilled water (liquid-assisted femtosecond laser drilling). This paper provides a review on these two techniques for fabrication of 3D micro and nanofluidic structures in glass based on our development and experimental results.

  12. A Patterned 3D Silicon Anode Fabricated by Electrodeposition on a Virus-Structured Current Collector

    SciTech Connect

    Chen, X L; Gerasopoulos, K; Guo, J C; Brown, A; Wang, Chunsheng; Ghodssi, Reza; Culver, J N

    2010-11-09

    Electrochemical methods were developed for the deposition of nanosilicon onto a 3D virus-structured nickel current collector. This nickel current collector is composed of self-assembled nanowire-like rods of genetically modified tobacco mosaic virus (TMV1cys), chemically coated in nickel to create a complex high surface area conductive substrate. The electrochemically depo­sited 3D silicon anodes demonstrate outstanding rate performance, cycling stability, and rate capability. Electrodeposition thus provides a unique means of fabricating silicon anode materials on complex substrates at low cost.

  13. 3D scanning and 3D printing as innovative technologies for fabricating personalized topical drug delivery systems.

    PubMed

    Goyanes, Alvaro; Det-Amornrat, Usanee; Wang, Jie; Basit, Abdul W; Gaisford, Simon

    2016-07-28

    Acne is a multifactorial inflammatory skin disease with high prevalence. In this work, the potential of 3D printing to produce flexible personalised-shape anti-acne drug (salicylic acid) loaded devices was demonstrated by two different 3D printing (3DP) technologies: Fused Deposition Modelling (FDM) and stereolithography (SLA). 3D scanning technology was used to obtain a 3D model of a nose adapted to the morphology of an individual. In FDM 3DP, commercially produced Flex EcoPLA™ (FPLA) and polycaprolactone (PCL) filaments were loaded with salicylic acid by hot melt extrusion (HME) (theoretical drug loading - 2% w/w) and used as feedstock material for 3D printing. Drug loading in the FPLA-salicylic acid and PCL-salicylic acid 3D printed patches was 0.4% w/w and 1.2% w/w respectively, indicating significant thermal degradation of drug during HME and 3D printing. Diffusion testing in Franz cells using a synthetic membrane revealed that the drug loaded printed samples released <187μg/cm(2) within 3h. FPLA-salicylic acid filament was successfully printed as a nose-shape mask by FDM 3DP, but the PCL-salicylic acid filament was not. In the SLA printing process, the drug was dissolved in different mixtures of poly(ethylene glycol) diacrylate (PEGDA) and poly(ethylene glycol) (PEG) that were solidified by the action of a laser beam. SLA printing led to 3D printed devices (nose-shape) with higher resolution and higher drug loading (1.9% w/w) than FDM, with no drug degradation. The results of drug diffusion tests revealed that drug diffusion was faster than with the FDM devices, 229 and 291μg/cm(2) within 3h for the two formulations evaluated. In this study, SLA printing was the more appropriate 3D printing technology to manufacture anti-acne devices with salicylic acid. The combination of 3D scanning and 3D printing has the potential to offer solutions to produce personalised drug loaded devices, adapted in shape and size to individual patients.

  14. 3D scanning and 3D printing as innovative technologies for fabricating personalized topical drug delivery systems.

    PubMed

    Goyanes, Alvaro; Det-Amornrat, Usanee; Wang, Jie; Basit, Abdul W; Gaisford, Simon

    2016-07-28

    Acne is a multifactorial inflammatory skin disease with high prevalence. In this work, the potential of 3D printing to produce flexible personalised-shape anti-acne drug (salicylic acid) loaded devices was demonstrated by two different 3D printing (3DP) technologies: Fused Deposition Modelling (FDM) and stereolithography (SLA). 3D scanning technology was used to obtain a 3D model of a nose adapted to the morphology of an individual. In FDM 3DP, commercially produced Flex EcoPLA™ (FPLA) and polycaprolactone (PCL) filaments were loaded with salicylic acid by hot melt extrusion (HME) (theoretical drug loading - 2% w/w) and used as feedstock material for 3D printing. Drug loading in the FPLA-salicylic acid and PCL-salicylic acid 3D printed patches was 0.4% w/w and 1.2% w/w respectively, indicating significant thermal degradation of drug during HME and 3D printing. Diffusion testing in Franz cells using a synthetic membrane revealed that the drug loaded printed samples released <187μg/cm(2) within 3h. FPLA-salicylic acid filament was successfully printed as a nose-shape mask by FDM 3DP, but the PCL-salicylic acid filament was not. In the SLA printing process, the drug was dissolved in different mixtures of poly(ethylene glycol) diacrylate (PEGDA) and poly(ethylene glycol) (PEG) that were solidified by the action of a laser beam. SLA printing led to 3D printed devices (nose-shape) with higher resolution and higher drug loading (1.9% w/w) than FDM, with no drug degradation. The results of drug diffusion tests revealed that drug diffusion was faster than with the FDM devices, 229 and 291μg/cm(2) within 3h for the two formulations evaluated. In this study, SLA printing was the more appropriate 3D printing technology to manufacture anti-acne devices with salicylic acid. The combination of 3D scanning and 3D printing has the potential to offer solutions to produce personalised drug loaded devices, adapted in shape and size to individual patients. PMID:27189134

  15. Using double-poured alginate impressions to fabricate bleaching trays.

    PubMed

    Haywood, V B; Powe, A

    1998-01-01

    Esthetic and diagnostic treatment often requires two casts of one arch, one for baseline and one for alterations (diagnostic wax-up, bleaching tray, occlusal analysis). The purpose of this study was to compare the accuracy of stone casts generated from a second pour of a properly handled alginate impression with first-poured casts. A maxillary dentoform was indexed with six reference spaces (#8-15, 9-2, 2-15, and incisal-to-gingival of #3, 9, 14). Irreversible hydrocolloid (Jeltrate) impressions were made in perforated steel trays by a single investigator. Impression material was spatulated for 1 minute. The seated impression and dentoform were wrapped in a damp paper towel to simulate intraoral conditions, and allowed to set for 2 minutes. Upon separation, the impression was stored in a damp towel for 5 minutes. The impression was poured in cast stone (Microstone) according to the manufacturer's instructions. The stone-filled impression was immediately rewrapped in a damp paper towel and allowed to set for 45 minutes at room temperature. Upon removal of the stone, the impression was rinsed with cold water, shaken dry, and repoured in the same manner. Ten impressions were made: the first five impressions were poured to make casts for Group A, then repoured as described above for casts for Group B. The remaining five impressions were poured once to make casts for Group C. The six spaces of each cast were measured three times in random order using a dial caliper and the space average calculated for the cast. At each space, analysis of variance showed no significant difference among Groups A, B, or C (P < 0.05). When alginate impressions that have been poured with cast stone are kept moist during stone setting and repoured within 45 minutes, two casts can be generated from one impression with the same degree of accuracy as two casts made from taking two separate impressions, providing the alginate does not tear during first cast removal. PMID:9656923

  16. 3D Porous Calcium-Alginate Scaffolds Cell Culture System Improved Human Osteoblast Cell Clusters for Cell Therapy

    PubMed Central

    Chen, Ching-Yun; Ke, Cherng-Jyh; Yen, Ko-Chung; Hsieh, Hui-Chen; Sun, Jui-Sheng; Lin, Feng-Huei

    2015-01-01

    Age-related orthopedic disorders and bone defects have become a critical public health issue, and cell-based therapy is potentially a novel solution for issues surrounding bone tissue engineering and regenerative medicine. Long-term cultures of primary bone cells exhibit phenotypic and functional degeneration; therefore, culturing cells or tissues suitable for clinical use remain a challenge. A platform consisting of human osteoblasts (hOBs), calcium-alginate (Ca-Alginate) scaffolds, and a self-made bioreactor system was established for autologous transplantation of human osteoblast cell clusters. The Ca-Alginate scaffold facilitated the growth and differentiation of human bone cell clusters, and the functionally-closed process bioreactor system supplied the soluble nutrients and osteogenic signals required to maintain the cell viability. This system preserved the proliferative ability of cells and cell viability and up-regulated bone-related gene expression and biological apatite crystals formation. The bone-like tissue generated could be extracted by removal of calcium ions via ethylenediaminetetraacetic acid (EDTA) chelation, and exhibited a size suitable for injection. The described strategy could be used in therapeutic application and opens new avenues for surgical interventions to correct skeletal defects. PMID:25825603

  17. A simple approach for the fabrication of 3D microelectrodes for impedimetric sensing

    NASA Astrophysics Data System (ADS)

    Tahsin Guler, Mustafa; Bilican, Ismail; Agan, Sedat; Elbuken, Caglar

    2015-09-01

    In this paper, we present a very simple method to fabricate three-dimensional (3D) microelectrodes integrated with microfluidic devices. We form the electrodes by etching a microwire placed across a microchannel. For precise control of the electrode spacing, we employ a hydrodynamic focusing microfluidic device and control the width of the etching solution stream. The focused widths of the etchant solution and the etching time determine the gap formed between the electrodes. Using the same microfluidic device, we can fabricate integrated 3D electrodes with different electrode gaps. We have demonstrated the functionality of these electrodes using an impedimetric particle counting setup. Using 3D microelectrodes with a diameter of 25 μm, we have detected 6 μm-diameter polystyrene beads in a buffer solution as well as erythrocytes in a PBS solution. We study the effect of electrode spacing on the signal-to-noise ratio of the impedance signal and we demonstrate that the smaller the electrode spacing the higher the signal obtained from a single microparticle. The sample stream is introduced to the system using the same hydrodynamic focusing device, which ensures the alignment of the sample in between the electrodes. Utilising a 3D hydrodynamic focusing approach, we force all the particles to go through the sensing region of the electrodes. This fabrication scheme not only provides a very low-cost and easy method for rapid prototyping, but which can also be used for applications requiring 3D electric field focused through a narrow section of the microchannel.

  18. CMOS compatible fabrication of 3D photonic crystals by nanoimprint lithography

    NASA Astrophysics Data System (ADS)

    Eibelhuber, M.; Uhrmann, T.; Glinsner, T.

    2015-03-01

    Nanoimprinting techniques are an attractive solution for next generation lithography methods for several areas including photonic devices. A variety of potential applications have been demonstrated using nanoimprint lithography (NIL) (e.g. SAW devices, vias and contact layers with dual damascene imprinting process, Bragg structures, patterned media) [1,2]. Nanoimprint lithography is considered for bridging the gap from R and D to high volume manufacturing. In addition, it is capable to adapt to the needs of the fragmented and less standardized photonic market easily. In this work UV-NIL has been selected for the fabrication process of 3D-photonic crystals. It has been shown that UVNIL using a multiple layer approach is well suited to fabricate a 3D woodpile photonic crystal. The necessary alignment accuracies below 100nm were achieved using a simple optical method. In order to obtain sufficient alignment of the stacks to each other, a two stage alignment process is performed: at first proximity alignment is done followed by the Moiré alignment in soft contact with the substrate. Multiple steps of imprinting, etching, Si deposition and chemical mechanical polishing were implemented to create high quality 3D photonic crystals with up to 5 layers. This work has proven the applicability of nanoimprint lithography in a CMOS compatible process on 3D photonic crystals with alignment accuracy down to 100nm. Optimizing the processes will allow scaling up these structures on full wafers while still meeting the requirements of the designated devices.

  19. Fabrication of 3D nanostructures by multidirectional UV lithography and predictive structural modeling

    NASA Astrophysics Data System (ADS)

    Kim, Jungkwun; Kim, Cheolbok; Allen, Mark G.; ‘YK' Yoon, Yong-Kyu

    2015-02-01

    This paper presents the fabrication and modeling of three-dimensional (3D) nanostructures by automated multidirectional ultraviolet (UV) lithography, which is a fast, cost-effective, manufacturable fabrication method. Multidirectional UV exposure is performed using a static UV light source equipped with a tilt-rotational substrate holder. A glass substrate with a nanopatterned chrome layer is utilized as both a photomask and a substrate, for which a backside UV exposure scheme is used. For the analytical modeling of the shape of fabricated nanostructures, UV exposure dosage, diffraction and refraction effects, and absorption rate are taken into account. For more accurate process predictive models, a commercially available multiphysics simulation tool is used. The structural shapes predicted from analytical calculation and simulation are compared with the fabricated ones for which various 3D nanoscale test structures are fabricated such as an inclined nanopillar array and a vertical triangular slab. Also, nanostructures with multiple heights are successfully implemented from single layer photoresist by controlling the UV exposure dosage and tilt angles. A tripod embedded horn and a triangular-slab embedded horn are demonstrated.

  20. 3D printing method for freeform fabrication of optical phantoms simulating heterogeneous biological tissue

    NASA Astrophysics Data System (ADS)

    Wang, Minjie; Shen, Shuwei; Yang, Jie; Dong, Erbao; Xu, Ronald

    2014-03-01

    The performance of biomedical optical imaging devices heavily relies on appropriate calibration. However, many of existing calibration phantoms for biomedical optical devices are based on homogenous materials without considering the multi-layer heterogeneous structures observed in biological tissue. Using such a phantom for optical calibration may result in measurement bias. To overcome this problem, we propose a 3D printing method for freeform fabrication of tissue simulating phantoms with multilayer heterogeneous structure. The phantom simulates not only the morphologic characteristics of biological tissue but also absorption and scattering properties. The printing system is based on a 3D motion platform with coordinated control of the DC motors. A special jet nozzle is designed to mix base, scattering, and absorption materials at different ratios. 3D tissue structures are fabricated through layer-by-layer printing with selective deposition of phantom materials of different ingredients. Different mixed ratios of base, scattering and absorption materials have been tested in order to optimize the printing outcome. A spectrometer and a tissue spectrophotometer are used for characterizing phantom absorption and scattering properties. The goal of this project is to fabricate skin tissue simulating phantoms as a traceable standard for the calibration of biomedical optical spectral devices.

  1. [A rapid prototype fabrication method of dental splint based on 3D simulation and technology].

    PubMed

    Lin, Yanping; Chen, Xiaojun; Zhang, Shilei; Wang, Chengtao

    2006-04-01

    The conventional design and fabrication of the dental splint (in orthognathic surgery) is based on the preoperative planning and model surgery so this process is of low precision and efficiency. In order to solve the problems and be up to the trend of computer-assisted surgery, we have developed a novel method to design and fabricate the dental splint--computer-generated dental splint, which is based on three-dimensional model simulation and rapid prototype technology. After the surgical planning and simulation of 3D model, we can modify the model to be superior in chewing action (functional) and overall facial appearance (aesthetic). Then, through the Boolean operation of the dental splint blank and the maxillofacial bone model the model of dental splint is formed. At last, the dental splint model is fabricated through rapid prototype machine and applied in clinic. The result indicates that, with the use of this method, the surgical precision and efficiency are improved.

  2. Fabrication of controlled-release budesonide tablets via desktop (FDM) 3D printing.

    PubMed

    Goyanes, Alvaro; Chang, Hanah; Sedough, Daniel; Hatton, Grace B; Wang, Jie; Buanz, Asma; Gaisford, Simon; Basit, Abdul W

    2015-12-30

    The aim of this work was to explore the feasibility of using fused deposition modelling (FDM) 3D printing (3DP) technology with hot melt extrusion (HME) and fluid bed coating to fabricate modified-release budesonide dosage forms. Budesonide was sucessfully loaded into polyvinyl alcohol filaments using HME. The filaments were engineered into capsule-shaped tablets (caplets) containing 9mg budesonide using a FDM 3D printer; the caplets were then overcoated with a layer of enteric polymer. The final printed formulation was tested in a dynamic dissolution bicarbonate buffer system, and two commercial budesonide products, Cortiment® (Uceris®) and Entocort®, were also investigated for comparison. Budesonide release from the Entocort® formulation was rapid in conditions of the upper small intestine while release from the Cortiment® product was more delayed and very slow. In contrast, the new 3D printed caplet formulation started to release in the mid-small intestine but release then continued in a sustained manner throughout the distal intestine and colon. This work has demonstrated the potential of combining FDM 3DP with established pharmaceutical processes, including HME and film coating, to fabricate modified release oral dosage forms.

  3. Fabrication of controlled-release budesonide tablets via desktop (FDM) 3D printing.

    PubMed

    Goyanes, Alvaro; Chang, Hanah; Sedough, Daniel; Hatton, Grace B; Wang, Jie; Buanz, Asma; Gaisford, Simon; Basit, Abdul W

    2015-12-30

    The aim of this work was to explore the feasibility of using fused deposition modelling (FDM) 3D printing (3DP) technology with hot melt extrusion (HME) and fluid bed coating to fabricate modified-release budesonide dosage forms. Budesonide was sucessfully loaded into polyvinyl alcohol filaments using HME. The filaments were engineered into capsule-shaped tablets (caplets) containing 9mg budesonide using a FDM 3D printer; the caplets were then overcoated with a layer of enteric polymer. The final printed formulation was tested in a dynamic dissolution bicarbonate buffer system, and two commercial budesonide products, Cortiment® (Uceris®) and Entocort®, were also investigated for comparison. Budesonide release from the Entocort® formulation was rapid in conditions of the upper small intestine while release from the Cortiment® product was more delayed and very slow. In contrast, the new 3D printed caplet formulation started to release in the mid-small intestine but release then continued in a sustained manner throughout the distal intestine and colon. This work has demonstrated the potential of combining FDM 3DP with established pharmaceutical processes, including HME and film coating, to fabricate modified release oral dosage forms. PMID:26481468

  4. Fabrication of a Layered Microstructured Polycaprolactone Construct for 3-D Tissue Engineering

    PubMed Central

    Sarkar, Sumona; Isenberg, Brett C.; Hodis, Eran; Leach, Jennie B.; Desai, Tejal A.; Wong, Joyce Y.

    2009-01-01

    Successful artificial tissue scaffolds support regeneration by promoting cellular organization as well as appropriate mechanical and biological functionality. We have previously shown in vitro that 2-D substrates with micron-scale grooves (5 μm deep, 18 μm wide, with 12 μm spacing) can induce cell orientation and ECM alignment. Here, we have transferred this microtopography onto biodegradable polycaprolactone (PCL) thin films. We further developed a technique to layer these cellularized microtextured scaffolds into a 3-D tissue construct. A surface modification technique was used to attach photoreactive acrylate groups on the PCL scaffold surface onto which polyethylene glycol (PEG-DA) -diacrylate gel could be photopolymerized. PEG-DA serves as an adhesive layer between PCL scaffolds, resulting in a VSMC-seeded layered 3-D composite structure that is highly organized and structurally stable. The PCL surface modification chemistry was confirmed via XPS, and the maintenance of cell number and orientation on the modified PCL scaffolds was demonstrated using colorometric and imaging techniques. Cell number and orientation were also investigated after cells were cultured in the layered 3-D configuration. Such 3-D tissue mimics fabricated with precise cellular organization will enable the systematic testing of the effects of cellular orientation on the functional and mechanical properties of tissue engineered blood vessels. PMID:18854127

  5. Injectable 3-D Fabrication of Medical Electronics at the Target Biological Tissues

    PubMed Central

    Jin, Chao; Zhang, Jie; Li, Xiaokang; Yang, Xueyao; Li, Jingjing; Liu, Jing

    2013-01-01

    Conventional transplantable biomedical devices generally request sophisticated surgery which however often causes big trauma and serious pain to the patients. Here, we show an alternative way of directly making three-dimensional (3-D) medical electronics inside the biological body through sequential injections of biocompatible packaging material and liquid metal ink. As the most typical electronics, a variety of medical electrodes with different embedded structures were demonstrated to be easily formed at the target tissues. Conceptual in vitro experiments provide strong evidences for the excellent performances of the injectable electrodes. Further in vivo animal experiments disclosed that the formed electrode could serve as both highly efficient ECG (Electrocardiograph) electrode and stimulator electrode. These findings clarified the unique features and practicability of the liquid metal based injectable 3-D fabrication of medical electronics. The present strategy opens the way for directly manufacturing electrophysiological sensors or therapeutic devices in situ via a truly minimally invasive approach. PMID:24309385

  6. Chitosan-g-lactide copolymers for fabrication of 3D scaffolds for tissue engineering

    NASA Astrophysics Data System (ADS)

    Demina, T. S.; Zaytseva-Zotova, D. S.; Timashev, P. S.; Bagratashvili, V. N.; Bardakova, K. N.; Sevrin, Ch; Svidchenko, E. A.; Surin, N. M.; Markvicheva, E. A.; Grandfils, Ch; Akopova, T. A.

    2015-07-01

    Chitosan-g-oligo (L, D-lactide) copolymers were synthesized and assessed to fabricate a number of 3D scaffolds using a variety of technologies such as oil/water emulsion evaporation technique, freeze-drying and two-photon photopolymerization. Solid-state copolymerization method allowed us to graft up to 160 wt-% of oligolactide onto chitosan backbone via chitosan amino group acetylation with substitution degree reaching up to 0.41. Grafting of hydrophobic oligolactide side chains with polymerization degree up to 10 results in chitosan amphiphilic properties. The synthesized chitosan-g-lactide copolymers were used to design 3D scaffolds for tissue engineering such as spherical microparticles and macroporous hydrogels.

  7. Injectable 3-D Fabrication of Medical Electronics at the Target Biological Tissues

    NASA Astrophysics Data System (ADS)

    Jin, Chao; Zhang, Jie; Li, Xiaokang; Yang, Xueyao; Li, Jingjing; Liu, Jing

    2013-12-01

    Conventional transplantable biomedical devices generally request sophisticated surgery which however often causes big trauma and serious pain to the patients. Here, we show an alternative way of directly making three-dimensional (3-D) medical electronics inside the biological body through sequential injections of biocompatible packaging material and liquid metal ink. As the most typical electronics, a variety of medical electrodes with different embedded structures were demonstrated to be easily formed at the target tissues. Conceptual in vitro experiments provide strong evidences for the excellent performances of the injectable electrodes. Further in vivo animal experiments disclosed that the formed electrode could serve as both highly efficient ECG (Electrocardiograph) electrode and stimulator electrode. These findings clarified the unique features and practicability of the liquid metal based injectable 3-D fabrication of medical electronics. The present strategy opens the way for directly manufacturing electrophysiological sensors or therapeutic devices in situ via a truly minimally invasive approach.

  8. Fused-filament 3D printing (3DP) for fabrication of tablets.

    PubMed

    Goyanes, Alvaro; Buanz, Asma B M; Basit, Abdul W; Gaisford, Simon

    2014-12-10

    The use of fused-filament 3D printing (FF 3DP) to fabricate individual tablets is demonstrated. The technology permits the manufacture of tablets containing drug doses tailored to individual patients, or to fabrication of tablets with specific drug-release profiles. Commercially produced polyvinyl alcohol (PVA) filament was loaded with a model drug (fluorescein) by swelling of the polymer in ethanolic drug solution. A final drug-loading of 0.29% w/w was achieved. Tablets of PVA/fluorescein (10 mm diameter) were printed using a 3D printer. It was found that changing the degree of infill percentage in the printer software varied the weight and volume of the printed tablets. The tablets were mechanically strong and no significant thermal degradation of the active occurred during printing. Dissolution tests were conducted in modified Hank's buffer. The results showed release profiles were dependent on the infill percentage used to print the tablet. The study indicates that FF 3DP has the potential to offer a new solution for fabricating personalized-dose medicines or unit dosage forms with controlled-release profiles. In addition, the low cost of FDM printers means the paradigm of extemporaneous or point-of-use manufacture of personalized-dose tablets is both feasible and attainable.

  9. A simple method for fabricating multi-layer PDMS structures for 3D microfluidic chips.

    PubMed

    Zhang, Mengying; Wu, Jinbo; Wang, Limu; Xiao, Kang; Wen, Weijia

    2010-05-01

    We report a simple methodology to fabricate PDMS multi-layer microfluidic chips. A PDMS slab was surface-treated by trichloro (1H,1H,2H,2H-perfluorooctyl) silane, and acts as a reusable transferring layer. Uniformity of the thickness of the patterned PDMS layer and the well-alignment could be achieved due to the transparency and proper flexibility of this transferring layer. Surface treatment results are confirmed by XPS and contact angle testing, while bonding forces between different layers were measured for better understanding of the transferring process. We have also designed and fabricated a few simple types of 3D PDMS chip, especially one consisting of 6 thin layers (each with thickness of 50 mum), to demonstrate the potential utilization of this technique. 3D fluorescence images were taken by a confocal microscope to illustrate the spatial characters of essential parts. This fabrication method is confirmed to be fast, simple, repeatable, low cost and possible to be mechanized for mass production.

  10. Fused-filament 3D printing (3DP) for fabrication of tablets.

    PubMed

    Goyanes, Alvaro; Buanz, Asma B M; Basit, Abdul W; Gaisford, Simon

    2014-12-10

    The use of fused-filament 3D printing (FF 3DP) to fabricate individual tablets is demonstrated. The technology permits the manufacture of tablets containing drug doses tailored to individual patients, or to fabrication of tablets with specific drug-release profiles. Commercially produced polyvinyl alcohol (PVA) filament was loaded with a model drug (fluorescein) by swelling of the polymer in ethanolic drug solution. A final drug-loading of 0.29% w/w was achieved. Tablets of PVA/fluorescein (10 mm diameter) were printed using a 3D printer. It was found that changing the degree of infill percentage in the printer software varied the weight and volume of the printed tablets. The tablets were mechanically strong and no significant thermal degradation of the active occurred during printing. Dissolution tests were conducted in modified Hank's buffer. The results showed release profiles were dependent on the infill percentage used to print the tablet. The study indicates that FF 3DP has the potential to offer a new solution for fabricating personalized-dose medicines or unit dosage forms with controlled-release profiles. In addition, the low cost of FDM printers means the paradigm of extemporaneous or point-of-use manufacture of personalized-dose tablets is both feasible and attainable. PMID:25275937

  11. Potential of 3D printing technologies for fabrication of electron bolus and proton compensators.

    PubMed

    Zou, Wei; Fisher, Ted; Zhang, Miao; Kim, Leonard; Chen, Ting; Narra, Venkat; Swann, Beth; Singh, Rachana; Siderit, Richard; Yin, Lingshu; Teo, Boon-Keng Kevin; McKenna, Michael; McDonough, James; Ning, Yue J

    2015-05-08

    In electron and proton radiotherapy, applications of patient-specific electron bolus or proton compensators during radiation treatments are often necessary to accommodate patient body surface irregularities, tissue inhomogeneity, and variations in PTV depths to achieve desired dose distributions. Emerging 3D printing technologies provide alternative fabrication methods for these bolus and compensators. This study investigated the potential of utilizing 3D printing technologies for the fabrication of the electron bolus and proton compensators. Two printing technologies, fused deposition modeling (FDM) and selective laser sintering (SLS), and two printing materials, PLA and polyamide, were investigated. Samples were printed and characterized with CT scan and under electron and proton beams. In addition, a software package was developed to convert electron bolus and proton compensator designs to printable Standard Tessellation Language file format. A phantom scalp electron bolus was printed with FDM technology with PLA material. The HU of the printed electron bolus was 106.5 ± 15.2. A prostate patient proton compensator was printed with SLS technology and polyamide material with -70.1 ± 8.1 HU. The profiles of the electron bolus and proton compensator were compared with the original designs. The average over all the CT slices of the largest Euclidean distance between the design and the fabricated bolus on each CT slice was found to be 0.84 ± 0.45 mm and for the compensator to be 0.40 ± 0.42 mm. It is recommended that the properties of specific 3D printed objects are understood before being applied to radiotherapy treatments.

  12. 3D chiral nanoplasmonics: fabrication, chiroptic engineering, mechanism, and application in enantioselection (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Huang, Zhifeng

    2015-09-01

    Chirality does naturally exist, and the building blocks of life (e.g. DNA, proteins, peptides and sugars) are usually chiral. Chirality inherently imposes chemical/biological selectivity on functional molecules; hence the discrimination in molecular chirality from an enantiomer to the other mirror image (i.e. enantioselection) has fundamental and application significance. Enantiomers interact with left and right handed circularly polarized light in a different manner with respect to optical extinction; hence, electronic circular dichroism (ECD) has been widely used for enantioselection. However, enantiomers usually have remarkably low ECD intensity, mainly owing to the small electric transition dipole moment induced by molecular sizes compared to the ECD-active wavelength in the UV-visible-near IR region. To enhance ECD magnitude, recently it has being developed 3D chiral nanoplasmonic structures having a helical path, and the dimensions are comparable to the ECD wavelength. However, it is still ambiguous the origin of 3D chiroplasmonics, and there is a lack of studying the interaction of 3D chiroplasmoncs with enantiomers for the application of enantioselection. Herein, we will present a one-step fabrication of 3D silver nanospirals (AgNSs) via low-substrate-temperature glancing angle deposition. AgNSs can be deposited on a wide range of substrates (including transparent and flexible substrates), in an area on the order of cm2. A set of spiral dimensions (such as spiral pitches, number of turns and handedness) have been easily engineered to tune the chiroptic properties, leading to studying the chiroplasmonic principles together with finite element simulation and the LC model. At the end, it will be demonstrated that 3D chiroplasmonics can differentiate molecular chirality of enantiomers with dramatic enhancement in the anisotropy g factor. This study opens a door to sensitively discriminate enantiomer chirality.

  13. Fabrication of 3D polymer photonic crystals for near-IR applications

    NASA Astrophysics Data System (ADS)

    Yao, Peng; Qiu, Liang; Shi, Shouyuan; Schneider, Garrett J.; Prather, Dennis W.; Sharkawy, Ahmed; Kelmelis, Eric

    2008-02-01

    Photonic crystals[1, 2] have stirred enormous research interest and became a growing enterprise in the last 15 years. Generally, PhCs consist of periodic structures that possess periodicity comparable with the wavelength that the PhCs are designed to modulate. If material and periodic pattern are properly selected, PhCs can be applied to many applications based on their unique properties, including photonic band gaps (PBG)[3], self-collimation[4], super prism[5], etc. Strictly speaking, PhCs need to possess periodicity in three dimensions to maximize their advantageous capabilities. However, many current research is based on scaled two-dimensional PhCs, mainly due to the difficulty of fabrication such three-dimensional PhCs. Many approaches have been explored for the fabrication of 3D photonic crystals, including layer-by-layer surface micromachining[6], glancing angle deposition[7], 3D micro-sculpture method[8], self-assembly[9] and lithographical methods[10-12]. Among them, lithographic methods became increasingly accepted due to low costs and precise control over the photonic crystal structure. There are three mostly developed lithographical methods, namely X-ray lithography[10], holographic lithography[11] and two-photon polymerization[12]. Although significant progress has been made in developing these lithography-based technologies, these approaches still suffer from significant disadvantages. X-ray lithography relies on an expensive radiation source. Holographic lithography lacks the flexibility to create engineered defects, and multi-photon polymerization is not suitable for parallel fabrication. In our previous work, we developed a multi-layer photolithography processes[13, 14] that is based on multiple resist application and enhanced absorption upon exposure. Using a negative lift-off resist (LOR) and 254nm DUV source, we have demonstrated fabrication of 3D arbitrary structures with feature size of several microns. However, severe intermixing problem

  14. Optical 3D Nano-fabrication: Drawing or Growing? (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kawata, Satoshi

    2016-05-01

    Conventional nanotechnology based on the lithography and scanning probe microscopy is limited to 2D fabrication and modification. Here, I will talk about the method for 3D laser fabrication with two-photon polymerization [1], two-photon isomerization [2], and two-photon photo-reduction [3]. Self-growth technology, such as self-grown fiber structures of polymer [4] and self-grown metallic fractal metamaterials structures [5] will be also discussed. [1] S. Kawata, et. al, Nature 412, 697-698, 2001. [2] S. Kawata and Y. Kawata, Chem Rev. 88, 083110, 2006. [3] Y. -Y. Cao, et. al., Small 5, 1144-1148, 2009 [4] S. Shoji and S. Kawata, Appl. Phys. Lett. 75, 737-739, 1999. [5] N. Takeyasu, N. Nishimura, S. Kawata, submitted.

  15. Mass fabrication and delivery of 3D multilayer μTags into living cells

    PubMed Central

    Chen, Lisa Y.; Parizi, Kokab B.; Kosuge, Hisanori; Milaninia, Kaveh M.; McConnell, Michael V.; Wong, H.-S. Philip; Poon, Ada S. Y.

    2013-01-01

    Continuous monitoring of in vivo biological processes and their evolution at the cellular level would enable major advances in our understanding of biology and disease. As a stepping stone towards chronic cellular monitoring, we demonstrate massively parallel fabrication and delivery of 3D multilayer micro-Tags (μTags) into living cells. Both 10 μm × 10 μm × 1.5 μm and 18 μm × 7 μm × 1.5 μm devices containing inductive and capacitive structures were designed and fabricated as potential passive radio-frequency identification tags. We show cellular internalization and persistence of μTags over a 5-day period. Our results represent a promising advance in technologies for studying biology and disease at the cellular level. PMID:23887586

  16. Size-Controlled Fabrication of Polyaniline Microfibers Based on 3D Hydrodynamic Focusing Approach.

    PubMed

    Yoo, Imsung; Song, Simon; Uh, Kyungchan; Lee, Chan Woo; Kim, Jong-Man

    2015-07-01

    Owing to the relatively high conductivity and unique redox behavior, polyaniline (PANI) has been one of the most technologically promising conducting polymers. Although various methodologies have been developed, fabrication of PANI microfibers has been a challenging task owing to the poor solubility in most organic solvents. By taking advantage of a microfluidic technology and organic soluble acid labile t-Boc-protected PANI (t-Boc-PANI) as the conducting polymer precursor, fabrication of PANI microfibers in a size-controlled manner is possible. Introduction of a THF solution containing t-Boc-PANI, and dodecylbenzenesulfonic acid (DBSA) as a core flow, and water as a sheath flow into a microfluidic channel with a 3D hydrodynamic focusing effect results in crystallization of the polymer fiber. By changing the flow rate, linear PANI microfibers that range from 16.2 to 39.4 μm in diameter are readily obtained.

  17. Fundamental Characteristics of Bioprint on Calcium Alginate Gel

    NASA Astrophysics Data System (ADS)

    Umezu, Shinjiro; Hatta, Tatsuru; Ohmori, Hitoshi

    2013-05-01

    The goal of this study is to fabricate precision three-dimensional (3D) biodevices those are micro fluidics and artificial organs utilizing digital fabrication. Digital fabrication is fabrication method utilizing inkjet technologies. Electrostatic inkjet is one of the inkjet technologies. The electrostatic inkjet method has following two merits; those are high resolution to print and ability to eject highly viscous liquid. These characteristics are suitable to print biomaterials precisely. We are now applying for bioprint. In this paper, the electrostatic inkjet method is applied for fabrication of 3D biodevices that has cave like blood vessel. When aqueous solution of sodium alginate is printed to aqueous solution of calcium chloride, calcium alginate is produced. 3D biodevices are fabricated in case that calcium alginate is piled.

  18. An appropriate selection of a 3D alginate culture model for hepatic Huh-7 cell line encapsulation intended for viral studies.

    PubMed

    Tran, Nhu Mai; Dufresne, Murielle; Duverlie, Gilles; Castelain, Sandrine; Défarge, Christian; Paullier, Patrick; Legallais, Cecile

    2013-01-01

    Three-dimensional (3D) culture systems have been introduced to provide cells with a biomimetic environment that is similar to in vivo conditions. Among the polymeric molecules available, sodium-alginate (Na-alg) salt is a material that is currently employed in different areas of drug delivery and tissue engineering, because it offers biocompatibility and optimal chemical properties, and its gelation with calcium chloride provides calcium-alginate (Ca-alg) scaffolds with mechanical stability and relative permeability. In this work, four different preparations of Ca-alg beads with varying Na-alg viscosity and concentration were used for a human hepatoma cell line (Huh-7) encapsulation. The effects of Ca-alg bead preparation on structural cell organization, liver-specific functions, and the expression of specific receptors implicated in hepatotropic virus permissivity were evaluated. Hepatic cells were cultured in 500 μm diameter Ca-alg beads for 7 days under dynamic conditions. For all culture systems, cell viability reached almost 100% at day 7. Cell proliferation was concomitantly followed by hepatocyte organization in aggregates, which adopted two different morphologies (spheroid aggregates or multicellular channel-like structures), depending on Ca-alg bead preparation. These cellular organizations established a real 3D hepatocyte architecture with cell polarity, cell junctions, and abundant bile canaliculi possessing microvillus-lined channels. The functionality of these 3D cultures was confirmed by the production of albumin and the exhibition of CYP1A activity over culture time, which were variable, according to Ca-alg bead condition. The expression of specific receptors of hepatitis C virus by Huh-7 cells suggests encouraging data for the further development of a new viral culture system in Ca-alg beads. In summary, this 3D hepatic cell culture represents a promising physiologically relevant system for further in vitro studies and demonstrates that an

  19. Fabrication of 2D and 3D constructs from reconstituted decellularized tissue extracellular matrices.

    PubMed

    Takeda, Yuji S; Xu, Qiaobing

    2014-12-01

    We demonstrated a novel process to reconstitute a decellularized extracellular matrix (Recon-ECM) of heart and liver tissue using a combination of mechanical homogenization and enzymatic digestion. Such Recon-ECM was used as a biomaterial to produce flat or micro-patterned 2D films after crosslinking using replica molding. The mechanical properties of the resulting films were tuned by changing the type of crosslinking reagents. We also demonstrated the fabrication of mechanically robust 3D scaffolds by freeze-drying of the Recon-ECM solution. The porosity of the 3D scaffold was controlled by changing the concentration of the Recon-ECM. HepG2 cells were used to investigate the potential substrate of these engineered 2D patterned and 3D porous structures. The cell attachment, proliferation, and urea synthesis were evaluated, and the results indicate that the scaffold generated from Recon-ECM provides a biologically friendly environment for cells to grow. This method provides a new way to use decellularized ECM as a source of biomaterial to produce novel scaffolds with better controlled micro- and nano-scale structures, tunable physicochemical properties with desired biological functions.

  20. Design and fabrication of an RF GRIN lens using 3D printing technology

    NASA Astrophysics Data System (ADS)

    Allen, J. W.; Wu, B.-I.

    2013-03-01

    Electromagnetic media and metamaterials have been explored in frequency regimes ranging from the acoustic to the visible domain over the past decade. A large part of the design, fabrication and prototyping of such materials has focused on planar structures and devices have been demonstrated primarily for certain propagation directions and/or defined polarization. Here, we present the design of a focusing GRadient INdex (GRIN) lens that operates at RF frequencies and is not polarization constrained. We compare the theoretical and experimental results from this lens designed to operate at X-band and fabricated using 3D printing technology to implement the effective medium. The lens with radially varying refractive index gradient was designed, optimized and analyzed by conducting full-wave simulations finite-element method based software. The permittivity was estimated by effective medium theory and calculated using HFSS®. The optimized design was used to fabricate the GRIN lens with isotropic, inhomogenous dielectric material. The refractive index was designed to match the theoretical results using mixing ratio of air/voids and a polymer. Further, we used the refractive index profile to predict the rays' trajectories and focus length to compare them to those predicted by the FEM simulations. The field distributions were also analyzed to compare performance of the theoretical design to the fabricated lens and were found to be in good agreement with each other.

  1. Design and fabrication of a foldable 3D silicon based package for solid state lighting applications

    NASA Astrophysics Data System (ADS)

    Sokolovskij, R.; Liu, P.; van Zeijl, H. W.; Mimoun, B.; Zhang, G. Q.

    2015-05-01

    Miniaturization of solid state lighting (SSL) luminaires as well as reduction of packaging and assembly costs are of prime interest for the SSL lighting industry. A novel silicon based LED package for lighting applications is presented in this paper. The proposed design consists of 5 rigid Si tiles connected by flexible polyimide hinges with embedded interconnects (ICs). Electrical, optical and thermal characteristics were taken into consideration during design. The fabrication process involved polyimide (PI) application and patterning, aluminium interconnect integration in the flexible hinge, LED reflector cavity formation and metalization followed by through wafer DRIE etching for chip formation and release. A method to connect chip front to backside without TSVs was also integrated into the process. Post-fabrication wafer level assembly included LED mounting and wirebond, phosphor-based colour conversion and silicone encapsulation. The package formation was finalized by vacuum assisted wrapping around an assembly structure to form a 3D geometry, which is beneficial for omnidirectional lighting. Bending tests were performed on the flexible ICs and optical performance at different temperatures was evaluated. It is suggested that 3D packages can be expanded to platforms for miniaturized luminaire applications by combining monolithic silicon integration and system-in-package (SiP) technologies.

  2. Fabrication of solution processed 3D nanostructured CuInGaS₂ thin film solar cells.

    PubMed

    Chu, Van Ben; Cho, Jin Woo; Park, Se Jin; Hwang, Yun Jeong; Park, Hoo Keun; Do, Young Rag; Min, Byoung Koun

    2014-03-28

    In this study we demonstrate the fabrication of CuInGaS₂ (CIGS) thin film solar cells with a three-dimensional (3D) nanostructure based on indium tin oxide (ITO) nanorod films and precursor solutions (Cu, In and Ga nitrates in alcohol). To obtain solution processed 3D nanostructured CIGS thin film solar cells, two different precursor solutions were applied to complete gap filling in ITO nanorods and achieve the desirable absorber film thickness. Specifically, a coating of precursor solution without polymer binder material was first applied to fill the gap between ITO nanorods followed by deposition of the second precursor solution in the presence of a binder to generate an absorber film thickness of ∼1.3 μm. A solar cell device with a (Al, Ni)/AZO/i-ZnO/CdS/CIGS/ITO nanorod/glass structure was constructed using the CIGS film, and the highest power conversion efficiency was measured to be ∼6.3% at standard irradiation conditions, which was 22.5% higher than the planar type of CIGS solar cell on ITO substrate fabricated using the same precursor solutions. PMID:24569126

  3. Fabrication of computationally designed scaffolds by low temperature 3D printing.

    PubMed

    Castilho, Miguel; Dias, Marta; Gbureck, Uwe; Groll, Jürgen; Fernandes, Paulo; Pires, Inês; Gouveia, Barbara; Rodrigues, Jorge; Vorndran, Elke

    2013-09-01

    The development of artificial bone substitutes that mimic the properties of bone and simultaneously promote the desired tissue regeneration is a current issue in bone tissue engineering research. An approach to create scaffolds with such characteristics is based on the combination of novel design and additive manufacturing processes. The objective of this work is to characterize the microstructural and the mechanical properties of scaffolds developed by coupling both topology optimization and a low temperature 3D printing process. The scaffold design was obtained using a topology optimization approach to maximize the permeability with constraints on the mechanical properties. This procedure was studied to be suitable for the fabrication of a cage prototype for tibial tuberosity advancement application, which is one of the most recent and promising techniques to treat cruciate ligament rupture in dogs. The microstructural and mechanical properties of the scaffolds manufactured by reacting α/β-tricalcium phosphate with diluted phosphoric acid were then assessed experimentally and the scaffolds strength reliability was determined. The results demonstrate that the low temperature 3D printing process is a reliable option to create synthetic scaffolds with tailored properties, and when coupled with topology optimization design it can be a powerful tool for the fabrication of patient-specific bone implants. PMID:23887064

  4. Fabrication of Capacitive Acoustic Resonators Combining 3D Printing and 2D Inkjet Printing Techniques

    PubMed Central

    Haque, Rubaiyet Iftekharul; Ogam, Erick; Loussert, Christophe; Benaben, Patrick; Boddaert, Xavier

    2015-01-01

    A capacitive acoustic resonator developed by combining three-dimensional (3D) printing and two-dimensional (2D) printed electronics technique is described. During this work, a patterned bottom structure with rigid backplate and cavity is fabricated directly by a 3D printing method, and then a direct write inkjet printing technique has been employed to print a silver conductive layer. A novel approach has been used to fabricate a diaphragm for the acoustic sensor as well, where the conductive layer is inkjet-printed on a pre-stressed thin organic film. After assembly, the resulting structure contains an electrically conductive diaphragm positioned at a distance from a fixed bottom electrode separated by a spacer. Measurements confirm that the transducer acts as capacitor. The deflection of the diaphragm in response to the incident acoustic single was observed by a laser Doppler vibrometer and the corresponding change of capacitance has been calculated, which is then compared with the numerical result. Observation confirms that the device performs as a resonator and provides adequate sensitivity and selectivity at its resonance frequency. PMID:26473878

  5. Fabrication of capacitive acoustic resonators combining 3D printing and 2D inkjet printing techniques.

    PubMed

    Haque, Rubaiyet Iftekharul; Ogam, Erick; Loussert, Christophe; Benaben, Patrick; Boddaert, Xavier

    2015-10-14

    A capacitive acoustic resonator developed by combining three-dimensional (3D) printing and two-dimensional (2D) printed electronics technique is described. During this work, a patterned bottom structure with rigid backplate and cavity is fabricated directly by a 3D printing method, and then a direct write inkjet printing technique has been employed to print a silver conductive layer. A novel approach has been used to fabricate a diaphragm for the acoustic sensor as well, where the conductive layer is inkjet-printed on a pre-stressed thin organic film. After assembly, the resulting structure contains an electrically conductive diaphragm positioned at a distance from a fixed bottom electrode separated by a spacer. Measurements confirm that the transducer acts as capacitor. The deflection of the diaphragm in response to the incident acoustic single was observed by a laser Doppler vibrometer and the corresponding change of capacitance has been calculated, which is then compared with the numerical result. Observation confirms that the device performs as a resonator and provides adequate sensitivity and selectivity at its resonance frequency.

  6. The study of simulated microgravity effects on cardiac myocytes using a 3D heart tissue-equivalent model encapsulated in alginate microbeads

    NASA Astrophysics Data System (ADS)

    Li, Yu; Tian, Weiming; Zheng, Hongxia; Yu, Lei; Zhang, Yao; Han, Fengtong

    Long duration spaceflight may increase the risk and occurrence of potentially life-threatening heart rhythm disturbances associated with alterations of cardiac myocytes, myocyte connec-tivity, and extracellular matrix resulting from prolonged exposure to zero-or low-gravity. For understanding of the effects of microgravity, either traditional 2-dimensional (2D) cell cultures of adherent cell populations or animal models were typically used. The 2D in vitro systems do not allow assessment of the dynamic effects of intercellular interactions within tissues, whereas potentially confounding factors tend to be overlooked in animal models. Therefore novel cell culture model representative of the cellular interactions and with extracellular matrix present in tissues needs to be used. In this study, 3D multi-cellular heart tissue-equivalent model was constructed by culturing neonatal rat myocardial cells in alginate microbeads for one week. With this model we studied the simulated microgravity effects on myocardiocytes by incubat-ing the microbeads in NASA rotary cell culture system with a rate of 15rpm. Cytoskeletal changes, mitochondrial membrane potential and reactive oxygen production were studied after incubating for 24h, 48h and 72h respectively. Compared with 3D ground-culture group, sig-nificant cytoskeleton depolymerization characterized by pseudo-feet disappearance, significant increase of mitochondrial membrane potential, and greater reactive oxygen production were observed in after incubating 24h, 48h, and 72h, in NASA system. The beating rate of 3D heart tissue-equivalent decreased significantly at 24h, and all the samples stopped beating after 48h incubation while the beating rate of control group did not change. This study indicated that mi-crogravity affects both the structure and function of myocardial cells. Our results suggest that a 3D heart tissue-equivalent model maybe better for attempting to elucidate the microgravity effects on myocardiocytes in

  7. 3D Dynamic Culture of Rabbit Articular Chondrocytes Encapsulated in Alginate Gel Beads Using Spinner Flasks for Cartilage Tissue Regeneration

    PubMed Central

    Xu, Feiyue; Xu, Lei; Wang, Qi; Ye, Zhaoyang; Zhou, Yan; Tan, Wen-Song

    2014-01-01

    Cell-based therapy using chondrocytes for cartilage repair suffers from chondrocyte dedifferentiation. In the present study, the effects of an integrated three-dimensional and dynamic culture on rabbit articular chondrocytes were investigated. Cells (passages 1 and 4) were encapsulated in alginate gel beads and cultured in spinner flasks in chondrogenic and chondrocyte growth media. Subcutaneous implantation of the cell-laden beads was performed to evaluate the ectopic chondrogenesis. It was found that cells remained viable after 35 days in the three-dimensional dynamic culture. Passage 1 cells demonstrated a proliferative growth in both media. Passage 4 cells showed a gradual reduction in DNA content in growth medium, which was attenuated in chondrogenic medium. Deposition of glycosaminoglycans (GAG) was found in all cultures. While passage 1 cells generally produced higher amounts of GAG than passage 4 cells, GAG/DNA became similar on day 35 for both cells in growth media. Interestingly, GAG/DNA in growth medium was greater than that in chondrogenic medium for both cells. Based on GAG quantification and gene expression analysis, encapsulated passage 1 cells cultured in growth medium displayed the best ectopic chondrogenesis. Taken together, the three-dimensional and dynamic culture for chondrocytes holds great potential in cartilage regeneration. PMID:25506593

  8. Increased sensitivity of 3D-Well enzyme-linked immunosorbent assay (ELISA) for infectious disease detection using 3D-printing fabrication technology.

    PubMed

    Singh, Harpal; Shimojima, Masayuki; Fukushi, Shuetsu; Le Van, An; Sugamata, Masami; Yang, Ming

    2015-01-01

    Enzyme-linked Immunosorbent Assay or ELISA -based diagnostics are considered the gold standard in the demonstration of various immunological reaction including in the measurement of antibody response to infectious diseases and to support pathogen identification with application potential in infectious disease outbreaks and individual patients' treatment and clinical care. The rapid prototyping of ELISA-based diagnostics using available 3D printing technologies provides an opportunity for a further exploration of this platform into immunodetection systems. In this study, a '3D-Well' was designed and fabricated using available 3D printing platforms to have an increased surface area of more than 4 times for protein-surface adsorption compared to those of 96-well plates. The ease and rapidity in designing-product development-feedback cycle offered through 3D printing platforms provided an opportunity for its rapid assessment, in which a chemical etching process was used to make the surface hydrophilic followed by validation through the diagnostic performance of ELISA for infectious disease without modifying current laboratory practices for ELISA. The higher sensitivity of the 3D-Well (3-folds higher) compared to the 96-well ELISA provides a potential for the expansion of this technology towards miniaturization platforms to reduce time, volume of reagents and samples needed for laboratory or field diagnosis of infectious diseases including applications in other disciplines.

  9. Increased sensitivity of 3D-Well enzyme-linked immunosorbent assay (ELISA) for infectious disease detection using 3D-printing fabrication technology.

    PubMed

    Singh, Harpal; Shimojima, Masayuki; Fukushi, Shuetsu; Le Van, An; Sugamata, Masami; Yang, Ming

    2015-01-01

    Enzyme-linked Immunosorbent Assay or ELISA -based diagnostics are considered the gold standard in the demonstration of various immunological reaction including in the measurement of antibody response to infectious diseases and to support pathogen identification with application potential in infectious disease outbreaks and individual patients' treatment and clinical care. The rapid prototyping of ELISA-based diagnostics using available 3D printing technologies provides an opportunity for a further exploration of this platform into immunodetection systems. In this study, a '3D-Well' was designed and fabricated using available 3D printing platforms to have an increased surface area of more than 4 times for protein-surface adsorption compared to those of 96-well plates. The ease and rapidity in designing-product development-feedback cycle offered through 3D printing platforms provided an opportunity for its rapid assessment, in which a chemical etching process was used to make the surface hydrophilic followed by validation through the diagnostic performance of ELISA for infectious disease without modifying current laboratory practices for ELISA. The higher sensitivity of the 3D-Well (3-folds higher) compared to the 96-well ELISA provides a potential for the expansion of this technology towards miniaturization platforms to reduce time, volume of reagents and samples needed for laboratory or field diagnosis of infectious diseases including applications in other disciplines. PMID:26406036

  10. Elasto-Capillary Folding Using Stop-Programmable Hinges Fabricated by 3D Micro-Machining

    PubMed Central

    Legrain, Antoine; Berenschot, Erwin J. W.; Tas, Niels R.; Abelmann, Leon

    2015-01-01

    We show elasto-capillary folding of silicon nitride objects with accurate folding angles between flaps of (70.6 ± 0.1)° and demonstrate the feasibility of such accurate micro-assembly with a final folding angle of 90°. The folding angle is defined by stop-programmable hinges that are fabricated starting from silicon molds employing accurate three-dimensional corner lithography. This nano-patterning method exploits the conformal deposition and the subsequent timed isotropic etching of a thin film in a 3D shaped silicon template. The technique leaves a residue of the thin film in sharp concave corners which can be used as an inversion mask in subsequent steps. Hinges designed to stop the folding at 70.6° were fabricated batchwise by machining the V-grooves obtained by KOH etching in (110) silicon wafers; 90° stop-programmable hinges were obtained starting from silicon molds obtained by dry etching on (100) wafers. The presented technique has potential to achieve any folding angle and opens a new route towards creating structures with increased complexity, which will ultimately lead to a novel method for device fabrication. PMID:25992886

  11. A Novel Bio-carrier Fabricated Using 3D Printing Technique for Wastewater Treatment

    PubMed Central

    Dong, Yang; Fan, Shu-Qian; Shen, Yu; Yang, Ji-Xiang; Yan, Peng; Chen, You-Peng; Li, Jing; Guo, Jin-Song; Duan, Xuan-Ming; Fang, Fang; Liu, Shao-Yang

    2015-01-01

    The structure of bio-carriers is one of the key operational characteristics of a biofilm reactor. The goal of this study is to develop a series of novel fullerene-type bio-carriers using the three-dimensional printing (3DP) technique. 3DP can fabricate bio-carriers with more specialized structures compared with traditional fabrication processes. In this research, three types of fullerene-type bio-carriers were fabricated using the 3DP technique and then compared with bio-carrier K3 (from AnoxKaldnes) in the areas of physicochemical properties and biofilm growth. Images acquired by 3D profiling and SEM indicated that the surface roughness of the 3DP bio-carrier was greater than that of K3. Furthermore, contact angle data indicated that the 3DP bio-carriers were more hydrophilic than K3. The biofilm on the 3DP bio-carriers exhibited higher microbial activity and stronger adhesion ability. These findings were attributed to excellent mass transfer of the substrate (and oxygen) between the vapour-liquid-solid tri-phase system and to the surface characteristics. It is concluded that the novel 3DP fullerene-type bio-carriers are ideal carriers for biofilm adherence and growth. PMID:26202477

  12. Fabrication of digital rainbow holograms and 3-D imaging using SEM based e-beam lithography.

    PubMed

    Firsov, An; Firsov, A; Loechel, B; Erko, A; Svintsov, A; Zaitsev, S

    2014-11-17

    Here we present an approach for creating full-color digital rainbow holograms based on mixing three basic colors. Much like in a color TV with three luminescent points per single screen pixel, each color pixel of initial image is presented by three (R, G, B) distinct diffractive gratings in a hologram structure. Change of either duty cycle or area of the gratings are used to provide proper R, G, B intensities. Special algorithms allow one to design rather complicated 3D images (that might even be replacing each other with hologram rotation). The software developed ("RainBow") provides stability of colorization of rotated image by means of equalizing of angular blur from gratings responsible for R, G, B basic colors. The approach based on R, G, B color synthesis allows one to fabricate gray-tone rainbow hologram containing white color what is hardly possible in traditional dot-matrix technology. Budgetary electron beam lithography based on SEM column was used to fabricate practical examples of digital rainbow hologram. The results of fabrication of large rainbow holograms from design to imprinting are presented. Advantages of the EBL in comparison to traditional optical (dot-matrix) technology is considered. PMID:25402115

  13. A Novel Bio-carrier Fabricated Using 3D Printing Technique for Wastewater Treatment.

    PubMed

    Dong, Yang; Fan, Shu-Qian; Shen, Yu; Yang, Ji-Xiang; Yan, Peng; Chen, You-Peng; Li, Jing; Guo, Jin-Song; Duan, Xuan-Ming; Fang, Fang; Liu, Shao-Yang

    2015-07-23

    The structure of bio-carriers is one of the key operational characteristics of a biofilm reactor. The goal of this study is to develop a series of novel fullerene-type bio-carriers using the three-dimensional printing (3DP) technique. 3DP can fabricate bio-carriers with more specialized structures compared with traditional fabrication processes. In this research, three types of fullerene-type bio-carriers were fabricated using the 3DP technique and then compared with bio-carrier K3 (from AnoxKaldnes) in the areas of physicochemical properties and biofilm growth. Images acquired by 3D profiling and SEM indicated that the surface roughness of the 3DP bio-carrier was greater than that of K3. Furthermore, contact angle data indicated that the 3DP bio-carriers were more hydrophilic than K3. The biofilm on the 3DP bio-carriers exhibited higher microbial activity and stronger adhesion ability. These findings were attributed to excellent mass transfer of the substrate (and oxygen) between the vapour-liquid-solid tri-phase system and to the surface characteristics. It is concluded that the novel 3DP fullerene-type bio-carriers are ideal carriers for biofilm adherence and growth.

  14. Fabrication of digital rainbow holograms and 3-D imaging using SEM based e-beam lithography.

    PubMed

    Firsov, An; Firsov, A; Loechel, B; Erko, A; Svintsov, A; Zaitsev, S

    2014-11-17

    Here we present an approach for creating full-color digital rainbow holograms based on mixing three basic colors. Much like in a color TV with three luminescent points per single screen pixel, each color pixel of initial image is presented by three (R, G, B) distinct diffractive gratings in a hologram structure. Change of either duty cycle or area of the gratings are used to provide proper R, G, B intensities. Special algorithms allow one to design rather complicated 3D images (that might even be replacing each other with hologram rotation). The software developed ("RainBow") provides stability of colorization of rotated image by means of equalizing of angular blur from gratings responsible for R, G, B basic colors. The approach based on R, G, B color synthesis allows one to fabricate gray-tone rainbow hologram containing white color what is hardly possible in traditional dot-matrix technology. Budgetary electron beam lithography based on SEM column was used to fabricate practical examples of digital rainbow hologram. The results of fabrication of large rainbow holograms from design to imprinting are presented. Advantages of the EBL in comparison to traditional optical (dot-matrix) technology is considered.

  15. Elasto-Capillary Folding Using Stop-Programmable Hinges Fabricated by 3D Micro-Machining.

    PubMed

    Legrain, Antoine; Berenschot, Erwin J W; Tas, Niels R; Abelmann, Leon

    2015-01-01

    We show elasto-capillary folding of silicon nitride objects with accurate folding angles between flaps of (70.6 ± 0.1)° and demonstrate the feasibility of such accurate micro-assembly with a final folding angle of 90°. The folding angle is defined by stop-programmable hinges that are fabricated starting from silicon molds employing accurate three-dimensional corner lithography. This nano-patterning method exploits the conformal deposition and the subsequent timed isotropic etching of a thin film in a 3D shaped silicon template. The technique leaves a residue of the thin film in sharp concave corners which can be used as an inversion mask in subsequent steps. Hinges designed to stop the folding at 70.6° were fabricated batchwise by machining the V-grooves obtained by KOH etching in (110) silicon wafers; 90° stop-programmable hinges were obtained starting from silicon molds obtained by dry etching on (100) wafers. The presented technique has potential to achieve any folding angle and opens a new route towards creating structures with increased complexity, which will ultimately lead to a novel method for device fabrication.

  16. 3D fabrication of all-polymer conductive microstructures by two photon polymerization.

    PubMed

    Kurselis, Kestutis; Kiyan, Roman; Bagratashvili, Victor N; Popov, Vladimir K; Chichkov, Boris N

    2013-12-16

    A technique to fabricate electrically conductive all-polymer 3D microstructures is reported. Superior conductivity, high spatial resolution and three-dimensionality are achieved by successive application of two-photon polymerization and in situ oxidative polymerization to a bi-component formulation, containing a photosensitive host matrix and an intrinsically conductive polymer precursor. By using polyethylene glycol diacrylate (PEG-DA) and 3,4-ethylenedioxythiophene (EDOT), the conductivity of 0.04 S/cm is reached, which is the highest value for the two-photon polymerized all-polymer microstructures to date. The measured electrical conductivity dependency on the EDOT concentration indicates percolation phenomenon and a three-dimensional nature of the conductive pathways. Tunable conductivity, biocompatibility, and environmental stability are the characteristics offered by PEG-DA/EDOT blends which can be employed in biomedicine, MEMS, microfluidics, and sensorics.

  17. A simple configuration for fabrication of 2D and 3D photonic quasicrystals with complex structures

    NASA Astrophysics Data System (ADS)

    Sun, XiaoHong; Wang, Shuai; Liu, Wei; Jiang, LiuDi

    2016-06-01

    A simple method using a single-prism common-path interferometer is presented for the fabrication of complex quasicrystals in sub-micrometer scales. Multiple types of two-dimensional (2D) and three-dimensional (3D) quasicrystalline structures are designed and their diffraction patterns are obtained by using Fourier Transform method. Multi-fold rotational symmetries are demonstrated and compared. By using this method, a wide range of quasicrystals types can be produced with arbitrary complexities and rotational symmetries. The transmittance studies of 12-fold and 18-fold structures also reveal the existence of complete photonic bandgaps, which also demonstrates increased symmetry and significantly improved characteristics of photonic band-gaps.

  18. In-chip fabrication of free-form 3D constructs for directed cell migration analysis.

    PubMed

    Olsen, Mark Holm; Hjortø, Gertrud Malene; Hansen, Morten; Met, Özcan; Svane, Inge Marie; Larsen, Niels B

    2013-12-21

    Free-form constructs with three-dimensional (3D) microporosity were fabricated by two-photon polymerization inside the closed microchannel of an injection-molded, commercially available polymer chip for analysis of directed cell migration. Acrylate constructs were produced as woodpile topologies with a range of pore sizes from 5 × 5 μm to 15 × 15 μm and prefilled with fibrillar collagen. Dendritic cells seeded into the polymer chip in a concentration gradient of the chemoattractant CCL21 efficiently negotiated the microporous maze structure for pore sizes of 8 × 8 μm or larger. The cells migrating through smaller pore sizes made significantly more turns than those through larger pores. The introduction of additional defined barriers in the microporous structure resulted in dendritic cells making more turns while still being able to follow the chemoattractant concentration gradient.

  19. Aerosol based direct-write micro-additive fabrication method for sub-mm 3D metal-dielectric structures

    NASA Astrophysics Data System (ADS)

    Rahman, Taibur; Renaud, Luke; Heo, Deuk; Renn, Michael; Panat, Rahul

    2015-10-01

    The fabrication of 3D metal-dielectric structures at sub-mm length scale is highly important in order to realize low-loss passives and GHz wavelength antennas with applications in wearable and Internet-of-Things (IoT) devices. The inherent 2D nature of lithographic processes severely limits the available manufacturing routes to fabricate 3D structures. Further, the lithographic processes are subtractive and require the use of environmentally harmful chemicals. In this letter, we demonstrate an additive manufacturing method to fabricate 3D metal-dielectric structures at sub-mm length scale. A UV curable dielectric is dispensed from an Aerosol Jet system at 10-100 µm length scale and instantaneously cured to build complex 3D shapes at a length scale  <1 mm. A metal nanoparticle ink is then dispensed over the 3D dielectric using a combination of jetting action and tilted dispense head, also using the Aerosol Jet technique and at a length scale 10-100 µm, followed by the nanoparticle sintering. Simulation studies are carried out to demonstrate the feasibility of using such structures as mm-wave antennas. The manufacturing method described in this letter opens up the possibility of fabricating an entirely new class of custom-shaped 3D structures at a sub-mm length scale with potential applications in 3D antennas and passives.

  20. Fabrication of 3-D Reconstituted Organoid Arrays by DNA-Programmed Assembly of Cells (DPAC).

    PubMed

    Todhunter, Michael E; Weber, Robert J; Farlow, Justin; Jee, Noel Y; Cerchiari, Alec E; Gartner, Zev J

    2016-01-01

    Tissues are the organizational units of function in metazoan organisms. Tissues comprise an assortment of cellular building blocks, soluble factors, and extracellular matrix (ECM) composed into specific three-dimensional (3-D) structures. The capacity to reconstitute tissues in vitro with the structural complexity observed in vivo is key to understanding processes such as morphogenesis, homeostasis, and disease. In this article, we describe DNA-programmed assembly of cells (DPAC), a method to fabricate viable, functional arrays of organoid-like tissues within 3-D ECM gels. In DPAC, dissociated cells are chemically functionalized with degradable oligonucleotide "Velcro," allowing rapid, specific, and reversible cell adhesion to a two-dimensional (2-D) template patterned with complementary DNA. An iterative assembly process builds up organoids, layer-by-layer, from this initial 2-D template and into the third dimension. Cleavage of the DNA releases the completed array of tissues that are captured and fully embedded in ECM gels for culture and observation. DPAC controls the size, shape, composition, and spatial heterogeneity of organoids and permits positioning of constituent cells with single-cell resolution even within cultures several centimeters long. © 2016 by John Wiley & Sons, Inc. PMID:27622567

  1. Bottom-up Fabrication of Multilayer Stacks of 3D Photonic Crystals from Titanium Dioxide.

    PubMed

    Kubrin, Roman; Pasquarelli, Robert M; Waleczek, Martin; Lee, Hooi Sing; Zierold, Robert; do Rosário, Jefferson J; Dyachenko, Pavel N; Montero Moreno, Josep M; Petrov, Alexander Yu; Janssen, Rolf; Eich, Manfred; Nielsch, Kornelius; Schneider, Gerold A

    2016-04-27

    A strategy for stacking multiple ceramic 3D photonic crystals is developed. Periodically structured porous films are produced by vertical convective self-assembly of polystyrene (PS) microspheres. After infiltration of the opaline templates by atomic layer deposition (ALD) of titania and thermal decomposition of the polystyrene matrix, a ceramic 3D photonic crystal is formed. Further layers with different sizes of pores are deposited subsequently by repetition of the process. The influence of process parameters on morphology and photonic properties of double and triple stacks is systematically studied. Prolonged contact of amorphous titania films with warm water during self-assembly of the successive templates is found to result in exaggerated roughness of the surfaces re-exposed to ALD. Random scattering on rough internal surfaces disrupts ballistic transport of incident photons into deeper layers of the multistacks. Substantially smoother interfaces are obtained by calcination of the structure after each infiltration, which converts amorphous titania into the crystalline anatase before resuming the ALD infiltration. High quality triple stacks consisting of anatase inverse opals with different pore sizes are demonstrated for the first time. The elaborated fabrication method shows promise for various applications demanding broadband dielectric reflectors or titania photonic crystals with a long mean free path of photons. PMID:27045887

  2. Bottom-up Fabrication of Multilayer Stacks of 3D Photonic Crystals from Titanium Dioxide.

    PubMed

    Kubrin, Roman; Pasquarelli, Robert M; Waleczek, Martin; Lee, Hooi Sing; Zierold, Robert; do Rosário, Jefferson J; Dyachenko, Pavel N; Montero Moreno, Josep M; Petrov, Alexander Yu; Janssen, Rolf; Eich, Manfred; Nielsch, Kornelius; Schneider, Gerold A

    2016-04-27

    A strategy for stacking multiple ceramic 3D photonic crystals is developed. Periodically structured porous films are produced by vertical convective self-assembly of polystyrene (PS) microspheres. After infiltration of the opaline templates by atomic layer deposition (ALD) of titania and thermal decomposition of the polystyrene matrix, a ceramic 3D photonic crystal is formed. Further layers with different sizes of pores are deposited subsequently by repetition of the process. The influence of process parameters on morphology and photonic properties of double and triple stacks is systematically studied. Prolonged contact of amorphous titania films with warm water during self-assembly of the successive templates is found to result in exaggerated roughness of the surfaces re-exposed to ALD. Random scattering on rough internal surfaces disrupts ballistic transport of incident photons into deeper layers of the multistacks. Substantially smoother interfaces are obtained by calcination of the structure after each infiltration, which converts amorphous titania into the crystalline anatase before resuming the ALD infiltration. High quality triple stacks consisting of anatase inverse opals with different pore sizes are demonstrated for the first time. The elaborated fabrication method shows promise for various applications demanding broadband dielectric reflectors or titania photonic crystals with a long mean free path of photons.

  3. In-vivo behavior of Si-hydroxyapatite/polycaprolactone/DMB scaffolds fabricated by 3D printing.

    PubMed

    Meseguer-Olmo, Luis; Vicente-Ortega, Vicente; Alcaraz-Baños, Miguel; Calvo-Guirado, José Luis; Vallet-Regí, María; Arcos, Daniel; Baeza, Alejandro

    2013-07-01

    Scaffolds made of polycaprolactone and nanocrystalline silicon-substituted hydroxyapatite have been fabricated by 3D printing rapid prototyping technique. To asses that the scaffolds fulfill the requirements to be considered for bone grafting applications, they were implanted in New Zealand rabbits. Histological and radiological studies have demonstrated that the scaffolds implanted in bone exhibited an excellent osteointegration without the interposition of fibrous tissue between bone and implants and without immune response after 4 months of implantation. In addition, we have evaluated the possibility of improving the scaffolds efficiency by incorporating demineralized bone matrix during the preparation by 3D printing. When demineralized bone matrix (DBM) is incorporated, the efficacy of the scaffolds is enhanced, as new bone formation occurs not only in the peripheral portions of the scaffolds but also within its pores after 4 months of implantation. This enhanced performance can be explained in terms of the osteoinductive properties of the DBM in the scaffolds, which have been assessed through the new bone tissue formation when the scaffolds are ectopically implanted.

  4. Alginate based 3D hydrogels as an in vitro co-culture model platform for the toxicity screening of new chemical entities

    SciTech Connect

    Lan, Shih-Feng; Starly, Binil

    2011-10-01

    Prediction of human response to potential therapeutic drugs is through conventional methods of in vitro cell culture assays and expensive in vivo animal testing. Alternatives to animal testing require sophisticated in vitro model systems that must replicate in vivo like function for reliable testing applications. Advancements in biomaterials have enabled the development of three-dimensional (3D) cell encapsulated hydrogels as in vitro drug screening tissue model systems. In this study, we have developed an in vitro platform to enable high density 3D culture of liver cells combined with a monolayer growth of target breast cancer cell line (MCF-7) in a static environment as a representative example of screening drug compounds for hepatotoxicity and drug efficacy. Alginate hydrogels encapsulated with serial cell densities of HepG2 cells (10{sup 5}-10{sup 8} cells/ml) are supported by a porous poly-carbonate disc platform and co-cultured with MCF-7 cells within standard cell culture plates during a 3 day study period. The clearance rates of drug transformation by HepG2 cells are measured using a coumarin based pro-drug. The platform was used to test for HepG2 cytotoxicity 50% (CT{sub 50}) using commercially available drugs which further correlated well with published in vivo LD{sub 50} values. The developed test platform allowed us to evaluate drug dose concentrations to predict hepatotoxicity and its effect on the target cells. The in vitro 3D co-culture platform provides a scalable and flexible approach to test multiple-cell types in a hybrid setting within standard cell culture plates which may open up novel 3D in vitro culture techniques to screen new chemical entity compounds. - Graphical abstract: Display Omitted Highlights: > A porous support disc design to support the culture of desired cells in 3D hydrogels. > Demonstrated the co-culture of two cell types within standard cell-culture plates. > A scalable, low cost approach to toxicity screening involving

  5. 3D printed electromagnetic transmission and electronic structures fabricated on a single platform using advanced process integration techniques

    NASA Astrophysics Data System (ADS)

    Deffenbaugh, Paul Issac

    3D printing has garnered immense attention from many fields including in-office rapid prototyping of mechanical parts, outer-space satellite replication, garage functional firearm manufacture, and NASA rocket engine component fabrication. 3D printing allows increased design flexibility in the fabrication of electronics, microwave circuits and wireless antennas and has reached a level of maturity which allows functional parts to be printed. Much more work is necessary in order to perfect the processes of 3D printed electronics especially in the area of automation. Chapter 1 shows several finished prototypes of 3D printed electronics as well as newly developed techniques in fabrication. Little is known about the RF and microwave properties and applications of the standard materials which have been developed for 3D printing. Measurement of a wide variety of materials over a broad spectrum of frequencies up to 10 GHz using a variety of well-established measurement methods is performed throughout chapter 2. Several types of high frequency RF transmission lines are fabricated and valuable model-matched data is gathered and provided in chapter 3 for future designers' use. Of particular note is a fully 3D printed stripline which was automatically fabricated in one process on one machine. Some core advantages of 3D printing RF/microwave components include rapid manufacturing of complex, dimensionally sensitive circuits (such as antennas and filters which are often iteratively tuned) and the ability to create new devices that cannot be made using standard fabrication techniques. Chapter 4 describes an exemplary fully 3D printed curved inverted-F antenna.

  6. Femtosecond laser 3D fabrication of whispering-gallery-mode microcavities

    NASA Astrophysics Data System (ADS)

    Xu, HuaiLiang; Sun, HongBo

    2015-11-01

    Whispering-gallery-mode (WGM) microcavities with high-quality factors and small volumes have attracted intense interests in the past decades because of their potential applications in various research fields such as quantum information, sensing, and optoelectronics. This leads to rapid advance in a variety of processing technologies that can create high-quality WGM micro- cavities. Due to the unique characteristics of femtosecond laser pulses with high peak intensity and ultrashort pulse duration, femtosecond laser shows the ability to carry out ultrahigh precision micromachining of a variety of transparent materials through nonlinear multiphoton absorption and tunneling ionization. This review paper describes the basic principle of femtosecond laser direct writing, and presents an overview of recent progress concerning femtosecond laser three-dimensional (3D) fabrications of optical WGM microcavities, which include the advances in the fabrications of passive and active WGMs microcavities in a variety of materials such as polymer, glass and crystals, as well as in processing the integrated WGM-microcavity device. Lastly, a summary of this dynamic field with a future perspective is given.

  7. Fabrication of scalable and structured tissue engineering scaffolds using water dissolvable sacrificial 3D printed moulds.

    PubMed

    Mohanty, Soumyaranjan; Larsen, Layla Bashir; Trifol, Jon; Szabo, Peter; Burri, Harsha Vardhan Reddy; Canali, Chiara; Dufva, Marin; Emnéus, Jenny; Wolff, Anders

    2015-10-01

    One of the major challenges in producing large scale engineered tissue is the lack of ability to create large highly perfused scaffolds in which cells can grow at a high cell density and viability. Here, we explore 3D printed polyvinyl alcohol (PVA) as a sacrificial mould in a polymer casting process. The PVA mould network defines the channels and is dissolved after curing the polymer casted around it. The printing parameters determined the PVA filament density in the sacrificial structure and this density resulted in different stiffness of the corresponding elastomer replica. It was possible to achieve 80% porosity corresponding to about 150 cm(2)/cm(3) surface to volume ratio. The process is easily scalable as demonstrated by fabricating a 75 cm(3) scaffold with about 16,000 interconnected channels (about 1m(2) surface area) and with a channel to channel distance of only 78 μm. To our knowledge this is the largest scaffold ever to be produced with such small feature sizes and with so many structured channels. The fabricated scaffolds were applied for in-vitro culturing of hepatocytes over a 12-day culture period. Smaller scaffolds (6×4 mm) were tested for cell culturing and could support homogeneous cell growth throughout the scaffold. Presumably, the diffusion of oxygen and nutrient throughout the channel network is rapid enough to support cell growth. In conclusion, the described process is scalable, compatible with cell culture, rapid, and inexpensive. PMID:26117791

  8. EFAB: low-cost automated electrochemical batch fabrication of arbitrary 3D microstructures

    NASA Astrophysics Data System (ADS)

    Cohen, Adam L.; Frodis, Uri; Tseng, Fan-Gang; Zhang, Gang; Mansfeld, Florian; Will, Peter M.

    1999-08-01

    EFAB is a new micromachining process promising to rapidly and automatically batch fabricate high-aspect-ratio microstructures with arbitrary 3D geometry using inexpensive equipment. Conventional microfabrication processes have so far produced fairly simple geometries, yet many MEMS could benefit if more sophisticated shapes could be manufactured. By using 'Instant Masking' (IM) - a novel in-situ micropatterning method - to simplify, accelerate, and automate through-mask electroplating, EFAB can produce extremely complex shapes by depositing hundreds-thousands of layers at high speed. While other processes of the do not allow integration with ICs, EFAB operates at less than 60 degrees C, making IC compatibility a possibility. Alternative processes require costly facilities and equipment; EFAB separates photolithography from device fabrication, requiring a cleanroom only for mask-making, then depositing all layers in a low-cost, self-contained machine. All IM required can be prepared simultaneously, without repeating the lithography on each layer. Selective electrodeposition requires simply mating the mask with the substrate and applying current; in this way we have patterned well-defined features as small as 20 X 20 micrometers . The procedures in EFAB are selective electrodeposition, blanket electrodeposition, and planarization. To date we have built metal structures with up to 12 layers consisting of independently-moving components.

  9. Cast and 3D printed ion exchange membranes for monolithic microbial fuel cell fabrication

    NASA Astrophysics Data System (ADS)

    Philamore, Hemma; Rossiter, Jonathan; Walters, Peter; Winfield, Jonathan; Ieropoulos, Ioannis

    2015-09-01

    We present novel solutions to a key challenge in microbial fuel cell (MFC) technology; greater power density through increased relative surface area of the ion exchange membrane that separates the anode and cathode electrodes. The first use of a 3D printed polymer and a cast latex membrane are compared to a conventionally used cation exchange membrane. These new techniques significantly expand the geometric versatility available to ion exchange membranes in MFCs, which may be instrumental in answering challenges in the design of MFCs including miniaturisation, cost and ease of fabrication. Under electrical load conditions selected for optimal power transfer, peak power production (mean 10 batch feeds) was 11.39 μW (CEM), 10.51 μW (latex) and 0.92 μW (Tangoplus). Change in conductivity and pH of anolyte were correlated with MFC power production. Digital and environmental scanning electron microscopy show structural changes to and biological precipitation on membrane materials following long term use in an MFC. The cost of the novel membranes was lower than the conventional CEM. The efficacy of two novel membranes for ion exchange indicates that further characterisation of these materials and their fabrication techniques, shows great potential to significantly increase the range and type of MFCs that can be produced.

  10. New fabrication techniques for ring-array transducers for real-time 3D intravascular ultrasound.

    PubMed

    Light, Edward D; Lieu, Victor; Smith, Stephen W

    2009-10-01

    We have previously described miniature 2D array transducers integrated into a Cook Medical, Inc. vena cava filter deployment device. While functional, the fabrication technique was very labor intensive and did not lend itself well to efficient fabrication of large numbers of devices. We developed two new fabrication methods that we believe can be used to efficiently manufacture these types of devices in greater than prototype numbers. One transducer consisted of 55 elements operating near 5 MHz. The interelement spacing is 0.20 mm. It was constructed on a flat piece of copper-clad polyimide and then wrapped around an 11 French catheter of a Cook Medical, Inc. inferior vena cava (IVC) filter deployment device. We used a braided wiring technology from Tyco Electronics Corp. to connect the elements to our real-time 3D ultrasound scanner. Typical measured transducer element bandwidth was 20% centered at 4.7 MHz and the 50 Omega round trip insertion loss was --82 dB. The mean of the nearest neighbor cross talk was -37.0 dB. The second method consisted of a 46-cm long single layer flex circuit from MicroConnex that terminates in an interconnect that plugs directly into our system cable. This transducer had 70 elements at 0.157 mm interelement spacing operating at 4.8 MHz. Typical measured transducer element bandwidth was 29% and the 50 Omega round trip insertion loss was -83 dB. The mean of the nearest neighbor cross talk was -33.0 dB. PMID:20458877

  11. Fabrication, Densification, and Replica Molding of 3D Carbon Nanotube Microstructures

    PubMed Central

    Copic, Davor; Park, Sei Jin; Tawfick, Sameh; De Volder, Michael; Hart, A. John

    2012-01-01

    The introduction of new materials and processes to microfabrication has, in large part, enabled many important advances in microsystems, lab-on-a-chip devices, and their applications. In particular, capabilities for cost-effective fabrication of polymer microstructures were transformed by the advent of soft lithography and other micromolding techniques 1, 2, and this led a revolution in applications of microfabrication to biomedical engineering and biology. Nevertheless, it remains challenging to fabricate microstructures with well-defined nanoscale surface textures, and to fabricate arbitrary 3D shapes at the micro-scale. Robustness of master molds and maintenance of shape integrity is especially important to achieve high fidelity replication of complex structures and preserving their nanoscale surface texture. The combination of hierarchical textures, and heterogeneous shapes, is a profound challenge to existing microfabrication methods that largely rely upon top-down etching using fixed mask templates. On the other hand, the bottom-up synthesis of nanostructures such as nanotubes and nanowires can offer new capabilities to microfabrication, in particular by taking advantage of the collective self-organization of nanostructures, and local control of their growth behavior with respect to microfabricated patterns. Our goal is to introduce vertically aligned carbon nanotubes (CNTs), which we refer to as CNT "forests", as a new microfabrication material. We present details of a suite of related methods recently developed by our group: fabrication of CNT forest microstructures by thermal CVD from lithographically patterned catalyst thin films; self-directed elastocapillary densification of CNT microstructures; and replica molding of polymer microstructures using CNT composite master molds. In particular, our work shows that self-directed capillary densification ("capillary forming"), which is performed by condensation of a solvent onto the substrate with CNT

  12. In Situ Fabrication of 3D Ag@ZnO Nanostructures for Microfluidic Surface-Enhanced Raman Scattering Systems

    PubMed Central

    2015-01-01

    In this work, we develop an in situ method to grow highly controllable, sensitive, three-dimensional (3D) surface-enhanced Raman scattering (SERS) substrates via an optothermal effect within microfluidic devices. Implementing this approach, we fabricate SERS substrates composed of Ag@ZnO structures at prescribed locations inside microfluidic channels, sites within which current fabrication of SERS structures has been arduous. Conveniently, properties of the 3D Ag@ZnO nanostructures such as length, packing density, and coverage can also be adjusted by tuning laser irradiation parameters. After exploring the fabrication of the 3D nanostructures, we demonstrate a SERS enhancement factor of up to ∼2 × 106 and investigate the optical properties of the 3D Ag@ZnO structures through finite-difference time-domain simulations. To illustrate the potential value of our technique, low concentrations of biomolecules in the liquid state are detected. Moreover, an integrated cell-trapping function of the 3D Ag@ZnO structures records the surface chemical fingerprint of a living cell. Overall, our optothermal-effect-based fabrication technique offers an effective combination of microfluidics with SERS, resolving problems associated with the fabrication of SERS substrates in microfluidic channels. With its advantages in functionality, simplicity, and sensitivity, the microfluidic-SERS platform presented should be valuable in many biological, biochemical, and biomedical applications. PMID:25402207

  13. Combination of thermal extrusion printing and ultrafast laser fabrication for the manufacturing of 3D composite scaffolds

    NASA Astrophysics Data System (ADS)

    Balčiūnas, Evaldas; Lukoševičius, Laurynas; Mackevičiūtė, Dovilė; Rekštytė, Sima; Rutkūnas, Vygandas; Paipulas, Domas; Stankevičiūtė, Karolina; Baltriukienė, Daiva; Bukelskienė, Virginija; Piskarskas, Algis P.; Malinauskas, Mangirdas

    2014-03-01

    We present a novel approach to manufacturing 3D microstructured composite scaffolds for tissue engineering applications. A thermal extrusion 3D printer - a simple, low-cost tabletop device enabling rapid materialization of CAD models in plastics - was used to produce cm-scale microporous scaffolds out of polylactic acid (PLA). The fabricated objects were subsequently immersed in a photosensitive monomer solution and direct laser writing technique (DLW) was used to refine its inner structure by fabricating a fine mesh inside the previously produced scaffold. In addition, a composite material structure out of four different materials fabricated via DLW is presented. This technique, empowered by ultrafast lasers allows 3D structuring with high spatial resolution in a great variety of photosensitive materials. A composite scaffold made of distinct materials and periodicities is acquired after the development process used to wash out non-linked monomers. Another way to modify the 3D printed PLA surfaces was also demonstrated - ablation with femtosecond laser beam. Structure geometry on macro- to micro- scales could be finely tuned by combining these fabrication techniques. Such artificial 3D substrates could be used for cell growth or as biocompatible-biodegradable implants. To our best knowledge, this is the first experimental demonstration showing the creation of composite 3D scaffolds using convenient 3D printing combined with DLW. This combination of distinct material processing techniques enables rapid fabrication of diverse functional micro-featured and integrated devices. Hopefully, the proposed approach will find numerous applications in the field of tissue engineering, as well as in microelectromechanical systems, microfluidics, microoptics and others.

  14. Fabrication of 3D Scaffolds with Nano-Hydroxyapatite for Improving the Preosteoblast Cell-Biological Performance.

    PubMed

    Roh, Hee-Sang; Myung, Sung-Woon; Jung, Sang-Chul; Kim, Byung-Hoon

    2015-08-01

    Three-dimensional (3D) scaffolds fabricated by rapid prototyping techniques have many merits for tissue engineering applications, due to its controllable properties such as porosity, pore size and structural shape. Nonetheless, low cell seeding efficiency remains drawback. In this study, poly-caprolactone (PCL) composite 3D extruded scaffolds were modified with nano hydroxyapatite (n-HAp). PCL/n-HAp 3D scaffold surface was treated with oxygen plasma to improve the preosteoblast cell seeding efficiency and proliferation. The results indicate that oxygen plasma is useful technique to improve the cell affinity.

  15. Fabrication of 3D fine scale PZT components by ink-jet prototyping process

    NASA Astrophysics Data System (ADS)

    Noguera, R.; Dossou-Yovo, C.; Lejeune, M.; Chartier, T.

    2005-09-01

    Different investigations have been carried out to optimize an ink-jet printing technique, devoted to the fabrication of 3D fine scale PZT parts, by adjustment of the fluid properties of the ceramic suspensions and by controlling the ejection and impact phenomena. A 10 vol% PZT loaded suspension characterized by a Newtonian behavior, corresponding to a viscosity of 10mPa.s and to a ratio Re/We1/2 of 5.98 has been selected. The ejection and impact phenomena strongly depend on the driving parameters of the printing head, in particular the formation of the droplet, with satellite or not, as well as its velocity and volume which are function of the pulse amplitude. Moreover, the conditions of ejection (droplet velocity and volume) control the characteristics of the deposit (definition, spreading, thickness uniformity). Sintered PZT pillar array has been achieved by ink-jet printing with a definition equal to 50μm. These structures could be very useful to improve the performances of 1-3 ceramic polymer composites for imaging probes or more generally for ultrasonic transducers and also of micro-deformable mirrors for optical adaptive systems.

  16. 3D template fabrication process for the dual damascene NIL approach

    NASA Astrophysics Data System (ADS)

    Butschke, Joerg; Irmscher, Mathias; Resnick, Douglas; Sailer, Holger; Thompson, Ecron

    2007-05-01

    NIL technique enables an easy replication of three dimensional patterns. Combined with a UV printable low-k material the NIL lithography can dramatically simplify the dual damascene process. Goal of this work was to develop a template process scheme which enables the generation of high resolution pillars on top of corresponding lines for direct printing of later vias and metal lines. The process flow is based on conventional 6025 photomask blanks. Exposure was done on a variable shaped e-beam writer Vistec SB350 using a sample of an advanced negative tone CAR and Fujifilm pCAR FEP171 for the first and the second layer, respectively. Chrome and quartz etching was accomplished in an Oerlikon mask etcher Gen III and Gen IV. Assessment of the developed template process was done in terms of overlay accuracy, feature profile and resolution capability depending on aspect ratio and line duty cycle. Finally the printability of 3D templates fabricated according the developed process scheme was proved.

  17. Characterization, fabrication, and analysis of soft dielectric elastomer actuators capable of complex 3D deformation

    NASA Astrophysics Data System (ADS)

    Lai, William

    Inspired by nature, the development of soft actuators has drawn large attention to provide higher flexibility and allow adaptation to more complex environment. This thesis is focused on utilizing electroactive polymers as active materials to develop soft planar dielectric elastomer actuators capable of complex 3D deformation. The potential applications of such soft actuators are in flexible robotic arms and grippers, morphing structures and flapping wings for micro aerial vehicles. The embraces design for a freestanding actuator utilizes the constrained deformation imposed by surface stiffeners on an electroactive membrane to avert the requirement of membrane pre-stretch and the supporting frames. The proposed design increases the overall actuator flexibility and degrees-of-freedom. Actuator design, fabrication, and performance are presented for different arrangement of stiffeners. Digital images correlation technique were utilized to evaluate the in-plane finite strain components, in order to elucidate the role of the stiffeners in controlling the three dimensional deformation. It was found that a key controlling factor was the localized deformation near the stiffeners, while the rest of the membrane would follow through. A detailed finite element modeling framework was developed with a user-material subroutine, built into the ABAQUS commercial finite element package. An experimentally calibrated Neo-Hookean based material model that coupled the applied electrical field to the actuator mechanical deformation was employed. The numerical model was used to optimize different geometrical features, electrode layup and stacking sequence of actuators. It was found that by splitting the stiffeners into finer segments, the force-stroke characteristics of actuator were able to be adjusted with stiffener configuration, while keeping the overall bending stiffness. The efficacy of actuators could also be greatly improved by increasing the stiffener periodicity. The developed

  18. Characterization of core-shell calcium-alginate macrocapsules fabricated by electro-coextrusion.

    PubMed

    Phawaphuthanon, Natthiya; Behnam, Shabnam; Koo, Song Yi; Pan, Cheol-Ho; Chung, Donghwa

    2014-04-01

    Spherical macrocapsules, where calcium-alginate shell enclosed olive oil as a model core medium, were fabricated by electro-coextrusion. The effects of three key process factors, including alginate concentration in shell fluid (0.5-4.0%), shell-to-core flow rate ratio (4-12 at a fixed core flow rate of 0.05 mL/min), and applied voltage (0-10 kV), on the morphological and textural characteristics of the macrocapsules were analyzed using response surface methodology. The analysis showed that the diameter, shell thickness, hardness, and breaking energy of the macrocapsules were in the ranges of 0.89-1.61 mm, 17.4-66.4 μm, 1.37-11.01 N, and 0.34-6.90 mJ, respectively, and strongly influenced by all the three factors, except that the surface appearance was only significantly affected by the shell-to-core flow rate ratio. The process factors were also optimized for the practically useful macrocapsules, having non-oily surface and hardness larger than 3 N, using a graphical optimization technique.

  19. Fabrication of Alginate/Calcium Carbonate Hybrid Microparticles for Synergistic Drug Delivery.

    PubMed

    Peng, Yan; Sun, Hua-Yan; Wang, Zong-Chun; Xu, Xiao-Ding; Song, Jin-Chun; Gong, Zuo-Jiong

    2016-01-01

    A hybrid drug delivery system coloaded with different drugs for synergistic drug delivery was developed. Alginate/calcium carbonate (CaCO3) hybrid microparticles (MPs) were fabricated via a facile coprecipitation method under mild conditions without using any organic solvent and surfactant. Due to the incorporation of negatively charged alginate chains onto the surface, the obtained hybrid MPs with spherical morphology showed good colloidal stability in an aqueous solution. An antitumor drug (doxorubicin, DOX) and a drug resistance reversal agent (verapamil, VP) were coloaded in the hybrid MPs simultaneously to obtain dual-drug-loaded MPs (DOX/VP/MP). Due to the presence of inorganic CaCO3 (∼54 wt%), the drugs could be loaded in the hybrid MPs with high encapsulation efficiency and the drug release could be effectively sustained. The cell growth inhibition of the drug-loaded MPs was evaluated in HeLa cells. An in vitro study showed DOX/VP/MP exhibited higher cell growth inhibition as compared with DOX monodrug-loaded MPs (DOX/MP). These results suggest the hybrid MPs can potentially be used as a synergistic drug delivery platform for cancer chemotherapy.

  20. Fabrication of Alginate/Calcium Carbonate Hybrid Microparticles for Synergistic Drug Delivery.

    PubMed

    Peng, Yan; Sun, Hua-Yan; Wang, Zong-Chun; Xu, Xiao-Ding; Song, Jin-Chun; Gong, Zuo-Jiong

    2016-01-01

    A hybrid drug delivery system coloaded with different drugs for synergistic drug delivery was developed. Alginate/calcium carbonate (CaCO3) hybrid microparticles (MPs) were fabricated via a facile coprecipitation method under mild conditions without using any organic solvent and surfactant. Due to the incorporation of negatively charged alginate chains onto the surface, the obtained hybrid MPs with spherical morphology showed good colloidal stability in an aqueous solution. An antitumor drug (doxorubicin, DOX) and a drug resistance reversal agent (verapamil, VP) were coloaded in the hybrid MPs simultaneously to obtain dual-drug-loaded MPs (DOX/VP/MP). Due to the presence of inorganic CaCO3 (∼54 wt%), the drugs could be loaded in the hybrid MPs with high encapsulation efficiency and the drug release could be effectively sustained. The cell growth inhibition of the drug-loaded MPs was evaluated in HeLa cells. An in vitro study showed DOX/VP/MP exhibited higher cell growth inhibition as compared with DOX monodrug-loaded MPs (DOX/MP). These results suggest the hybrid MPs can potentially be used as a synergistic drug delivery platform for cancer chemotherapy. PMID:26528767

  1. Alginate bead fabrication and encapsulation of living cells under centrifugally induced artificial gravity conditions.

    PubMed

    Haeberle, Stefan; Naegele, Lars; Burger, Robert; von Stetten, Felix; Zengerle, Roland; Ducrée, Jens

    2008-06-01

    This study presents a novel method for the direct, centrifugally induced fabrication of small, Ca2+-hardened alginate beads at polymer-tube micronozzles. The bead diameter can arbitrarily be adjusted between 180-800 microm by the nozzle geometry and spinning frequencies between 5-28 Hz. The size distribution of the main peak features a CV of 7-16%, only. Up to 600 beads per second and channel are issued from the micronozzle through an air gap towards the curing agent contained in a standard lab tube ('Eppi'). Several tubes can be mounted on a 'flying bucket' rotor where they align horizontally under rotation and return to a vertical position as soon as the rotor is at rest. The centrifugally induced, ultra-high artificial gravity conditions (up to 180 g) even allow the micro-encapsulation of alginate solutions displaying viscosities up to 50 Pa s, i.e. approximately 50,000 times the viscosity of water! With this low cost technology for microencapsulation, HN25 and PC12 cells have successfully been encapsulated while maintaining vitality.

  2. Fabrication of distilled water-soluble chitosan/alginate functional multilayer composite microspheres.

    PubMed

    Xiao, Congming; Sun, Fei

    2013-11-01

    Polysaccharides-based functional microspheres were fabricated under mild conditions. Firstly, magnetic alginate microspheres were prepared by emulsification/internal gelation and acted as substrates. Then the multilayer composite microspheres (MCM) were obtained through the layer-by-layer assembly of the distilled water-soluble chitosan and alginate. The components, morphology, and size distribution of the microspheres were characterized by element analysis (EA), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and laser particle size analyzer (LPSA). Both EA and XPS analysis results indicated that alternate immersion was an effective method for preparing MCM. Vibrating sample magnetometer, SEM and LPSA results showed that the microspheres had good dispersion, uniform particle size and were superparamagnetic. In addition, in vitro drug release behaviors of the microspheres were investigated by using hemoglobin (HB) and Coomassie brilliant blue G250 (CBB) as model drugs. It was found that the release rates of both HB and CBB from the composite microspheres were slower than those from the substrates.

  3. Hierarchical Fabrication of Engineered Vascularized Bone Biphasic Constructs via Dual 3D Bioprinting: Integrating Regional Bioactive Factors into Architectural Design.

    PubMed

    Cui, Haitao; Zhu, Wei; Nowicki, Margaret; Zhou, Xuan; Khademhosseini, Ali; Zhang, Lijie Grace

    2016-09-01

    A biphasic artificial vascularized bone construct with regional bioactive factors is presented using dual 3D bioprinting platform technique, thereby forming a large functional bone grafts with organized vascular networks. Biocompatible mussel-inspired chemistry and "thiol-ene" click reaction are used to regionally immobilize bioactive factors during construct fabrication for modulating or improving cellular events.

  4. Design, simulation, fabrication, and preliminary tests of 3D CMS pixel detectors for the super-LHC

    SciTech Connect

    Koybasi, Ozhan; Bortoletto, Daniela; Hansen, Thor-Erik; Kok, Angela; Hansen, Trond Andreas; Lietaer, Nicolas; Jensen, Geir Uri; Summanwar, Anand; Bolla, Gino; Kwan, Simon Wing Lok; /Fermilab

    2010-01-01

    The Super-LHC upgrade puts strong demands on the radiation hardness of the innermost tracking detectors of the CMS, which cannot be fulfilled with any conventional planar detector design. The so-called 3D detector architectures, which feature columnar electrodes passing through the substrate thickness, are under investigation as a potential solution for the closest operation points to the beams, where the radiation fluence is estimated to reach 10{sup 16} n{sub eq}/cm{sup 2}. Two different 3D detector designs with CMS pixel readout electronics are being developed and evaluated for their advantages and drawbacks. The fabrication of full-3D active edge CMS pixel devices with p-type substrate has been successfully completed at SINTEF. In this paper, we study the expected post-irradiation behaviors of these devices with simulations and, after a brief description of their fabrication, we report the first leakage current measurement results as performed on wafer.

  5. Fabrication of continuous flow microfluidics device with 3D electrode structures for high throughput DEP applications using mechanical machining.

    PubMed

    Zeinali, Soheila; Çetin, Barbaros; Oliaei, Samad Nadimi Bavil; Karpat, Yiğit

    2015-07-01

    Microfluidics is the combination of micro/nano fabrication techniques with fluid flow at microscale to pursue powerful techniques in controlling and manipulating chemical and biological processes. Sorting and separation of bio-particles are highly considered in diagnostics and biological analyses. Dielectrophoresis (DEP) has offered unique advantages for microfluidic devices. In DEP devices, asymmetric pair of planar electrodes could be employed to generate non-uniform electric fields. In DEP applications, facing 3D sidewall electrodes is considered to be one of the key solutions to increase device throughput due to the generated homogeneous electric fields along the height of microchannels. Despite the advantages, fabrication of 3D vertical electrodes requires a considerable challenge. In this study, two alternative fabrication techniques have been proposed for the fabrication of a microfluidic device with 3D sidewall electrodes. In the first method, both the mold and the electrodes are fabricated using high precision machining. In the second method, the mold with tilted sidewalls is fabricated using high precision machining and the electrodes are deposited on the sidewall using sputtering together with a shadow mask fabricated by electric discharge machining. Both fabrication processes are assessed as highly repeatable and robust. Moreover, the two methods are found to be complementary with respect to the channel height. Only the manipulation of particles with negative-DEP is demonstrated in the experiments, and the throughput values up to 105 particles / min is reached in a continuous flow. The experimental results are compared with the simulation results and the limitations on the fabrication techniques are also discussed.

  6. FOREWORD: Focus on Novel Nanoelectromechanical 3D Structures: Fabrication and Properties Focus on Novel Nanoelectromechanical 3D Structures: Fabrication and Properties

    NASA Astrophysics Data System (ADS)

    Yamada, Shooji; Yamaguchi, Hiroshi; Ishihara, Sunao

    2009-06-01

    Microelectromechanical systems (MEMS) are widely used small electromechanical systems made of micrometre-sized components. Presently, we are witnessing a transition from MEMS to nanoelectromechanical systems (NEMS), which comprise devices integrating electrical and mechanical functionality on the nanoscale and offer new exciting applications. Similarly to MEMS, NEMS typically include a central transistor-like nanoelectronic unit for data processing, as well as mechanical actuators, pumps, and motors; and they may combine with physical, biological and chemical sensors. In the transition from MEMS to NEMS, component sizes need to be reduced. Therefore, many fabrication methods previously developed for MEMS are unsuitable for the production of high-precision NEMS components. The key challenge in NEMS is therefore the development of new methods for routine and reproducible nanofabrication. Two complementary types of method for NEMS fabrication are available: 'top-down' and 'bottom-up'. The top-down approach uses traditional lithography technologies, whereas bottom-up techniques include molecular self-organization, self-assembly and nanodeposition. The NT2008 conference, held at Ishikawa High-Tech Conference Center, Ishikawa, Japan, between 23-25 October 2008, focused on novel NEMS fabricated from new materials and on process technologies. The topics included compound semiconductors, small mechanical structures, nanostructures for micro-fluid and bio-sensors, bio-hybrid micro-machines, as well as their design and simulation. This focus issue compiles seven articles selected from 13 submitted manuscripts. The articles by Prinz et al and Kehrbusch et al introduce the frontiers of the top-down production of various operational NEMS devices, and Kometani et al present an example of the bottom-up approach, namely ion-beam induced deposition of MEMS and NEMS. The remaining articles report novel technologies for biological sensors. Taira et al have used manganese nanoparticles

  7. Fabrication, Characterization, And Deformation of 3D Structural Meta-Materials

    NASA Astrophysics Data System (ADS)

    Montemayor, Lauren C.

    Current technological advances in fabrication methods have provided pathways to creating architected structural meta-materials similar to those found in natural organisms that are structurally robust and lightweight, such as diatoms. Structural meta-materials are materials with mechanical properties that are determined by material properties at various length scales, which range from the material microstructure (nm) to the macro-scale architecture (mum -- mm). It is now possible to exploit material size effect, which emerge at the nanometer length scale, as well as structural effects to tune the material properties and failure mechanisms of small-scale cellular solids, such as nanolattices. This work demonstrates the fabrication and mechanical properties of 3-dimensional hollow nanolattices in both tension and compression. Hollow gold nanolattices loaded in uniaxial compression demonstrate that strength and stiffness vary as a function of geometry and tube wall thickness. Structural effects were explored by increasing the unit cell angle from 30° to 60° while keeping all other parameters constant; material size effects were probed by varying the tube wall thickness, t, from 200nm to 635nm, at a constant relative density and grain size. In-situ uniaxial compression experiments reveal an order-of-magnitude increase in yield stress and modulus in nanolattices with greater lattice angles, and a 150% increase in the yield strength without a concomitant change in modulus in thicker-walled nanolattices for fixed lattice angles. These results imply that independent control of structural and material size effects enables tunability of mechanical properties of 3-dimensional architected meta-materials and highlight the importance of material, geometric, and microstructural effects in small-scale mechanics. This work also explores the flaw tolerance of 3D hollow-tube alumina kagome nanolattices with and without pre-fabricated notches, both in experiment and simulation

  8. A rapid, straightforward, and print house compatible mass fabrication method for integrating 3D paper-based microfluidics.

    PubMed

    Xiao, Liangpin; Liu, Xianming; Zhong, Runtao; Zhang, Kaiqing; Zhang, Xiaodi; Zhou, Xiaomian; Lin, Bingcheng; Du, Yuguang

    2013-11-01

    Three-dimensional (3D) paper-based microfluidics, which is featured with high performance and speedy determination, promise to carry out multistep sample pretreatment and orderly chemical reaction, which have been used for medical diagnosis, cell culture, environment determination, and so on with broad market prospect. However, there are some drawbacks in the existing fabrication methods for 3D paper-based microfluidics, such as, cumbersome and time-consuming device assembly; expensive and difficult process for manufacture; contamination caused by organic reagents from their fabrication process. Here, we present a simple printing-bookbinding method for mass fabricating 3D paper-based microfluidics. This approach involves two main steps: (i) wax-printing, (ii) bookbinding. We tested the delivery capability, diffusion rate, homogeneity and demonstrated the applicability of the device to chemical analysis by nitrite colorimetric assays. The described method is rapid (<30 s), cheap, easy to manipulate, and compatible with the flat stitching method that is common in a print house, making itself an ideal scheme for large-scale production of 3D paper-based microfluidics.

  9. Fabrication of 3D tissue equivalent: an in vitro platform for understanding collagen evolution in healthy and diseased models

    NASA Astrophysics Data System (ADS)

    Urciuolo, F.; Imparato, G.; Casale, C.; Scamardella, S.; Netti, P.

    2013-04-01

    In this study we realized a three-dimensional human dermis equivalent (3D-HDE) and, by exploiting multi-photon microscopy (MPM) we validated its use as an in vitro model to study collagen network re-arrangement under simulated solar exposure. The realization of 3D-HDE has been pursed by means of a bottom-up tissue engineering strategy that comprises firstly the fabrication of micron sized tissue building blocks and then their assembly in a 3D tissue construct. The building blocks injected in a maturation chamber, and cultured under optimized culture condition, were able to fuse due to the establishment of cell-cell and cell-extra cellular matrix (ECM) interactions that induced a biological sintering process resulting in 3D-HDE production. The final 3D tissue was made-up by fibroblasts embedded in their own ECM rich in endogenous collagen type I, resembling the composition and the architecture of native human dermis. Second Harmonic Generation (SHG) and Two-Photon Excited Fluorescence (TPEF) imaging have been exploited to assess modification in collagen assembly before and after UV irradiation. Textural features and SHG to TPFE ratio of the endogenous ECM within 3D-HDE have been shown to vary after UVA irradiation, proving the hypothesis that the 3DHDE realized can be used as biological platform in vitro to study ECM modifications induced by photo-damage.

  10. Direct fabrication of complex 3D hierarchical nanostructures by reactive ion etching of hollow sphere colloidal crystals.

    PubMed

    Zhong, Kuo; Li, Jiaqi; Van Cleuvenbergen, Stijn; Clays, Koen

    2016-09-21

    Direct reactive ion etching (RIE) of hollow SiO2 sphere colloidal crystals (HSCCs) is employed as a facile, low-cost method to fabricate complex three-dimensional (3D) hierarchical nanostructures. These multilayered structures are gradually transformed into nanostructures of increasing complexity by controlling the etching time, without complicated procedures (no mask needed). The resulting 3D topologies are unique, and cannot be obtained through traditional approaches. The formation mechanism of these structures is explained in detail by geometrical modeling during the different etching stages, through shadow effects of the higher layers. SEM images confirm the modeled morphological changes. The nanostructures obtained by our approach show very fine features as small as ∼30 nm. Our approach opens new avenues to directly obtain complex 3D nanostructures from colloidal crystals and can find applications in sensing, templating, and catalysis where fine tuning the specific surface might be critical. PMID:27545098

  11. Light-driven 3D droplet manipulation on flexible optoelectrowetting devices fabricated by a simple spin-coating method.

    PubMed

    Jiang, Dongyue; Park, Sung-Yong

    2016-05-21

    Technical advances in electrowetting-on-dielectric (EWOD) over the past few years have extended our attraction to three-dimensional (3D) devices capable of providing more flexibility and functionality with larger volumetric capacity than conventional 2D planar ones. However, typical 3D EWOD devices require complex and expensive fabrication processes for patterning and wiring of pixelated electrodes that also restrict the minimum droplet size to be manipulated. Here, we present a flexible single-sided continuous optoelectrowetting (SCOEW) device which is not only fabricated by a spin-coating method without the need for patterning and wiring processes, but also enables light-driven 3D droplet manipulations. To provide photoconductive properties, previous optoelectrowetting (OEW) devices have used amorphous silicon (a-Si) typically fabricated through high-temperature processes over 300 °C such as CVD or PECVD. However, most of the commercially-available flexible substrates such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) experience serious thermal deformation under such high-temperature processes. Because of this compatibility issue of conventional OEW devices with flexible substrates, light-driven 3D droplet manipulations have not yet been demonstrated on flexible substrates. Our study overcomes this compatibility issue by using a polymer-based photoconductive material, titanium oxide phthalocyanine (TiOPc) and thus SCOEW devices can be simply fabricated on flexible substrates through a low-cost, spin-coating method. In this paper, analytical studies were conducted to understand the effects of light patterns on static contact angles and EWOD forces. For experimental validations of our study, flexible SCOEW devices were successfully fabricated through the TiOPc-based spin-coating method and light-driven droplet manipulations (e.g. transportation, merging, and splitting) have been demonstrated on various 3D terrains such as inclined

  12. Light-driven 3D droplet manipulation on flexible optoelectrowetting devices fabricated by a simple spin-coating method.

    PubMed

    Jiang, Dongyue; Park, Sung-Yong

    2016-05-21

    Technical advances in electrowetting-on-dielectric (EWOD) over the past few years have extended our attraction to three-dimensional (3D) devices capable of providing more flexibility and functionality with larger volumetric capacity than conventional 2D planar ones. However, typical 3D EWOD devices require complex and expensive fabrication processes for patterning and wiring of pixelated electrodes that also restrict the minimum droplet size to be manipulated. Here, we present a flexible single-sided continuous optoelectrowetting (SCOEW) device which is not only fabricated by a spin-coating method without the need for patterning and wiring processes, but also enables light-driven 3D droplet manipulations. To provide photoconductive properties, previous optoelectrowetting (OEW) devices have used amorphous silicon (a-Si) typically fabricated through high-temperature processes over 300 °C such as CVD or PECVD. However, most of the commercially-available flexible substrates such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) experience serious thermal deformation under such high-temperature processes. Because of this compatibility issue of conventional OEW devices with flexible substrates, light-driven 3D droplet manipulations have not yet been demonstrated on flexible substrates. Our study overcomes this compatibility issue by using a polymer-based photoconductive material, titanium oxide phthalocyanine (TiOPc) and thus SCOEW devices can be simply fabricated on flexible substrates through a low-cost, spin-coating method. In this paper, analytical studies were conducted to understand the effects of light patterns on static contact angles and EWOD forces. For experimental validations of our study, flexible SCOEW devices were successfully fabricated through the TiOPc-based spin-coating method and light-driven droplet manipulations (e.g. transportation, merging, and splitting) have been demonstrated on various 3D terrains such as inclined

  13. Fabrication of 10 nm-scale complex 3D nanopatterns with multiple shapes and components by secondary sputtering phenomenon.

    PubMed

    Jeon, Hwan-Jin; Jeong, Hyeon Su; Kim, Yun Ho; Jung, Woo-Bin; Kim, Jeong Yeon; Jung, Hee-Tae

    2014-02-25

    We introduce an advanced ultrahigh-resolution (∼ 15 nm) patterning technique that enables the fabrication of various 3D high aspect ratio multicomponents/shaped nanostructures. This methodology utilizes the repetitive secondary sputtering phenomenon under etching plasma conditions and prepatterned fabrication control. The secondary sputtering phenomenon repetitively generates an angular distribution of target particles during ion-bombardment. This method, advanced repetitive secondary sputtering lithography, provides many strategies to fabricate complex continuous patterns and multilayer/material patterns with 10 nm-scale resolution. To demonstrate the versatility of this method, we show induced vertical alignment of liquid crystals (LCs) on indium-tin-oxide (ITO) grid patterns without any alignment layers. The ITO grid pattern fabricated in this method is found to have not only an alignment capability but also electrode properties without electrical or optical damage.

  14. Design and Fabrication of Novel Resonators for Scalable 3D cQED

    NASA Astrophysics Data System (ADS)

    Brecht, T.; Wang, C.; Axline, C.; Reagor, M.; Hatridge, M.; Reinhold, P.; Frunzio, L.; Schoelkopf, R. J.

    2014-03-01

    Experiments in three-dimensional circuit quantum electrodynamics (3D cQED) champion the use of superconducting microwave cavities as a quantum resource. The transmon qubit coupled to a 3D superconducting waveguide cavity has yielded enormous gains in coherence times. Cavity coherence times are now approaching 10 milliseconds at single photon power. By virtue of their low surface-to-volume ratio and concomitant low surface dielectric participation, microwave cavities machined out of bulk pieces of superconducting metal are longer lived than planar resonator geometries in the presence of surface losses. However, issues of reproducibility, assembly, and integration become more challenging as we design systems containing many resonators and many qubits. We present a novel architecture for superconducting resonators that retains the superb coherence of 3D structures while achieving superior scalability and compatibility with planar circuitry and integrated readout electronics. Work supported by ARO and IARPA.

  15. Electrochemical fabrication of 2D and 3D nickel nanowires using porous anodic alumina templates

    NASA Astrophysics Data System (ADS)

    Mebed, A. M.; Abd-Elnaiem, Alaa M.; Al-Hosiny, Najm M.

    2016-06-01

    Mechanically stable nickel (Ni) nanowires array and nanowires network were synthesized by pulse electrochemical deposition using 2D and 3D porous anodic alumina (PAA) templates. The structures and morphologies of as-prepared films were characterized by X-ray diffraction and scanning electron microscopy, respectively. The grown Ni nanowire using 3D PAA revealed more strength and larger surface area than has grown Ni use 2D PAA template. The prepared nanowires have a face-centered cubic crystal structure with average grain size 15 nm, and the preferred orientation of the nucleation of the nanowires is (111). The diameter of the nanowires is about 50-70 nm with length 3 µm. The resulting 3D Ni nanowire lattice, which provides enhanced mechanical stability and an increased surface area, benefits energy storage and many other applications which utilize the large surface area.

  16. Construction and Myogenic Differentiation of 3D Myoblast Tissues Fabricated by Fibronectin-Gelatin Nanofilm Coating

    PubMed Central

    Gribova, Varvara; Liu, Chen Yun; Nishiguchi, Akihiro; Matsusaki, Michiya; Boudou, Thomas; Picart, Catherine; Akashi, Mitsuru

    2016-01-01

    In this study, we used a recently developed approach of coating the cells with fibronectin-gelatin nanofilms to build 3D skeletal muscle tissue models. We constructed the microtissues from C2C12 myoblasts and subsequently differentiated them to form muscle-like tissue. The thickness of the constructs could be successfully controlled by altering the number of seeded cells. We were able to build up to ~ 76 µm thick 3D constructs that formed multinucleated myotubes. We also found that Rho-kinase inhibitor Y27632 improved myotube formation in thick constructs. Our approach makes it possible to rapidly form 3D muscle tissues and is promising for the in vitro construction of physiologically relevant human skeletal muscle tissue models. PMID:27125461

  17. Femtosecond laser 3D micromachining: a powerful tool for the fabrication of microfluidic, optofluidic, and electrofluidic devices based on glass.

    PubMed

    Sugioka, Koji; Xu, Jian; Wu, Dong; Hanada, Yasutaka; Wang, Zhongke; Cheng, Ya; Midorikawa, Katsumi

    2014-09-21

    Femtosecond lasers have unique characteristics of ultrashort pulse width and extremely high peak intensity; however, one of the most important features of femtosecond laser processing is that strong absorption can be induced only at the focus position inside transparent materials due to nonlinear multiphoton absorption. This exclusive feature makes it possible to directly fabricate three-dimensional (3D) microfluidic devices in glass microchips by two methods: 3D internal modification using direct femtosecond laser writing followed by chemical wet etching (femtosecond laser-assisted etching, FLAE) and direct ablation of glass in water (water-assisted femtosecond laser drilling, WAFLD). Direct femtosecond laser writing also enables the integration of micromechanical, microelectronic, and microoptical components into the 3D microfluidic devices without stacking or bonding substrates. This paper gives a comprehensive review on the state-of-the-art femtosecond laser 3D micromachining for the fabrication of microfluidic, optofluidic, and electrofluidic devices. A new strategy (hybrid femtosecond laser processing) is also presented, in which FLAE is combined with femtosecond laser two-photon polymerization to realize a new type of biochip termed the ship-in-a-bottle biochip. PMID:25012238

  18. Spun-wrapped aligned nanofiber (SWAN) lithography for fabrication of micro/nano-structures on 3D objects.

    PubMed

    Ye, Zhou; Nain, Amrinder S; Behkam, Bahareh

    2016-07-01

    Fabrication of micro/nano-structures on irregularly shaped substrates and three-dimensional (3D) objects is of significant interest in diverse technological fields. However, it remains a formidable challenge thwarted by limited adaptability of the state-of-the-art nanolithography techniques for nanofabrication on non-planar surfaces. In this work, we introduce Spun-Wrapped Aligned Nanofiber (SWAN) lithography, a versatile, scalable, and cost-effective technique for fabrication of multiscale (nano to microscale) structures on 3D objects without restriction on substrate material and geometry. SWAN lithography combines precise deposition of polymeric nanofiber masks, in aligned single or multilayer configurations, with well-controlled solvent vapor treatment and etching processes to enable high throughput (>10(-7) m(2) s(-1)) and large-area fabrication of sub-50 nm to several micron features with high pattern fidelity. Using this technique, we demonstrate whole-surface nanopatterning of bulk and thin film surfaces of cubes, cylinders, and hyperbola-shaped objects that would be difficult, if not impossible to achieve with existing methods. We demonstrate that the fabricated feature size (b) scales with the fiber mask diameter (D) as b(1.5)∝D. This scaling law is in excellent agreement with theoretical predictions using the Johnson, Kendall, and Roberts (JKR) contact theory, thus providing a rational design framework for fabrication of systems and devices that require precisely designed multiscale features.

  19. Spun-wrapped aligned nanofiber (SWAN) lithography for fabrication of micro/nano-structures on 3D objects.

    PubMed

    Ye, Zhou; Nain, Amrinder S; Behkam, Bahareh

    2016-07-01

    Fabrication of micro/nano-structures on irregularly shaped substrates and three-dimensional (3D) objects is of significant interest in diverse technological fields. However, it remains a formidable challenge thwarted by limited adaptability of the state-of-the-art nanolithography techniques for nanofabrication on non-planar surfaces. In this work, we introduce Spun-Wrapped Aligned Nanofiber (SWAN) lithography, a versatile, scalable, and cost-effective technique for fabrication of multiscale (nano to microscale) structures on 3D objects without restriction on substrate material and geometry. SWAN lithography combines precise deposition of polymeric nanofiber masks, in aligned single or multilayer configurations, with well-controlled solvent vapor treatment and etching processes to enable high throughput (>10(-7) m(2) s(-1)) and large-area fabrication of sub-50 nm to several micron features with high pattern fidelity. Using this technique, we demonstrate whole-surface nanopatterning of bulk and thin film surfaces of cubes, cylinders, and hyperbola-shaped objects that would be difficult, if not impossible to achieve with existing methods. We demonstrate that the fabricated feature size (b) scales with the fiber mask diameter (D) as b(1.5)∝D. This scaling law is in excellent agreement with theoretical predictions using the Johnson, Kendall, and Roberts (JKR) contact theory, thus providing a rational design framework for fabrication of systems and devices that require precisely designed multiscale features. PMID:27283144

  20. Fabrication and characterization of direct-written 3D TiO2 woodpile electromagnetic bandgap structures

    NASA Astrophysics Data System (ADS)

    Li, Ji-Jiao; Li, Bo; Peng, Qin-Mei; Zhou, Ji; Li, Long-Tu

    2014-09-01

    Three groups of three-dimensional (3D) TiO2 woodpile electromagnetic gap materials with tailed rheological properties were developed for direct-written fabrication. Appropriate amount of polyethyleneimine (PEI) dispersants allow the preparation of TiO2 inks with a high solid content of 42 vol.%, which enables them to flow through the nozzles easily. The inks exhibit pseudoplastic behavior. The measured microwave characteristics of the results agree well with simulations based on plane wave expansion (PWE).

  1. Improvements in Fabrication of 3D SU-8 Prisms for Low-Coupling-Loss Interconnections Between Fibers and Waveguides

    NASA Astrophysics Data System (ADS)

    Nguyen, Minh-Hang; Chu, Thi-Xuan; Nguyen, Long; Nguyen, Hai-Binh; Lee, Chun-Wei; Tseng, Fan-Gang; Chen, Te-Chang; Lee, Ming-Chang

    2016-07-01

    Fabrication of three-dimensional (3D) SU-8 (an epoxy-based negative photoresist from MicroChem) prisms as low-loss couplers for interconnection between optical components, particularly optical fibers and silicon-on-isolator waveguides (SOI WGs), which have mismatched mode sizes, has been investigated. With an interfacial structure formed by a 3D SU-8 prism partly overlaying an SOI WG end with a portion of buried oxide (BOX) removed under the interface, low-loss coupling is ensured and the transmission efficiency can reach 70%. To fabricate these 3D SU-8 prisms, a simple method with two photolithography steps was used for SU-8 hinges and CYTOP (an amorphous fluoropolymer from AGC Chemicals) prism windows, with mild soft and hard bakes, to define the prism profiles with diluted SU-8 filled in the CYTOP prism windows. A buffered oxide etchant is used to remove BOX parts under the interfaces. Some of the fabricated structures were tested, demonstrating the contribution of overlaying SU-8 prisms to the transmission efficiency of optical interconnections between fibers and SOI WGs.

  2. Improvements in Fabrication of 3D SU-8 Prisms for Low-Coupling-Loss Interconnections Between Fibers and Waveguides

    NASA Astrophysics Data System (ADS)

    Nguyen, Minh-Hang; Chu, Thi-Xuan; Nguyen, Long; Nguyen, Hai-Binh; Lee, Chun-Wei; Tseng, Fan-Gang; Chen, Te-Chang; Lee, Ming-Chang

    2016-11-01

    Fabrication of three-dimensional (3D) SU-8 (an epoxy-based negative photoresist from MicroChem) prisms as low-loss couplers for interconnection between optical components, particularly optical fibers and silicon-on-isolator waveguides (SOI WGs), which have mismatched mode sizes, has been investigated. With an interfacial structure formed by a 3D SU-8 prism partly overlaying an SOI WG end with a portion of buried oxide (BOX) removed under the interface, low-loss coupling is ensured and the transmission efficiency can reach 70%. To fabricate these 3D SU-8 prisms, a simple method with two photolithography steps was used for SU-8 hinges and CYTOP (an amorphous fluoropolymer from AGC Chemicals) prism windows, with mild soft and hard bakes, to define the prism profiles with diluted SU-8 filled in the CYTOP prism windows. A buffered oxide etchant is used to remove BOX parts under the interfaces. Some of the fabricated structures were tested, demonstrating the contribution of overlaying SU-8 prisms to the transmission efficiency of optical interconnections between fibers and SOI WGs.

  3. Fabrication of Single, Vertically Aligned Carbon Nanotubes in 3D Nanoscale Architectures

    NASA Technical Reports Server (NTRS)

    Kaul, Anupama B.; Megerian, Krikor G.; Von Allmen, Paul A.; Baron, Richard L.

    2010-01-01

    Plasma-enhanced chemical vapor deposition (PECVD) and high-throughput manufacturing techniques for integrating single, aligned carbon nanotubes (CNTs) into novel 3D nanoscale architectures have been developed. First, the PECVD growth technique ensures excellent alignment of the tubes, since the tubes align in the direction of the electric field in the plasma as they are growing. Second, the tubes generated with this technique are all metallic, so their chirality is predetermined, which is important for electronic applications. Third, a wafer-scale manufacturing process was developed that is high-throughput and low-cost, and yet enables the integration of just single, aligned tubes with nanoscale 3D architectures with unprecedented placement accuracy and does not rely on e-beam lithography. Such techniques should lend themselves to the integration of PECVD grown tubes for applications ranging from interconnects, nanoelectromechanical systems (NEMS), sensors, bioprobes, or other 3D electronic devices. Chemically amplified polyhydroxystyrene-resin-based deep UV resists were used in conjunction with excimer laser-based (lambda = 248 nm) step-and-repeat lithography to form Ni catalyst dots = 300 nm in diameter that nucleated single, vertically aligned tubes with high yield using dc PECVD growth. This is the first time such chemically amplified resists have been used, resulting in the nucleation of single, vertically aligned tubes. In addition, novel 3D nanoscale architectures have been created using topdown techniques that integrate single, vertically aligned tubes. These were enabled by implementing techniques that use deep-UV chemically amplified resists for small-feature-size resolution; optical lithography units that allow unprecedented control over layer-to-layer registration; and ICP (inductively coupled plasma) etching techniques that result in near-vertical, high-aspect-ratio, 3D nanoscale architectures, in conjunction with the use of materials that are

  4. [EVALUATION OF CHANGES OF GEOMETRICAL PARAMETERS OF ALGINATE DENTAL IMPRESSIONS DUE TO THE INFLUENCE OF CHEMICAL AND MICROWAVE DISINFECTION METHOD USING 3D TECHNOLOGIES].

    PubMed

    Nespraydko, V P; Shevchuk, V A; Michaylov, A A; Lyseyko, N V

    2015-01-01

    This clinical and laboratory study evaluated the effect of two methods of disinfection in different modes at the volume changes of alginate dental impressions and plaster models poured from them, as compared to the same parameters of plastic master models (PMM), using three-dimensional non-contact laser scanner and software. Immersion chemical disinfection for 15 min, microwave disinfection at 354 W for 10 minutes and combined disinfection with the power of 319 W for 4 minutes did not significantly affect the volumetric dimensional accuracy of the alginate impressions (P > 0.05). PMID:27491163

  5. Rapid fabrication of complex 3D extracellular microenvironments by dynamic optical projection stereolithography.

    PubMed

    Zhang, A Ping; Qu, Xin; Soman, Pranav; Hribar, Kolin C; Lee, Jin W; Chen, Shaochen; He, Sailing

    2012-08-16

    The topographic features of the extracelluar matrix (ECM) lay the foundation for cellular behavior. A novel biofabrication method using a digital-mirror device (DMD), called dynamic optical projection stereolithography (DOPsL) is demonstrated. This robust and versatile platform can generate complex biomimetic scaffolds within seconds. Such 3D scaffolds have promising potentials for studying cell interactions with microenvironments in vitro and in vivo.

  6. Characterization of the first double-sided 3D radiation sensors fabricated at FBK on 6-inch silicon wafers

    NASA Astrophysics Data System (ADS)

    Sultan, D. M. S.; Mendicino, R.; Boscardin, M.; Ronchin, S.; Zorzi, N.; Dalla Betta, G.-F.

    2015-12-01

    Following 3D pixel sensor production for the ATLAS Insertable B-Layer, Fondazione Bruno Kessler (FBK) fabrication facility has recently been upgraded to process 6-inch wafers. In 2014, a test batch was fabricated to check for possible issues relevant to this upgrade. While maintaining a double-sided fabrication technology, some process modifications have been investigated. We report here on the technology and the design of this batch, and present selected results from the electrical characterization of sensors and test structures. Notably, the breakdown voltage is shown to exceed 200 V before irradiation, much higher than in earlier productions, demonstrating robustness in terms of radiation hardness for forthcoming productions aimed at High Luminosity LHC upgrades.

  7. Fabrication of scalable tissue engineering scaffolds with dual-pore microarchitecture by combining 3D printing and particle leaching.

    PubMed

    Mohanty, Soumyaranjan; Sanger, Kuldeep; Heiskanen, Arto; Trifol, Jon; Szabo, Peter; Dufva, Marin; Emnéus, Jenny; Wolff, Anders

    2016-04-01

    Limitations in controlling scaffold architecture using traditional fabrication techniques are a problem when constructing engineered tissues/organs. Recently, integration of two pore architectures to generate dual-pore scaffolds with tailored physical properties has attracted wide attention in tissue engineering community. Such scaffolds features primary structured pores which can efficiently enhance nutrient/oxygen supply to the surrounding, in combination with secondary random pores, which give high surface area for cell adhesion and proliferation. Here, we present a new technique to fabricate dual-pore scaffolds for various tissue engineering applications where 3D printing of poly(vinyl alcohol) (PVA) mould is combined with salt leaching process. In this technique the sacrificial PVA mould, determining the structured pore architecture, was filled with salt crystals to define the random pore regions of the scaffold. After crosslinking the casted polymer the combined PVA-salt mould was dissolved in water. The technique has advantages over previously reported ones, such as automated assembly of the sacrificial mould, and precise control over pore architecture/dimensions by 3D printing parameters. In this study, polydimethylsiloxane and biodegradable poly(ϵ-caprolactone) were used for fabrication. However, we show that this technique is also suitable for other biocompatible/biodegradable polymers. Various physical and mechanical properties of the dual-pore scaffolds were compared with control scaffolds with either only structured or only random pores, fabricated using previously reported methods. The fabricated dual-pore scaffolds supported high cell density, due to the random pores, in combination with uniform cell distribution throughout the scaffold, and higher cell proliferation and viability due to efficient nutrient/oxygen transport through the structured pores. In conclusion, the described fabrication technique is rapid, inexpensive, scalable, and compatible

  8. Fabrication of scalable tissue engineering scaffolds with dual-pore microarchitecture by combining 3D printing and particle leaching.

    PubMed

    Mohanty, Soumyaranjan; Sanger, Kuldeep; Heiskanen, Arto; Trifol, Jon; Szabo, Peter; Dufva, Marin; Emnéus, Jenny; Wolff, Anders

    2016-04-01

    Limitations in controlling scaffold architecture using traditional fabrication techniques are a problem when constructing engineered tissues/organs. Recently, integration of two pore architectures to generate dual-pore scaffolds with tailored physical properties has attracted wide attention in tissue engineering community. Such scaffolds features primary structured pores which can efficiently enhance nutrient/oxygen supply to the surrounding, in combination with secondary random pores, which give high surface area for cell adhesion and proliferation. Here, we present a new technique to fabricate dual-pore scaffolds for various tissue engineering applications where 3D printing of poly(vinyl alcohol) (PVA) mould is combined with salt leaching process. In this technique the sacrificial PVA mould, determining the structured pore architecture, was filled with salt crystals to define the random pore regions of the scaffold. After crosslinking the casted polymer the combined PVA-salt mould was dissolved in water. The technique has advantages over previously reported ones, such as automated assembly of the sacrificial mould, and precise control over pore architecture/dimensions by 3D printing parameters. In this study, polydimethylsiloxane and biodegradable poly(ϵ-caprolactone) were used for fabrication. However, we show that this technique is also suitable for other biocompatible/biodegradable polymers. Various physical and mechanical properties of the dual-pore scaffolds were compared with control scaffolds with either only structured or only random pores, fabricated using previously reported methods. The fabricated dual-pore scaffolds supported high cell density, due to the random pores, in combination with uniform cell distribution throughout the scaffold, and higher cell proliferation and viability due to efficient nutrient/oxygen transport through the structured pores. In conclusion, the described fabrication technique is rapid, inexpensive, scalable, and compatible

  9. Fabrication of 3D photocatalytic α-Fe2O3 structure using direct ink writing method

    NASA Astrophysics Data System (ADS)

    Li, Yayun; Li, Bo; Li, Longtu

    2014-02-01

    Three-dimensional (3D) photocatalytic devices are economical and environmental, since they can be easily recycled and reused. In this paper, a kind of 3D photocatalytic device with a rod diameter of 250 μm was fabricated using the aqueous-based α-Fe2O3 ceramic inks by direct ink writing (DIW) method. The properties of the DIW woodpile samples were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and optical microscope. The result shows that the ink with solid content of 71.4 wt.% exhibits a shear thinning behavior and proper viscoelastic properties, which ensure a feasible extrusion in the whole shaping process. The sample sintered at 800°C in air causes photocatalytic degradation of methylene blue (MB) solution under the ultraviolet (UV) light. The photocatalytic properties of the α-Fe2O3 woodpile structure was characterized by the UV-visible light spectrophotometer, and it was found to be better than that of bulk sample with same weight for its higher specific surface. The DIW technique would offer a potential method for the design and fabrication of 3D photocatalytic devices.

  10. Meshing Preprocessor for the Mesoscopic 3D Finite Element Simulation of 2D and Interlock Fabric Deformation

    NASA Astrophysics Data System (ADS)

    Wendling, A.; Daniel, J. L.; Hivet, G.; Vidal-Sallé, E.; Boisse, P.

    2015-12-01

    Numerical simulation is a powerful tool to predict the mechanical behavior and the feasibility of composite parts. Among the available numerical approaches, as far as woven reinforced composites are concerned, 3D finite element simulation at the mesoscopic scale leads to a good compromise between realism and complexity. At this scale, the fibrous reinforcement is modeled by an interlacement of yarns assumed to be homogeneous that have to be accurately represented. Among the numerous issues induced by these simulations, the first one consists in providing a representative meshed geometrical model of the unit cell at the mesoscopic scale. The second one consists in enabling a fast data input in the finite element software (contacts definition, boundary conditions, elements reorientation, etc.) so as to obtain results within reasonable time. Based on parameterized 3D CAD modeling tool of unit-cells of dry fabrics already developed, this paper presents an efficient strategy which permits an automated meshing of the models with 3D hexahedral elements and to accelerate of several orders of magnitude the simulation data input. Finally, the overall modeling strategy is illustrated by examples of finite element simulation of the mechanical behavior of fabrics.

  11. Spun-wrapped aligned nanofiber (SWAN) lithography for fabrication of micro/nano-structures on 3D objects

    NASA Astrophysics Data System (ADS)

    Ye, Zhou; Nain, Amrinder S.; Behkam, Bahareh

    2016-06-01

    Fabrication of micro/nano-structures on irregularly shaped substrates and three-dimensional (3D) objects is of significant interest in diverse technological fields. However, it remains a formidable challenge thwarted by limited adaptability of the state-of-the-art nanolithography techniques for nanofabrication on non-planar surfaces. In this work, we introduce Spun-Wrapped Aligned Nanofiber (SWAN) lithography, a versatile, scalable, and cost-effective technique for fabrication of multiscale (nano to microscale) structures on 3D objects without restriction on substrate material and geometry. SWAN lithography combines precise deposition of polymeric nanofiber masks, in aligned single or multilayer configurations, with well-controlled solvent vapor treatment and etching processes to enable high throughput (>10-7 m2 s-1) and large-area fabrication of sub-50 nm to several micron features with high pattern fidelity. Using this technique, we demonstrate whole-surface nanopatterning of bulk and thin film surfaces of cubes, cylinders, and hyperbola-shaped objects that would be difficult, if not impossible to achieve with existing methods. We demonstrate that the fabricated feature size (b) scales with the fiber mask diameter (D) as b1.5 ~ D. This scaling law is in excellent agreement with theoretical predictions using the Johnson, Kendall, and Roberts (JKR) contact theory, thus providing a rational design framework for fabrication of systems and devices that require precisely designed multiscale features.Fabrication of micro/nano-structures on irregularly shaped substrates and three-dimensional (3D) objects is of significant interest in diverse technological fields. However, it remains a formidable challenge thwarted by limited adaptability of the state-of-the-art nanolithography techniques for nanofabrication on non-planar surfaces. In this work, we introduce Spun-Wrapped Aligned Nanofiber (SWAN) lithography, a versatile, scalable, and cost-effective technique for

  12. Ship-in-a-bottle integration by hybrid femtosecond laser technology for fabrication of true 3D biochips

    NASA Astrophysics Data System (ADS)

    Sima, Felix; Wu, Dong; Xu, Jian; Midorikawa, Katsumi; Sugioka, Koji

    2015-03-01

    We propose herein the "ship-in-a-bottle" integration of three-dimensional (3D) polymeric sinusoidal ridges inside photosensitive glass microfluidic channel by a hybrid subtractive - additive femtosecond laser processing method. It consists of Femtosecond Laser Assisted Wet Etching (FLAE) of a photosensitive Foturan glass followed by Two-Photon Polymerization (TPP) of a SU-8 negative epoxy-resin. Both subtractive and additive processes are carried out using the same set-up with the change of laser focusing objective only. A 522 nm wavelength of the second harmonic generation from an amplified femtosecond Yb-fiber laser (FCPA µJewel D-400, IMRA America, 1045 nm; pulse width 360 fs, repetition rate 200 kHz) was employed for irradiation. The new method allows lowering the size limit of 3D objects created inside channels to smaller details down to the dimensions of a cell, and improve the structure stability. Sinusoidal periodic patterns and ridges are of great use as base scaffolds for building up new structures on their top or for modulating cell migration, guidance and orientation while created interspaces can be exploited for microfluidic applications. The glass microchannel offers robustness and appropriate dynamic flow conditions for cellular studies while the integrated patterns are reducing the size of structure to the level of cells responsiveness. Taking advantage of the ability to directly fabricate 3D complex shapes, both glass channels and polymeric integrated patterns enable us to 3D spatially design biochips for specific applications.

  13. 3D MEMS in Standard Processes: Fabrication, Quality Assurance, and Novel Measurement Microstructures

    NASA Technical Reports Server (NTRS)

    Lin, Gisela; Lawton, Russell A.

    2000-01-01

    Three-dimensional MEMS microsystems that are commercially fabricated require minimal post-processing and are easily integrated with CMOS signal processing electronics. Measurements to evaluate the fabrication process (such as cross-sectional imaging and device performance characterization) provide much needed feedback in terms of reliability and quality assurance. MEMS technology is bringing a new class of microscale measurements to fruition. The relatively small size of MEMS microsystems offers the potential for higher fidelity recordings compared to macrosize counterparts, as illustrated in the measurement of muscle cell forces.

  14. Fabrication and Characterization of a Multichannel 3D Thermopile for Chip Calorimeter Applications

    PubMed Central

    Huynh, Tho Phuoc; Zhang, Yilei; Yehuda, Cohen

    2015-01-01

    Thermal sensors based on thermopiles are some of the most robust and popular temperature sensing technologies across industries and research disciplines. A chip calorimeter with a 3D thermopile layout with a large sensing area and multichannel capacity has been developed, which is highly desired for many applications requiring large reaction chambers or high throughputs, such as biofilm research, drug screening, etc. The performance of the device, including temperature sensitivity and heat power sensitivity, was evaluated. The capability to split the chip calorimeter to multiple channels was also demonstrated, which makes the chip calorimeter very flexible and powerful in many applications. PMID:25654716

  15. Fabrication of chitosan-silver nanoparticle hybrid 3D porous structure as a SERS substrate for biomedical applications

    NASA Astrophysics Data System (ADS)

    Jung, Gyeong-Bok; Kim, Ji-Hye; Burm, Jin Sik; Park, Hun-Kuk

    2013-05-01

    We propose a simple, low-cost, large-area, and functional surface enhanced Raman scattering (SERS) substrate for biomedical applications. The SERS substrate with chitosan-silver nanoparticles (chitosan-Ag NPs) hybrid 3D porous structure was fabricated simply by a one-step method. The chitosan was used as a template for the Ag NPs deposition. SERS enhancement by the chitosan-Ag NPs substrate was experimentally verified using rhodamine B as an analyte. Thiolated single stranded DNA was also measured for atopic dermatitis genetic markers (chemokines CCL17) at a low concentration of 5 pM. We successfully designed a novel SERS substrate with silver nanoparticle hybridized 3D porous chitosan that has the potential to become a highly sensitive and selective tool for biomedical applications.

  16. Novel fabrication technique of hybrid structure lens array for 3D images

    NASA Astrophysics Data System (ADS)

    Lee, Junsik; Kim, Junoh; Kim, Cheoljoong; Shin, Dooseub; Koo, Gyohyun; Won, Yong Hyub

    2016-03-01

    Tunable liquid lens arrays can produce three dimensional images by using electrowetting principle that alters surface tensions by applying voltage. This method has advantages of fast response time and low power consumption. However, it is challenging to fabricate a high fill factor liquid lens array and operate three dimensional images which demand high diopter. This study describes a hybrid structure lens array which has not only a liquid lens array but a solid lens array. A concave-shape lens array is unavoidable when using only the liquid lens array and some voltages are needed to make the lens flat. By placing the solid lens array on the liquid lens array, initial diopter can be positive. To fabricate the hybrid structure lens array, a conventional lithographic process in semiconductor manufacturing is needed. A negative photoresist SU-8 was used as chamber master molds. PDMS and UV adhesive replica molding are done sequentially. Two immiscible liquids, DI water and dodecane, are injected in the fabricated chamber, followed by sealing. The fabricated structure has a 20 by 20 pattern of cylindrical shaped circle array and the aperture size of each lens is 1mm. The thickness of the overall hybrid structure is about 2.8mm. Hybrid structure lens array has many advantages. Solid lens array has almost 100% fill factor and allow high efficiency. Diopter can be increased by more than 200 and negative diopter can be shifted to the positive region. This experiment showed several properties of the hybrid structure and demonstrated its superiority.

  17. 3D Imaging with a Single-Aperture 3-mm Objective Lens: Concept, Fabrication and Test

    NASA Technical Reports Server (NTRS)

    Korniski, Ron; Bae, Sam Y.; Shearn, Mike; Manohara, Harish; Shahinian, Hrayr

    2011-01-01

    There are many advantages to minimally invasive surgery (MIS). An endoscope is the optical system of choice by the surgeon for MIS. The smaller the incision or opening made to perform the surgery, the smaller the optical system needed. For minimally invasive neurological and skull base surgeries the openings are typically 10-mm in diameter (dime sized) or less. The largest outside diameter (OD) endoscope used is 4mm. A significant drawback to endoscopic MIS is that it only provides a monocular view of the surgical site thereby lacking depth information for the surgeon. A stereo view would provide the surgeon instantaneous depth information of the surroundings within the field of view, a significant advantage especially during brain surgery. Providing 3D imaging in an endoscopic objective lens system presents significant challenges because of the tight packaging constraints. This paper presents a promising new technique for endoscopic 3D imaging that uses a single lens system with complementary multi-bandpass filters (CMBFs), and describes the proof-of-concept demonstrations performed to date validating the technique. These demonstrations of the technique have utilized many commercial off-the-shelf (COTS) components including the ones used in the endoscope objective.

  18. Design and fabrication of cast orthopedic implants with freeform surface textures from 3-D printed ceramic shell.

    PubMed

    Curodeau, A; Sachs, E; Caldarise, S

    2000-09-01

    Three-dimensional printing is a solid freeform fabrication process, which creates parts directly from a computer model. The parts are built by repetitively spreading a layer of powder and selectively joining the powder in the layer by ink-jet printing of a binder material. 3D printing was applied to the fabrication of sub-millimeter surface textures with overhang and undercut geometries for use in orthopedic prostheses as bony ingrowth structures. 3D printing is used to fabricate ceramic molds of alumina powder and silica binder, and these molds are used to cast the bony ingrowth surfaces of Co-Cr (ASTM F75) alloy. Minimum positive feature sizes of the ceramic mold and, therefore, minimum negative feature sizes of castings were determined to be approximately 200 x 200 x 175 microm and were limited by the strength of ceramic needed to withstand handling. Minimum negative feature sizes in the ceramic mold and, therefore, minimum positive features in the casting were found to be approximately 350 x 350 x 175 microm and were determined by limitations on removal of powder from the ceramic and the pressure required to fill these small features with molten metal during casting. Textures were designed with 5 layers of distinct geometric definition, allowing for the design of overhung geometry with overall porosity ranging from 30-70%. Features as small as 350 x 350 x 200 microm were included in these designs and successfully cast.

  19. Fabrication of extended-release patient-tailored prednisolone tablets via fused deposition modelling (FDM) 3D printing.

    PubMed

    Skowyra, Justyna; Pietrzak, Katarzyna; Alhnan, Mohamed A

    2015-02-20

    Rapid and reliable tailoring of the dose of controlled release tablets to suit an individual patient is a major challenge for personalized medicine. The aim of this work was to investigate the feasibility of using a fused deposition modelling (FDM) based 3D printer to fabricate extended release tablet using prednisolone loaded poly(vinyl alcohol) (PVA) filaments and to control its dose. Prednisolone was loaded into a PVA-based (1.75 mm) filament at approximately 1.9% w/w via incubation in a saturated methanolic solution of prednisolone. The physical form of the drug was assessed using differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD). Dose accuracy and in vitro drug release patterns were assessed using HPLC and pH change flow-through dissolution test. Prednisolone loaded PVA filament demonstrated an ability to be fabricated into regular ellipse-shaped solid tablets using the FDM-based 3D printer. It was possible to control the mass of printed tablet through manipulating the volume of the design (R(2) = 0.9983). On printing tablets with target drug contents of 2, 3, 4, 5, 7.5 and 10mg, a good correlation between target and achieved dose was obtained (R(2) = 0.9904) with a dose accuracy range of 88.7-107%. Thermal analysis and XRPD indicated that the majority of prednisolone existed in amorphous form within the tablets. In vitro drug release from 3D printed tablets was extended up to 24h. FDM based 3D printing is a promising method to produce and control the dose of extended release tablets, providing a highly adjustable, affordable, minimally sized, digitally controlled platform for producing patient-tailored medicines. PMID:25460545

  20. Calcium alginate microcapsule generation on a microfluidic system fabricated using the optical disk process

    NASA Astrophysics Data System (ADS)

    Huang, Keng-Shiang; Liu, Ming-Kai; Wu, Chun-Han; Yen, Yu-Tang; Lin, Yu-Cheng

    2007-08-01

    This paper describes the generation of monodisperse calcium alginate (Ca-alginate) microcapsules on a microfluidic platform using the commercial optical disk process. Our strategy is based on combining the rapid injection molding process for a cross-junction microchannel with the sheath focusing effect to form uniform water-in-oil (w/o) emulsions. These emulsions, consisting of 1.5% (w/v) sodium alginate (Na-alginate), are then dripped into a solution containing 20% (w/v) calcium chloride (CaCl2) creating Ca-alginate microparticles in an efficient manner. This paper demonstrates that the size of Ca-alginate microparticles can be controlled from 20 µm to 50 µm in diameter with a variation of less than 10%, simply by altering the relative sheath/sample flow rate ratio. Experimental data show that for a given fixed dispersed phase flow (sample flow), the emulsion size decreases as the average flow rate of the continuous phase flow (sheath flow) increases. The proposed microfluidic platform is capable of generating relatively uniform emulsions and has the advantages of active control of the emulsion diameter, a simple and low cost process and a high throughput.

  1. Design and fabrication of 3D-printed anatomically shaped lumbar cage for intervertebral disc (IVD) degeneration treatment.

    PubMed

    Serra, T; Capelli, C; Toumpaniari, R; Orriss, I R; Leong, J J H; Dalgarno, K; Kalaskar, D M

    2016-01-01

    Spinal fusion is the gold standard surgical procedure for degenerative spinal conditions when conservative therapies have been unsuccessful in rehabilitation of patients. Novel strategies are required to improve biocompatibility and osseointegration of traditionally used materials for lumbar cages. Furthermore, new design and technologies are needed to bridge the gap due to the shortage of optimal implant sizes to fill the intervertebral disc defect. Within this context, additive manufacturing technology presents an excellent opportunity to fabricate ergonomic shape medical implants. The goal of this study is to design and manufacture a 3D-printed lumbar cage for lumbar interbody fusion. Optimisations of the proposed implant design and its printing parameters were achieved via in silico analysis. The final construct was characterised via scanning electron microscopy, contact angle, x-ray micro computed tomography (μCT), atomic force microscopy, and compressive test. Preliminary in vitro cell culture tests such as morphological assessment and metabolic activities were performed to access biocompatibility of 3D-printed constructs. Results of in silico analysis provided a useful platform to test preliminary cage design and to find an optimal value of filling density for 3D printing process. Surface characterisation confirmed a uniform coating of nHAp with nanoscale topography. Mechanical evaluation showed mechanical properties of final cage design similar to that of trabecular bone. Preliminary cell culture results showed promising results in terms of cell growth and activity confirming biocompatibility of constructs. Thus for the first time, design optimisation based on computational and experimental analysis combined with the 3D-printing technique for intervertebral fusion cage has been reported in a single study. 3D-printing is a promising technique for medical applications and this study paves the way for future development of customised implants in spinal

  2. Fabrication of fiber reinforced plates with curvilinear layout by 3-D photolithography

    SciTech Connect

    Ogale, A.A.; Renault, T.; Charan, R.; Bagchi, A.

    1994-12-31

    A new technique to rapidly process fiber reinforced resins by 3-D photolithography was recently developed. Reinforcing fibers are added in situ to obtain parts with improved strength, stiffness, and toughness. An automated desktop photolithography unit (ADPU) was designed and built in-house, to add continuous E-glass fibers to the photoresin. The unique feature of this machine is its capability to dispense in situ continuous fibers in any desired direction. To demonstrate the advantages of this process, a case study was conducted, where a rectangular plate with a circular hole in the center was subjected to tensile loading. The parts were made with Somos 3100 resin as the matrix and continuous glass fibers as the reinforcement. The failure load of plates reinforced with a straightline fiber layout and a curvilinear fiber layout are compared. In the curvilinear format, the fibers were dispensed along the principal stress directions.

  3. Mesenchymal stem cell interactions with 3D ECM modules fabricated via multiphoton excited photochemistry.

    PubMed

    Su, Ping-Jung; Tran, Quyen A; Fong, Jimmy J; Eliceiri, Kevin W; Ogle, Brenda M; Campagnola, Paul J

    2012-09-10

    To understand complex micro/nanoscale ECM stem cell interactions, reproducible in vitro models are needed that can strictly recapitulate the relative content and spatial arrangement of native tissue. Additionally, whole ECM proteins are required to most accurately reflect native binding dynamics. To address this need, we use multiphoton excited photochemistry to create 3D whole protein constructs or "modules" to study how the ECM governs stem cell migration. The constructs were created from mixtures of BSA/laminin (LN) and BSA alone, whose comparison afforded studying how the migration dynamics are governed from the combination of morphological and ECM cues. We found that mesenchymal stem cells interacted for significantly longer durations with the BSA/LN constructs than pure BSA, pointing to the importance of binding cues of the LN. Critical to this work was the development of an automated system with feedback based on fluorescence imaging to provide quality control when synthesizing multiple identical constructs.

  4. Fabrication of 3-D Photonic Band Gap Crystals Via Colloidal Self-Assembly

    NASA Technical Reports Server (NTRS)

    Subramaniam, Girija; Blank, Shannon

    2005-01-01

    The behavior of photons in a Photonic Crystals, PCs, is like that of electrons in a semiconductor in that, it prohibits light propagation over a band of frequencies, called Photonic Band Gap, PBG. Photons cannot exist in these band gaps like the forbidden bands of electrons. Thus, PCs lend themselves as potential candidates for devices based on the gap phenomenon. The popular research on PCs stem from their ability to confine light with minimal losses. Large scale 3-D PCs with a PBG in the visible or near infra red region will make optical transistors and sharp bent optical fibers. Efforts are directed to use PCs for information processing and it is not long before we can have optical integrated circuits in the place of electronic ones.

  5. Directed assembly of cell-laden microgels for fabrication of 3D tissue constructs.

    PubMed

    Du, Yanan; Lo, Edward; Ali, Shamsher; Khademhosseini, Ali

    2008-07-15

    We present a bottom-up approach to direct the assembly of cell-laden microgels to generate tissue constructs with tunable microarchitecture and complexity. This assembly process is driven by the tendency of multiphase liquid-liquid systems to minimize the surface area and the resulting surface free energy between the phases. We demonstrate that shape-controlled microgels spontaneously assemble within multiphase reactor systems into predetermined geometric configurations. Furthermore, we characterize the parameters that influence the assembly process, such as external energy input, surface tension, and microgel dimensions. Finally, we show that multicomponent cell-laden constructs could be generated by assembling microgel building blocks and performing a secondary cross-linking reaction. This bottom-up approach for the directed assembly of cell-laden microgels provides a powerful and highly scalable approach to form biomimetic 3D tissue constructs and opens a paradigm for directing the assembly of mesoscale materials.

  6. Challenges and limitations of patient-specific vascular phantom fabrication using 3D Polyjet printing

    PubMed Central

    Ionita, Ciprian N; Mokin, Maxim; Varble, Nicole; Bednarek, Daniel R; Xiang, Jianping; Snyder, Kenneth V; Siddiqui, Adnan H; Levy, Elad I; Meng, Hui; Rudin, Stephen

    2014-01-01

    Additive manufacturing (3D printing) technology offers a great opportunity towards development of patient-specific vascular anatomic models, for medical device testing and physiological condition evaluation. However, the development process is not yet well established and there are various limitations depending on the printing materials, the technology and the printer resolution. Patient-specific neuro-vascular anatomy was acquired from computed tomography angiography and rotational digital subtraction angiography (DSA). The volumes were imported into a Vitrea 3D workstation (Vital Images Inc.) and the vascular lumen of various vessels and pathologies were segmented using a “marching cubes” algorithm. The results were exported as Stereo Lithographic (STL) files and were further processed by smoothing, trimming, and wall extrusion (to add a custom wall to the model). The models were printed using a Polyjet printer, Eden 260V (Objet-Stratasys). To verify the phantom geometry accuracy, the phantom was reimaged using rotational DSA, and the new data was compared with the initial patient data. The most challenging part of the phantom manufacturing was removal of support material. This aspect could be a serious hurdle in building very tortuous phantoms or small vessels. The accuracy of the printed models was very good: distance analysis showed average differences of 120 μm between the patient and the phantom reconstructed volume dimensions. Most errors were due to residual support material left in the lumen of the phantom. Despite the post-printing challenges experienced during the support cleaning, this technology could be a tremendous benefit to medical research such as in device development and testing. PMID:25300886

  7. Challenges and limitations of patient-specific vascular phantom fabrication using 3D Polyjet printing

    NASA Astrophysics Data System (ADS)

    Ionita, Ciprian N.; Mokin, Maxim; Varble, Nicole; Bednarek, Daniel R.; Xiang, Jianping; Snyder, Kenneth V.; Siddiqui, Adnan H.; Levy, Elad I.; Meng, Hui; Rudin, Stephen

    2014-03-01

    Additive manufacturing (3D printing) technology offers a great opportunity towards development of patient-specific vascular anatomic models, for medical device testing and physiological condition evaluation. However, the development process is not yet well established and there are various limitations depending on the printing materials, the technology and the printer resolution. Patient-specific neuro-vascular anatomy was acquired from computed tomography angiography and rotational digital subtraction angiography (DSA). The volumes were imported into a Vitrea 3D workstation (Vital Images Inc.) and the vascular lumen of various vessels and pathologies were segmented using a "marching cubes" algorithm. The results were exported as Stereo Lithographic (STL) files and were further processed by smoothing, trimming, and wall extrusion (to add a custom wall to the model). The models were printed using a Polyjet printer, Eden 260V (Objet-Stratasys). To verify the phantom geometry accuracy, the phantom was reimaged using rotational DSA, and the new data was compared with the initial patient data. The most challenging part of the phantom manufacturing was removal of support material. This aspect could be a serious hurdle in building very tortuous phantoms or small vessels. The accuracy of the printed models was very good: distance analysis showed average differences of 120 μm between the patient and the phantom reconstructed volume dimensions. Most errors were due to residual support material left in the lumen of the phantom. Despite the post-printing challenges experienced during the support cleaning, this technology could be a tremendous benefit to medical research such as in device development and testing.

  8. Fabrication and mechanical characterization of 3D electrospun scaffolds for tissue engineering.

    PubMed

    Wright, L D; Young, R T; Andric, T; Freeman, J W

    2010-10-01

    Electrospinning is a polymer processing technique that produces fibrous structures comparable to the extracellular matrix of many tissues. Electrospinning, however, has been severely limited in its tissue engineering capabilities because this technique has produced few three-dimensional structures. Sintering of electrospun materials provides a method to fabricate unique architectures and allow much larger structures to be made. Electrospun mats were sintered into strips and cylinders, and their tensile and compressive mechanical properties were measured. In addition, electrospun materials with salt pores (salt embedded within the material and then leached out) were fabricated to improve porosity of the electrospun materials for tissue engineering scaffolds. Sintered electrospun poly(D,L-lactide) and poly(L-lactide) (PDLA/PLLA) materials have higher tensile mechanical properties (modulus: 72.3 MPa, yield: 960 kPa) compared to unsintered PLLA (modulus: 40.36 MPa, yield: 675.5 kPa). Electrospun PDLA/PLLA cylinders with and without salt-leached pores had compressive moduli of 6.69 and 26.86 MPa, respectively, and compressive yields of 1.36 and 0.56 MPa, respectively. Sintering of electrospun materials is a novel technique that improves electrospinning application in tissue engineering by increasing the size and types of electrospun structures that can be fabricated.

  9. Inverted Yablonovite-like 3D photonic crystals fabricated by laser nanolithography

    NASA Astrophysics Data System (ADS)

    Shishkin, Ivan I.; Samusev, Kirill B.; Rybin, Mikhail V.; Limonov, Mikhail F.; Kivshar, Yuri S.; Gaidukeviciute, Arune; Kiyan, Roman V.; Chichkov, Boris N.

    2012-06-01

    We report on the fabrication of inverted Yablonovite-like three-dimensional photonic crystals by nonlinear optical nanolithography based on two-photon polymerization of a zirconium propoxide hybrid organic-inorganic material with Irgacure 369 as photo-initiator. Advantage of this material is ultra-low shrinkage that guaranty high fabrication fidelity. Images of the fabricated structure are obtained with a scanning electron microscope. The photonic crystal consists of three sets of nearly cylindrical structural elements directed along the three lattice vectors of the fcc lattice and cross each other at certain angles to produce inverted Yablonovite geometry. To investigate photonic properties of the inverted Yablonovite structures, we calculate the photonic band structure for ten lowest-frequency electromagnetic modes. In contrast to the direct Yablonovite structure that has a complete photonic band gap between the second and third bands, we find no complete photonic band gaps in the inverted Yablonovite lattice. This situation is opposite to the case of fcc lattice of close-packed dielectric spheres in air that has a complete photonic band gap only for the inverted geometry.

  10. Fabrication of 3D nano-structures using reverse imprint lithography

    NASA Astrophysics Data System (ADS)

    Han, Kang-Soo; Hong, Sung-Hoon; Kim, Kang-In; Cho, Joong-Yeon; Choi, Kyung-woo; Lee, Heon

    2013-02-01

    In spite of the fact that the fabrication process of three-dimensional nano-structures is complicated and expensive, it can be applied to a range of devices to increase their efficiency and sensitivity. Simple and inexpensive fabrication of three-dimensional nano-structures is necessary. In this study, reverse imprint lithography (RIL) with UV-curable benzylmethacrylate, methacryloxypropyl terminated poly-dimethylsiloxane (M-PDMS) resin and ZnO-nano-particle-dispersed resin was used to fabricate three-dimensional nano-structures. UV-curable resins were placed between a silicon stamp and a PVA transfer template, followed by a UV curing process. Then, the silicon stamp was detached and a 2D pattern layer was transferred to the substrate using diluted UV-curable glue. Consequently, three-dimensional nano-structures were formed by stacking the two-dimensional nano-patterned layers. RIL was applied to a light-emitting diode (LED) to evaluate the optical effects of a nano-patterned layer. As a result, the light extraction of the patterned LED was increased by about 12% compared to an unpatterned LED.

  11. 3D printing in X-ray and Gamma-Ray Imaging: A novel method for fabricating high-density imaging apertures.

    PubMed

    Miller, Brian W; Moore, Jared W; Barrett, Harrison H; Fryé, Teresa; Adler, Steven; Sery, Joe; Furenlid, Lars R

    2011-12-10

    Advances in 3D rapid-prototyping printers, 3D modeling software, and casting techniques allow for cost-effective fabrication of custom components in gamma-ray and X-ray imaging systems. Applications extend to new fabrication methods for custom collimators, pinholes, calibration and resolution phantoms, mounting and shielding components, and imaging apertures. Details of the fabrication process for these components, specifically the 3D printing process, cold casting with a tungsten epoxy, and lost-wax casting in platinum are presented.

  12. Flow-through polymerase chain reaction inside a seamless 3D helical microreactor fabricated utilizing a silicone tube and a paraffin mold.

    PubMed

    Wu, Wenming; Trinh, Kieu The Loan; Lee, Nae Yoon

    2015-03-01

    We introduce a new strategy for fabricating a seamless three-dimensional (3D) helical microreactor utilizing a silicone tube and a paraffin mold. With this method, various shapes and sizes of 3D helical microreactors were fabricated, and a complicated and laborious photolithographic process, or 3D printing, was eliminated. With dramatically enhanced portability at a significantly reduced fabrication cost, such a device can be considered to be the simplest microreactor, developed to date, for performing the flow-through polymerase chain reaction (PCR).

  13. 3D printing in X-ray and Gamma-Ray Imaging: A novel method for fabricating high-density imaging apertures☆

    PubMed Central

    Miller, Brian W.; Moore, Jared W.; Barrett, Harrison H.; Fryé, Teresa; Adler, Steven; Sery, Joe; Furenlid, Lars R.

    2011-01-01

    Advances in 3D rapid-prototyping printers, 3D modeling software, and casting techniques allow for cost-effective fabrication of custom components in gamma-ray and X-ray imaging systems. Applications extend to new fabrication methods for custom collimators, pinholes, calibration and resolution phantoms, mounting and shielding components, and imaging apertures. Details of the fabrication process for these components, specifically the 3D printing process, cold casting with a tungsten epoxy, and lost-wax casting in platinum are presented. PMID:22199414

  14. Design and Fabrication of a Biodegradable, Covalently Crosslinked Shape-Memory Alginate Scaffold for Cell and Growth Factor Delivery

    PubMed Central

    Wang, Lin; Shansky, Janet; Borselli, Cristina; Mooney, David

    2012-01-01

    The successful use of transplanted cells and/or growth factors for tissue repair is limited by a significant cell loss and/or rapid growth factor diffusion soon after implantation. Highly porous alginate scaffolds formed with covalent crosslinking have been used to improve cell survival and growth factor release kinetics, but require open-wound surgical procedures for insertion and have not previously been designed to readily degrade in vivo. In this study, a biodegradable, partially crosslinked alginate scaffold with shape-memory properties was fabricated for minimally invasive surgical applications. A mixture of high and low molecular weight partially oxidized alginate modified with RGD peptides was covalently crosslinked using carbodiimide chemistry. The scaffold was compressible 11-fold and returned to its original shape when rehydrated. Scaffold degradation properties in vitro indicated ∼85% mass loss by 28 days. The greater than 90% porous scaffolds released the recombinant growth factor insulin-like growth factor-1 over several days in vitro and allowed skeletal muscle cell survival, proliferation, and migration from the scaffold over a 28-day period. The compressible scaffold thus has the potential to be delivered by a minimally invasive technique, and when rehydrated in vivo with cells and/or growth factors, could serve as a temporary delivery vehicle for tissue repair. PMID:22646518

  15. Direct fabrication of 3D graphene on nanoporous anodic alumina by plasma-enhanced chemical vapor deposition

    PubMed Central

    Zhan, Hualin; Garrett, David J.; Apollo, Nicholas V.; Ganesan, Kumaravelu; Lau, Desmond; Prawer, Steven; Cervenka, Jiri

    2016-01-01

    High surface area electrode materials are of interest for a wide range of potential applications such as super-capacitors and electrochemical cells. This paper describes a fabrication method of three-dimensional (3D) graphene conformally coated on nanoporous insulating substrate with uniform nanopore size. 3D graphene films were formed by controlled graphitization of diamond-like amorphous carbon precursor films, deposited by plasma-enhanced chemical vapour deposition (PECVD). Plasma-assisted graphitization was found to produce better quality graphene than a simple thermal graphitization process. The resulting 3D graphene/amorphous carbon/alumina structure has a very high surface area, good electrical conductivity and exhibits excellent chemically stability, providing a good material platform for electrochemical applications. Consequently very large electrochemical capacitance values, as high as 2.1 mF for a sample of 10 mm3, were achieved. The electrochemical capacitance of the material exhibits a dependence on bias voltage, a phenomenon observed by other groups when studying graphene quantum capacitance. The plasma-assisted graphitization, which dominates the graphitization process, is analyzed and discussed in detail. PMID:26805546

  16. Direct fabrication of 3D graphene on nanoporous anodic alumina by plasma-enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Zhan, Hualin; Garrett, David J.; Apollo, Nicholas V.; Ganesan, Kumaravelu; Lau, Desmond; Prawer, Steven; Cervenka, Jiri

    2016-01-01

    High surface area electrode materials are of interest for a wide range of potential applications such as super-capacitors and electrochemical cells. This paper describes a fabrication method of three-dimensional (3D) graphene conformally coated on nanoporous insulating substrate with uniform nanopore size. 3D graphene films were formed by controlled graphitization of diamond-like amorphous carbon precursor films, deposited by plasma-enhanced chemical vapour deposition (PECVD). Plasma-assisted graphitization was found to produce better quality graphene than a simple thermal graphitization process. The resulting 3D graphene/amorphous carbon/alumina structure has a very high surface area, good electrical conductivity and exhibits excellent chemically stability, providing a good material platform for electrochemical applications. Consequently very large electrochemical capacitance values, as high as 2.1 mF for a sample of 10 mm3, were achieved. The electrochemical capacitance of the material exhibits a dependence on bias voltage, a phenomenon observed by other groups when studying graphene quantum capacitance. The plasma-assisted graphitization, which dominates the graphitization process, is analyzed and discussed in detail.

  17. Fabrication of fully undercut ZnO-based photonic crystal membranes with 3D optical confinement

    NASA Astrophysics Data System (ADS)

    Hoffmann, Sandro Phil; Albert, Maximilian; Meier, Cedrik

    2016-09-01

    For studying nonlinear photonics, a highly controllable emission of photons with specific properties is essential. Two-dimensional photonic crystals (PhCs) have proven to be an excellent candidate for manipulating photon emission due to resonator-based effects. Additionally, zinc oxide (ZnO) has high susceptibility coefficients and therefore shows pronounced nonlinear effects. However, in order to fabricate such a cavity, a fully undercut ZnO membrane is required, which is a challenging problem due to poor selectivity of the known etching chemistry for typical substrates such as sapphire or ZnO. The aim of this paper is to demonstrate and characterize fully undercut photonic crystal membranes based on a thin ZnO film sandwiched between two layers of silicon dioxide (SiO2) on silicon substrates, from the initial growth of the heterostructure throughout the entire fabrication process. This process leads to a fully undercut ZnO-based membrane with adjustable optical confinement in all three dimensions. Finally, photonic resonances within the tailored photonic band gap are achieved due to optimized PhC-design (in-plane) and total internal reflection in the z-direction. The presented approach enables a variety of photon based resonator structures in the UV regime for studying nonlinear effects, including photon-exciton coupling and all-optical switching.

  18. Fabrication of a three dimensional particle focusing microfluidic device using a 3D printer, PDMS, and glass

    NASA Astrophysics Data System (ADS)

    Collette, Robyn; Rosen, Daniel; Shirk, Kathryn

    Microfluidic devices have high importance in fields such as bioanalysis because they can manipulate volumes of fluid in the range of microliters to picoliters. Small samples can be quickly and easily tested using complex microfluidic devices. Typically, these devices are created through lithography techniques, which can be costly and time consuming. It has been shown that inexpensive microfluidic devices can be produced quickly using a 3D printer and PDMS. However, a size limitation prohibits the fabrication of precisely controlled microchannels. By using shrinking materials in combination with 3D printing of flow-focusing geometries, this limitation can be overcome. This research seeks to employ these techniques to quickly fabricate an inexpensive, working device with three dimensional particle focusing capabilities. By modifying the channel geometry, colloidal particles in a solution will be focused into a single beam when passed through this device. The ability to focus particles is necessary for a variety of biological applications which requires precise detection and characterization of particles in a sample. We would like to thank the Shippensburg University Undergraduate Research Grant Program for their generous funding.

  19. Fabrication of 3D porous SF/β-TCP hybrid scaffolds for bone tissue reconstruction.

    PubMed

    Park, Hyun Jung; Min, Kyung Dan; Lee, Min Chae; Kim, Soo Hyeon; Lee, Ok Joo; Ju, Hyung Woo; Moon, Bo Mi; Lee, Jung Min; Park, Ye Ri; Kim, Dong Wook; Jeong, Ju Yeon; Park, Chan Hum

    2016-07-01

    Bio-ceramic is a biomaterial actively studied in the field of bone tissue engineering. But, only certain ceramic materials can resolve the corrosion problem and possess the biological affinity of conventional metal biomaterials. Therefore, the recent development of composites of hybrid composites and polymers has been widely studied. In this study, we aimed to select the best scaffold of silk fibroin and β-TCP hybrid for bone tissue engineering. We fabricated three groups of scaffold such as SF (silk fibroin scaffold), GS (silk fibroin/small granule size of β-TCP scaffold) and GM (silk fibroin/medium granule size of β-TCP scaffold), and we compared the characteristics of each group. During characterization of the scaffold, we used scanning electron microscopy (SEM) and a Fourier transform infrared spectroscopy (FTIR) for structural analysis. We compared the physiological properties of the scaffold regarding the swelling ratio, water uptake and porosity. To evaluate the mechanical properties, we examined the compressive strength of the scaffold. During in vitro testing, we evaluated cell attachment and cell proliferation (CCK-8). Finally, we confirmed in vivo new bone regeneration from the implanted scaffolds using histological staining and micro-CT. From these evaluations, the fabricated scaffold demonstrated high porosity with good inter-pore connectivity, showed good biocompatibility and high compressive strength and modulus. In particular, the present study indicates that the GM scaffold using β-TCP accelerates new bone regeneration of implanted scaffolds. Accordingly, our scaffold is expected to act a useful application in the field of bone tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1779-1787, 2016. PMID:26999521

  20. The fabrication of double layer tubular vascular tissue engineering scaffold via coaxial electrospinning and its 3D cell coculture.

    PubMed

    Ye, Lin; Cao, Jie; Chen, Lamei; Geng, Xue; Zhang, Ai-Ying; Guo, Lian-Rui; Gu, Yong-Quan; Feng, Zeng-Guo

    2015-12-01

    A continuous electrospinning technique was applied to fabricate double layer tubular tissue engineering vascular graft (TEVG) scaffold. The luminal layer was made from poly(ɛ-caprolac-tone)(PCL) ultrafine fibers via common single axial electrospinning followed by the outer layer of core-shell structured nanofibers via coaxial electrospinning. For preparing the outer layernano-fibers, the PCL was electrospun into the shell and both bovine serum albumin (BSA) and tetrapeptide val-gal-pro-gly (VAPG) were encapsulated into the core. The core-shell structure in the outer layer fibers was observed by transmission electron microscope (TEM). The in vitro release tests exhibited the sustainable release behavior of BSA and VAPG so that they provided a better cell growth environment in the interior of tubular scaffold wall. The in vitro culture of smooth muscle cells (SMCs) demonstrated their potential to penetrate into the scaffold wall for the 3D cell culture. Subsequently, 3D cell coculture was conducted. First, SMCs were seeded on the luminal surface of the scaffold and cultured for 5 days, and then endothelial cells (ECs) were also seeded on the luminal surface and cocultured with SMCs for another 2 days. After stained with antibodies, 3D cell distribution on the scaffold was revealed by confocal laser scanning microscopy (CLSM) where ECs were mainly located on the luminal surface whereas SMCs penetrated into the surface and distributed inside the scaffold wall. This double layer tubular scaffold with 3D cell distribution showed the promise to develop it into a novel TEVG for clinical trials in the near future.

  1. Cells (MC3T3-E1)-laden alginate scaffolds fabricated by a modified solid-freeform fabrication process supplemented with an aerosol spraying.

    PubMed

    Ahn, SeungHyun; Lee, HyeongJin; Bonassar, Lawrence J; Kim, GeunHyung

    2012-09-10

    In this study, we propose a new cell encapsulation method consisting of a dispensing method and an aerosol-spraying method. The aerosol spray using a cross-linking agent, calcium chloride (CaCl(2)), was used to control the surface gelation of dispensed alginate struts during dispensing. To show the feasibility of the method, we used preosteoblast (MC3T3-E1) cells. By changing the relationship between the various dispensing/aerosol-spraying conditions and cell viability, we could determine the optimal cell-dispensing process: a nozzle size (240 μm) and an aerosol spray flow rate (0.93 ± 0.12 mL min(-1)), 10 mm s(-1) nozzle moving speed, a 10 wt % concentration of CaCl(2) in the aerosol solution, and 2 wt % concentration of CaCl(2) in the second cross-linking process. Based on these optimized process conditions, we successfully fabricated a three-dimensional, pore-structured, cell-laden alginate scaffold of 20 × 20 × 4.6 mm(3) and 84% cell viability. During long cell culture periods (16, 25, 33, and 45 days), the preosteoblasts in the alginate scaffold survived and proliferated well.

  2. 3D finite element simulation of non-crimp fabric composites ultrasonic testing

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Saffari, N.; Fromme, P.

    2012-05-01

    Composite materials offer many advantages for aerospace applications, e.g., good strength to weight ratio. Different types of composites, such as non-crimp fabrics (NCF), are currently being investigated as they offer reduced manufacturing costs and improved damage tolerance as compared to traditional pre-impregnated composite materials. NCF composites are made from stitched fiber bundles (tows), which typically have a width and thickness of less than a millimeter. This results in strongly inhomogeneous and anisotropic material properties. Different types of manufacturing imperfections, such as porosity, resin pockets, tow crimp and misalignment can lead to reduced material strength and thus to defects following excessive loads or impact, e.g., fracture and delaminations. The ultrasonic non-destructive testing of NCF composites is difficult, as the tow size is comparable to the wavelength, leading to multiple scattering in this inherently three-dimensional structure. For typical material properties and geometry of an NCF composite, a full three-dimensional Finite Element (FE) model has been developed in ABAQUS. The propagation of longitudinal ultrasonic waves has been simulated and the effect of multiple scattering at the fiber tows investigated. The influence of porosity in the epoxy matrix as a typical manufacturing defect on the ultrasonic wave propagation and attenuation has been studied.

  3. Fabrication and characterization of novel nano-biocomposite scaffold of chitosan-gelatin-alginate-hydroxyapatite for bone tissue engineering.

    PubMed

    Sharma, Chhavi; Dinda, Amit Kumar; Potdar, Pravin D; Chou, Chia-Fu; Mishra, Narayan Chandra

    2016-07-01

    A novel nano-biocomposite scaffold was fabricated in bead form by applying simple foaming method, using a combination of natural polymers-chitosan, gelatin, alginate and a bioceramic-nano-hydroxyapatite (nHAp). This approach of combining nHAp with natural polymers to fabricate the composite scaffold, can provide good mechanical strength and biological property mimicking natural bone. Environmental scanning electron microscopy (ESEM) images of the nano-biocomposite scaffold revealed the presence of interconnected pores, mostly spread over the whole surface of the scaffold. The nHAp particulates have covered the surface of the composite matrix and made the surface of the scaffold rougher. The scaffold has a porosity of 82% with a mean pore size of 112±19.0μm. Swelling and degradation studies of the scaffold showed that the scaffold possesses excellent properties of hydrophilicity and biodegradability. Short term mechanical testing of the scaffold does not reveal any rupturing after agitation under physiological conditions, which is an indicative of good mechanical stability of the scaffold. In vitro cell culture studies by seeding osteoblast cells over the composite scaffold showed good cell viability, proliferation rate, adhesion and maintenance of osteoblastic phenotype as indicated by MTT assay, ESEM of cell-scaffold construct, histological staining and gene expression studies, respectively. Thus, it could be stated that the nano-biocomposite scaffold of chitosan-gelatin-alginate-nHAp has the paramount importance for applications in bone tissue-engineering in future regenerative therapies.

  4. Fabrication, characterization and in vitro profile based interaction with eukaryotic and prokaryotic cells of alginate-chitosan-silica biocomposite.

    PubMed

    Balaure, Paul Catalin; Andronescu, Ecaterina; Grumezescu, Alexandru Mihai; Ficai, Anton; Huang, Keng-Shiang; Yang, Chih-Hui; Chifiriuc, Carmen Mariana; Lin, Yung-Sheng

    2013-01-30

    This work is focused on the fabrication of a new drug delivery system based on polyanionic matrix (e.g. sodium alginate), polycationic matrix (e.g. chitosan) and silica network. The FT-IR, SEM, DTA-TG, eukaryotic cell cycle and viability, and in vitro assay of the influence of the biocomposite on the efficacy of antibiotic drugs were investigated. The obtained results demonstrated the biocompatibility and the ability of the fabricated biocomposite to maintain or improve the efficacy of the following antibiotics: piperacillin-tazobactam, cefepime, piperacillin, imipenem, gentamicin, ceftazidime against Pseudomonas aeruginosa ATCC 27853 and cefazolin, cefaclor, cefuroxime, ceftriaxone, cefoxitin, trimethoprim/sulfamethoxazole against Escherichia coli ATCC 25922 reference strains.

  5. Fabrication, characterization and in vitro profile based interaction with eukaryotic and prokaryotic cells of alginate-chitosan-silica biocomposite.

    PubMed

    Balaure, Paul Catalin; Andronescu, Ecaterina; Grumezescu, Alexandru Mihai; Ficai, Anton; Huang, Keng-Shiang; Yang, Chih-Hui; Chifiriuc, Carmen Mariana; Lin, Yung-Sheng

    2013-01-30

    This work is focused on the fabrication of a new drug delivery system based on polyanionic matrix (e.g. sodium alginate), polycationic matrix (e.g. chitosan) and silica network. The FT-IR, SEM, DTA-TG, eukaryotic cell cycle and viability, and in vitro assay of the influence of the biocomposite on the efficacy of antibiotic drugs were investigated. The obtained results demonstrated the biocompatibility and the ability of the fabricated biocomposite to maintain or improve the efficacy of the following antibiotics: piperacillin-tazobactam, cefepime, piperacillin, imipenem, gentamicin, ceftazidime against Pseudomonas aeruginosa ATCC 27853 and cefazolin, cefaclor, cefuroxime, ceftriaxone, cefoxitin, trimethoprim/sulfamethoxazole against Escherichia coli ATCC 25922 reference strains. PMID:23178215

  6. Fabrication of corner cube array retro-reflective structure with DLP-based 3D printing technology

    NASA Astrophysics Data System (ADS)

    Riahi, Mohammadreza

    2016-06-01

    In this article, the fabrication of a corner cube array retro-reflective structure is presented by using DLP-based 3D printing technology. In this additive manufacturing technology a pattern of a cube corner array is designed in a computer and sliced with specific software. The image of each slice is then projected from the bottom side of a reservoir, containing UV cure resin, utilizing a DLP video projector. The projected area is cured and attached to a base plate. This process is repeated until the entire part is made. The best orientation of the printing process and the effect of layer thicknesses on the surface finish of the cube has been investigated. The thermal reflow surface finishing and replication with soft molding has also been presented in this article.

  7. Fabrication of Large-Scale Microlens Arrays Based on Screen Printing for Integral Imaging 3D Display.

    PubMed

    Zhou, Xiongtu; Peng, Yuyan; Peng, Rong; Zeng, Xiangyao; Zhang, Yong-Ai; Guo, Tailiang

    2016-09-14

    The low-cost large-scale fabrication of microlens arrays (MLAs) with precise alignment, great uniformity of focusing, and good converging performance are of great importance for integral imaging 3D display. In this work, a simple and effective method for large-scale polymer microlens arrays using screen printing has been successfully presented. The results show that the MLAs possess high-quality surface morphology and excellent optical performances. Furthermore, the microlens' shape and size, i.e., the diameter, the height, and the distance between two adjacent microlenses of the MLAs can be easily controlled by modifying the reflowing time and the size of open apertures of the screen. MLAs with the neighboring microlenses almost tangent can be achieved under suitable size of open apertures of the screen and reflowing time, which can remarkably reduce the color moiré patterns caused by the stray light between the blank areas of the MLAs in the integral imaging 3D display system, exhibiting much better reconstruction performance. PMID:27540754

  8. SU-C-213-02: Characterizing 3D Printing in the Fabrication of Variable Density Phantoms

    SciTech Connect

    Madamesila, J; McGeachy, P; Villarreal-Barajas, J; Khan, R

    2015-06-15

    Purpose: In this work, we present characterization, process flow, quality control and application of 3D fabricated low density phantoms for radiotherapy quality assurance. Methods: A Rostock delta 3D printer using polystyrene filament of diameter 1.75 mm was used to print geometric volumes of 2×2×1 cm{sup 3} of varying densities. The variable densities of 0.1 to 0.75 g/cm {sup 3} were created by modulating the infill. A computed tomography (CT) scan was performed to establish an infill-density calibration curve as well as characterize the quality of the print such as uniformity and the infill pattern. The time required to print these volumes was also recorded. Using the calibration, two low density cones (0.19, 0.52 g/cm{sup 3}) were printed and benchmarked against commercially available phantoms. The dosimetric validation of the low density scaling of Anisotropic Analytical Algorithm (AAA) was performed by using a 0.5 g/cm{sup 3} slab of 10×10×2.4 cm{sup 3} with EBT3 GafChromic film. The gamma analysis at 3%/3mm criteria were compared for the measured and computed dose planes. Results: Analysis of the volume of air pockets in the infill resulted in a reasonable uniformity for densities 0.4 to 0.75 g/cm{sup 3}. Printed phantoms with densities below 0.4 g/cm{sup 3} exhibited a higher ratio of air to polystyrene resulting in large non-uniformity. Compared to the commercial inserts, good agreement was observed only for the printed 0.52 g/cm{sup 3} cone. Dosimetric comparison for a printed low density volume placed in-between layers of solid water resulted in >95% gamma agreement between AAA calculated dose planes and measured EBT3 films for a 6MV 5×5 cm{sup 2} clinical beam. The comparison showed disagreement in the penumbra region. Conclusion: In conclusion, 3D printing technology opens the door to desktop fabrication of variable density phantoms at economical prices in an efficient manner for the quality assurance needs of a small clinic.

  9. Holographic fabrication of 3D photonic crystal templates with 4, 5, and 6-fold rotational symmetry using a single beam and single exposure

    NASA Astrophysics Data System (ADS)

    Lowell, David; George, David; Lutkenhaus, Jeffery; Philipose, Usha; Zhang, Hualiang; Lin, Yuankun

    2016-03-01

    A method of fabricating large-volume three-dimensional (3D) photonic crystal and quasicrystal templates using holographic lithography is presented. Fabrication is accomplished using a single-beam and single exposure by a reflective optical element (ROE). The ROE is 3D printed support structure which holds reflecting surfaces composed of silicon or gallium arsenide. Large-volume 3D photonic crystal and quasicrystal templates with 4-fold, 5-fold, and 6-fold symmetry were fabricated and found to be in good agreement with simulation. Although the reflective surfaces were setup away from the Brewster's angle, the interference among the reflected s and p-polarizations still generated bicontinuous structures, demonstrating the flexibility of the ROE. The ROE, being a compact and inexpensive alternative to diffractive optical elements and top-cut prisms, facilitates the large-scale integration of holographically fabricated photonic structures into on-chip applications.

  10. Carbon-dot-loaded alginate gels as recoverable probes: fabrication and mechanism of fluorescent detection.

    PubMed

    Hu, Shengliang; Zhao, Qing; Dong, Yingge; Yang, Jinlong; Liu, Jun; Chang, Qing

    2013-10-01

    We prepare a solid and green film of carbon-dot-loaded alginate gels with a pore structure. Compared to carbon dot suspension, the film exhibits stronger blue light emission. The porous structure of the film enables ion diffusion and contact with the CDs incorporated in the gel network, and thus the photoluminescence (PL) behavior of the film can be influenced by ions. The PL of the film shows a sensitive and selective quenching effect to Cu(2+), and it can be repeatedly used as a fluorescent probe to recognize Cu(2+) with a detection limit of 5 ppm. A band bending mechanism is proposed to understand the effects of surface/interface states and metal ions on the PL behavior of carbon-dot-loaded alginate gels, and it has been supported by our further experimental results. This band bending mechanism provides a clear physical insight into ion detection by PL behavior.

  11. Facile bench-top fabrication of enclosed circular microchannels provides 3D confined structure for growth of prostate epithelial cells.

    PubMed

    Dolega, Monika E; Wagh, Jayesh; Gerbaud, Sophie; Kermarrec, Frederique; Alcaraz, Jean-Pierre; Martin, Donald K; Gidrol, Xavier; Picollet-D'hahan, Nathalie

    2014-01-01

    We present a simple bench-top method to fabricate enclosed circular channels for biological experiments. Fabricating the channels takes less than 2 hours by using glass capillaries of various diameters (from 100 µm up to 400 µm) as a mould in PDMS. The inner surface of microchannels prepared in this way was coated with a thin membrane of either Matrigel or a layer-by-layer polyelectrolyte to control cellular adhesion. The microchannels were then used as scaffolds for 3D-confined epithelial cell culture. To show that our device can be used with several epithelial cell types from exocrine glandular tissues, we performed our biological studies on adherent epithelial prostate cells (non-malignant RWPE-1 and invasive PC3) and also on breast (non-malignant MCF10A) cells We observed that in static conditions cells adhere and proliferate to form a confluent layer in channels of 150 µm in diameter and larger, whereas cellular viability decreases with decreasing diameter of the channel. Matrigel and PSS (poly (sodium 4-styrenesulphonate)) promote cell adhesion, whereas the cell proliferation rate was reduced on the PAH (poly (allylamine hydrochloride))-terminated surface. Moreover infusing channels with a continuous flow did not induce any cellular detachment. Our system is designed to simply grow cells in a microchannel structure and could be easily fabricated in any biological laboratory. It offers opportunities to grow epithelial cells that support the formation of a light. This system could be eventually used, for example, to collect cellular secretions, or study cell responses to graduated hypoxia conditions, to chemicals (drugs, siRNA, …) and/or physiological shear stress.

  12. Fabrication of a novel dual mode cholesterol biosensor using titanium dioxide nanowire bridged 3D graphene nanostacks.

    PubMed

    Komathi, S; Muthuchamy, N; Lee, K-P; Gopalan, A-I

    2016-10-15

    Herein, we fabricated a novel electrochemical-photoelectrochemical (PEC) dual-mode cholesterol biosensor based on graphene (G) sheets interconnected-graphene embedded titanium nanowires (TiO2(G)-NWs) 3D nanostacks (designated as G/Ti(G) 3DNS) by exploiting the beneficial characteristics of G and TiO2-NWs to achieve good selectivity and high sensitivity for cholesterol detection. The G/Ti(G) 3DNS was fabricated by the reaction between functionalized G and TiO2(G)-NWs. Cholesterol oxidase (ChOx) was subsequently immobilized in to G/Ti(G) 3DNS using chitosan (CS) as the binder and the dual mode G/Ti(G) 3DNS/CS/ChOx biosensor was fabricated. The electro-optical properties of the G/Ti(G) 3DNS/CS/ChOx bioelectrode were characterized by cyclic voltammetry and UV-vis diffuse reflection spectroscopy. The cyclic voltammetry of immobilized ChOx showed a pair of well-defined redox peaks indicating direct electron transfer (DET) of ChOx. The amperometric reduction peak current (at -0.05V) linearly increased with increase in cholesterol concentration. The G/Ti(G) 3DNS/CS/ChOx bioelectrode was selective to cholesterol with a remarkable sensitivity (3.82μA/cm(2)mM) and a lower detection limit (6μM). Also, G/Ti(G) 3DNS/CS/ChOx functioned as photoelectrode and exhibited selective detection of cholesterol under a low bias voltage and light irradiation. Kinetic parameters, reproducibility, repeatability, storage stability and effect of temperature and pH were evaluated. We envisage that G/Ti(G) 3DNS with its prospective characteristics, would be a promising material for wide range of biosensing applications.

  13. Facile Bench-Top Fabrication of Enclosed Circular Microchannels Provides 3D Confined Structure for Growth of Prostate Epithelial Cells

    PubMed Central

    Dolega, Monika E.; Wagh, Jayesh; Gerbaud, Sophie; Kermarrec, Frederique; Alcaraz, Jean-Pierre; Martin, Donald K.; Gidrol, Xavier; Picollet-D’hahan, Nathalie

    2014-01-01

    We present a simple bench-top method to fabricate enclosed circular channels for biological experiments. Fabricating the channels takes less than 2 hours by using glass capillaries of various diameters (from 100 µm up to 400 µm) as a mould in PDMS. The inner surface of microchannels prepared in this way was coated with a thin membrane of either Matrigel or a layer-by-layer polyelectrolyte to control cellular adhesion. The microchannels were then used as scaffolds for 3D-confined epithelial cell culture. To show that our device can be used with several epithelial cell types from exocrine glandular tissues, we performed our biological studies on adherent epithelial prostate cells (non-malignant RWPE-1 and invasive PC3) and also on breast (non-malignant MCF10A) cells We observed that in static conditions cells adhere and proliferate to form a confluent layer in channels of 150 µm in diameter and larger, whereas cellular viability decreases with decreasing diameter of the channel. Matrigel and PSS (poly (sodium 4-styrenesulphonate)) promote cell adhesion, whereas the cell proliferation rate was reduced on the PAH (poly (allylamine hydrochloride))-terminated surface. Moreover infusing channels with a continuous flow did not induce any cellular detachment. Our system is designed to simply grow cells in a microchannel structure and could be easily fabricated in any biological laboratory. It offers opportunities to grow epithelial cells that support the formation of a light. This system could be eventually used, for example, to collect cellular secretions, or study cell responses to graduated hypoxia conditions, to chemicals (drugs, siRNA, …) and/or physiological shear stress. PMID:24945245

  14. Design and Fabrication of Anatomical Bioreactor Systems Containing Alginate Scaffolds for Cartilage Tissue Engineering

    PubMed Central

    Gharravi, Anneh Mohammad; Orazizadeh, Mahmoud; Ansari-Asl, Karim; Banoni, Salem; Izadi, Sina; Hashemitabar, Mahmoud

    2012-01-01

    The aim of the present study was to develop a tissue-engineering approach through alginate gel molding to mimic cartilage tissue in a three-dimensional culture system. The perfusion biomimetic bioreactor was designed to mimic natural joint. The shear stresses exerting on the bioreactor chamber were calculated by Computational Fluid Dynamic (CFD). Several alginate/bovine chondrocyte constructs were prepared, and were cultured in the bioreactor. Histochemical and immunohistochemical staining methods for the presence of glycosaminoglycan(GAG), overall matrix production and type II collagen protein were performed, respectively. The dynamic mechanical device applied a linear mechanical displacement of 2 mm to 10 mm. The CFD modeling indicated peak velocity and maximum wall shear stress were 1.706×10−3 m/s and 0.02407 dyne/cm 2, respectively. Histochemical and immunohistochemical analysis revealed evidence of cartilage-like tissue with lacunas similar to those of natural cartilage and the production of sulfated GAG of matrix by the chondrons, metachromatic territorial matrix-surrounded cells and accumulation of type II collagen around the cells. The present study indicated that when chondrocytes were seeded in alginate hydrogel and cultured in biomimetic cell culture system, cells survived well and secreted newly synthesized matrix led to improvement of chondrogenesis. PMID:23408660

  15. Novel crosslinked alginate/hyaluronic acid hydrogels for nerve tissue engineering

    NASA Astrophysics Data System (ADS)

    Wang, Min-Dan; Zhai, Peng; Schreyer, David J.; Zheng, Ruo-Shi; Sun, Xiao-Dan; Cui, Fu-Zhai; Chen, Xiong-Biao

    2013-09-01

    Artificial tissue engineering scaffolds can potentially provide support and guidance for the regrowth of severed axons following nerve injury. In this study, a hybrid biomaterial composed of alginate and hyaluronic acid (HA) was synthesized and characterized in terms of its suitability for covalent modification, biocompatibility for living Schwann cells and feasibility to construct three dimensional (3D) scaffolds. Carbodiimide mediated amide formation for the purpose of covalent crosslinking of the HA was carried out in the presence of calciumions that ionically crosslink alginate. Amide formation was found to be dependent on the concentrations of carbodiimide and calcium chloride. The double-crosslinked composite hydrogels display biocompatibility that is comparable to simple HA hydrogels, allowing for Schwann cell survival and growth. No significant difference was found between composite hydrogels made from different ratios of alginate and HA. A 3D BioPlotter™ rapid prototyping system was used to fabricate 3D scaffolds. The result indicated that combining HA with alginate facilitated the fabrication process and that 3D scaffolds with porous inner structure can be fabricated from the composite hydrogels, but not from HA alone. This information provides a basis for continuing in vitro and in vivo tests of the suitability of alginate/HA hydrogel as a biomaterial to create living cell scaffolds to support nerve regeneration.

  16. Granular gel support-enabled extrusion of three-dimensional alginate and cellular structures.

    PubMed

    Jin, Yifei; Compaan, Ashley; Bhattacharjee, Tapomoy; Huang, Yong

    2016-06-01

    Freeform fabrication of soft structures has been of great interest in recent years. In particular, it is viewed as a critical step toward the grand vision of organ printing--the on-demand design and fabrication of three-dimensional (3D) human organ constructs for implantation and regenerative medicine. The objective of this study is to develop a novel granular gel support material-enabled, two-step gelation-based 'printing-then-gelation' approach to fabricate 3D alginate structures using filament extrusion. Specifically, a granular Carbopol microgel bath holds the ungelled alginate structure being extruded, avoiding the instantaneous gelation of each printed layer as well as resultant surface tension-induced nozzle clogging. Since Carbopol microgels react with multivalent cations, which are needed for alginate crosslinking, gelatin is introduced as a sacrificial material to make an alginate and gelatin bioink for extrusion, which gels thermally (step-one gelation) to initially stabilize the printed structure for removal from Carbopol. Then gelatin is melted and diffused away while alginate is ionically crosslinked in a 37 °C calcium chloride bath (step-two gelation), resulting in an alginate structure. The proposed 'printing-then-gelation' approach works for alginate structure fabrication, and it is also applicable for the printing of cellular constructs and other similar homogeneous soft structures using a two-step or even multi-step approach. The main conclusions are: (1) 0.8% (w/v) Carbopol bath with a neutral pH value may be most suitable for soft structure printing; (2) it is most effective to use a 0.9% (w/v) NaCl solution to facilitate the removal of residual Carbopol; and (3) alginate structures fabricated using the proposed approach demonstrate better mechanical properties than those fabricated using the conventional 'gelation-while-printing' approach. PMID:27257095

  17. Fabrication and characterization of a 3-D non-homogeneous tissue-like mouse phantom for optical imaging

    NASA Astrophysics Data System (ADS)

    Avtzi, Stella; Zacharopoulos, Athanasios; Psycharakis, Stylianos; Zacharakis, Giannis

    2013-11-01

    In vivo optical imaging of biological tissue not only requires the development of new theoretical models and experimental procedures, but also the design and construction of realistic tissue-mimicking phantoms. However, most of the phantoms available currently in literature or the market, have either simple geometrical shapes (cubes, slabs, cylinders) or when realistic in shape they use homogeneous approximations of the tissue or animal under investigation. The goal of this study is to develop a non-homogeneous realistic phantom that matches the anatomical geometry and optical characteristics of the mouse head in the visible and near-infrared spectral range. The fabrication of the phantom consisted of three stages. Initially, anatomical information extracted from either mouse head atlases or structural imaging modalities (MRI, XCT) was used to design a digital phantom comprising of the three main layers of the mouse head; the brain, skull and skin. Based on that, initial prototypes were manufactured by using accurate 3D printing, allowing complex objects to be built layer by layer with sub-millimeter resolution. During the second stage the fabrication of individual molds was performed by embedding the prototypes into a rubber-like silicone mixture. In the final stage the detailed phantom was constructed by loading the molds with epoxy resin of controlled optical properties. The optical properties of the resin were regulated by using appropriate quantities of India ink and intralipid. The final phantom consisted of 3 layers, each one with different absorption and scattering coefficient (μa,μs) to simulate the region of the mouse brain, skull and skin.

  18. Portable, Easy-to-Operate, and Antifouling Microcapsule Array Chips Fabricated by 3D Ice Printing for Visual Target Detection.

    PubMed

    Zhang, Hong-Ze; Zhang, Fang-Ting; Zhang, Xiao-Hui; Huang, Dong; Zhou, Ying-Lin; Li, Zhi-Hong; Zhang, Xin-Xiang

    2015-06-16

    Herein, we proposed a portable, easy-to-operate, and antifouling microcapsule array chip for target detection. This prepackaged chip was fabricated by innovative and cost-effective 3D ice printing integrating with photopolymerization sealing which could eliminate complicated preparation of wet chemistry and effectively resist outside contaminants. Only a small volume of sample (2 μL for each microcapsule) was consumed to fulfill the assay. All the reagents required for the analysis were stored in ice form within the microcapsule before use, which guaranteed the long-term stability of microcapsule array chips. Nitrite and glucose were chosen as models for proof of concept to achieve an instant quantitative detection by naked eyes without the need of external sophisticated instruments. The simplicity, low cost, and small sample consumption endowed ice-printing microcapsule array chips with potential commercial value in the fields of on-site environmental monitoring, medical diagnostics, and rapid high-throughput point-of-care quantitative assay. PMID:25970032

  19. Portable, Easy-to-Operate, and Antifouling Microcapsule Array Chips Fabricated by 3D Ice Printing for Visual Target Detection.

    PubMed

    Zhang, Hong-Ze; Zhang, Fang-Ting; Zhang, Xiao-Hui; Huang, Dong; Zhou, Ying-Lin; Li, Zhi-Hong; Zhang, Xin-Xiang

    2015-06-16

    Herein, we proposed a portable, easy-to-operate, and antifouling microcapsule array chip for target detection. This prepackaged chip was fabricated by innovative and cost-effective 3D ice printing integrating with photopolymerization sealing which could eliminate complicated preparation of wet chemistry and effectively resist outside contaminants. Only a small volume of sample (2 μL for each microcapsule) was consumed to fulfill the assay. All the reagents required for the analysis were stored in ice form within the microcapsule before use, which guaranteed the long-term stability of microcapsule array chips. Nitrite and glucose were chosen as models for proof of concept to achieve an instant quantitative detection by naked eyes without the need of external sophisticated instruments. The simplicity, low cost, and small sample consumption endowed ice-printing microcapsule array chips with potential commercial value in the fields of on-site environmental monitoring, medical diagnostics, and rapid high-throughput point-of-care quantitative assay.

  20. Design, Fabrication and Characterization of a Low-Impedance 3D Electrode Array System for Neuro-Electrophysiology

    PubMed Central

    Kusko, Mihaela; Craciunoiu, Florea; Amuzescu, Bogdan; Halitzchi, Ferdinand; Selescu, Tudor; Radoi, Antonio; Popescu, Marian; Simion, Monica; Bragaru, Adina; Ignat, Teodora

    2012-01-01

    Recent progress in patterned microelectrode manufacturing technology and microfluidics has opened the way to a large variety of cellular and molecular biosensor-based applications. In this extremely diverse and rapidly expanding landscape, silicon-based technologies occupy a special position, given their statute of mature, consolidated, and highly accessible areas of development. Within the present work we report microfabrication procedures and workflows for 3D patterned gold-plated microelectrode arrays (MEA) of different shapes (pyramidal, conical and high aspect ratio), and we provide a detailed characterization of their physical features during all the fabrication steps to have in the end a reliable technology. Moreover, the electrical performances of MEA silicon chips mounted on standardized connector boards via ultrasound wire-bonding have been tested using non-destructive electrochemical methods: linear sweep and cyclic voltammetry, impedance spectroscopy. Further, an experimental recording chamber package suitable for in vitro electrophysiology experiments has been realized using custom-design electronics for electrical stimulus delivery and local field potential recording, included in a complete electrophysiology setup, and the experimental structures have been tested on newborn rat hippocampal slices, yielding similar performance compared to commercially available MEA equipments. PMID:23208555

  1. Structure, Properties, and In Vitro Behavior of Heat-Treated Calcium Sulfate Scaffolds Fabricated by 3D Printing.

    PubMed

    Asadi-Eydivand, Mitra; Solati-Hashjin, Mehran; Shafiei, Seyedeh Sara; Mohammadi, Sepideh; Hafezi, Masoud; Abu Osman, Noor Azuan

    2016-01-01

    The ability of inkjet-based 3D printing (3DP) to fabricate biocompatible ceramics has made it one of the most favorable techniques to generate bone tissue engineering (BTE) scaffolds. Calcium sulfates exhibit various beneficial characteristics, and they can be used as a promising biomaterial in BTE. However, low mechanical performance caused by the brittle character of ceramic materials is the main weakness of 3DP calcium sulfate scaffolds. Moreover, the presence of certain organic matters in the starting powder and binder solution causes products to have high toxicity levels. A post-processing treatment is usually employed to improve the physical, chemical, and biological behaviors of the printed scaffolds. In this study, the effects of heat treatment on the structural, mechanical, and physical characteristics of 3DP calcium sulfate prototypes were investigated. Different microscopy and spectroscopy methods were employed to characterize the printed prototypes. The in vitro cytotoxicity of the specimens was also evaluated before and after heat treatment. Results showed that the as-printed scaffolds and specimens heat treated at 300°C exhibited severe toxicity in vitro but had almost adequate strength. By contrast, the specimens heat treated in the 500°C-1000°C temperature range, although non-toxic, had insufficient mechanical strength, which was mainly attributed to the exit of the organic binder before 500°C and the absence of sufficient densification below 1000°C. The sintering process was accelerated at temperatures higher than 1000°C, resulting in higher compressive strength and less cytotoxicity. An anhydrous form of calcium sulfate was the only crystalline phase existing in the samples heated at 500°C-1150°C. The formation of calcium oxide caused by partial decomposition of calcium sulfate was observed in the specimens heat treated at temperatures higher than 1200°C. Although considerable improvements in cell viability of heat-treated scaffolds were

  2. Structure, Properties, and In Vitro Behavior of Heat-Treated Calcium Sulfate Scaffolds Fabricated by 3D Printing.

    PubMed

    Asadi-Eydivand, Mitra; Solati-Hashjin, Mehran; Shafiei, Seyedeh Sara; Mohammadi, Sepideh; Hafezi, Masoud; Abu Osman, Noor Azuan

    2016-01-01

    The ability of inkjet-based 3D printing (3DP) to fabricate biocompatible ceramics has made it one of the most favorable techniques to generate bone tissue engineering (BTE) scaffolds. Calcium sulfates exhibit various beneficial characteristics, and they can be used as a promising biomaterial in BTE. However, low mechanical performance caused by the brittle character of ceramic materials is the main weakness of 3DP calcium sulfate scaffolds. Moreover, the presence of certain organic matters in the starting powder and binder solution causes products to have high toxicity levels. A post-processing treatment is usually employed to improve the physical, chemical, and biological behaviors of the printed scaffolds. In this study, the effects of heat treatment on the structural, mechanical, and physical characteristics of 3DP calcium sulfate prototypes were investigated. Different microscopy and spectroscopy methods were employed to characterize the printed prototypes. The in vitro cytotoxicity of the specimens was also evaluated before and after heat treatment. Results showed that the as-printed scaffolds and specimens heat treated at 300°C exhibited severe toxicity in vitro but had almost adequate strength. By contrast, the specimens heat treated in the 500°C-1000°C temperature range, although non-toxic, had insufficient mechanical strength, which was mainly attributed to the exit of the organic binder before 500°C and the absence of sufficient densification below 1000°C. The sintering process was accelerated at temperatures higher than 1000°C, resulting in higher compressive strength and less cytotoxicity. An anhydrous form of calcium sulfate was the only crystalline phase existing in the samples heated at 500°C-1150°C. The formation of calcium oxide caused by partial decomposition of calcium sulfate was observed in the specimens heat treated at temperatures higher than 1200°C. Although considerable improvements in cell viability of heat-treated scaffolds were

  3. Structure, Properties, and In Vitro Behavior of Heat-Treated Calcium Sulfate Scaffolds Fabricated by 3D Printing

    PubMed Central

    Asadi-Eydivand, Mitra; Solati-Hashjin, Mehran; Shafiei, Seyedeh Sara; Mohammadi, Sepideh; Hafezi, Masoud; Abu Osman, Noor Azuan

    2016-01-01

    The ability of inkjet-based 3D printing (3DP) to fabricate biocompatible ceramics has made it one of the most favorable techniques to generate bone tissue engineering (BTE) scaffolds. Calcium sulfates exhibit various beneficial characteristics, and they can be used as a promising biomaterial in BTE. However, low mechanical performance caused by the brittle character of ceramic materials is the main weakness of 3DP calcium sulfate scaffolds. Moreover, the presence of certain organic matters in the starting powder and binder solution causes products to have high toxicity levels. A post-processing treatment is usually employed to improve the physical, chemical, and biological behaviors of the printed scaffolds. In this study, the effects of heat treatment on the structural, mechanical, and physical characteristics of 3DP calcium sulfate prototypes were investigated. Different microscopy and spectroscopy methods were employed to characterize the printed prototypes. The in vitro cytotoxicity of the specimens was also evaluated before and after heat treatment. Results showed that the as-printed scaffolds and specimens heat treated at 300°C exhibited severe toxicity in vitro but had almost adequate strength. By contrast, the specimens heat treated in the 500°C–1000°C temperature range, although non-toxic, had insufficient mechanical strength, which was mainly attributed to the exit of the organic binder before 500°C and the absence of sufficient densification below 1000°C. The sintering process was accelerated at temperatures higher than 1000°C, resulting in higher compressive strength and less cytotoxicity. An anhydrous form of calcium sulfate was the only crystalline phase existing in the samples heated at 500°C–1150°C. The formation of calcium oxide caused by partial decomposition of calcium sulfate was observed in the specimens heat treated at temperatures higher than 1200°C. Although considerable improvements in cell viability of heat-treated scaffolds

  4. A simple strategy to fabricate poly (acrylamide-co-alginate)/gold nanocomposites for inactivation of bacteria

    NASA Astrophysics Data System (ADS)

    Zhang, Yanan; Lou, Zhichao; Zhang, Xiaohong; Hu, Xiaodan; Zhang, Haiqian

    2014-12-01

    A facile and efficient approach to prepare uniform gold nanoparticles (Au NPs) in hybrid hydrogel consisting of acrylamide (AM) and alginate (SA) for antibacterial applications is reported. In this study, reduction of gold ions by acrylamide and alginate (AM-SA) occurred before the polymerization and as-obtained gold colloids are stabilized by AM-SA immediately in the absence of commonly used reducing agents and protective reagents. Via transmittance electron microscopy results, we can conclude that the obtained gold nanoparticles in hydrogel are well dispersed. Furthermore, ultraviolet-visible absorption spectroscopy, Fourier transform infrared and thermogravimetric analysis were used to characterize the structure and composition of the synthetic nanocomposites. Our approach provides well-dispersed nanoparticles around 8 mm in size. It is important to underline that nanoparticle aggregation was not observed during and after gel formation. The prepared Au NPs exhibited remarkable stability in the presence of high pH s, and a range of salt concentrations. Importantly, the hydrogel/gold nanocomposites showed a non-compromised activity to inhibit the growth of a model bacterium, Escherichia coli. With their excellent mechanical behavior, as well as the remained antibacterial activity, the nanocomposites should get various potential applications in the fields of pharmaceutical science and tissue engineering.

  5. Cell-Laden Poly(ɛ-caprolactone)/Alginate Hybrid Scaffolds Fabricated by an Aerosol Cross-Linking Process for Obtaining Homogeneous Cell Distribution: Fabrication, Seeding Efficiency, and Cell Proliferation and Distribution

    PubMed Central

    Lee, HyeongJin; Ahn, SeungHyun; Bonassar, Lawrence J.; Chun, Wook

    2013-01-01

    Generally, solid-freeform fabricated scaffolds show a controllable pore structure (pore size, porosity, pore connectivity, and permeability) and mechanical properties by using computer-aided techniques. Although the scaffolds can provide repeated and appropriate pore structures for tissue regeneration, they have a low biological activity, such as low cell-seeding efficiency and nonuniform cell density in the scaffold interior after a long culture period, due to a large pore size and completely open pores. Here we fabricated three different poly(ɛ-caprolactone) (PCL)/alginate scaffolds: (1) a rapid prototyped porous PCL scaffold coated with an alginate, (2) the same PCL scaffold coated with a mixture of alginate and cells, and (3) a multidispensed hybrid PCL/alginate scaffold embedded with cell-laden alginate struts. The three scaffolds had similar micropore structures (pore size=430–580 μm, porosity=62%–68%, square pore shape). Preosteoblast cells (MC3T3-E1) were used at the same cell density in each scaffold. By measuring cell-seeding efficiency, cell viability, and cell distribution after various periods of culturing, we sought to determine which scaffold was more appropriate for homogeneously regenerated tissues. PMID:23469894

  6. Cell-laden poly(ɛ-caprolactone)/alginate hybrid scaffolds fabricated by an aerosol cross-linking process for obtaining homogeneous cell distribution: fabrication, seeding efficiency, and cell proliferation and distribution.

    PubMed

    Lee, HyeongJin; Ahn, SeungHyun; Bonassar, Lawrence J; Chun, Wook; Kim, GeunHyung

    2013-10-01

    Generally, solid-freeform fabricated scaffolds show a controllable pore structure (pore size, porosity, pore connectivity, and permeability) and mechanical properties by using computer-aided techniques. Although the scaffolds can provide repeated and appropriate pore structures for tissue regeneration, they have a low biological activity, such as low cell-seeding efficiency and nonuniform cell density in the scaffold interior after a long culture period, due to a large pore size and completely open pores. Here we fabricated three different poly(ɛ-caprolactone) (PCL)/alginate scaffolds: (1) a rapid prototyped porous PCL scaffold coated with an alginate, (2) the same PCL scaffold coated with a mixture of alginate and cells, and (3) a multidispensed hybrid PCL/alginate scaffold embedded with cell-laden alginate struts. The three scaffolds had similar micropore structures (pore size = 430-580 μm, porosity = 62%-68%, square pore shape). Preosteoblast cells (MC3T3-E1) were used at the same cell density in each scaffold. By measuring cell-seeding efficiency, cell viability, and cell distribution after various periods of culturing, we sought to determine which scaffold was more appropriate for homogeneously regenerated tissues.

  7. Novel 3D scaffold with enhanced physical and cell response properties for bone tissue regeneration, fabricated by patterned electrospinning/electrospraying.

    PubMed

    Hejazi, Fatemeh; Mirzadeh, Hamid

    2016-09-01

    Developing three dimensional scaffolds mimicking the nanoscale structure of native extracellular matrix is a key parameter in tissue regeneration. In this study, we aimed to introduce a novel 3D structures composed of nanofibers (NF) and micro particles (MP) and compare their efficiency with 2D nanofibrous scaffold. The conventional nanofibrous PCL scaffolds are 2D mats fabricated by the electrospinning technique, whereas the NF/MP and patterned NF/MP PCL scaffolds are three dimensional structures fabricated by a modified electrospinning/electrospraying technique. The mentioned method was carried out by varying the electrospinning solution parameters and use of a metal mesh as the collector. Detailed fabrication process and morphological properties of the fabricated structures is discussed and porosity, pore size and PBS solution absorption value of the prepared structures are reported. Compared with the 2D structure, 3D scaffolds possessed enhanced porosity and pore size which led to the significant increase in their water uptake capacity. In vitro cell experiments were carried out on the prepared structures by the use of MG-63 osteosarcoma cell line. The fabricated 3D structures offered significantly increased cell attachment, spread and diffusion which were confirmed by SEM analysis. In vitro cytocompatibility assessed by MTT colorimetric assay indicated a continuous cell proliferation over 21 days on the innovative 3D structure, while on 2D mat cell proliferation stopped at early time points. Enhanced osteogenic differentiation of the seeded MG-63 cells on 3D scaffold was confirmed by the remarkable ALP activity together with increased and accelerated calcium deposition on this structure compared to 2D mat. Massive and well distributed bone minerals formed on patterned 3D structure were shown by EDX analysis. In comparison between NF/MP quasi-3D and Patterned NF/MP 3D scaffolds, patterned structures proceeded in all of the above properties. As such, the

  8. Novel 3D scaffold with enhanced physical and cell response properties for bone tissue regeneration, fabricated by patterned electrospinning/electrospraying.

    PubMed

    Hejazi, Fatemeh; Mirzadeh, Hamid

    2016-09-01

    Developing three dimensional scaffolds mimicking the nanoscale structure of native extracellular matrix is a key parameter in tissue regeneration. In this study, we aimed to introduce a novel 3D structures composed of nanofibers (NF) and micro particles (MP) and compare their efficiency with 2D nanofibrous scaffold. The conventional nanofibrous PCL scaffolds are 2D mats fabricated by the electrospinning technique, whereas the NF/MP and patterned NF/MP PCL scaffolds are three dimensional structures fabricated by a modified electrospinning/electrospraying technique. The mentioned method was carried out by varying the electrospinning solution parameters and use of a metal mesh as the collector. Detailed fabrication process and morphological properties of the fabricated structures is discussed and porosity, pore size and PBS solution absorption value of the prepared structures are reported. Compared with the 2D structure, 3D scaffolds possessed enhanced porosity and pore size which led to the significant increase in their water uptake capacity. In vitro cell experiments were carried out on the prepared structures by the use of MG-63 osteosarcoma cell line. The fabricated 3D structures offered significantly increased cell attachment, spread and diffusion which were confirmed by SEM analysis. In vitro cytocompatibility assessed by MTT colorimetric assay indicated a continuous cell proliferation over 21 days on the innovative 3D structure, while on 2D mat cell proliferation stopped at early time points. Enhanced osteogenic differentiation of the seeded MG-63 cells on 3D scaffold was confirmed by the remarkable ALP activity together with increased and accelerated calcium deposition on this structure compared to 2D mat. Massive and well distributed bone minerals formed on patterned 3D structure were shown by EDX analysis. In comparison between NF/MP quasi-3D and Patterned NF/MP 3D scaffolds, patterned structures proceeded in all of the above properties. As such, the

  9. Improving stability and biocompatibility of alginate/chitosan microcapsule by fabricating bi-functional membrane.

    PubMed

    Zheng, Guoshuang; Liu, Xiudong; Wang, Xiuli; Chen, Li; Xie, Hongguo; Wang, Feng; Zheng, Huizhen; Yu, Weiting; Ma, Xiaojun

    2014-05-01

    Cell encapsulation technology holds promise for the cell-based therapy. But poor mechanical strength and biocompatibility of microcapsule membrane are still obstacles for the clinical applications. A novel strategy is presented to prepare AC₁ C₂ A microcapsules with bi-functional membrane (that is, both desirable biocompatibility and membrane stability) by sequentially complexing chitosans with higher deacetylation degree (C₁) and lower deacetylation degree (C₂) on alginate (A) gel beads. Both in vitro and in vivo evaluation of AC₁C₂ A microcapsules demonstrate higher membrane stability and less cell adhesion, because the introduction of C₂ increases membrane strength and decreases surface roughness. Moreover, diffusion test of AC₁C₂ A microcapsules displays no inward permeation of IgG protein suggesting good immunoisolation function. The results demonstrate that AC₁C₂ A microcapsules with bi-functional membrane could be a promising candidate for microencapsulated cell implantation with cost effective usage of naturally biocompatible polysaccharides.

  10. Fabrication of Highly Stretchable Conductors Based on 3D Printed Porous Poly(dimethylsiloxane) and Conductive Carbon Nanotubes/Graphene Network.

    PubMed

    Duan, Shasha; Yang, Ke; Wang, Zhihui; Chen, Mengting; Zhang, Ling; Zhang, Hongbo; Li, Chunzhong

    2016-01-27

    The combination of carbon nanomaterial with three-dimensional (3D) porous polymer substrates has been demonstrated to be an effective approach to manufacture high-performance stretchable conductive materials (SCMs). However, it remains a challenge to fabricate 3D-structured SCMs with outstanding electrical conductivity capability under large strain in a facile way. In this work, the 3D printing technique was employed to prepare 3D porous poly(dimethylsiloxane) (O-PDMS) which was then integrated with carbon nanotubes and graphene conductive network and resulted in highly stretchable conductors (OPCG). Two types of OPCG were prepared, and it has been demonstrated that the OPCG with split-level structure exhibited both higher electrical conductivity and superior retention capability under deformations, which was illustrated by using a finite element method. The specially designed split-level OPCG is capable of sustaining both large strain and repeated deformations showing huge potential in the application of next-generation stretchable electronics.

  11. Microstructure and Properties of DCP-Derived W-ZrC Composite Using Nontoxic Sodium Alginate to Fabricate WC Preform

    NASA Astrophysics Data System (ADS)

    Najafzadeh Khoee, Ali Asghar; Habibolahzadeh, Ali; Qods, Fathallah; Baharvandi, Hamidreza

    2015-04-01

    In the present work, tungsten carbide (WC) preforms were fabricated by gel-casting process, using different nontoxic Na-alginate to tertiary calcium phosphate ratios and different loadings of WC powder in the initial slurries. The gel-cast green bodies were dried and pre-sintered at 1723 K for 4 h and then reactively infiltrated by molten Zr2Cu at 1623 K for 0.5 h, to produce W-ZrC composite via displacive compensation of porosity process. The phases, microstructures, and mechanical properties of the preforms and the W-ZrC composites were investigated by Fourier transform infrared spectroscope, x-ray diffractometer (XRD), scanning electron microscope (SEM), image analyzer, and universal mechanical testing machine. XRD results, SEM micrographs, and elemental maps indicated uniform distribution of phases (W and ZrC) and elements (W, Zr, and C). Flexural strengths and hardness of the fabricated composites were in the ranges of 429-460 MPa and 7.5-9.5 GPa, respectively. Fractography studies revealed two types of dimple rupture and cleavage fracture modes in different composite samples. The W-ZrC composite was ablated by an oxyacetylene flame for 60 s. The mean value of mass and linear ablation rates of the composite were 2.1 ± 0.1 mg/s and 3.6 ± 0.5 µm/s, respectively.

  12. Double-Network Hydrogel with Tunable Mechanical Performance and Biocompatibility for the Fabrication of Stem Cells-Encapsulated Fibers and 3D Assemble.

    PubMed

    Liang, Zhe; Liu, Chenguang; Li, Lili; Xu, Peidi; Luo, Guoan; Ding, Mingyu; Liang, Qionglin

    2016-01-01

    Fabrication of cell-encapsulated fibers could greatly contribute to tissue engineering and regenerative medicine. However, existing methods suffered from not only unavoidability of cell damaging conditions and/or sophisticated equipment, but also unavailability of proper materials to satisfy both mechanical and biological expectations. In this work, a simple method is proposed to prepare cell-encapsulated fibers with tunable mechanical strength and stretching behavior as well as diameter and microstructure. The hydrogel fibers are made from optimal combination of alginate and poly(N-iso-propylacrylamide)-poly(ethylene glycol), characteristics of double-network hydrogel, with enough stiffness and flexibility to create a variety of three dimensional structures like parallel helical and different knots without crack. Furthermore, such hydrogel fibers exhibit better compatibility as indicated by the viability, proliferation and expression of pluripotency markers of embryonic stem cells encapsulated after 4-day culture. The double-network hydrogel possesses specific quick responses to either of alginate lyase, EDTA or lower environmental temperature which facilitate the optional degradation of fibers or fibrous assemblies to release the cells encapsulated for subsequent assay or treatment. PMID:27628933

  13. Double-Network Hydrogel with Tunable Mechanical Performance and Biocompatibility for the Fabrication of Stem Cells-Encapsulated Fibers and 3D Assemble

    PubMed Central

    Liang, Zhe; Liu, Chenguang; Li, Lili; Xu, Peidi; Luo, Guoan; Ding, Mingyu; Liang, Qionglin

    2016-01-01

    Fabrication of cell-encapsulated fibers could greatly contribute to tissue engineering and regenerative medicine. However, existing methods suffered from not only unavoidability of cell damaging conditions and/or sophisticated equipment, but also unavailability of proper materials to satisfy both mechanical and biological expectations. In this work, a simple method is proposed to prepare cell-encapsulated fibers with tunable mechanical strength and stretching behavior as well as diameter and microstructure. The hydrogel fibers are made from optimal combination of alginate and poly(N-iso-propylacrylamide)-poly(ethylene glycol), characteristics of double-network hydrogel, with enough stiffness and flexibility to create a variety of three dimensional structures like parallel helical and different knots without crack. Furthermore, such hydrogel fibers exhibit better compatibility as indicated by the viability, proliferation and expression of pluripotency markers of embryonic stem cells encapsulated after 4-day culture. The double-network hydrogel possesses specific quick responses to either of alginate lyase, EDTA or lower environmental temperature which facilitate the optional degradation of fibers or fibrous assemblies to release the cells encapsulated for subsequent assay or treatment. PMID:27628933

  14. Laser Scanning Holographic Lithography for Flexible 3D Fabrication of Multi-Scale Integrated Nano-structures and Optical Biosensors.

    PubMed

    Yuan, Liang Leon; Herman, Peter R

    2016-01-01

    Three-dimensional (3D) periodic nanostructures underpin a promising research direction on the frontiers of nanoscience and technology to generate advanced materials for exploiting novel photonic crystal (PC) and nanofluidic functionalities. However, formation of uniform and defect-free 3D periodic structures over large areas that can further integrate into multifunctional devices has remained a major challenge. Here, we introduce a laser scanning holographic method for 3D exposure in thick photoresist that combines the unique advantages of large area 3D holographic interference lithography (HIL) with the flexible patterning of laser direct writing to form both micro- and nano-structures in a single exposure step. Phase mask interference patterns accumulated over multiple overlapping scans are shown to stitch seamlessly and form uniform 3D nanostructure with beam size scaled to small 200 μm diameter. In this way, laser scanning is presented as a facile means to embed 3D PC structure within microfluidic channels for integration into an optofluidic lab-on-chip, demonstrating a new laser HIL writing approach for creating multi-scale integrated microsystems.

  15. Laser Scanning Holographic Lithography for Flexible 3D Fabrication of Multi-Scale Integrated Nano-structures and Optical Biosensors

    NASA Astrophysics Data System (ADS)

    Yuan, Liang (Leon); Herman, Peter R.

    2016-02-01

    Three-dimensional (3D) periodic nanostructures underpin a promising research direction on the frontiers of nanoscience and technology to generate advanced materials for exploiting novel photonic crystal (PC) and nanofluidic functionalities. However, formation of uniform and defect-free 3D periodic structures over large areas that can further integrate into multifunctional devices has remained a major challenge. Here, we introduce a laser scanning holographic method for 3D exposure in thick photoresist that combines the unique advantages of large area 3D holographic interference lithography (HIL) with the flexible patterning of laser direct writing to form both micro- and nano-structures in a single exposure step. Phase mask interference patterns accumulated over multiple overlapping scans are shown to stitch seamlessly and form uniform 3D nanostructure with beam size scaled to small 200 μm diameter. In this way, laser scanning is presented as a facile means to embed 3D PC structure within microfluidic channels for integration into an optofluidic lab-on-chip, demonstrating a new laser HIL writing approach for creating multi-scale integrated microsystems.

  16. Laser Scanning Holographic Lithography for Flexible 3D Fabrication of Multi-Scale Integrated Nano-structures and Optical Biosensors

    PubMed Central

    Yuan, Liang (Leon); Herman, Peter R.

    2016-01-01

    Three-dimensional (3D) periodic nanostructures underpin a promising research direction on the frontiers of nanoscience and technology to generate advanced materials for exploiting novel photonic crystal (PC) and nanofluidic functionalities. However, formation of uniform and defect-free 3D periodic structures over large areas that can further integrate into multifunctional devices has remained a major challenge. Here, we introduce a laser scanning holographic method for 3D exposure in thick photoresist that combines the unique advantages of large area 3D holographic interference lithography (HIL) with the flexible patterning of laser direct writing to form both micro- and nano-structures in a single exposure step. Phase mask interference patterns accumulated over multiple overlapping scans are shown to stitch seamlessly and form uniform 3D nanostructure with beam size scaled to small 200 μm diameter. In this way, laser scanning is presented as a facile means to embed 3D PC structure within microfluidic channels for integration into an optofluidic lab-on-chip, demonstrating a new laser HIL writing approach for creating multi-scale integrated microsystems. PMID:26922872

  17. Large Area 2D and 3D Colloidal Photonic Crystals Fabricated by a Roll-to-Roll Langmuir-Blodgett Method.

    PubMed

    Parchine, Mikhail; McGrath, Joe; Bardosova, Maria; Pemble, Martyn E

    2016-06-14

    We present our results on the fabrication of large area colloidal photonic crystals on flexible poly(ethylene terephthalate) (PET) film using a roll-to-roll Langmuir-Blodgett technique. Two-dimensional (2D) and three-dimensional (3D) colloidal photonic crystals from silica nanospheres (250 and 550 nm diameter) with a total area of up to 340 cm(2) have been fabricated in a continuous manner compatible with high volume manufacturing. In addition, the antireflective properties and structural integrity of the films have been enhanced via the use of a second roll-to-roll process, employing a slot-die coating of an optical adhesive over the photonic crystal films. Scanning electron microscopy images, atomic force microscopy images, and UV-vis optical transmission and reflection spectra of the fabricated photonic crystals are analyzed. This analysis confirms the high quality of the 2D and 3D photonic crystals fabricated by the roll-to-roll LB technique. Potential device applications of the large area 2D and 3D colloidal photonic crystals on flexible PET film are briefly reviewed. PMID:27218474

  18. Large Area 2D and 3D Colloidal Photonic Crystals Fabricated by a Roll-to-Roll Langmuir-Blodgett Method.

    PubMed

    Parchine, Mikhail; McGrath, Joe; Bardosova, Maria; Pemble, Martyn E

    2016-06-14

    We present our results on the fabrication of large area colloidal photonic crystals on flexible poly(ethylene terephthalate) (PET) film using a roll-to-roll Langmuir-Blodgett technique. Two-dimensional (2D) and three-dimensional (3D) colloidal photonic crystals from silica nanospheres (250 and 550 nm diameter) with a total area of up to 340 cm(2) have been fabricated in a continuous manner compatible with high volume manufacturing. In addition, the antireflective properties and structural integrity of the films have been enhanced via the use of a second roll-to-roll process, employing a slot-die coating of an optical adhesive over the photonic crystal films. Scanning electron microscopy images, atomic force microscopy images, and UV-vis optical transmission and reflection spectra of the fabricated photonic crystals are analyzed. This analysis confirms the high quality of the 2D and 3D photonic crystals fabricated by the roll-to-roll LB technique. Potential device applications of the large area 2D and 3D colloidal photonic crystals on flexible PET film are briefly reviewed.

  19. Electrohydrodynamic jet process for pore-structure-controlled 3D fibrous architecture as a tissue regenerative material: fabrication and cellular activities.

    PubMed

    Kim, Min Seong; Kim, GeunHyung

    2014-07-22

    In this study, we propose a new scaffold fabrication method, "direct electro-hydrodynamic jet process," using the initial jet of an electrospinning process and ethanol media as a target. The fabricated three-dimensional (3D) fibrous structure was configured with multilayered microsized struts consisting of randomly entangled micro/nanofibrous architecture, similar to that of native extracellular matrixes. The fabrication of the structure was highly dependent on various processing parameters, such as the surface tension of the target media, and the flow rate and weight fraction of the polymer solution. As a tissue regenerative material, the 3D fibrous scaffold was cultured with preosteoblasts to observe the initial cellular activities in comparison with a solid-freeform fabricated 3D scaffold sharing a similar structural geometry. The cell-culture results showed that the newly developed scaffold provided outstanding microcellular environmental conditions to the seeded cells (about 3.5-fold better initial cell attachment and 2.1-fold better cell proliferation).

  20. An additive manufacturing-based PCL-alginate-chondrocyte bioprinted scaffold for cartilage tissue engineering.

    PubMed

    Kundu, Joydip; Shim, Jin-Hyung; Jang, Jinah; Kim, Sung-Won; Cho, Dong-Woo

    2015-11-01

    Regenerative medicine is targeted to improve, restore or replace damaged tissues or organs using a combination of cells, materials and growth factors. Both tissue engineering and developmental biology currently deal with the process of tissue self-assembly and extracellular matrix (ECM) deposition. In this investigation, additive manufacturing (AM) with a multihead deposition system (MHDS) was used to fabricate three-dimensional (3D) cell-printed scaffolds using layer-by-layer (LBL) deposition of polycaprolactone (PCL) and chondrocyte cell-encapsulated alginate hydrogel. Appropriate cell dispensing conditions and optimum alginate concentrations for maintaining cell viability were determined. In vitro cell-based biochemical assays were performed to determine glycosaminoglycans (GAGs), DNA and total collagen contents from different PCL-alginate gel constructs. PCL-alginate gels containing transforming growth factor-β (TGFβ) showed higher ECM formation. The 3D cell-printed scaffolds of PCL-alginate gel were implanted in the dorsal subcutaneous spaces of female nude mice. Histochemical [Alcian blue and haematoxylin and eosin (H&E) staining] and immunohistochemical (type II collagen) analyses of the retrieved implants after 4 weeks revealed enhanced cartilage tissue and type II collagen fibril formation in the PCL-alginate gel (+TGFβ) hybrid scaffold. In conclusion, we present an innovative cell-printed scaffold for cartilage regeneration fabricated by an advanced bioprinting technology.

  1. SU-E-J-49: Design and Fabrication of Custom 3D Printed Phantoms for Radiation Therapy Research and Quality Assurance

    SciTech Connect

    Jenkins, C; Xing, L

    2015-06-15

    Purpose The rapid proliferation of affordable 3D printing techniques has enabled the custom fabrication of items ranging from paper weights to medical implants. This study investigates the feasibility of utilizing the technology for developing novel phantoms for use in radiation therapy quality assurance (QA) procedures. Methods A phantom for measuring the geometric parameters of linear accelerator (LINAC) on-board imaging (OBI) systems was designed using SolidWorks. The design was transferred to a 3D printer and fabricated using a fused deposition modeling (FDM) technique. Fiducials were embedded in the phantom by placing 1.6 mm diameter steel balls in predefined holes and securing them with silicone. Several MV and kV images of the phantom were collected and the visibility and geometric accuracy were evaluated. A second phantom, for use in the experimental evaluation of a high dose rate (HDR) brachytherapy dosimeter, was designed to secure several applicator needles in water. The applicator was fabricated in the same 3D printer and used for experiments. Results The general accuracy of printed parts was determined to be 0.1 mm. The cost of materials for the imaging and QA phantoms were $22 and $5 respectively. Both the plastic structure and fiducial markers of the imaging phantom were visible in MV and kV images. Fiducial marker locations were determined to be within 1mm of desired locations, with the discrepancy being attributed to the fiducial attachment process. The HDR phantom secured the applicators within 0.5 mm of the desired locations. Conclusion 3D printing offers an inexpensive method for fabricating custom phantoms for use in radiation therapy quality assurance. While the geometric accuracy of such parts is limited compared to more expensive methods, the phantoms are still highly functional and provide a unique opportunity for rapid fabrication of custom phantoms for use in radiation therapy QA and research.

  2. Surface Modification and Characterisation of Silk Fibroin Fabric Produced by the Layer-by-Layer Self-Assembly of Multilayer Alginate/Regenerated Silk Fibroin

    PubMed Central

    Shen, Gaotian; Hu, Xingyou; Guan, Guoping; Wang, Lu

    2015-01-01

    Silk-based medical products have a long history of use as a material for surgical sutures because of their desirable mechanical properties. However, silk fibroin fabric has been reported to be haemolytic when in direct contact with blood. The layer-by-layer self-assembly technique provides a method for surface modification to improve the biocompatibility of silk fibroin fabrics. Regenerated silk fibroin and alginate, which have excellent biocompatibility and low immunogenicity, are outstanding candidates for polyelectrolyte deposition. In this study, silk fabric was degummed and positively charged to create a silk fibroin fabric that could undergo self-assembly. The multilayer self-assembly of the silk fibroin fabric was achieved by alternating the polyelectrolyte deposition of a negatively charged alginate solution (pH = 8) and a positively charged regenerated silk fibroin solution (pH = 2). Finally, the negatively charged regenerated silk fibroin solution (pH = 8) was used to assemble the outermost layer of the fabric so that the surface would be negatively charged. A stable structural transition was induced using 75% ethanol. The thickness and morphology were characterised using atomic force microscopy. The properties of the self-assembled silk fibroin fabric, such as the bursting strength, thermal stability and flushing stability, indicated that the fabric was stable. In addition, the cytocompatibility and haemocompatibility of the self-assembled silk fibroin fabrics were evaluated. The results indicated that the biocompatibility of the self-assembled multilayers was acceptable and that it improved markedly. In particular, after the self-assembly, the fabric was able to prevent platelet adhesion. Furthermore, other non-haemolytic biomaterials can be created through self-assembly of more than 1.5 bilayers, and we propose that self-assembled silk fibroin fabric may be an attractive candidate for anticoagulation applications and for promoting endothelial cell

  3. Fabrication of 3D Printed Metal Structures by Use of High-Viscosity Cu Paste and a Screw Extruder

    NASA Astrophysics Data System (ADS)

    Hong, Seongik; Sanchez, Cesar; Du, Hanuel; Kim, Namsoo

    2015-03-01

    Three-dimensional (3D) printing is an important, rapidly growing industry. However, traditional 3D printing technology has problems with some materials. To solve the problem of the limited number of 3D-printable materials, high-viscosity materials and a new method for 3D printing were investigated. As an example of a high-viscosity material, Cu paste was synthesized and a screw extruder printer was developed to print the paste. As a fundamental part of the research, the viscosity of the Cu paste was measured for different Cu content. The viscosity of the paste increased with increasing Cu content. To print high-viscosity Cu paste, printing conditions were optimized. 3D structures were printed, by use of an extruder and high-viscosity metal paste with appropriate printing conditions, and then heat treated. After sintering, however, approximately 75% shrinkage of the final product was observed. To achieve less shrinkage, the packing factor of the Cu paste was increased by adding more Cu particles. The shrinkage factor decreased as the packing factor increased, and the size of final product was 77% of that expected.

  4. Microfluidic vascular channels in gels using commercial 3D printers

    NASA Astrophysics Data System (ADS)

    Selvaganapathy, P. Ravi; Attalla, Rana

    2016-03-01

    This paper details the development of a three dimensional (3D) printing system with a modified microfluidic printhead used for the generation of complex vascular tissue scaffolds. The print-head features an integrated coaxial nozzle that allows the fabrication of hollow, calcium-polymerized alginate tubes that can easily be patterned using 3Dbioprinting techniques. This microfluidic design allows the incorporation of a wide range of scaffold materials as well as biological constituents such as cells, growth factors, and ECM material. With this setup, gel constructs with embedded arrays of hollow channels can be created and used as a potential substitute for blood vessel networks.

  5. Carbon cladded TiO2 nanotubes: fabrication and use in 3D-RuO2 based supercapacitors.

    PubMed

    Gao, Zhi-Da; Zhu, Xu; Li, Ya-Hang; Zhou, Xuemei; Song, Yan-Yan; Schmuki, Patrik

    2015-05-01

    In this work we introduce a facile procedure that allows a highly conformal coating of self-organized TiO2 nanotubes (NTs) with a graphite-like thin carbon layer. This provides a platform to enhance the functionality of TiO2 nanotubes for a wide range of applications. Here we show that such modified nanotubes can serve as a 3D scaffold for an ideal decoration with RuO2 nanoparticles. Used as 3D pseudocapacitor electrode, capacitance values of up to 80 times higher than plain TiO2 NTs, and a very high yield of utilization of RuO2 (872 F g(-1)) and excellent long-term cycling stability can be reached. PMID:25848658

  6. Engineering Multi-scale Electrospun Structure for Integration into Architected 3-D Nanofibers for Cimex Annihilation: Fabrication and Mechanism Study

    NASA Astrophysics Data System (ADS)

    He, Shan; Zhang, Linxi; Liu, Ying; Rafailovich, Miriam; Garcia CenterPolymers at Engineered Interfaces Team

    In this study, engineered electrospun scaffolds with fibers oriented with designed curvature in three dimensions (3D) including the looped structure were developed based on the principle of electrostatic repulsion. Here we illustrate that 3D electrospun recycled polystyrene fibers could closely mimic the unique architectures of multi-direction and multi-layer nano-spiderweb. In contrast to virgin PS, the recycled PS (Dart Styrofoam) are known to contain zinc stearate which acts as a surfactant resulting in higher electrical charge and larger fiber curvature, hence, lower modulus. The surfactant, which is known to decrease the surface tension, may have also been effective at decreasing the confinement of the PS, where chain stretching was shown to occur, in response to the high surface tension at the air interface. Three dimensional flexible architecture with complex structures are shown to be necessary in order to block the motion of Cimex lectularius. Here we show how an engineered electrospun network of surfactant modified polymer fibers with calculated dimensions can be used to immobilize the insects. The mechanical response of the fibers has to be specifically tailored so that it is elastically deformed, without fracturing or flowing. Carefully controlling and tailoring the electrospinning parameters we can now utilize architected 3D nanofiber to create an environmental-friendly Cimex immobilization device which can lead to annihilation solution for all the other harmful insects.

  7. Custom fabrication of biomass containment devices using 3-D printing enables bacterial growth analyses with complex insoluble substrates

    DOE PAGES

    Nelson, Cassandra E.; Beri, Nina R.; Gardner, Jeffrey G.

    2016-09-21

    Physiological studies of recalcitrant polysaccharide degradation are challenging for several reasons, one of which is the difficulty in obtaining a reproducibly accurate real-time measurement of bacterial growth using insoluble substrates. Current methods suffer from several problems including (i) high background noise due to the insoluble material interspersed with cells, (ii) high consumable and reagent cost and (iii) significant time delay between sampling and data acquisition. A customizable substrate and cell separation device would provide an option to study bacterial growth using optical density measurements. To test this hypothesis we used 3-D printing to create biomass containment devices that allow interactionmore » between insoluble substrates and microbial cells but do not interfere with spectrophotometer measurements. Evaluation of materials available for 3-D printing indicated that UV-cured acrylic plastic was the best material, being superior to nylon or stainless steel when examined for heat tolerance, reactivity, and ability to be sterilized. Cost analysis of the 3-D printed devices indicated they are a competitive way to quantitate bacterial growth compared to viable cell counting or protein measurements, and experimental conditions were scalable over a 100-fold range. The presence of the devices did not alter growth phenotypes when using either soluble substrates or insoluble substrates. Furthermore, we applied biomass containment to characterize growth of Cellvibrio japonicus on authentic lignocellulose (non-pretreated corn stover), and found physiological evidence that xylan is a significant nutritional source despite an abundance of cellulose present.« less

  8. 3D porous and ultralight carbon hybrid nanostructure fabricated from carbon foam covered by monolayer of nitrogen-doped carbon nanotubes for high performance supercapacitors

    NASA Astrophysics Data System (ADS)

    He, Shuijian; Hou, Haoqing; Chen, Wei

    2015-04-01

    3D porous and self-supported carbon hybrids are promising electrode materials for supercapacitor application attributed to their prominent properties such as binder-free electrode fabrication process, excellent electric conductivity and high power density etc. We present here a facile chemical vapor deposition method to fabricate a novel 3D flexible carbon hybrid nanostructure by growing a monolayer of nitrogen-doped carbon nanotubes on the skeleton of carbon foam (N-CNTs/CF) with Fe nanoparticle as catalyst. With such 3D porous, flexible and ultralight carbon nanostructure as binder-free electrode material, large surface area is available and fast ionic transport is facilitated. Moreover, the carbon-based network can provide excellent electronic conductivity. The electrochemical studies demonstrate that the supercapacitor constructed from the N-CNTs/CF hybrid exhibit high power density of 69.3 kW kg-1 and good stability with capacitance retention ration above 95% after cycled at 50 A g-1 for 5000 cycles. Therefore, the prepared porous N-CNTs/CF nanostructure is expected to be a type of excellent electrode material for electrical double layer capacitors.

  9. Developing an Ear Prosthesis Fabricated in Polyvinylidene Fluoride by a 3D Printer with Sensory Intrinsic Properties of Pressure and Temperature.

    PubMed

    Suaste-Gómez, Ernesto; Rodríguez-Roldán, Grissel; Reyes-Cruz, Héctor; Terán-Jiménez, Omar

    2016-03-04

    An ear prosthesis was designed in 3D computer graphics software and fabricated using a 3D printing process of polyvinylidene fluoride (PVDF) for use as a hearing aid. In addition, the prosthesis response to pressure and temperature was observed. Pyroelectric and piezoelectric properties of this ear prosthesis were investigated using an astable multivibrator circuit, as changes in PVDF permittivity were observed according to variations of pressure and temperature. The results show that this prosthesis is reliable for use under different conditions of pressure (0 Pa to 16,350 Pa) and temperature (2 °C to 90 °C). The experimental results show an almost linear and inversely proportional behavior between the stimuli of pressure and temperature with the frequency response. This 3D-printed ear prosthesis is a promising tool and has a great potentiality in the biomedical engineering field because of its ability to generate an electrical potential proportional to pressure and temperature, and it is the first time that such a device has been processed by the additive manufacturing process (3D printing). More work needs to be carried out to improve the performance, such as electrical stimulation of the nervous system, thereby extending the purpose of a prosthesis to the area of sensory perception.

  10. Developing an Ear Prosthesis Fabricated in Polyvinylidene Fluoride by a 3D Printer with Sensory Intrinsic Properties of Pressure and Temperature.

    PubMed

    Suaste-Gómez, Ernesto; Rodríguez-Roldán, Grissel; Reyes-Cruz, Héctor; Terán-Jiménez, Omar

    2016-01-01

    An ear prosthesis was designed in 3D computer graphics software and fabricated using a 3D printing process of polyvinylidene fluoride (PVDF) for use as a hearing aid. In addition, the prosthesis response to pressure and temperature was observed. Pyroelectric and piezoelectric properties of this ear prosthesis were investigated using an astable multivibrator circuit, as changes in PVDF permittivity were observed according to variations of pressure and temperature. The results show that this prosthesis is reliable for use under different conditions of pressure (0 Pa to 16,350 Pa) and temperature (2 °C to 90 °C). The experimental results show an almost linear and inversely proportional behavior between the stimuli of pressure and temperature with the frequency response. This 3D-printed ear prosthesis is a promising tool and has a great potentiality in the biomedical engineering field because of its ability to generate an electrical potential proportional to pressure and temperature, and it is the first time that such a device has been processed by the additive manufacturing process (3D printing). More work needs to be carried out to improve the performance, such as electrical stimulation of the nervous system, thereby extending the purpose of a prosthesis to the area of sensory perception. PMID:26959026

  11. A synergistic approach to the design, fabrication and evaluation of 3D printed micro and nano featured scaffolds for vascularized bone tissue repair

    NASA Astrophysics Data System (ADS)

    Holmes, Benjamin; Bulusu, Kartik; Plesniak, Michael; Zhang, Lijie Grace

    2016-02-01

    3D bioprinting has begun to show great promise in advancing the development of functional tissue/organ replacements. However, to realize the true potential of 3D bioprinted tissues for clinical use requires the fabrication of an interconnected and effective vascular network. Solving this challenge is critical, as human tissue relies on an adequate network of blood vessels to transport oxygen, nutrients, other chemicals, biological factors and waste, in and out of the tissue. Here, we have successfully designed and printed a series of novel 3D bone scaffolds with both bone formation supporting structures and highly interconnected 3D microvascular mimicking channels, for efficient and enhanced osteogenic bone regeneration as well as vascular cell growth. Using a chemical functionalization process, we have conjugated our samples with nano hydroxyapatite (nHA), for the creation of novel micro and nano featured devices for vascularized bone growth. We evaluated our scaffolds with mechanical testing, hydrodynamic measurements and in vitro human mesenchymal stem cell (hMSC) adhesion (4 h), proliferation (1, 3 and 5 d) and osteogenic differentiation (1, 2 and 3 weeks). These tests confirmed bone-like physical properties and vascular-like flow profiles, as well as demonstrated enhanced hMSC adhesion, proliferation and osteogenic differentiation. Additional in vitro experiments with human umbilical vein endothelial cells also demonstrated improved vascular cell growth, migration and organization on micro-nano featured scaffolds.

  12. Developing an Ear Prosthesis Fabricated in Polyvinylidene Fluoride by a 3D Printer with Sensory Intrinsic Properties of Pressure and Temperature

    PubMed Central

    Suaste-Gómez, Ernesto; Rodríguez-Roldán, Grissel; Reyes-Cruz, Héctor; Terán-Jiménez, Omar

    2016-01-01

    An ear prosthesis was designed in 3D computer graphics software and fabricated using a 3D printing process of polyvinylidene fluoride (PVDF) for use as a hearing aid. In addition, the prosthesis response to pressure and temperature was observed. Pyroelectric and piezoelectric properties of this ear prosthesis were investigated using an astable multivibrator circuit, as changes in PVDF permittivity were observed according to variations of pressure and temperature. The results show that this prosthesis is reliable for use under different conditions of pressure (0 Pa to 16,350 Pa) and temperature (2 °C to 90 °C). The experimental results show an almost linear and inversely proportional behavior between the stimuli of pressure and temperature with the frequency response. This 3D-printed ear prosthesis is a promising tool and has a great potentiality in the biomedical engineering field because of its ability to generate an electrical potential proportional to pressure and temperature, and it is the first time that such a device has been processed by the additive manufacturing process (3D printing). More work needs to be carried out to improve the performance, such as electrical stimulation of the nervous system, thereby extending the purpose of a prosthesis to the area of sensory perception. PMID:26959026

  13. Hierarchical fabrication of heterojunctioned SrTiO3/TiO2 nanotubes on 3D microporous Ti substrate with enhanced photocatalytic activity and adhesive strength

    NASA Astrophysics Data System (ADS)

    Zhou, Jie; Yin, Lu; Zha, Kang; Li, Huirong; Liu, Zhiyuan; Wang, Jianxin; Duan, Ke; Feng, Bo

    2016-03-01

    Recently, construction of three-dimensional (3D) architecture and design of heterostructure have been proved to be two important approaches for improving photocatalytic (PC) properties of TiO2-based catalysts. In this work, a 3D microporous surface on Ti substrate (MPT) was prepared by simple acid etching. Then, heterojunctioned SrTiO3/TiO2 nanotubes with dominant {001} facets of anatase TiO2were successfully fabricated on MPT by combining anodization with hydrothermal treatment. The 3D microporous-patterned SrTiO3/TiO2 nanotubes heterojunction shows significantly enhanced photo-current density and ∼200% improved PC effect in degradation of Rhodamine B owing to its higher specific surface area, stronger light-harvesting ability and positive heterojunction effect in comparison with TiO2 nanotubes formed on flat Ti substrate. Moreover, the 3D microporous structure on Ti substrate improved the adhesive strength between the nanotubes layer and Ti substrate, which can be ascribed to the effective release of internal stress. Therefore, this present strategy is expected to expand the application of TiO2-based catalysts in many fields which require excellent PC properties and mechanical stability.

  14. A synergistic approach to the design, fabrication and evaluation of 3D printed micro and nano featured scaffolds for vascularized bone tissue repair

    PubMed Central

    Holmes, Benjamin; Bulusu, Kartik; Plesniak, Michael; Zhang, Lijie Grace

    2016-01-01

    3D bioprinting has begun to show great promise in advancing the development of functional tissue/organ replacements. However, to realize the true potential of 3D bioprinted tissues for clinical use requires the fabrication of an interconnected and effective vascular network. Solving this challenge is critical, as human tissue relies on an adequate network of blood vessels to transport oxygen, nutrients, other chemicals, biological factors and waste, in and out of the tissue. Here, we have successfully designed and printed a series of novel 3D bone scaffolds with both bone formation supporting structures and highly interconnected 3D microvascular mimicking channels, for efficient and enhanced osteogenic bone regeneration as well as vascular cell growth. Using a chemical functionalization process, we have conjugated our samples with nano hydroxyapatite (nHA), for the creation of novel micro and nano featured devices for vascularized bone growth. We evaluated our scaffolds with mechanical testing, hydrodynamic measurements and in vitro human mesenchymal stem cell (hMSC) adhesion (4 h), proliferation (1, 3 and 5 d) and osteogenic differentiation (1, 2 and 3 weeks). These tests confirmed bone-like physical properties and vascular-like flow profiles, as well as demonstrated enhanced hMSC adhesion, proliferation and osteogenic differentiation. Additional in vitro experiments with human umbilical vein endothelial cells also demonstrated improved vascular cell growth, migration and organization on micro-nano featured scaffolds. PMID:26758780

  15. A synergistic approach to the design, fabrication and evaluation of 3D printed micro and nano featured scaffolds for vascularized bone tissue repair.

    PubMed

    Holmes, Benjamin; Bulusu, Kartik; Plesniak, Michael; Zhang, Lijie Grace

    2016-02-12

    3D bioprinting has begun to show great promise in advancing the development of functional tissue/organ replacements. However, to realize the true potential of 3D bioprinted tissues for clinical use requires the fabrication of an interconnected and effective vascular network. Solving this challenge is critical, as human tissue relies on an adequate network of blood vessels to transport oxygen, nutrients, other chemicals, biological factors and waste, in and out of the tissue. Here, we have successfully designed and printed a series of novel 3D bone scaffolds with both bone formation supporting structures and highly interconnected 3D microvascular mimicking channels, for efficient and enhanced osteogenic bone regeneration as well as vascular cell growth. Using a chemical functionalization process, we have conjugated our samples with nano hydroxyapatite (nHA), for the creation of novel micro and nano featured devices for vascularized bone growth. We evaluated our scaffolds with mechanical testing, hydrodynamic measurements and in vitro human mesenchymal stem cell (hMSC) adhesion (4 h), proliferation (1, 3 and 5 d) and osteogenic differentiation (1, 2 and 3 weeks). These tests confirmed bone-like physical properties and vascular-like flow profiles, as well as demonstrated enhanced hMSC adhesion, proliferation and osteogenic differentiation. Additional in vitro experiments with human umbilical vein endothelial cells also demonstrated improved vascular cell growth, migration and organization on micro-nano featured scaffolds.

  16. Fabrication of high sensitivity 3D nanoSQUIDs based on a focused ion beam sculpting technique

    NASA Astrophysics Data System (ADS)

    De Leo, Natascia; Fretto, Matteo; Lacquaniti, Vincenzo; Granata, Carmine; Vettoliere, Antonio

    2016-09-01

    In this paper a nanofabrication process, based on a focused ion beam (FIB) nanosculpting technique, for high sensitivity three-dimensional nanoscale superconducting quantum interference devices (nanoSQUIDs) is reported. The crucial steps of the fabrication process are described, as are some peculiar features of the superconductor-normal metal-insulator-superconductor (SNIS) Josephson junctions, which may useful for applications in cryocooler systems. This fabrication procedure is employed to fabricate sandwich nanojunctions and high sensitivity nanoSQUIDs. Specifically, the superconductive nanosensors have a rectangular loop of 1 × 0.2-0.4 μm2 interrupted by two square Nb/Al-AlO x /Nb SNIS Josephson junctions with side lengths of 0.3 μm. The characterization of a typical nanoSQUID has been carried out and a spectral density of magnetic flux noise as low as 0.8 μΦ0 Hz-1/2 has been measured.

  17. Fabrication of high sensitivity 3D nanoSQUIDs based on a focused ion beam sculpting technique

    NASA Astrophysics Data System (ADS)

    De Leo, Natascia; Fretto, Matteo; Lacquaniti, Vincenzo; Granata, Carmine; Vettoliere, Antonio

    2016-09-01

    In this paper a nanofabrication process, based on a focused ion beam (FIB) nanosculpting technique, for high sensitivity three-dimensional nanoscale superconducting quantum interference devices (nanoSQUIDs) is reported. The crucial steps of the fabrication process are described, as are some peculiar features of the superconductor–normal metal–insulator–superconductor (SNIS) Josephson junctions, which may useful for applications in cryocooler systems. This fabrication procedure is employed to fabricate sandwich nanojunctions and high sensitivity nanoSQUIDs. Specifically, the superconductive nanosensors have a rectangular loop of 1 × 0.2–0.4 μm2 interrupted by two square Nb/Al–AlO x /Nb SNIS Josephson junctions with side lengths of 0.3 μm. The characterization of a typical nanoSQUID has been carried out and a spectral density of magnetic flux noise as low as 0.8 μΦ0 Hz–1/2 has been measured.

  18. Contrast Enhancement of MicroCT Scans to Aid 3D Modelling of Carbon Fibre Fabric Composites

    NASA Astrophysics Data System (ADS)

    Djukic, Luke P.; Pearce, Garth M.; Herszberg, Israel; Bannister, Michael K.; Mollenhauer, David H.

    2013-12-01

    This paper presents a methodology for volume capture and rendering of plain weave and multi-layer fabric meso-architectures within a consolidated, cured laminate. Micro X-ray Computed Tomography (MicroCT) is an excellent tool for the non-destructive visualisation of material microstructures however the contrast between tows and resin is poor for carbon fibre composites. Firstly, this paper demonstrates techniques to improve the contrast of the microCT images by introducing higher density materials such as gold, iodine and glass into the fabric. Two approaches were demonstrated to be effective for enhancing the differentiation between the tows in the reconstructed microCT visualisations. Secondly, a method of generating three-dimensional volume models of woven composites using microCT scan data is discussed. The process of generating a model is explained from initial manufacture with the aid of an example plain weave fabric. These methods are to be used in the finite element modelling of three-dimensional fabric preforms in future work.

  19. Sharp beveled tip hollow microneedle arrays fabricated by LIGA and 3D soft lithography with polyvinyl alcohol

    NASA Astrophysics Data System (ADS)

    Pérennès, F.; Marmiroli, B.; Matteucci, M.; Tormen, M.; Vaccari, L.; Di Fabrizio, E.

    2006-03-01

    This paper describes a fabrication process of hollow microneedle arrays with a sharp beveled tip for transdermal drug delivery. A master is fabricated through a double deep x-ray lithography process. First, a polymethylmethacrylate (PMMA) sheet is exposed to produce single PMMA parts with a sawtooth profile. The tip angle of each tooth determines the final tip angle of the microneedles. The PMMA parts are assembled and glued on a conductive substrate and then exposed through a second x-ray mask containing an array of hollow triangles as absorbing structures. A metal layer is then electrodeposited around the needles in order to form the future base of the array. A polyvinyl alcohol (PVA) solution is cast on top of the master to form a negative mold of the microneedle array after a low temperature curing and peel-off steps. A liquid PMMA solution is cast on top of the PVA negative mold and after the full PMMA polymerization the PVA is dissolved in water. This fabrication method can be performed in a non-clean room environment and requires little instrumentation. It is therefore compatible with a low-cost mass-fabrication scheme.

  20. Fabrication and characterization of a magnetic micro-actuator based on deformable Fe-doped PDMS artificial cilium using 3D printing

    NASA Astrophysics Data System (ADS)

    Liu, Fengli; Alici, Gursel; Zhang, Binbin; Beirne, Stephen; Li, Weihua

    2015-03-01

    This paper proposes the use of a 3D extrusion printer to fabricate artificial magnetic cilium. The cilia are fabricated using polydimethylsiloxane (PDMS) doped with iron particles so that they remain slender and flexible. They can be driven by a magnetic field to closely mimic the behaviour of biological cilia. Doping iron particles to the polymers has already been done; however, to the best of our knowledge, printing such active and soft magnetic structures has not. The existing methods for manufacturing magnetic polymeric structures are complex and difficult to use for the fabrication of micro-sized high-aspect-ratio cilia. The 3D printing technique we propose here is simple and inexpensive compared to previously suggested fabrication methods. In this study, free-standing magnetic PDMS cilia were fabricated in different sizes up to 5 mm in length and 1 mm in width. The stress-strain curves of the PDMS cilia were experimentally obtained to quantify the effect of the concentration of the iron particles on the modulus of elasticity of the cilia. The higher the iron concentration, the higher the modulus of elasticity. We have quantified the characteristics of the cilia made of 40% w/w iron particles in PDMS. A single cilium (5 × 1 × 0.0035 mm) can output up to 27 μN blocking force under a magnetic field of 160 mT. These cilia can be used as a mixer in lap-on-chip applications and as the anchoring and propulsion legs of endoscopic capsule robots operating within the gastrointestinal tract of humans. Analytical expressions estimating the blocking force are established and compared with the experimental results.

  1. Effect of cold plasma pre-treatment on photocatalytic activity of 3D fabric loaded with nano-photocatalysts: Response surface methodology

    NASA Astrophysics Data System (ADS)

    Ghoreishian, Seyed Majid; Badii, Khashayar; Norouzi, Mohammad; Malek, Kaveh

    2016-03-01

    In this study, the physico-chemical effects occasioned by the cold plasma discharge (CPD) on the photo-decolorization of Reactive Orange 16 (RO16) by 3D fabrics (spacer fabrics) loaded with ZnO:TiO2 nano-photocatalysts (nphs) were optimized via response surface methodology (RSM). CPD was employed to improve the surface characteristics of the spacer fabrics for nphs loading. Surface morphology and color variation were studied utilizing scanning electron microscopy (SEM) and CIE-Lab system, respectively. The effect of CPD on the wetting ability of the spacer fabrics was examined using dynamic adsorption measurement (DAM). Also, X-ray fluorescence (XRF) was utilized to investigate the durability of the nphs on the spacer fabrics. All the experiments were implemented in a Box-Behnken design (BBD) with three independent variables (CPD treatment time, dye concentration and irradiation time) in order to optimize the decolorization of RO16. The anticipated values of the decolorization efficiency were found to be in excellent agreement with the experimental values (R2 = 0.9996, Adjusted R2 = 0.9992). The kinetic analysis demonstrated that the photocatalytic decolorization followed the Langmuir-Hinshelwood kinetic model. In conclusion, this heterogeneous photocatalytic process is capable of decolorizing and mineralizing azoic reactive dye in textile wastewater. Moreover, the results confirmed that RSM based on the BBD was a suitable method to optimize the operating conditions of RO16 degradation.

  2. Flexible Fabrication of Shape-Controlled Collagen Building Blocks for Self-Assembly of 3D Microtissues.

    PubMed

    Zhang, Xu; Meng, Zhaoxu; Ma, Jingyun; Shi, Yang; Xu, Hui; Lykkemark, Simon; Qin, Jianhua

    2015-08-12

    Creating artificial tissue-like structures that possess the functionality, specificity, and architecture of native tissues remains a big challenge. A new and straightforward strategy for generating shape-controlled collagen building blocks with a well-defined architecture is presented, which can be used for self-assembly of complex 3D microtissues. Collagen blocks with tunable geometries are controllably produced and released via a membrane-templated microdevice. The formation of functional microtissues by embedding tissue-specific cells into collagen blocks with expression of specific proteins is described. The spontaneous self-assembly of cell-laden collagen blocks into organized tissue constructs with predetermined configurations is demonstrated, which are largely driven by the synergistic effects of cell-cell and cell-matrix interactions. This new strategy would open up new avenues for the study of tissue/organ morphogenesis, and tissue engineering applications.

  3. Flexible Fabrication of Shape-Controlled Collagen Building Blocks for Self-Assembly of 3D Microtissues.

    PubMed

    Zhang, Xu; Meng, Zhaoxu; Ma, Jingyun; Shi, Yang; Xu, Hui; Lykkemark, Simon; Qin, Jianhua

    2015-08-12

    Creating artificial tissue-like structures that possess the functionality, specificity, and architecture of native tissues remains a big challenge. A new and straightforward strategy for generating shape-controlled collagen building blocks with a well-defined architecture is presented, which can be used for self-assembly of complex 3D microtissues. Collagen blocks with tunable geometries are controllably produced and released via a membrane-templated microdevice. The formation of functional microtissues by embedding tissue-specific cells into collagen blocks with expression of specific proteins is described. The spontaneous self-assembly of cell-laden collagen blocks into organized tissue constructs with predetermined configurations is demonstrated, which are largely driven by the synergistic effects of cell-cell and cell-matrix interactions. This new strategy would open up new avenues for the study of tissue/organ morphogenesis, and tissue engineering applications. PMID:25920010

  4. Indirect solid free form fabrication of local and global porous, biomimetic and composite 3D polymer-ceramic scaffolds.

    PubMed

    Taboas, J M; Maddox, R D; Krebsbach, P H; Hollister, S J

    2003-01-01

    Precise control over scaffold material, porosity, and internal pore architecture is essential for tissue engineering. By coupling solid free form (SFF) manufacturing with conventional sponge scaffold fabrication procedures, we have developed methods for casting scaffolds that contain designed and controlled locally porous and globally porous internal architectures. These methods are compatible with numerous bioresorbable and non-resorbable polymers, ceramics, and biologic materials. Phase separation, emulsion-solvent diffusion, and porogen leaching were used to create poly(L)lactide (PLA) scaffolds containing both computationally designed global pores (500, 600, or 800 microm wide channels) and solvent fashioned local pores (50-100 microm wide voids or 5-10 microm length plates). Globally porous PLA and polyglycolide/PLA discrete composites were made using melt processing. Biphasic scaffolds with mechanically interdigitated PLA and sintered hydroxyapatite regions were fabricated with 500 and 600 microm wide global pores. PLA scaffolds with complex internal architectures that mimicked human trabecular bone were produced. Our indirect fabrication using casting in SFF molds provided enhanced control over scaffold shape, material, porosity and pore architecture, including size, geometry, orientation, branching, and interconnectivity. These scaffolds that contain concurrent local and global pores, discrete material regions, and biomimetic internal architectures may prove valuable for multi-tissue and structural tissue interface engineering. PMID:12417192

  5. Fabrication of PDMS (poly-dimethyl siloxane) molding and 3D structure by two-photon absorption induced by an ultrafast laser

    NASA Astrophysics Data System (ADS)

    Yi, Shin Wook; Lee, Seong Ku; Cho, Mi Jung; Kong, Hong Jin; Yang, Dong-Yol; Park, Sang-hu; Lim, Tae-woo; Kim, Ran Hee; Lee, Kwang-Sup

    2004-12-01

    Multi-photon absorption phenomena induced by ultra fast laser have been considered for many applications of microfabrications such as metal ablation, glass etching and photopolymerization. Among the applications, the photopolymerization by two-photon absorption (TPA) has been regarded as a new microfabricating method. It is possible to be used in photo mask correcting, diffractive optical element and micro machining. The TPA photopolymerization is made possible to fabricate a complicated three dimensional structure which the conventional photomask technology has not been able to make. Furthermore the TPA photopolymerization process applied to a two dimensional structure fabrication may take shorter time than the old process since the absence of etching and deposition processes. Recently we have made a simple 3D structure and applied the technique to PDMS(poly-dimethyl siloxane) molding.

  6. 3D Printing, Additive Manufacturing, and Solid Freeform Fabrication: The Technologies of the Past, Present and Future

    NASA Astrophysics Data System (ADS)

    Beaman, Joseph

    2015-03-01

    Starting in the late 1980's, several new technologies were created that have the potential to revolutionize manufacturing. These technologies are, for the most part, additive processes that build up parts layer by layer. In addition, the processes that are being touted for hard-core manufacturing are primarily laser or e-beam based processes. This presentation gives a brief history of Additive Manufacturing and gives an assessment for these technologies. These technologies initially grew out of a commercial need for rapid prototyping. This market has a different requirement for process and quality control than traditional manufacturing. The relatively poor process control of the existing commercial Additive Manufacturing equipment is a vestige of this history. This presentation discusses this history and improvements in quality over time. The emphasis will be on Additive Manufacturing processes that are being considered for direct manufacturing, which is a different market than the 3D Printing ``Makerbot'' market. Topics discussed include past and present machine sensors, materials, and operational methods that were used in the past and those that are used today to create manufactured parts. Finally, a discussion of new methods and future directions of AM is presented.

  7. Image-based analysis of the internal microstructure of bone replacement scaffolds fabricated by 3D printing

    NASA Astrophysics Data System (ADS)

    Irsen, Stephan H.; Leukers, Barbara; Bruckschen, Björn; Tille, Carsten; Seitz, Hermann; Beckmann, Felix; Müller, Bert

    2006-08-01

    Rapid Prototyping and especially the 3D printing, allows generating complex porous ceramic scaffolds directly from powders. Furthermore, these technologies allow manufacturing patient-specific implants of centimeter size with an internal pore network to mimic bony structures including vascularization. Besides the biocompatibility properties of the base material, a high degree of open, interconnected porosity is crucial for the success of the synthetic bone graft. Pores with diameters between 100 and 500 μm are the prerequisite for vascularization to supply the cells with nutrients and oxygen, because simple diffusion transport is ineffective. The quantification of porosity on the macro-, micro-, and nanometer scale using well-established techniques such as Hg-porosimetry and electron microscopy is restricted. Alternatively, we have applied synchrotron-radiation-based micro computed tomography (SRμCT) to determine the porosity with high precision and to validate the macroscopic internal structure of the scaffold. We report on the difficulties in intensity-based segmentation for nanoporous materials but we also elucidate the power of SRμCT in the quantitative analysis of the pores at the different length scales.

  8. WE-F-16A-02: Design, Fabrication, and Validation of a 3D-Printed Proton Filter for Range Spreading

    SciTech Connect

    Remmes, N; Courneyea, L; Corner, S; Beltran, C; Kemp, B; Kruse, J; Herman, M; Stoker, J

    2014-06-15

    Purpose: To design, fabricate and test a 3D-printed filter for proton range spreading in scanned proton beams. The narrow Bragg peak in lower-energy synchrotron-based scanned proton beams can result in longer treatment times for shallow targets due to energy switching time and plan quality degradation due to minimum monitor unit limitations. A filter with variable thicknesses patterned on the same scale as the beam's lateral spot size will widen the Bragg peak. Methods: The filter consists of pyramids dimensioned to have a Gaussian distribution in thickness. The pyramids are 2.5mm wide at the base, 0.6 mm wide at the peak, 5mm tall, and are repeated in a 2.5mm pseudo-hexagonal lattice. Monte Carlo simulations of the filter in a proton beam were run using TOPAS to assess the change in depth profiles and lateral beam profiles. The prototypes were constrained to a 2.5cm diameter disk to allow for micro-CT imaging of promising prototypes. Three different 3D printers were tested. Depth-doses with and without the prototype filter were then measured in a ~70MeV proton beam using a multilayer ion chamber. Results: The simulation results were consistent with design expectations. Prototypes printed on one printer were clearly unacceptable on visual inspection. Prototypes on a second printer looked acceptable, but the micro-CT image showed unacceptable voids within the pyramids. Prototypes from the third printer appeared acceptable visually and on micro-CT imaging. Depth dose scans using the prototype from the third printer were consistent with simulation results. Bragg peak width increased by about 3x. Conclusions: A prototype 3D printer pyramid filter for range spreading was successfully designed, fabricated and tested. The filter has greater design flexibility and lower prototyping and production costs compared to traditional ridge filters. Printer and material selection played a large role in the successful development of the filter.

  9. The fabrication of foam-like 3D mesoporous NiO-Ni as anode for high performance Li-ion batteries

    SciTech Connect

    Huang, Peng; Zhang, Xin; Wei, Jumeng; Pan, Jiaqi; Sheng, Yingzhou; Feng, Boxue

    2015-03-15

    Graphical abstract: Foam-like 3 dimensional (3D) mesoporous NiO on 3D micro-porous Ni was fabricated. - Highlights: • We prepare NiO-Ni foam composite via hydrothermal etching and subsequent annealing. • The NiO exhibits novel foam-like 3D mesoporous architecture. • The NiO-Ni anode shows good cycle stability. - Abstract: Foam-like three dimensional mesoporous NiO on Ni foam was fabricated via facile hydrothermal etching and subsequent annealing treatment. The porous NiO consists of a large number of nanosheets with mean thickness about 50 nm, among which a large number of mesoscopic pores with size ranges from 100 nm to 1 μm distribute. The electrochemical performance of the as-prepared NiO-Ni as anode for lithium ion battery was studied by conventional charge/discharge test, which shows excellent cycle stability and rate capability. It exhibits initial discharge and charge capacities of 979 and 707 mA h g{sup −1} at a charge/discharge rate of 0.7 C, which maintain of 747 and 738 mA h g{sup −1} after 100 cycles. Even after 60 cycles at various rates from 0.06 to 14 C, the 10th discharge and charge capacities of the NiO-Ni electrode can revert to 699 and 683 mA h g{sup −1} when lowering the charge/discharge rate to 0.06 C.

  10. Fabrication of Compositionally and Topographically Complex Robust Tissue Forms by 3D-Electrochemical Compaction of Collagen

    PubMed Central

    Younesi, Mousa; Islam, Anowarul; Kishore, Vipuil; Panit, Stefi; Akkus, Ozan

    2015-01-01

    Collagen solutions are phase-transformed to mechanically robust shell structures with curviplanar topographies using electrochemically induced pH gradients. The process enables rapid layer-by-layer deposition of collagen-rich mixtures over the entire field simultaneously to obtain compositionally diverse multilayered structures. In-plane tensile strength and modulus of the electrocompacted collagen sheet samples were 5200 -fold and 2300 -fold greater than that of uncompacted collagen samples. Out of plane compression tests showed 27 -fold and fold increase in compressive stress and 46 -fold increase in compressive modulus compared to uncompacted collagen sheets. Cells proliferated 4.9 times faster, and cellular area spread was 2.7 times greater on compacted collagen sheets. Electrocompaction also resulted in 2.9 times greater focal adhesion area than on regular collagen hydrogel. The reported improvements in the cell-matrix interactions with electrocompaction would serve to expedite the population of electrocompacted collagen scaffolds by cells. The capacity of the method to fabricate nonlinear curved topographies with compositional heterogeneous layers is demonstrated by sequential deposition of collagenhydroxyapatite layer over a collagen layer. The complex curved topography of the nasal structure is replicated by the electrochemical compaction method. The presented electrochemical compaction process is an enabling modality which holds significant promise for reconstruction of a wide spectrum of topographically complex systems such as joint surfaces, craniofacial defects, ears, nose or urogenital forms. PMID:26069162

  11. Insulin and heparin co-immobilized 3D polyester fabrics for the cultivation of fibroblasts in low-serum media.

    PubMed

    Türkoğlu Saşmazel, Hilal; Aday, Sezin; Gümüşderelioğlu, Menemşe

    2007-08-01

    Insulin and/or heparin immobilized/co-immobilized non-woven polyester fabric (NWPF) discs were developed for the cultivation of L929 mouse fibroblasts in low-serum media. At first, NWPF discs were hydrolyzed to obtain a carboxylic acid group-introduced matrix (NWPF-hydrolyzed). Insulin and heparin co-immobilized NWPF (NWPF-insulin-heparin) was prepared by the grafting of PEO onto NWPF-hydrolyzed disc (NWPF-PEO), followed by the reaction first with insulin and then heparin. In the presence of spacer arm, PEO, the amount of immobilized insulin molecules significantly increased from 6.96 to 84.45 microg/cm(2). The amount of heparin bound to the NWPF-PEO (5.93 microg/cm(2)) was higher than that of the insulin immobilized surface (4.59 microg/cm(2)). Insulin and heparin immobilized NWPF discs were observed with fluorescence microscopy by labeling the insulin and heparin with 8-anilino-1-naphthalene sulfonic acid (ANS) or fluorescein isothiocyanate (FITC), respectively. L929 fibroblasts were used to check the cell adhesion and cell growth capabilities of modified NWPF discs in low-serum media (containing 5% fetal bovine serum). Optical photographs showed that after 2nd day of the culture, fibroblastic cells spread along the length of modified fibers, eventually filling the interfiber space. At the end of 6-day growth period, cell yield in the presence of immobilized heparin was a little bit higher than that of the immobilized insulin. Co-immobilized (insulin/heparin) NWPF discs did not accelerate the cell growth as well as insulin or heparin immobilized discs. PMID:17576003

  12. A microfluidic opto-caloric switch for sorting of particles by using 3D-hydrodynamic focusing based on SLE fabrication capabilities.

    PubMed

    Meineke, G; Hermans, M; Klos, J; Lenenbach, A; Noll, R

    2016-03-01

    In a miniaturised flow switch fluid flows are controlled by reducing the local viscosity via absorption of laser radiation. Through this, the local flow rates are increased to switch the outlet port of a fluid flow carrying the analyte. The microfluidic chip is fabricated using Selective Laser-Induced Etching (SLE). SLE allows novel 3D-hydrodynamic focusing, realising circular shaped channel cross-sections and adapting interaction volume geometries to the profile of the laser radiation for optimised absorption. The performance of the switch is validated experimentally with a dyed analyte and video image processing. The ability to sort particles like cells is demonstrated at 8 Hz using polystyrene beads having a diameter of 8 μm.

  13. Graphene-Protected 3D Sb-based Anodes Fabricated via Electrostatic Assembly and Confinement Replacement for Enhanced Lithium and Sodium Storage.

    PubMed

    Ding, Yuan-Li; Wu, Chao; Kopold, Peter; van Aken, Peter A; Maier, Joachim; Yu, Yan

    2015-12-01

    Alloy anodes have shown great potential for next-generation lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). However, these applications are still limited by inherent huge volume changes and sluggish kinetics. To overcome such limitations, graphene-protected 3D Sb-based anodes grown on conductive substrate are designed and fabricated by a facile electrostatic-assembling and subsequent confinement replacement strategy. As binder-free anodes for LIBs, the obtained electrode exhibits reversible capacities of 442 mAh g(-1) at 100 mA g(-1) and 295 mAh g(-1) at 1000 mA g(-1), and a capacity retention of above 90% (based on the 10th cycle) after 200 cycles at 500 mA g(-1). As for sodium storage properties, the reversible capacities of 517 mAh g(-1) at 50 mA g(-1) and 315 mAh g(-1) at 1000 mA g(-1), the capacity retention of 305 mAh g(-1) after 100 cycles at 300 mA g(-1) are obtained, respectively. Furthermore, the 3D architecture retains good structural integrity after cycling, confirming that the introduction of high-stretchy and robust graphene layers can effectively buffer alloying anodes, and simultaneously provide sustainable contact and protection of the active materials. Such findings show its great potential as superior binder-free anodes for LIBs and SIBs.

  14. Influence of mechanical properties of alginate-based substrates on the performance of Schwann cells in culture.

    PubMed

    Ning, Liqun; Xu, Yitong; Chen, Xiongbiao; Schreyer, David J

    2016-06-01

    In tissue engineering, artificial tissue scaffolds containing living cells have been studied for tissue repair and regeneration. Notably, the performance of these encapsulated-in-scaffolds cells in terms of cell viability, proliferation, and expression of function during and after the scaffold fabrication process, has not been well documented because of the influence of mechanical, chemical, and physical properties of the scaffold substrate materials. This paper presents our study on the influence of mechanical properties of alginate-based substrates on the performance of Schwann cells, which are the major glial cells of peripheral nervous system. Given the fact that alginate polysaccharide hydrogel has poor cell adhesion properties, in this study, we examined several types of cell-adhesion supplements and found that alginate covalently modified with RGD peptide provided improved cell proliferation and adhesion. We prepared alginate-based substrates for cell culture using varying alginate concentrations for altering their mechanical properties, which were confirmed by compression testing. Then, we examined the viability, proliferation, morphology, and expression of the extracellular matrix protein laminin of Schwann cells that were seeded on the surface of alginate-based substrates (or 2D culture) or encapsulated within alginate-based substrates (3D cultures), and correlated the examined cell performance to the alginate concentration (or mechanical properties) of hydrogel substrates. Our findings suggest that covalent attachment of RGD peptide can improve the success of Schwann cell encapsulation within alginate-based scaffolds, and provide guidance for regulating the mechanical properties of alginate-based scaffolds containing Schwann cells for applications in peripheral nervous system regeneration and repair. PMID:27012482

  15. Influence of mechanical properties of alginate-based substrates on the performance of Schwann cells in culture.

    PubMed

    Ning, Liqun; Xu, Yitong; Chen, Xiongbiao; Schreyer, David J

    2016-06-01

    In tissue engineering, artificial tissue scaffolds containing living cells have been studied for tissue repair and regeneration. Notably, the performance of these encapsulated-in-scaffolds cells in terms of cell viability, proliferation, and expression of function during and after the scaffold fabrication process, has not been well documented because of the influence of mechanical, chemical, and physical properties of the scaffold substrate materials. This paper presents our study on the influence of mechanical properties of alginate-based substrates on the performance of Schwann cells, which are the major glial cells of peripheral nervous system. Given the fact that alginate polysaccharide hydrogel has poor cell adhesion properties, in this study, we examined several types of cell-adhesion supplements and found that alginate covalently modified with RGD peptide provided improved cell proliferation and adhesion. We prepared alginate-based substrates for cell culture using varying alginate concentrations for altering their mechanical properties, which were confirmed by compression testing. Then, we examined the viability, proliferation, morphology, and expression of the extracellular matrix protein laminin of Schwann cells that were seeded on the surface of alginate-based substrates (or 2D culture) or encapsulated within alginate-based substrates (3D cultures), and correlated the examined cell performance to the alginate concentration (or mechanical properties) of hydrogel substrates. Our findings suggest that covalent attachment of RGD peptide can improve the success of Schwann cell encapsulation within alginate-based scaffolds, and provide guidance for regulating the mechanical properties of alginate-based scaffolds containing Schwann cells for applications in peripheral nervous system regeneration and repair.

  16. Engineering alginate as bioink for bioprinting.

    PubMed

    Jia, Jia; Richards, Dylan J; Pollard, Samuel; Tan, Yu; Rodriguez, Joshua; Visconti, Richard P; Trusk, Thomas C; Yost, Michael J; Yao, Hai; Markwald, Roger R; Mei, Ying

    2014-10-01

    Recent advances in three-dimensional (3-D) printing offer an excellent opportunity to address critical challenges faced by current tissue engineering approaches. Alginate hydrogels have been used extensively as bioinks for 3-D bioprinting. However, most previous research has focused on native alginates with limited degradation. The application of oxidized alginates with controlled degradation in bioprinting has not been explored. Here, a collection of 30 different alginate hydrogels with varied oxidation percentages and concentrations was prepared to develop a bioink platform that can be applied to a multitude of tissue engineering applications. The authors systematically investigated the effects of two key material properties (i.e. viscosity and density) of alginate solutions on their printabilities to identify a suitable range of material properties of alginates to be applied to bioprinting. Further, four alginate solutions with varied biodegradability were printed with human adipose-derived stem cells (hADSCs) into lattice-structured, cell-laden hydrogels with high accuracy. Notably, these alginate-based bioinks were shown to be capable of modulating proliferation and spreading of hADSCs without affecting the structure integrity of the lattice structures (except the highly degradable one) after 8days in culture. This research lays a foundation for the development of alginate-based bioink for tissue-specific tissue engineering applications. PMID:24998183

  17. Engineering alginate as bioink for bioprinting

    PubMed Central

    Jia, Jia; Richards, Dylan J.; Pollard, Samuel; Tan, Yu; Rodriguez, Joshua; Visconti, Richard P.; Trusk, Thomas C.; Yost, Michael J.; Yao, Hai; Markwald, Roger R.; Mei, Ying

    2015-01-01

    Recent advances in 3D printing offer an excellent opportunity to address critical challenges faced by current tissue engineering approaches. Alginate hydrogels have been extensively utilized as bioinks for 3D bioprinting. However, most previous research has focused on native alginates with limited degradation. The application of oxidized alginates with controlled degradation in bioprinting has not been explored. Here, we prepared a collection of 30 different alginate hydrogels with varied oxidation percentages and concentrations to develop a bioink platform that can be applied to a multitude of tissue engineering applications. We systematically investigated the effects of two key material properties (i.e. viscosity and density) of alginate solutions on their printabilities to identify a suitable range of material properties of alginates to be applied to bioprinting. Further, four alginate solutions with varied biodegradability were printed with human adipose-derived stem cells (hADSCs) into lattice-structured, cell-laden hydrogels with high accuracy. Notably, these alginate-based bioinks were shown to be capable of modulating proliferation and spreading of hADSCs without affecting structure integrity of the lattice structures (except the highly degradable one) after 8 days in culture. This research lays a foundation for the development of alginate-based bioink for tissue-specific tissue engineering applications. PMID:24998183

  18. Fabrication and detection of tissue engineered bone aggregates based on encapsulated human ADSCs within hybrid calcium alginate/bone powder gel-beads in a spinner flask.

    PubMed

    Song, Kedong; Yang, Yanfei; Xu, Lili; Tian, Jiaxin; Fan, Jiangli; Jiao, Zeren; Feng, Shihao; Wang, Hong; Wang, Yiwei; Wang, Ling; Liu, Tianqing

    2016-05-01

    Traditional treatment for bone diseases limits their clinical application due to undesirable host immune rejection, limited donator sources and severe pain and suffering for patients. Bone tissue engineering therefore is expected to be a more effective way in treating bone diseases. In the present study, hybrid calcium alginate/bone powder gel-beads with a uniform size distribution, good biocompatibility and osteoinductive capability, were prepared to be used as an in-vitro niche-like matrix. The beads were optimized using 2.5% (w/v) sodium alginate solution, 4.5% (w/v) CaCl2 solution and 5.0mg/mL bone powder using an easy-to-use method. Human ADSCs were cultured and induced into chondrocytes and osteoblasts, respectively. The cells were characterized by histological staining showing the ADSCs were able to maintain their characteristic morphology with multipotent differentiation ability. ADSCs at density of 5 × 10(6)cells/mL were encapsulated into the gel-beads aiming to explore cell expansion under different conditions and the osteogenic induction of ADSCs was verified by specific staining. Results demonstrated that the encapsulated ADSCs expanded 5.6 folds in 10 days under dynamic condition via spinner flask, and were able to differentiate into osteoblasts (OBs) with extensive mineralized nodules forming the bone aggregates over 3 weeks postosteogenic induction. In summary, hybrid gel-beads encapsulating ADSCs are proved to be feasible as a new method to fabricate tissue engineered bone aggregation with potential to treat skeletal injury in the near future. PMID:26952485

  19. Fabrication and evaluation of electrohydrodynamic jet 3D printed polycaprolactone/chitosan cell carriers using human embryonic stem cell-derived fibroblasts.

    PubMed

    Wu, Yang; Sriram, Gopu; Fawzy, Amr S; Fuh, Jerry Yh; Rosa, Vinicius; Cao, Tong; Wong, Yoke San

    2016-08-01

    Biological function of adherent cells depends on the cell-cell and cell-matrix interactions in three-dimensional space. To understand the behavior of cells in 3D environment and their interactions with neighboring cells and matrix requires 3D culture systems. Here, we present a novel 3D cell carrier scaffold that provides an environment for routine 3D cell growth in vitro We have developed thin, mechanically stable electrohydrodynamic jet (E-jet) 3D printed polycaprolactone and polycaprolactone/Chitosan macroporous scaffolds with precise fiber orientation for basic 3D cell culture application. We have evaluated the application of this technology by growing human embryonic stem cell-derived fibroblasts within these 3D scaffolds. Assessment of cell viability and proliferation of cells seeded on polycaprolactone and polycaprolactone/Chitosan 3D-scaffolds show that the human embryonic stem cell-derived fibroblasts could adhere and proliferate on the scaffolds over time. Further, using confocal microscopy we demonstrate the ability to use fluorescence-labelled cells that could be microscopically monitored in real-time. Hence, these 3D printed polycaprolactone and polycaprolactone/Chitosan scaffolds could be used as a cell carrier for in vitro 3D cell culture-, bioreactor- and tissue engineering-related applications in the future.

  20. Fabrication and evaluation of electrohydrodynamic jet 3D printed polycaprolactone/chitosan cell carriers using human embryonic stem cell-derived fibroblasts.

    PubMed

    Wu, Yang; Sriram, Gopu; Fawzy, Amr S; Fuh, Jerry Yh; Rosa, Vinicius; Cao, Tong; Wong, Yoke San

    2016-08-01

    Biological function of adherent cells depends on the cell-cell and cell-matrix interactions in three-dimensional space. To understand the behavior of cells in 3D environment and their interactions with neighboring cells and matrix requires 3D culture systems. Here, we present a novel 3D cell carrier scaffold that provides an environment for routine 3D cell growth in vitro We have developed thin, mechanically stable electrohydrodynamic jet (E-jet) 3D printed polycaprolactone and polycaprolactone/Chitosan macroporous scaffolds with precise fiber orientation for basic 3D cell culture application. We have evaluated the application of this technology by growing human embryonic stem cell-derived fibroblasts within these 3D scaffolds. Assessment of cell viability and proliferation of cells seeded on polycaprolactone and polycaprolactone/Chitosan 3D-scaffolds show that the human embryonic stem cell-derived fibroblasts could adhere and proliferate on the scaffolds over time. Further, using confocal microscopy we demonstrate the ability to use fluorescence-labelled cells that could be microscopically monitored in real-time. Hence, these 3D printed polycaprolactone and polycaprolactone/Chitosan scaffolds could be used as a cell carrier for in vitro 3D cell culture-, bioreactor- and tissue engineering-related applications in the future. PMID:27252227

  1. Fabrication of a novel bone ash-reinforced gelatin/alginate/hyaluronic acid composite film for controlled drug delivery.

    PubMed

    Alemdar, Neslihan

    2016-10-20

    In this study, a novel pH-sensitive composite film with enhanced thermal and mechanical properties was prepared by the incorporation of bone ash at varying concentrations from 0 to 10v.% into gelatin/sodium alginate/hyaluronic acid (Gel/SA/HyA) polymeric structure for colon-specific drug delivery system. Films were characterized by FT-IR, SEM, and XRD analyses. Thermal and mechanical performances of films were determined by DSC, TGA and universal mechanical tester, respectively. Results proved that thermal stability and mechanical properties of bone ash-reinforced composite films improved significantly with respect to that of neat Gel/SA/HyA film. Cytotoxicity assay for composite films was carried out by using L929 cells. Water uptake capacity of films was determined by swelling test. Herein, release experiments of 5-Fluorouracil (5-FU) were performed in two different solutions (pH 2.1 and 7.4). The results assured that Gel/SA/HyA film containing BA could be considered as a potential biomaterial for controlled drug delivery systems. PMID:27474650

  2. FABRICATION AND IN VITRO EVALUATION OF 5-FLOROURACIL LOADED CHONDROITIN SULFATE-SODIUM ALGINATE MICROSPHERES FOR COLON SPECIFIC DELIVERY.

    PubMed

    Raza, Hina; Ranjha, Nazar Muhammad; Razzaq, Rabia; Ansari, Mehvish; Mahmood, Asif; Rashid, Zermina

    2016-01-01

    Chondroitin sulfate and sodium alginate were incorporated in different ratios to prepare glutaraldehyde (GA) crosslinked microspheres by water-in-oil emulsion crosslinking method for delivery of 5-flurouracil (5-FU) to colon. Chemical interaction, surface morphology, thermal degradability, crystallinity evaluation, elemental analysis and drug release results were computed by using FTIR, SEM, DSC and TGA, PXRD, EXD and dissolution studies at pH 1.2, pH 6.8 and pH 7.4, respectively. Results revealed an acetal ring formation, non-porous surfaces, stability up to 450 degrees C with mass loss of 84.31%, variation in carbon and oxygen contents and targeted release at pH 7.4. Different kinetic models were applied on release studies i.e., zero order, first order, Higuchi and Korsmeyer-Peppas. Higuchi model was declared as best fit model based on r2 value (0.99) and mechanism of release was non-Fickian diffusion. A potential approach for colonic delivery of 5-FU was successfully developed.

  3. FABRICATION AND IN VITRO EVALUATION OF 5-FLOROURACIL LOADED CHONDROITIN SULFATE-SODIUM ALGINATE MICROSPHERES FOR COLON SPECIFIC DELIVERY.

    PubMed

    Raza, Hina; Ranjha, Nazar Muhammad; Razzaq, Rabia; Ansari, Mehvish; Mahmood, Asif; Rashid, Zermina

    2016-01-01

    Chondroitin sulfate and sodium alginate were incorporated in different ratios to prepare glutaraldehyde (GA) crosslinked microspheres by water-in-oil emulsion crosslinking method for delivery of 5-flurouracil (5-FU) to colon. Chemical interaction, surface morphology, thermal degradability, crystallinity evaluation, elemental analysis and drug release results were computed by using FTIR, SEM, DSC and TGA, PXRD, EXD and dissolution studies at pH 1.2, pH 6.8 and pH 7.4, respectively. Results revealed an acetal ring formation, non-porous surfaces, stability up to 450 degrees C with mass loss of 84.31%, variation in carbon and oxygen contents and targeted release at pH 7.4. Different kinetic models were applied on release studies i.e., zero order, first order, Higuchi and Korsmeyer-Peppas. Higuchi model was declared as best fit model based on r2 value (0.99) and mechanism of release was non-Fickian diffusion. A potential approach for colonic delivery of 5-FU was successfully developed. PMID:27180443

  4. 3D Printing of Graphene Aerogels.

    PubMed

    Zhang, Qiangqiang; Zhang, Feng; Medarametla, Sai Pradeep; Li, Hui; Zhou, Chi; Lin, Dong

    2016-04-01

    3D printing of a graphene aerogel with true 3D overhang structures is highlighted. The aerogel is fabricated by combining drop-on-demand 3D printing and freeze casting. The water-based GO ink is ejected and freeze-cast into designed 3D structures. The lightweight (<10 mg cm(-3) ) 3D printed graphene aerogel presents superelastic and high electrical conduction.

  5. 3D Printing of Graphene Aerogels.

    PubMed

    Zhang, Qiangqiang; Zhang, Feng; Medarametla, Sai Pradeep; Li, Hui; Zhou, Chi; Lin, Dong

    2016-04-01

    3D printing of a graphene aerogel with true 3D overhang structures is highlighted. The aerogel is fabricated by combining drop-on-demand 3D printing and freeze casting. The water-based GO ink is ejected and freeze-cast into designed 3D structures. The lightweight (<10 mg cm(-3) ) 3D printed graphene aerogel presents superelastic and high electrical conduction. PMID:26861680

  6. Fast and safe fabrication of a free-standing chitosan/alginate nanomembrane to promote stem cell delivery and wound healing.

    PubMed

    Kong, Yi; Xu, Rui; Darabi, Mohammad Ali; Zhong, Wen; Luo, Gaoxing; Xing, Malcolm Mq; Wu, Jun

    2016-01-01

    Polymeric ultrathin membranes that are compatible with cells offer tremendous advantages for tissue engineering. In this article, we report a free-standing nanomembrane that was developed using a layer-by-layer self-assembly technique with a safe and sacrificial substrate method. After ionization, two oppositely charged polyelectrolytes, alginate and chitosan, were alternately deposited on a substrate of a solidified gelatin block to form an ultrathin nanomembrane. The space between the two adjacent layers was ∼200 nm. The thickness of the nanomembrane was proportional to the number of layers. The temperature-sensitive gelatin gel served as a sacrificial template at 37°C. The free-standing nanomembrane promoted bone marrow stem cell adhesion and proliferation. Fluorescence-activated cell sorting was used to analyze green-fluorescent-protein-positive mesenchymal stem cells from the wounds, which showed a significantly high survival and proliferation from the nanomembrane when cells were transplanted to mouse dorsal skin that had a full-thickness burn. The bone-marrow-stem-cell-loaded nanomembrane also accelerated wound contraction and epidermalization. Therefore, this methodology provides a fast and facile approach to construct free-standing ultrathin scaffolds for tissue engineering. The biocompatibility and free-standing nature of the fabricated nanomembrane may be particularly useful for stem cell delivery and wound healing.

  7. Fast and safe fabrication of a free-standing chitosan/alginate nanomembrane to promote stem cell delivery and wound healing

    PubMed Central

    Kong, Yi; Xu, Rui; Darabi, Mohammad Ali; Zhong, Wen; Luo, Gaoxing; Xing, Malcolm MQ; Wu, Jun

    2016-01-01

    Polymeric ultrathin membranes that are compatible with cells offer tremendous advantages for tissue engineering. In this article, we report a free-standing nanomembrane that was developed using a layer-by-layer self-assembly technique with a safe and sacrificial substrate method. After ionization, two oppositely charged polyelectrolytes, alginate and chitosan, were alternately deposited on a substrate of a solidified gelatin block to form an ultrathin nanomembrane. The space between the two adjacent layers was ∼200 nm. The thickness of the nanomembrane was proportional to the number of layers. The temperature-sensitive gelatin gel served as a sacrificial template at 37°C. The free-standing nanomembrane promoted bone marrow stem cell adhesion and proliferation. Fluorescence-activated cell sorting was used to analyze green-fluorescent-protein-positive mesenchymal stem cells from the wounds, which showed a significantly high survival and proliferation from the nanomembrane when cells were transplanted to mouse dorsal skin that had a full-thickness burn. The bone-marrow-stem-cell-loaded nanomembrane also accelerated wound contraction and epidermalization. Therefore, this methodology provides a fast and facile approach to construct free-standing ultrathin scaffolds for tissue engineering. The biocompatibility and free-standing nature of the fabricated nanomembrane may be particularly useful for stem cell delivery and wound healing. PMID:27354789

  8. Fast and safe fabrication of a free-standing chitosan/alginate nanomembrane to promote stem cell delivery and wound healing.

    PubMed

    Kong, Yi; Xu, Rui; Darabi, Mohammad Ali; Zhong, Wen; Luo, Gaoxing; Xing, Malcolm Mq; Wu, Jun

    2016-01-01

    Polymeric ultrathin membranes that are compatible with cells offer tremendous advantages for tissue engineering. In this article, we report a free-standing nanomembrane that was developed using a layer-by-layer self-assembly technique with a safe and sacrificial substrate method. After ionization, two oppositely charged polyelectrolytes, alginate and chitosan, were alternately deposited on a substrate of a solidified gelatin block to form an ultrathin nanomembrane. The space between the two adjacent layers was ∼200 nm. The thickness of the nanomembrane was proportional to the number of layers. The temperature-sensitive gelatin gel served as a sacrificial template at 37°C. The free-standing nanomembrane promoted bone marrow stem cell adhesion and proliferation. Fluorescence-activated cell sorting was used to analyze green-fluorescent-protein-positive mesenchymal stem cells from the wounds, which showed a significantly high survival and proliferation from the nanomembrane when cells were transplanted to mouse dorsal skin that had a full-thickness burn. The bone-marrow-stem-cell-loaded nanomembrane also accelerated wound contraction and epidermalization. Therefore, this methodology provides a fast and facile approach to construct free-standing ultrathin scaffolds for tissue engineering. The biocompatibility and free-standing nature of the fabricated nanomembrane may be particularly useful for stem cell delivery and wound healing. PMID:27354789

  9. 3D printing in dentistry.

    PubMed

    Dawood, A; Marti Marti, B; Sauret-Jackson, V; Darwood, A

    2015-12-01

    3D printing has been hailed as a disruptive technology which will change manufacturing. Used in aerospace, defence, art and design, 3D printing is becoming a subject of great interest in surgery. The technology has a particular resonance with dentistry, and with advances in 3D imaging and modelling technologies such as cone beam computed tomography and intraoral scanning, and with the relatively long history of the use of CAD CAM technologies in dentistry, it will become of increasing importance. Uses of 3D printing include the production of drill guides for dental implants, the production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxillofacial and orthopaedic implants, and the fabrication of copings and frameworks for implant and dental restorations. This paper reviews the types of 3D printing technologies available and their various applications in dentistry and in maxillofacial surgery. PMID:26657435

  10. 3D printing in dentistry.

    PubMed

    Dawood, A; Marti Marti, B; Sauret-Jackson, V; Darwood, A

    2015-12-01

    3D printing has been hailed as a disruptive technology which will change manufacturing. Used in aerospace, defence, art and design, 3D printing is becoming a subject of great interest in surgery. The technology has a particular resonance with dentistry, and with advances in 3D imaging and modelling technologies such as cone beam computed tomography and intraoral scanning, and with the relatively long history of the use of CAD CAM technologies in dentistry, it will become of increasing importance. Uses of 3D printing include the production of drill guides for dental implants, the production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxillofacial and orthopaedic implants, and the fabrication of copings and frameworks for implant and dental restorations. This paper reviews the types of 3D printing technologies available and their various applications in dentistry and in maxillofacial surgery.

  11. Real-time monitoring of 3D cell culture using a 3D capacitance biosensor.

    PubMed

    Lee, Sun-Mi; Han, Nalae; Lee, Rimi; Choi, In-Hong; Park, Yong-Beom; Shin, Jeon-Soo; Yoo, Kyung-Hwa

    2016-03-15

    Three-dimensional (3D) cell cultures have recently received attention because they represent a more physiologically relevant environment compared to conventional two-dimensional (2D) cell cultures. However, 2D-based imaging techniques or cell sensors are insufficient for real-time monitoring of cellular behavior in 3D cell culture. Here, we report investigations conducted with a 3D capacitance cell sensor consisting of vertically aligned pairs of electrodes. When GFP-expressing human breast cancer cells (GFP-MCF-7) encapsulated in alginate hydrogel were cultured in a 3D cell culture system, cellular activities, such as cell proliferation and apoptosis at different heights, could be monitored non-invasively and in real-time by measuring the change in capacitance with the 3D capacitance sensor. Moreover, we were able to monitor cell migration of human mesenchymal stem cells (hMSCs) with our 3D capacitance sensor.

  12. Real-time monitoring of 3D cell culture using a 3D capacitance biosensor.

    PubMed

    Lee, Sun-Mi; Han, Nalae; Lee, Rimi; Choi, In-Hong; Park, Yong-Beom; Shin, Jeon-Soo; Yoo, Kyung-Hwa

    2016-03-15

    Three-dimensional (3D) cell cultures have recently received attention because they represent a more physiologically relevant environment compared to conventional two-dimensional (2D) cell cultures. However, 2D-based imaging techniques or cell sensors are insufficient for real-time monitoring of cellular behavior in 3D cell culture. Here, we report investigations conducted with a 3D capacitance cell sensor consisting of vertically aligned pairs of electrodes. When GFP-expressing human breast cancer cells (GFP-MCF-7) encapsulated in alginate hydrogel were cultured in a 3D cell culture system, cellular activities, such as cell proliferation and apoptosis at different heights, could be monitored non-invasively and in real-time by measuring the change in capacitance with the 3D capacitance sensor. Moreover, we were able to monitor cell migration of human mesenchymal stem cells (hMSCs) with our 3D capacitance sensor. PMID:26386332

  13. Fabrication and assessment of 3D printed anatomical models of the lower limb for anatomical teaching and femoral vessel access training in medicine.

    PubMed

    O'Reilly, Michael K; Reese, Sven; Herlihy, Therese; Geoghegan, Tony; Cantwell, Colin P; Feeney, Robin N M; Jones, James F X

    2016-01-01

    For centuries, cadaveric dissection has been the touchstone of anatomy education. It offers a medical student intimate access to his or her first patient. In contrast to idealized artisan anatomical models, it presents the natural variation of anatomy in fine detail. However, a new teaching construct has appeared recently in which artificial cadavers are manufactured through three-dimensional (3D) printing of patient specific radiological data sets. In this article, a simple powder based printer is made more versatile to manufacture hard bones, silicone muscles and perfusable blood vessels. The approach involves blending modern approaches (3D printing) with more ancient ones (casting and lost-wax techniques). These anatomically accurate models can augment the approach to anatomy teaching from dissection to synthesis of 3D-printed parts held together with embedded rare earth magnets. Vascular simulation is possible through application of pumps and artificial blood. The resulting arteries and veins can be cannulated and imaged with Doppler ultrasound. In some respects, 3D-printed anatomy is superior to older teaching methods because the parts are cheap, scalable, they can cover the entire age span, they can be both dissected and reassembled and the data files can be printed anywhere in the world and mass produced. Anatomical diversity can be collated as a digital repository and reprinted rather than waiting for the rare variant to appear in the dissection room. It is predicted that 3D printing will revolutionize anatomy when poly-material printing is perfected in the early 21st century.

  14. Development of paper-based microfluidic analytical device for iron assay using photomask printed with 3D printer for fabrication of hydrophilic and hydrophobic zones on paper by photolithography.

    PubMed

    Asano, Hitoshi; Shiraishi, Yukihide

    2015-07-01

    This paper describes a paper-based microfluidic analytical device for iron assay using a photomask printed with a 3D printer for fabrication of hydrophilic and hydrophobic zones on the paper by photolithography. Several designed photomasks for patterning paper-based microfluidic analytical devices can be printed with a 3D printer easily, rapidly and inexpensively. A chromatography paper was impregnated with the octadecyltrichlorosilane n-hexane solution and hydrophobized. After the hydrophobic zone of the paper was exposed to the UV light through the photomask, the hydrophilic zone was generated. The smallest functional hydrophilic channel and hydrophobic barrier were ca. 500 μm and ca. 100 μm in width, respectively. The fabrication method has high stability, resolution and precision for hydrophilic channel and hydrophobic barrier. This test paper was applied to the analysis of iron in water samples using a colorimetry with phenanthroline.

  15. Fabrication of biofunctionalized, cell-laden macroporous 3D PEG hydrogels as bone marrow analogs for the cultivation of human hematopoietic stem and progenitor cells.

    PubMed

    Rödling, Lisa; Raic, Annamarija; Lee-Thedieck, Cornelia

    2014-01-01

    In vitro proliferation of hematopoietic stem cells (HSCs) is yet an unresolved challenge. Found in the bone marrow, HSCs can undergo self-renewing cell division and thereby multiply. Recapitulation of the bone marrow environment in order to provide the required signals for their expansion is a promising approach.Here, we describe a technique to produce biofunctionalized, macroporous poly(ethylene glycol) diacrylate (PEGDA) hydrogels that mimic the spongy 3D architecture of trabecular bones, which host the red, blood-forming bone marrow. After seeding these scaffolds with cells, they can be used as simplified bone marrow analogs for the cultivation of HSCs. This method can easily be conducted with standard laboratory chemicals and equipment. The 3D hydrogels are produced via salt leaching and biofunctionalization of the material is achieved by co-polymerizing the PEGDA with an RGD peptide. Finally, cell seeding and retrieval are described.

  16. 3D volume assessment techniques and computer-aided design and manufacturing for preoperative fabrication of implants in head and neck reconstruction.

    PubMed

    Patel, Ashish; Otterburn, David; Saadeh, Pierre; Levine, Jamie; Hirsch, David L

    2011-11-01

    Cases in subdisciplines of craniomaxillofacial surgery--corrective jaw surgery, maxillofacial trauma, temporomandibular joint/skull base, jaw reconstruction, and postablative reconstruction-illustrate the ease of use, cost effectiveness, and superior results that can be achieved when using computer-assisted design and 3D volumetric analysis in preoperative surgical planning. This article discusses the materials and methods needed to plan cases, illustrates implementation of guides and implants, and describes postoperative analysis in relation to the virtually planned surgery.

  17. A New Total Digital Smile Planning Technique (3D-DSP) to Fabricate CAD-CAM Mockups for Esthetic Crowns and Veneers.

    PubMed

    Cattoni, F; Mastrangelo, F; Gherlone, E F; Gastaldi, G

    2016-01-01

    Purpose. Recently, the request of patients is changed in terms of not only esthetic but also previsualization therapy planning. The aim of this study is to evaluate a new 3D-CAD-CAM digital planning technique that uses a total digital smile process. Materials and Methods. Study participants included 28 adult dental patients, aged 19 to 53 years, with no oral, periodontal, or systemic diseases. For each patient, 3 intra- and extraoral pictures and intraoral digital impressions were taken. The digital images improved from the 2D Digital Smile System software and the scanner stereolithographic (STL) file was matched into the 3D-Digital Smile System to obtain a virtual previsualization of teeth and smile design. Then, the mockups were milled using a CAM system. Minimally invasive preparation was carried out on the enamel surface with the mockups as position guides. Results. The patients found both the digital smile design previsualization (64.3%) and the milling mockup test (85.7%) very effective. Conclusions. The new total 3D digital planning technique is a predictably and minimally invasive technique, allows easy diagnosis, and improves the communication with the patient and helps to reduce the working time and the errors usually associated with the classical prosthodontic manual step. PMID:27478442

  18. A New Total Digital Smile Planning Technique (3D-DSP) to Fabricate CAD-CAM Mockups for Esthetic Crowns and Veneers

    PubMed Central

    Mastrangelo, F.; Gherlone, E. F.; Gastaldi, G.

    2016-01-01

    Purpose. Recently, the request of patients is changed in terms of not only esthetic but also previsualization therapy planning. The aim of this study is to evaluate a new 3D-CAD-CAM digital planning technique that uses a total digital smile process. Materials and Methods. Study participants included 28 adult dental patients, aged 19 to 53 years, with no oral, periodontal, or systemic diseases. For each patient, 3 intra- and extraoral pictures and intraoral digital impressions were taken. The digital images improved from the 2D Digital Smile System software and the scanner stereolithographic (STL) file was matched into the 3D-Digital Smile System to obtain a virtual previsualization of teeth and smile design. Then, the mockups were milled using a CAM system. Minimally invasive preparation was carried out on the enamel surface with the mockups as position guides. Results. The patients found both the digital smile design previsualization (64.3%) and the milling mockup test (85.7%) very effective. Conclusions. The new total 3D digital planning technique is a predictably and minimally invasive technique, allows easy diagnosis, and improves the communication with the patient and helps to reduce the working time and the errors usually associated with the classical prosthodontic manual step. PMID:27478442

  19. A New Total Digital Smile Planning Technique (3D-DSP) to Fabricate CAD-CAM Mockups for Esthetic Crowns and Veneers.

    PubMed

    Cattoni, F; Mastrangelo, F; Gherlone, E F; Gastaldi, G

    2016-01-01

    Purpose. Recently, the request of patients is changed in terms of not only esthetic but also previsualization therapy planning. The aim of this study is to evaluate a new 3D-CAD-CAM digital planning technique that uses a total digital smile process. Materials and Methods. Study participants included 28 adult dental patients, aged 19 to 53 years, with no oral, periodontal, or systemic diseases. For each patient, 3 intra- and extraoral pictures and intraoral digital impressions were taken. The digital images improved from the 2D Digital Smile System software and the scanner stereolithographic (STL) file was matched into the 3D-Digital Smile System to obtain a virtual previsualization of teeth and smile design. Then, the mockups were milled using a CAM system. Minimally invasive preparation was carried out on the enamel surface with the mockups as position guides. Results. The patients found both the digital smile design previsualization (64.3%) and the milling mockup test (85.7%) very effective. Conclusions. The new total 3D digital planning technique is a predictably and minimally invasive technique, allows easy diagnosis, and improves the communication with the patient and helps to reduce the working time and the errors usually associated with the classical prosthodontic manual step.

  20. Europeana and 3D

    NASA Astrophysics Data System (ADS)

    Pletinckx, D.

    2011-09-01

    The current 3D hype creates a lot of interest in 3D. People go to 3D movies, but are we ready to use 3D in our homes, in our offices, in our communication? Are we ready to deliver real 3D to a general public and use interactive 3D in a meaningful way to enjoy, learn, communicate? The CARARE project is realising this for the moment in the domain of monuments and archaeology, so that real 3D of archaeological sites and European monuments will be available to the general public by 2012. There are several aspects to this endeavour. First of all is the technical aspect of flawlessly delivering 3D content over all platforms and operating systems, without installing software. We have currently a working solution in PDF, but HTML5 will probably be the future. Secondly, there is still little knowledge on how to create 3D learning objects, 3D tourist information or 3D scholarly communication. We are still in a prototype phase when it comes to integrate 3D objects in physical or virtual museums. Nevertheless, Europeana has a tremendous potential as a multi-facetted virtual museum. Finally, 3D has a large potential to act as a hub of information, linking to related 2D imagery, texts, video, sound. We describe how to create such rich, explorable 3D objects that can be used intuitively by the generic Europeana user and what metadata is needed to support the semantic linking.

  1. Fabrication of 3D interconnected porous TiO2 nanotubes templated by poly(vinyl chloride-g-4-vinyl pyridine) for dye-sensitized solar cells.

    PubMed

    Koh, Joo Hwan; Koh, Jong Kwan; Seo, Jin Ah; Shin, Jong-Shik; Kim, Jong Hak

    2011-09-01

    Porous TiO(2) nanotube arrays with three-dimensional (3D) interconnectivity were prepared using a sol-gel process assisted by poly(vinyl chloride-graft-4-vinyl pyridine), PVC-g-P4VP graft copolymer and a ZnO nanorod template. A 7 µm long ZnO nanorod array was grown from the fluorine-doped tin oxide (FTO) glass via a liquid phase deposition method. The TiO(2) sol-gel solution templated by the PVC-g-P4VP graft copolymer produced a random 3D interconnection between the adjacent ZnO nanorods during spin coating. Upon etching of ZnO, TiO(2) nanotubes consisting of 10-15 nm nanoparticles were generated, as confirmed by wide-angle x-ray scattering (WAXS), energy-filtering transmission electron microscopy (EF-TEM) and field-emission scanning electron microscopy (FE-SEM). The ordered and interconnected nanotube architecture showed an enhanced light scattering effect and increased penetration of polymer electrolytes in dye-sensitized solar cells (DSSC). The energy conversion efficiency reached 1.82% for liquid electrolyte, and 1.46% for low molecular weight (M(w)) and 0.74% for high M(w) polymer electrolytes.

  2. A novel method of hotspot temperature reduction for a 3D stacked CMOS IC chip device fabricated on an ultrathin substrate

    NASA Astrophysics Data System (ADS)

    Kato, Fumiki; Nakagawa, Hiroshi; Aoyagi, Masahiro

    2013-02-01

    A high-performance thermal management method for three-dimensional integrated circuit (IC) integration has been developed for use in conjunction with a three-dimensional (3D) large-scale integration (LSI) technology. By depositing a 10 µm thick high thermal conductivity (HTC) film consisting of 1680 alternating layers of silicon and graphite nano-films directly onto the backside of a Si substrate via an automatic sequencing sputtering method, reduction in the transient hotspot temperature in a thin-substrate CMOS IC chip is achieved. It is shown that this novel HTC film is able to overcome the thermal problems associated with thin substrates and allow the cooling of stacked ICs. In the work described in this paper, we demonstrated the performance of the HTC using a 100 µm thick substrate IC chip consisting of a complementary metal-oxide semiconductor (CMOS) ring oscillator circuit film. Our experimental results, which were confirmed in simulation, reveal a 28% reduction in the hotspot temperature rise owing to the presence of the HTC film. This technology is applicable to future developments in the 3D ultrathin substrate LSI chip stacking technology utilizing through-silicon vias (TSVs) and micro-bumps.

  3. 21 CFR 184.1133 - Ammonium alginate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... prepared by the neutralization of purified alginic acid with appropriate pH control agents. (b) The ingredient meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 18, which is incorporated... food Maximum level of use in food (as served) (percent) Functional use Confections, frostings, §...

  4. Design, fabrication, and implementation of voxel-based 3D printed textured phantoms for task-based image quality assessment in CT

    NASA Astrophysics Data System (ADS)

    Solomon, Justin; Ba, Alexandre; Diao, Andrew; Lo, Joseph; Bier, Elianna; Bochud, François; Gehm, Michael; Samei, Ehsan

    2016-03-01

    In x-ray computed tomography (CT), task-based image quality studies are typically performed using uniform background phantoms with low-contrast signals. Such studies may have limited clinical relevancy for modern non-linear CT systems due to possible influence of background texture on image quality. The purpose of this study was to design and implement anatomically informed textured phantoms for task-based assessment of low-contrast detection. Liver volumes were segmented from 23 abdominal CT cases. The volumes were characterized in terms of texture features from gray-level co-occurrence and run-length matrices. Using a 3D clustered lumpy background (CLB) model, a fitting technique based on a genetic optimization algorithm was used to find the CLB parameters that were most reflective of the liver textures, accounting for CT system factors of spatial blurring and noise. With the modeled background texture as a guide, a cylinder phantom (165 mm in diameter and 30 mm height) was designed, containing 20 low-contrast spherical signals (6 mm in diameter at targeted contrast levels of ~3.2, 5.2, 7.2, 10, and 14 HU, 4 repeats per signal). The phantom was voxelized and input into a commercial multi-material 3D printer (Object Connex 350), with custom software for voxel-based printing. Using principles of digital half-toning and dithering, the 3D printer was programmed to distribute two base materials (VeroWhite and TangoPlus, nominal voxel size of 42x84x30 microns) to achieve the targeted spatial distribution of x-ray attenuation properties. The phantom was used for task-based image quality assessment of a clinically available iterative reconstruction algorithm (Sinogram Affirmed Iterative Reconstruction, SAFIRE) using a channelized Hotelling observer paradigm. Images of the textured phantom and a corresponding uniform phantom were acquired at six dose levels and observer model performance was estimated for each condition (5 contrasts x 6 doses x 2 reconstructions x 2

  5. 3D-Printed Microfluidics.

    PubMed

    Au, Anthony K; Huynh, Wilson; Horowitz, Lisa F; Folch, Albert

    2016-03-14

    The advent of soft lithography allowed for an unprecedented expansion in the field of microfluidics. However, the vast majority of PDMS microfluidic devices are still made with extensive manual labor, are tethered to bulky control systems, and have cumbersome user interfaces, which all render commercialization difficult. On the other hand, 3D printing has begun to embrace the range of sizes and materials that appeal to the developers of microfluidic devices. Prior to fabrication, a design is digitally built as a detailed 3D CAD file. The design can be assembled in modules by remotely collaborating teams, and its mechanical and fluidic behavior can be simulated using finite-element modeling. As structures are created by adding materials without the need for etching or dissolution, processing is environmentally friendly and economically efficient. We predict that in the next few years, 3D printing will replace most PDMS and plastic molding techniques in academia.

  6. 3d-3d correspondence revisited

    NASA Astrophysics Data System (ADS)

    Chung, Hee-Joong; Dimofte, Tudor; Gukov, Sergei; Sułkowski, Piotr

    2016-04-01

    In fivebrane compactifications on 3-manifolds, we point out the importance of all flat connections in the proper definition of the effective 3d {N}=2 theory. The Lagrangians of some theories with the desired properties can be constructed with the help of homological knot invariants that categorify colored Jones polynomials. Higgsing the full 3d theories constructed this way recovers theories found previously by Dimofte-Gaiotto-Gukov. We also consider the cutting and gluing of 3-manifolds along smooth boundaries and the role played by all flat connections in this operation.

  7. 3d-3d correspondence revisited

    DOE PAGES

    Chung, Hee -Joong; Dimofte, Tudor; Gukov, Sergei; Sułkowski, Piotr

    2016-04-21

    In fivebrane compactifications on 3-manifolds, we point out the importance of all flat connections in the proper definition of the effective 3d N = 2 theory. The Lagrangians of some theories with the desired properties can be constructed with the help of homological knot invariants that categorify colored Jones polynomials. Higgsing the full 3d theories constructed this way recovers theories found previously by Dimofte-Gaiotto-Gukov. As a result, we also consider the cutting and gluing of 3-manifolds along smooth boundaries and the role played by all flat connections in this operation.

  8. Characterization and preparation of bio-tubular scaffolds for fabricating artificial vascular grafts by combining electrospinning and a 3D printing system.

    PubMed

    Lee, Sang Jin; Heo, Dong Nyoung; Park, Ji Sun; Kwon, Seong Keun; Lee, Jin Ho; Lee, Jun Hee; Kim, Wan Doo; Kwon, Il Keun; Park, Su A

    2015-02-01

    The last decade has seen artificial blood vessels composed of natural polymer nanofibers grafted into human bodies to facilitate the recovery of damaged blood vessels. However, electrospun nanofibers (ENs) of biocompatible materials such as chitosan (CTS) suffer from poor mechanical properties. This study describes the design and fabrication of artificial blood vessels composed of a blend of CTS and PCL ENs and coated with PCL strands using rapid prototyping technology. The resulting tubular vessels exhibited excellent mechanical properties and showed that this process may be useful for vascular reconstruction. PMID:25557615

  9. Characterization and preparation of bio-tubular scaffolds for fabricating artificial vascular grafts by combining electrospinning and a 3D printing system.

    PubMed

    Lee, Sang Jin; Heo, Dong Nyoung; Park, Ji Sun; Kwon, Seong Keun; Lee, Jin Ho; Lee, Jun Hee; Kim, Wan Doo; Kwon, Il Keun; Park, Su A

    2015-02-01

    The last decade has seen artificial blood vessels composed of natural polymer nanofibers grafted into human bodies to facilitate the recovery of damaged blood vessels. However, electrospun nanofibers (ENs) of biocompatible materials such as chitosan (CTS) suffer from poor mechanical properties. This study describes the design and fabrication of artificial blood vessels composed of a blend of CTS and PCL ENs and coated with PCL strands using rapid prototyping technology. The resulting tubular vessels exhibited excellent mechanical properties and showed that this process may be useful for vascular reconstruction.

  10. Control of Alginate Core Size in Alginate-Poly (Lactic-Co-Glycolic) Acid Microparticles

    NASA Astrophysics Data System (ADS)

    Lio, Daniel; Yeo, David; Xu, Chenjie

    2016-01-01

    Core-shell alginate-poly (lactic-co-glycolic) acid (PLGA) microparticles are potential candidates to improve hydrophilic drug loading while facilitating controlled release. This report studies the influence of the alginate core size on the drug release profile of alginate-PLGA microparticles and its size. Microparticles are synthesized through double-emulsion fabrication via a concurrent ionotropic gelation and solvent extraction. The size of alginate core ranges from approximately 10, 50, to 100 μm when the emulsification method at the first step is homogenization, vortexing, or magnetic stirring, respectively. The second step emulsification for all three conditions is performed with magnetic stirring. Interestingly, although the alginate core has different sizes, alginate-PLGA microparticle diameter does not change. However, drug release profiles are dramatically different for microparticles comprising different-sized alginate cores. Specifically, taking calcein as a model drug, microparticles containing the smallest alginate core (10 μm) show the slowest release over a period of 26 days with burst release less than 1 %.

  11. Perfluorinated alginate for cellular encapsulation.

    PubMed

    Gattás-Asfura, Kerim M; Fraker, Christopher A; Stabler, Cherie L

    2012-08-01

    Molecules of pentadecafluorooctanoyl chloride (PFC) were grafted onto alginate (Alg) using a linear poly(ethylene glycol) linker and amide bonds. The resulting Alg-PFC material was characterized by proton nuclear magnetic resonance and infrared spectroscopies. The degree of PFC functionalization significantly influenced the physical and chemical properties of Alg-PFC, particularly when the resulting polymer was ionically crosslinked into hydrogels. Alg-PFC hydrogel beads fabricated via Ba(2+) crosslinking were found to match the permeability properties of control alginate beads, except upon swelling over time in culture media. When used to encapsulate MIN6 cells, a beta cell line, Alg-PFC beads demonstrated enhanced cell proliferation over alginate control beads. These results indicate that Alg-PFC hydrogels retain some of the PFC's biological-relevant benefits, such as enhancement of mass transport and bioinertness, to enhance cellular viability within alginate three-dimensional hydrogel environments. We envision these functionalized hydrogels to be particularly useful in the encapsulation of cells with a high metabolic demand, such as pancreatic islets.

  12. 3D Printing for Tissue Engineering

    PubMed Central

    Jia, Jia; Yao, Hai; Mei, Ying

    2016-01-01

    Tissue engineering aims to fabricate functional tissue for applications in regenerative medicine and drug testing. More recently, 3D printing has shown great promise in tissue fabrication with a structural control from micro- to macro-scale by using a layer-by-layer approach. Whether through scaffold-based or scaffold-free approaches, the standard for 3D printed tissue engineering constructs is to provide a biomimetic structural environment that facilitates tissue formation and promotes host tissue integration (e.g., cellular infiltration, vascularization, and active remodeling). This review will cover several approaches that have advanced the field of 3D printing through novel fabrication methods of tissue engineering constructs. It will also discuss the applications of synthetic and natural materials for 3D printing facilitated tissue fabrication. PMID:26869728

  13. A Controlled Design of Aligned and Random Nanofibers for 3D Bi-functionalized Nerve Conduits Fabricated via a Novel Electrospinning Set-up

    PubMed Central

    Kim, Jeong In; Hwang, Tae In; Aguilar, Ludwig Erik; Park, Chan Hee; Kim, Cheol Sang

    2016-01-01

    Scaffolds made of aligned nanofibers are favorable for nerve regeneration due to their superior nerve cell attachment and proliferation. However, it is challenging not only to produce a neat mat or a conduit form with aligned nanofibers but also to use these for surgical applications as a nerve guide conduit due to their insufficient mechanical strength. Furthermore, no studies have been reported on the fabrication of aligned nanofibers and randomly-oriented nanofibers on the same mat. In this study, we have successfully produced a mat with both aligned and randomly-oriented nanofibers by using a novel electrospinning set up. A new conduit with a highly-aligned electrospun mat is produced with this modified electrospinning method, and this proposed conduit with favorable features, such as selective permeability, hydrophilicity and nerve growth directional steering, were fabricated as nerve guide conduits (NGCs). The inner surface of the nerve conduit is covered with highly aligned electrospun nanofibers and is able to enhance the proliferation of neural cells. The central part of the tube is double-coated with randomly-oriented nanofibers over the aligned nanofibers, strengthening the weak mechanical strength of the aligned nanofibers. PMID:27021221

  14. A 60-GHz-band 2 x 4 planar dipole array antenna module fabricated by 3-D SiP technology

    NASA Astrophysics Data System (ADS)

    Suematsu, Noriharu; Suzuki, Yuya; Yoshida, Satoshi; Tanifuji, Shoichi; Kameda, Suguru; Takagi, Tadashi; Tsubouchi, Kazuo

    2014-08-01

    A 2 × 4 phased array antenna module has been developed for 60-GHz-band short- range high-speed wireless communication terminals. To realize the required vertical distance between the antenna elements, the module is made of five sheets of multi-layered organic substrates vertically stacked with Cu balls, and the 1 x 4 dipole array antenna is placed on both the top and bottom organic substrates. To reduce the mutual coupling between the element antennas, a monolithic microwave integrated circuit (MMIC) is flip-chip mounted on the feed line of each element antenna. The Au-stud bump flip-chip mounting technique helps achieve a lower return loss in the transition section at the MMIC than the Au-wire bonded. The placement accuracy of each antenna element in the vertical direction, 60-GHz signal vertical interconnection between the substrates with Cu balls, and flip-chip mounting of the MMIC are confirmed by 3-D computed tomography (CT) scans.

  15. A New Approach for Fabricating Collagen/ECM-Based Bioinks Using Preosteoblasts and Human Adipose Stem Cells.

    PubMed

    Lee, Hyeong Jin; Kim, Yong Bok; Ahn, Seung Hyun; Lee, Ji-Seon; Jang, Chul Ho; Yoon, Hyeon; Chun, Wook; Kim, Geun Hyung

    2015-06-24

    Cell-printing methods have been used widely in tissue regeneration because they enable fabricating biomimetic 3D structures laden with various cells. To achieve a cell-matrix block, various natural hydrogels that are nontoxic, biocompatible, and printable have been combined to obtain "bioinks." Unfortunately, most bioinks, including those with alginates, show low cell-activating properties. Here, a strategy for obtaining highly bioactive ink, which consisted of collagen/extracellular matrix (ECM) and alginate, for printing 3D porous cell blocks is developed. An in vitro assessment of the 3D porous structures laden with preosteoblasts and human adipose stem cells (hASCs) demonstrates that the cells in the bioinks are viable. Osteogenic activities with the designed bioinks show much higher levels than with the "conventional" alginate-based bioink. Furthermore, the hepatogenic differentiation ability of hASCs with the bioink is evaluated using the liver-specific genes, albumin, and TDO2, under hepatogenic differentiation conditions. The genes are activated within the 3D cell block fabricated using the new bioink. These results demonstrate that the 3D cell-laden structure fabricated using collagen/ECM-based bioinks can provide a novel platform for various tissue engineering applications.

  16. SU-C-213-07: Fabrication and Testing of a 3D-Printed Small Animal Rectal Cooling Device to Evaluate Local Hypothermia as a Radioprotector During Prostate SBRT

    SciTech Connect

    Hrycushko, B; Chopra, R; Futch, C; Bing, C; Wodzak, M; Stojadinovic, S; Jiang, S; Medin, P

    2015-06-15

    Purpose: The protective effects of induced or even accidental hypothermia on the human body are widespread with several medical uses currently under active research. In vitro experiments using human cell lines have shown hypothermia provides a radioprotective effect that becomes more pronounced at large, single-fraction doses common to SBRT treatments. Relevant to prostate SBRT, this work details the fabrication and testing of a 3D-printed cooling device to facilitate the investigation of the radioprotective effect of local hypothermia on the rat rectum. Methods: A 3cm long, two-channel rectal cooling device was designed in SOLIDWORKS CAD for 3D printing. The water intake nozzle is connected to a 1mm diameter brass pipe from which water flows and circulates back around to the exit nozzle. Both nozzles are connected by plastic tubing to a water chiller pump. Following leak-proof testing, fiber optic temperature probes were used to evaluate the temperature over time when placed adjacent to the cooling device within a rat rectum. MRI thermometry characterized the relative temperature distribution in concentric ROIs surrounding the probe. CBCT images from a small-animal irradiator were evaluated for imaging artifacts which could affect Monte Carlo dose calculations during treatment planning. Results: The rectal temperature adjacent to the cooling device decreased from body temperature (37°C) to 15°C in 10–20 minutes from device insertion. Rectal temperature was maintained at 15±3°C during active cooling. MRI thermometry tests revealed a steep temperature gradient with increasing distance from the cooling device, with the desired temperature range maintained within the surrounding few millimeters. Conclusion: A 3D printed rectal cooling device was fabricated for the purpose of inducing local hypothermia in rat rectums. Rectal cooling capabilities were characterized in-vivo to facilitate an investigation of the radioprotective effect of hypothermia for late rectal

  17. Design and fabrication of a 3D-structured gold film with nanopores for local electric field enhancement in the pore.

    PubMed

    Grant-Jacob, James A; Oo, Swe Zin; Carpignano, Francesca; Boden, Stuart A; Brocklesby, William S; Charlton, Martin D B; Melvin, Tracy

    2016-02-12

    Three-dimensionally structured gold membrane films with nanopores of defined, periodic geometries are designed and fabricated to provide the spatially localised enhancement of electric fields by manipulation of the plasmons inside nanopores. Square nanopores of different size and orientation relative to the pyramid are considered for films in aqueous and air environments, which allow for control of the position of electric fields within the structure. Designs suitable for use with 780 nm light were created. Here, periodic pyramidal cavities produced by potassium hydroxide etching to the {111} planes of (100) silicon substrates are used as templates for creating a periodic, pyramidal structured, free-standing thin gold film. Consistent with the findings from the theoretical studies, a nano-sized hole of 50 nm square was milled through the gold film at a specific location in the cavity to provide electric field control which can subsequently used for enhancement of fluorescence or Raman scattering of molecules in the nanopore.

  18. Design and Fabrication of 3D printed Scaffolds with a Mechanical Strength Comparable to Cortical Bone to Repair Large Bone Defects

    PubMed Central

    Roohani-Esfahani, Seyed-Iman; Newman, Peter; Zreiqat, Hala

    2016-01-01

    A challenge in regenerating large bone defects under load is to create scaffolds with large and interconnected pores while providing a compressive strength comparable to cortical bone (100–150 MPa). Here we design a novel hexagonal architecture for a glass-ceramic scaffold to fabricate an anisotropic, highly porous three dimensional scaffolds with a compressive strength of 110 MPa. Scaffolds with hexagonal design demonstrated a high fatigue resistance (1,000,000 cycles at 1–10 MPa compressive cyclic load), failure reliability and flexural strength (30 MPa) compared with those for conventional architecture. The obtained strength is 150 times greater than values reported for polymeric and composite scaffolds and 5 times greater than reported values for ceramic and glass scaffolds at similar porosity. These scaffolds open avenues for treatment of load bearing bone defects in orthopaedic, dental and maxillofacial applications. PMID:26782020

  19. Design and Fabrication of 3D printed Scaffolds with a Mechanical Strength Comparable to Cortical Bone to Repair Large Bone Defects.

    PubMed

    Roohani-Esfahani, Seyed-Iman; Newman, Peter; Zreiqat, Hala

    2016-01-01

    A challenge in regenerating large bone defects under load is to create scaffolds with large and interconnected pores while providing a compressive strength comparable to cortical bone (100-150 MPa). Here we design a novel hexagonal architecture for a glass-ceramic scaffold to fabricate an anisotropic, highly porous three dimensional scaffolds with a compressive strength of 110 MPa. Scaffolds with hexagonal design demonstrated a high fatigue resistance (1,000,000 cycles at 1-10 MPa compressive cyclic load), failure reliability and flexural strength (30 MPa) compared with those for conventional architecture. The obtained strength is 150 times greater than values reported for polymeric and composite scaffolds and 5 times greater than reported values for ceramic and glass scaffolds at similar porosity. These scaffolds open avenues for treatment of load bearing bone defects in orthopaedic, dental and maxillofacial applications.

  20. Design and Fabrication of 3D printed Scaffolds with a Mechanical Strength Comparable to Cortical Bone to Repair Large Bone Defects

    NASA Astrophysics Data System (ADS)

    Roohani-Esfahani, Seyed-Iman; Newman, Peter; Zreiqat, Hala

    2016-01-01

    A challenge in regenerating large bone defects under load is to create scaffolds with large and interconnected pores while providing a compressive strength comparable to cortical bone (100-150 MPa). Here we design a novel hexagonal architecture for a glass-ceramic scaffold to fabricate an anisotropic, highly porous three dimensional scaffolds with a compressive strength of 110 MPa. Scaffolds with hexagonal design demonstrated a high fatigue resistance (1,000,000 cycles at 1-10 MPa compressive cyclic load), failure reliability and flexural strength (30 MPa) compared with those for conventional architecture. The obtained strength is 150 times greater than values reported for polymeric and composite scaffolds and 5 times greater than reported values for ceramic and glass scaffolds at similar porosity. These scaffolds open avenues for treatment of load bearing bone defects in orthopaedic, dental and maxillofacial applications.

  1. 3D and Education

    NASA Astrophysics Data System (ADS)

    Meulien Ohlmann, Odile

    2013-02-01

    Today the industry offers a chain of 3D products. Learning to "read" and to "create in 3D" becomes an issue of education of primary importance. 25 years professional experience in France, the United States and Germany, Odile Meulien set up a personal method of initiation to 3D creation that entails the spatial/temporal experience of the holographic visual. She will present some different tools and techniques used for this learning, their advantages and disadvantages, programs and issues of educational policies, constraints and expectations related to the development of new techniques for 3D imaging. Although the creation of display holograms is very much reduced compared to the creation of the 90ies, the holographic concept is spreading in all scientific, social, and artistic activities of our present time. She will also raise many questions: What means 3D? Is it communication? Is it perception? How the seeing and none seeing is interferes? What else has to be taken in consideration to communicate in 3D? How to handle the non visible relations of moving objects with subjects? Does this transform our model of exchange with others? What kind of interaction this has with our everyday life? Then come more practical questions: How to learn creating 3D visualization, to learn 3D grammar, 3D language, 3D thinking? What for? At what level? In which matter? for whom?

  2. Digital microfluidic three-dimensional cell culture and chemical screening platform using alginate hydrogels

    PubMed Central

    2015-01-01

    Electro wetting-on-dielectric (EWOD) digital microfluidics (DMF) can be used to develop improved chemical screening platforms using 3-dimensional (3D) cell culture. Alginate hydrogels are one common method by which a 3D cell culture environment is created. This paper presents a study of alginate gelation on EWOD DMF and investigates designs to obtain uniform alginate hydrogels that can be repeatedly addressed by any desired liquids. A design which allows for gels to be retained in place during liquid delivery and removal without using any physical barriers or hydrophilic patterning of substrates is presented. A proof of concept screening platform is demonstrated by examining the effects of different concentrations of a test chemical on 3D cells in alginate hydrogels. In addition, the temporal effects of the various chemical concentrations on different hydrogel posts are demonstrated, thereby establishing the benefits of an EWOD DMF 3D cell culture and chemical screening platform using alginate hydrogels. PMID:25945142

  3. Digital microfluidic three-dimensional cell culture and chemical screening platform using alginate hydrogels.

    PubMed

    George, Subin M; Moon, Hyejin

    2015-03-01

    Electro wetting-on-dielectric (EWOD) digital microfluidics (DMF) can be used to develop improved chemical screening platforms using 3-dimensional (3D) cell culture. Alginate hydrogels are one common method by which a 3D cell culture environment is created. This paper presents a study of alginate gelation on EWOD DMF and investigates designs to obtain uniform alginate hydrogels that can be repeatedly addressed by any desired liquids. A design which allows for gels to be retained in place during liquid delivery and removal without using any physical barriers or hydrophilic patterning of substrates is presented. A proof of concept screening platform is demonstrated by examining the effects of different concentrations of a test chemical on 3D cells in alginate hydrogels. In addition, the temporal effects of the various chemical concentrations on different hydrogel posts are demonstrated, thereby establishing the benefits of an EWOD DMF 3D cell culture and chemical screening platform using alginate hydrogels. PMID:25945142

  4. Simulation and Fabrication of a New Novel 3D Injectable Biosensor for High Throughput Genomics and Proteomics in a Lab-On-a-Chip Device

    PubMed Central

    Esfandyarpour, Rahim; Esfandyarpour, Hesaam; Harris, James S.; Davis, Ronald W.

    2013-01-01

    Biosensors are used for the detection of biochemical molecules such as proteins and nucleic acids. Traditional techniques, such as Enzyme-linked Immuno-sorbent Assay (ELISA) are sensitive but require several hours to yield an assay and usually require attaching a fluorophore molecule to the target molecule. Micromachined biosensors that employ electrical detection are now being developed. Here we describe one such device, which is ultrasensitive, real time, label-free and localized. It’s called the nanoneedle biosensor and shows promise to overcome some of the current limitations of biosensors. The key element about this device is a 10nm wide annular gap at the end of the needle, which is the sensitive part of the sensor. The total diameter of the sensor is about 100nm. Any change in the population of molecules in this gap results in a change of impedance across the gap. Single molecule detection should be possible because the sensory part of the sensor is in the range of bio molecules of interest. To increase throughput we can flow the solution containing the target molecules over an array of such structures, each with its own integrated readout circuitry to allow ‘real-time’ detection (i.e. several minutes) of label free molecules without sacrificing sensitivity. To fabricate the arrays we used electron beam lithography together with associated pattern transfer techniques. Preliminary measurements on individual needle structures in water are consistent with the design. Since the proposed sensor has a rigid nano-structure, this technology, once fully developed, could ultimately be used to directly monitor protein quantities within a single living cell, an application that would have significant utility for drug screening and studying various intracellular signaling pathways. PMID:24149048

  5. Simulation and fabrication of a new novel 3D injectable biosensor for high throughput genomics and proteomics in a lab-on-a-chip device

    NASA Astrophysics Data System (ADS)

    Esfandyarpour, Rahim; Esfandyarpour, Hesaam; Harris, James S.; Davis, Ronald W.

    2013-11-01

    Biosensors are used for the detection of biochemical molecules such as proteins and nucleic acids. Traditional techniques, such as enzyme-linked immuno-sorbent assay (ELISA), are sensitive but require several hours to yield a result and usually require the attachment of a fluorophore molecule to the target molecule. Micromachined biosensors that employ electrical detection are now being developed. Here we describe one such device, which is ultrasensitive, real-time, label free and localized. It is called the nanoneedle biosensor and shows promise to overcome some of the current limitations of biosensors. The key element of this device is a 10 nm wide annular gap at the end of the needle, which is the sensitive part of the sensor. The total diameter of the sensor is about 100 nm. Any change in the population of molecules in this gap results in a change of impedance across the gap. Single molecule detection should be possible because the sensory part of the sensor is in the range of bio-molecules of interest. To increase throughput we can flow the solution containing the target molecules over an array of such structures, each with its own integrated read-out circuitry to allow ‘real-time’ detection (i.e. several minutes) of label free molecules without sacrificing sensitivity. To fabricate the arrays we used electron beam lithography together with associated pattern transfer techniques. Preliminary measurements on individual needle structures in water are consistent with the design. Since the proposed sensor has a rigid nano-structure, this technology, once fully developed, could ultimately be used to directly monitor protein quantities within a single living cell, an application that would have significant utility for drug screening and studying various intracellular signaling pathways.

  6. 3D Imaging.

    ERIC Educational Resources Information Center

    Hastings, S. K.

    2002-01-01

    Discusses 3 D imaging as it relates to digital representations in virtual library collections. Highlights include X-ray computed tomography (X-ray CT); the National Science Foundation (NSF) Digital Library Initiatives; output peripherals; image retrieval systems, including metadata; and applications of 3 D imaging for libraries and museums. (LRW)

  7. Multifunctional, Highly Flexible, Free-Standing 3D Polypyrrole Foam.

    PubMed

    Wang, Chunhui; Ding, Yujie; Yuan, Ye; Cao, Anyuan; He, Xiaodong; Peng, Qingyu; Li, Yibin

    2016-08-01

    Multifunctional, highly flexible 3D polypyrrole (PPy) foam is fabricated via a simple electrodeposition method by using nickel foam as the template. The 3D PPy foam has a unique interior structure and is robust enough to manipulate directly.

  8. Microfluidic direct writer with integrated declogging mechanism for fabricating cell-laden hydrogel constructs.

    PubMed

    Ghorbanian, Setareh; Qasaimeh, Mohammad A; Akbari, Mohsen; Tamayol, Ali; Juncker, David

    2014-06-01

    Cell distribution and nutrient supply in 3D cell-laden hydrogel scaffolds are critical and should mimic the in vivo cellular environment, but been difficult to control with conventional fabrication methods. Here, we present a microfluidic direct writer (MFDW) to construct 3D cell-laden hydrogel structures with openings permitting media exchange. The MFDW comprises a monolithic microfluidic head, which delivers coaxial streams of cell-laden sodium alginate and calcium chloride solutions to form hydrogel fibers. Fiber diameter is controlled by adjusting the ratio of the volumetric flow rates. The MFDW head is mounted on a motorized stage, which is automatically controlled and moves at a speed synchronized with the speed of fiber fabrication. Head geometry, flow rates, and viscosity of the writing solutions were optimized to prevent the occurrence of curling and bulging. For continuous use, a highly reliable process is needed, which was accomplished with the integration of a declogging conduit supplying a solvent to dissolve the clogging gel. The MFDW was used for layer-by-layer fabrication of simple 3D structures with encapsulated cells. Assembly of 3D structures with distinct fibers is demonstrated by alternatively delivering two different alginate gel solutions. The MFDW head can be built rapidly and easily, and will allow 3D constructs for tissue engineering to be fabricated with multiple hydrogels and cell types.

  9. Maintenance of a bone collagen phenotype by osteoblast-like cells in 3D periodic porous titanium (Ti-6Al-4 V) structures fabricated by selective electron beam melting.

    PubMed

    Hrabe, Nikolas W; Heinl, Peter; Bordia, Rajendra K; Körner, Carolin; Fernandes, Russell J

    2013-01-01

    Regular 3D periodic porous Ti-6Al-4 V structures were fabricated by the selective electron beam melting method (EBM) over a range of relative densities (0.17-0.40) and pore sizes (500-1500 µm). Structures were seeded with human osteoblast-like cells (SAOS-2) and cultured for four weeks. Cells multiplied within these structures and extracellular matrix collagen content increased. Type I and type V collagens typically synthesized by osteoblasts were deposited in the newly formed matrix with time in culture. High magnification scanning electron microscopy revealed cells attached to surfaces on the interior of the structures with an increasingly fibrous matrix. The in-vitro results demonstrate that the novel EBM-processed porous structures, designed to address the effect of stress-shielding, are conducive to osteoblast attachment, proliferation and deposition of a collagenous matrix characteristic of bone.

  10. A General Strategy to Fabricate Carbon‐Coated 3D Porous Interconnected Metal Sulfides: Case Study of SnS/C Nanocomposite for High‐Performance Lithium and Sodium Ion Batteries

    PubMed Central

    Zhu, Changbao; Kopold, Peter; Li, Weihan; van Aken, Peter A.; Maier, Joachim

    2015-01-01

    Transition metal sulfides have a great potential for energy storage due to the pronouncedly higher capacity (owing to conversion to metal or even alloy) than traditional insertion electrode materials. However, the poor cycling stability still limits the development and application in lithium and sodium ion batteries. Here, taking SnS as a model material, a novel general strategy is proposed to fabricate a 3D porous interconnected metal sulfide/carbon nanocomposite by the electrostatic spray deposition technique without adding any expensive carbonaceous materials such as graphene or carbon nanotube. In this way, small nanorods of SnS are generated with sizes of ≈10–20 nm embedded in amorphous carbon and self‐assembled into a 3D porous interconnected nanocomposite. The SnS:C is directly deposited on the Ti foil as a current collector and neither conductive additives nor binder are needed for battery assembly. Such electrodes exhibit a high reversible capacity, high rate capability, and long cycling stability for both lithium and sodium storage. PMID:27722078

  11. Efficacy of rhBMP-2 loaded PCL/PLGA/β-TCP guided bone regeneration membrane fabricated by 3D printing technology for reconstruction of calvaria defects in rabbit.

    PubMed

    Shim, Jin-Hyung; Yoon, Min-Chul; Jeong, Chang-Mo; Jang, Jinah; Jeong, Sung-In; Cho, Dong-Woo; Huh, Jung-Bo

    2014-11-10

    We successfully fabricated a three-dimensional (3D) printing-based PCL/PLGA/β-TCP guided bone regeneration (GBR) membrane that slowly released rhBMP-2. To impregnate the GBR membrane with intact rhBMP-2, collagen solution encapsulating rhBMP-2 (5 µg ml(-1)) was infused into pores of a PCL/PLGA/β-TCP membrane constructed using a 3D printing system with four dispensing heads. In a release profile test, sustained release of rhBMP-2 was observed for up to 28 d. To investigate the efficacy of the GBR membrane on bone regeneration, PCL/PLGA/β-TCP membranes with or without rhBMP-2 were implanted in an 8 mm calvaria defect of rabbits. Bone formation was evaluated at weeks 4 and 8 histologically and histomorphometrically. A space making ability of the GBR membrane was successfully maintained in both groups, and significantly more new bone was formed at post-implantation weeks 4 and 8 by rhBMP-2 loaded GBR membranes. Interestingly, implantation with rhBMP-2 loaded GBR membranes led to almost entire healing of calvaria defects within 8 weeks.

  12. Quarantine control of Hessian fly (Diptera: Cecidomyiidae) in exported hay: a new treatment for large-size, polypropylene fabric-wrapped bales and a 3-d fumigation for compressed standard bales.

    PubMed

    Yokoyama, Victoria Y; Miller, Gina T

    2003-08-01

    Hessian fly puparia (37,167), Mayetiola destructor (Say), did not survive a large-scale commercial test (three freight containers) of a new quarantine treatment using compression (32 kg/cm2) and hydrogen phosphide fumigation (61 g/28.2 m3) for large-size, polypropylene fabric-wrapped bales of hay exported to Japan. Mean +/- SEM temperatures in the large-size bales in different locations in the freight containers ranged from 18.0 +/- 0.9 to 26.0 +/- 1.3 degrees C during the 7-d test conducted in a heated building at 20.1 +/- 1.1 degrees C. Highest concentrations of hydrogen phosphide in most locations in the freight containers were observed after 3 d of fumigation and ranged from 366.7 +/- 96.1 to 425.0 +/- 162.7 ppm (mean +/- SEM) and throughout the 7 d of fumigation ranged from 253.6 +/- 59.9 to 407.1 +/- 76.5 ppm (mean +/- SEM). Hydrogen phosphide residues after fumigation and aeration were <10 ppb and were below the U.S. Environmental Protection Agency tolerance of 0.1 ppm in animal feeds. The results of the test fulfills regulatory agency testing requirements and confirms the efficacy of the treatment to control Hessian fly in large-size, polypropylene fabric-wrapped bales of hay. Hessian fly puparia (2,160) did not survive a large-scale commercial test of compression (105 kg/cm2) and a 3-d hydrogen phosphide (60 g/28.3 m3) fumigation for standard bales.

  13. Microfluidic generation of hollow Ca-alginate microfibers.

    PubMed

    Meng, Zhi-Jun; Wang, Wei; Xie, Rui; Ju, Xiao-Jie; Liu, Zhuang; Chu, Liang-Yin

    2016-07-01

    This work reports on an efficient microfluidic approach for continuous production of hollow Ca-alginate microfibers with controllable structures and functions. A coaxial microcapillary microfluidic device combined with a rotator is constructed to produce a cylindrical flow jet with four aqueous solutions as templates for continuous fabrication and collection of microfibers. A four-aqueous-phase flow jet with an intermediate buffer flow between the Ca(2+)-containing and alginate-containing flows is used as the template for microfiber fabrication. The buffer flow efficiently controls the diffusion of Ca(2+) into the alginate-containing flow as well as the crosslinking reaction, thus ensuring the continuous fabrication of hollow Ca-alginate microfibers under relatively low flow rates without clogging of the microchannel. The structure of the hollow microfibers can be flexibly adjusted by changing the flow rates and device dimensions. Meanwhile, the continuous fabrication process of the microfibers allows flexible incorporation of a functional component into the sheath flow for functionalization and addition of active substances in the core flow for encapsulation. This is demonstrated by fabricating hollow Ca-alginate microfibers with a wall containing magnetic nanoparticles for magnetic functionalization and with hollow internals containing Chlorella pyrenoidosa cells for confined growth. This work provides an efficient strategy for continuous fabrication of functional hollow Ca-alginate microfibers with controllable structures and functions.

  14. Microfluidic generation of hollow Ca-alginate microfibers.

    PubMed

    Meng, Zhi-Jun; Wang, Wei; Xie, Rui; Ju, Xiao-Jie; Liu, Zhuang; Chu, Liang-Yin

    2016-07-01

    This work reports on an efficient microfluidic approach for continuous production of hollow Ca-alginate microfibers with controllable structures and functions. A coaxial microcapillary microfluidic device combined with a rotator is constructed to produce a cylindrical flow jet with four aqueous solutions as templates for continuous fabrication and collection of microfibers. A four-aqueous-phase flow jet with an intermediate buffer flow between the Ca(2+)-containing and alginate-containing flows is used as the template for microfiber fabrication. The buffer flow efficiently controls the diffusion of Ca(2+) into the alginate-containing flow as well as the crosslinking reaction, thus ensuring the continuous fabrication of hollow Ca-alginate microfibers under relatively low flow rates without clogging of the microchannel. The structure of the hollow microfibers can be flexibly adjusted by changing the flow rates and device dimensions. Meanwhile, the continuous fabrication process of the microfibers allows flexible incorporation of a functional component into the sheath flow for functionalization and addition of active substances in the core flow for encapsulation. This is demonstrated by fabricating hollow Ca-alginate microfibers with a wall containing magnetic nanoparticles for magnetic functionalization and with hollow internals containing Chlorella pyrenoidosa cells for confined growth. This work provides an efficient strategy for continuous fabrication of functional hollow Ca-alginate microfibers with controllable structures and functions. PMID:27302737

  15. 3-D Technology Approaches for Biological Ecologies

    NASA Astrophysics Data System (ADS)

    Liu, Liyu; Austin, Robert; U. S-China Physical-Oncology Sciences Alliance (PS-OA) Team

    Constructing three dimensional (3-D) landscapes is an inevitable issue in deep study of biological ecologies, because in whatever scales in nature, all of the ecosystems are composed by complex 3-D environments and biological behaviors. Just imagine if a 3-D technology could help complex ecosystems be built easily and mimic in vivo microenvironment realistically with flexible environmental controls, it will be a fantastic and powerful thrust to assist researchers for explorations. For years, we have been utilizing and developing different technologies for constructing 3-D micro landscapes for biophysics studies in in vitro. Here, I will review our past efforts, including probing cancer cell invasiveness with 3-D silicon based Tepuis, constructing 3-D microenvironment for cell invasion and metastasis through polydimethylsiloxane (PDMS) soft lithography, as well as explorations of optimized stenting positions for coronary bifurcation disease with 3-D wax printing and the latest home designed 3-D bio-printer. Although 3-D technologies is currently considered not mature enough for arbitrary 3-D micro-ecological models with easy design and fabrication, I hope through my talk, the audiences will be able to sense its significance and predictable breakthroughs in the near future. This work was supported by the State Key Development Program for Basic Research of China (Grant No. 2013CB837200), the National Natural Science Foundation of China (Grant No. 11474345) and the Beijing Natural Science Foundation (Grant No. 7154221).

  16. Characteristics of biochar derived from marine macroalgae and fabrication of granular biochar by entrapment in calcium-alginate beads for phosphate removal from aqueous solution.

    PubMed

    Jung, Kyung-Won; Jeong, Tae-Un; Kang, Ho-Jeong; Ahn, Kyu-Hong

    2016-07-01

    In this work, granular biochar, Laminaria japonica-derived biochar (LB)-calcium alginate beads (LB-CAB), was successfully prepared by dropping a mixture of powder biochar and alginate solution into a calcium chloride solution for phosphate adsorption. Among different marine macroalgae derived biochars, LB exhibited the best performance, showing a phosphate removal rate of 97.02%, which was attributed to its high Ca/P and Mg/P ratios. With increasing pyrolysis temperature up to 600°C, the physicochemical properties of LB became suitable for adsorbing phosphate. Experimental results of kinetics and equilibrium isotherms at different temperatures (10-30°C) showed that the phosphate adsorption process is endothermic and is mainly controlled by external mass transfer and the intraparticle diffusion rate. The maximum adsorption capacity was found to be 157.7mgg(-1) at 30°C, as fitted by the Langmuir-Freundlich model, which is higher than capacities of other powder form of biochars.

  17. Immobilization of electroporated cells for fabrication of cellular biosensors: physiological effects of the shape of calcium alginate matrices and foetal calf serum.

    PubMed

    Katsanakis, Nikos; Katsivelis, Andreas; Kintzios, Spiridon

    2009-01-01

    In order to investigate the physiological effect of transfected cell immobilization in calcium alginate gels, we immobilized electroporated Vero cells in gels shaped either as spherical beads or as thin membrane layers. In addition, we investigated whether serum addition had a positive effect on cell proliferation and viability in either gel configuration. The gels were stored for four weeks in a medium supplemented or not with 20% (v/v) foetal calf serum. Throughout a culture period of four weeks, cell proliferation and cell viability were assayed by optical microscopy after provision of Trypan Blue. Non-elaborate culture conditions (room temperature, non-CO(2) enriched culture atmosphere) were applied throughout the experimental period in order to evaluate cell viability under less than optimal storage conditions. Immobilization of electroporated cells was associated with an initially reduced cell viability, which was gradually increased. Immobilization was associated with maintenance of cell growth for the duration of the experimental period, whereas electroporated cells essentially died after a week in suspension culture. Considerable proliferation of immobilized cells was observed in spherical alginate beads. In both gel configurations, addition of serum was associated with increased cell proliferation. The results of the present study could contribute to an improvement of the storability of biosensors based on electroporated, genetically or membrane-engineered cells.

  18. Conducting Polymer 3D Microelectrodes

    PubMed Central

    Sasso, Luigi; Vazquez, Patricia; Vedarethinam, Indumathi; Castillo-León, Jaime; Emnéus, Jenny; Svendsen, Winnie E.

    2010-01-01

    Conducting polymer 3D microelectrodes have been fabricated for possible future neurological applications. A combination of micro-fabrication techniques and chemical polymerization methods has been used to create pillar electrodes in polyaniline and polypyrrole. The thin polymer films obtained showed uniformity and good adhesion to both horizontal and vertical surfaces. Electrodes in combination with metal/conducting polymer materials have been characterized by cyclic voltammetry and the presence of the conducting polymer film has shown to increase the electrochemical activity when compared with electrodes coated with only metal. An electrochemical characterization of gold/polypyrrole electrodes showed exceptional electrochemical behavior and activity. PC12 cells were finally cultured on the investigated materials as a preliminary biocompatibility assessment. These results show that the described electrodes are possibly suitable for future in-vitro neurological measurements. PMID:22163508

  19. Controlled Fabrication of Bioactive Microfibers for Creating Tissue Constructs Using Microfluidic Techniques.

    PubMed

    Cheng, Yao; Yu, Yunru; Fu, Fanfan; Wang, Jie; Shang, Luoran; Gu, Zhongze; Zhao, Yuanjin

    2016-01-20

    The fabrication of heterogeneous microstructures, which exert precise control over the distribution of different cell types within biocompatible constructs, is important for many tissue engineering applications. Here, bioactive microfibers with tunable morphologies, structures, and components are generated and employed for creating different tissue constructs. Multibarrel capillary microfluidics with multiple laminar flows are used for continuously spinning these microfibers. With an immediate gelation reaction of the cell dispersed alginate solutions, the cell-laden alginate microfibers with the tunable morphologies and structures as the designed multiple laminar flows can be generated. The performances of the microfibers in cell culture are improved by incorporating bioactive polymers, such as extracellular matrix (ECM) or methacrylated gelatin (GelMA), into the alginate. It is demonstrated that a series of complex three-dimensional (3D) architectural cellular buildings, including biomimic vessels and scaffolds, can be created using these bioactive microfibers.

  20. Fabrication of 3D carbon nanotube networks

    NASA Astrophysics Data System (ADS)

    Laera, Anna Maria; Mirenghi, Luciana; Schioppa, Monica; Nobile, Concetta; Capodieci, Laura; Grazia Scalone, Anna; Di Benedetto, Francesca; Tapfer, Leander

    2016-08-01

    We report on the synthesis and characterization of a hyperbranched polymer englobing single-wall carbon nanotubes (SWCNTs). This new material was obtained by using SWCNTs functionalized with carboxylic groups as starting reagent. The acid groups were firstly converted in acyl chloride moieties and afterwards were bound to hexamethylenediamine (HMDA) via formation of amide functionality. The acquired spectra of attenuated total reflectance and the analysis performed through x-ray photoelectron spectroscopy confirmed the amide bond formation. The hyperbranched polymer characterization was completed by using scanning and transmission electron microscopy, thermo-gravimetric analysis and Raman spectroscopy. The electron microscopy analyses showed the formation of an amorphous polymeric material englobing a dense network of SWCNTs without phase segregation, demonstrating that the reaction with HMDA allows a reorganization of SWCNTs in a complex three-dimensional network.

  1. Radiochromic 3D Detectors

    NASA Astrophysics Data System (ADS)

    Oldham, Mark

    2015-01-01

    Radiochromic materials exhibit a colour change when exposed to ionising radiation. Radiochromic film has been used for clinical dosimetry for many years and increasingly so recently, as films of higher sensitivities have become available. The two principle advantages of radiochromic dosimetry include greater tissue equivalence (radiologically) and the lack of requirement for development of the colour change. In a radiochromic material, the colour change arises direct from ionising interactions affecting dye molecules, without requiring any latent chemical, optical or thermal development, with important implications for increased accuracy and convenience. It is only relatively recently however, that 3D radiochromic dosimetry has become possible. In this article we review recent developments and the current state-of-the-art of 3D radiochromic dosimetry, and the potential for a more comprehensive solution for the verification of complex radiation therapy treatments, and 3D dose measurement in general.

  2. 3-D Seismic Interpretation

    NASA Astrophysics Data System (ADS)

    Moore, Gregory F.

    2009-05-01

    This volume is a brief introduction aimed at those who wish to gain a basic and relatively quick understanding of the interpretation of three-dimensional (3-D) seismic reflection data. The book is well written, clearly illustrated, and easy to follow. Enough elementary mathematics are presented for a basic understanding of seismic methods, but more complex mathematical derivations are avoided. References are listed for readers interested in more advanced explanations. After a brief introduction, the book logically begins with a succinct chapter on modern 3-D seismic data acquisition and processing. Standard 3-D acquisition methods are presented, and an appendix expands on more recent acquisition techniques, such as multiple-azimuth and wide-azimuth acquisition. Although this chapter covers the basics of standard time processing quite well, there is only a single sentence about prestack depth imaging, and anisotropic processing is not mentioned at all, even though both techniques are now becoming standard.

  3. 3D-printed microfluidic devices.

    PubMed

    Amin, Reza; Knowlton, Stephanie; Hart, Alexander; Yenilmez, Bekir; Ghaderinezhad, Fariba; Katebifar, Sara; Messina, Michael; Khademhosseini, Ali; Tasoglu, Savas

    2016-06-20

    Microfluidics is a flourishing field, enabling a wide range of biochemical and clinical applications such as cancer screening, micro-physiological system engineering, high-throughput drug testing, and point-of-care diagnostics. However, fabrication of microfluidic devices is often complicated, time consuming, and requires expensive equipment and sophisticated cleanroom facilities. Three-dimensional (3D) printing presents a promising alternative to traditional techniques such as lithography and PDMS-glass bonding, not only by enabling rapid design iterations in the development stage, but also by reducing the costs associated with institutional infrastructure, equipment installation, maintenance, and physical space. With the recent advancements in 3D printing technologies, highly complex microfluidic devices can be fabricated via single-step, rapid, and cost-effective protocols, making microfluidics more accessible to users. In this review, we discuss a broad range of approaches for the application of 3D printing technology to fabrication of micro-scale lab-on-a-chip devices.

  4. Bootstrapping 3D fermions

    DOE PAGES

    Iliesiu, Luca; Kos, Filip; Poland, David; Pufu, Silviu S.; Simmons-Duffin, David; Yacoby, Ran

    2016-03-17

    We study the conformal bootstrap for a 4-point function of fermions <ψψψψ> in 3D. We first introduce an embedding formalism for 3D spinors and compute the conformal blocks appearing in fermion 4-point functions. Using these results, we find general bounds on the dimensions of operators appearing in the ψ × ψ OPE, and also on the central charge CT. We observe features in our bounds that coincide with scaling dimensions in the GrossNeveu models at large N. Finally, we also speculate that other features could coincide with a fermionic CFT containing no relevant scalar operators.

  5. Direct 3D bioprinting of perfusable vascular constructs using a blend bioink.

    PubMed

    Jia, Weitao; Gungor-Ozkerim, P Selcan; Zhang, Yu Shrike; Yue, Kan; Zhu, Kai; Liu, Wanjun; Pi, Qingment; Byambaa, Batzaya; Dokmeci, Mehmet Remzi; Shin, Su Ryon; Khademhosseini, Ali

    2016-11-01

    Despite the significant technological advancement in tissue engineering, challenges still exist towards the development of complex and fully functional tissue constructs that mimic their natural counterparts. To address these challenges, bioprinting has emerged as an enabling technology to create highly organized three-dimensional (3D) vascular networks within engineered tissue constructs to promote the transport of oxygen, nutrients, and waste products, which can hardly be realized using conventional microfabrication techniques. Here, we report the development of a versatile 3D bioprinting strategy that employs biomimetic biomaterials and an advanced extrusion system to deposit perfusable vascular structures with highly ordered arrangements in a single-step process. In particular, a specially designed cell-responsive bioink consisting of gelatin methacryloyl (GelMA), sodium alginate, and 4-arm poly(ethylene glycol)-tetra-acrylate (PEGTA) was used in combination with a multilayered coaxial extrusion system to achieve direct 3D bioprinting. This blend bioink could be first ionically crosslinked by calcium ions followed by covalent photocrosslinking of GelMA and PEGTA to form stable constructs. The rheological properties of the bioink and the mechanical strengths of the resulting constructs were tuned by the introduction of PEGTA, which facilitated the precise deposition of complex multilayered 3D perfusable hollow tubes. This blend bioink also displayed favorable biological characteristics that supported the spreading and proliferation of encapsulated endothelial and stem cells in the bioprinted constructs, leading to the formation of biologically relevant, highly organized, perfusable vessels. These characteristics make this novel 3D bioprinting technique superior to conventional microfabrication or sacrificial templating approaches for fabrication of the perfusable vasculature. We envision that our advanced bioprinting technology and bioink formulation may also

  6. Direct 3D bioprinting of perfusable vascular constructs using a blend bioink.

    PubMed

    Jia, Weitao; Gungor-Ozkerim, P Selcan; Zhang, Yu Shrike; Yue, Kan; Zhu, Kai; Liu, Wanjun; Pi, Qingment; Byambaa, Batzaya; Dokmeci, Mehmet Remzi; Shin, Su Ryon; Khademhosseini, Ali

    2016-11-01

    Despite the significant technological advancement in tissue engineering, challenges still exist towards the development of complex and fully functional tissue constructs that mimic their natural counterparts. To address these challenges, bioprinting has emerged as an enabling technology to create highly organized three-dimensional (3D) vascular networks within engineered tissue constructs to promote the transport of oxygen, nutrients, and waste products, which can hardly be realized using conventional microfabrication techniques. Here, we report the development of a versatile 3D bioprinting strategy that employs biomimetic biomaterials and an advanced extrusion system to deposit perfusable vascular structures with highly ordered arrangements in a single-step process. In particular, a specially designed cell-responsive bioink consisting of gelatin methacryloyl (GelMA), sodium alginate, and 4-arm poly(ethylene glycol)-tetra-acrylate (PEGTA) was used in combination with a multilayered coaxial extrusion system to achieve direct 3D bioprinting. This blend bioink could be first ionically crosslinked by calcium ions followed by covalent photocrosslinking of GelMA and PEGTA to form stable constructs. The rheological properties of the bioink and the mechanical strengths of the resulting constructs were tuned by the introduction of PEGTA, which facilitated the precise deposition of complex multilayered 3D perfusable hollow tubes. This blend bioink also displayed favorable biological characteristics that supported the spreading and proliferation of encapsulated endothelial and stem cells in the bioprinted constructs, leading to the formation of biologically relevant, highly organized, perfusable vessels. These characteristics make this novel 3D bioprinting technique superior to conventional microfabrication or sacrificial templating approaches for fabrication of the perfusable vasculature. We envision that our advanced bioprinting technology and bioink formulation may also

  7. Venus in 3D

    NASA Astrophysics Data System (ADS)

    Plaut, J. J.

    1993-08-01

    Stereographic images of the surface of Venus which enable geologists to reconstruct the details of the planet's evolution are discussed. The 120-meter resolution of these 3D images make it possible to construct digital topographic maps from which precise measurements can be made of the heights, depths, slopes, and volumes of geologic structures.

  8. 3D reservoir visualization

    SciTech Connect

    Van, B.T.; Pajon, J.L.; Joseph, P. )

    1991-11-01

    This paper shows how some simple 3D computer graphics tools can be combined to provide efficient software for visualizing and analyzing data obtained from reservoir simulators and geological simulations. The animation and interactive capabilities of the software quickly provide a deep understanding of the fluid-flow behavior and an accurate idea of the internal architecture of a reservoir.

  9. 3D rapid mapping

    NASA Astrophysics Data System (ADS)

    Isaksson, Folke; Borg, Johan; Haglund, Leif

    2008-04-01

    In this paper the performance of passive range measurement imaging using stereo technique in real time applications is described. Stereo vision uses multiple images to get depth resolution in a similar way as Synthetic Aperture Radar (SAR) uses multiple measurements to obtain better spatial resolution. This technique has been used in photogrammetry for a long time but it will be shown that it is now possible to do the calculations, with carefully designed image processing algorithms, in e.g. a PC in real time. In order to get high resolution and quantitative data in the stereo estimation a mathematical camera model is used. The parameters to the camera model are settled in a calibration rig or in the case of a moving camera the scene itself can be used for calibration of most of the parameters. After calibration an ordinary TV camera has an angular resolution like a theodolite, but to a much lower price. The paper will present results from high resolution 3D imagery from air to ground. The 3D-results from stereo calculation of image pairs are stitched together into a large database to form a 3D-model of the area covered.

  10. Fabrication of granular activated carbons derived from spent coffee grounds by entrapment in calcium alginate beads for adsorption of acid orange 7 and methylene blue.

    PubMed

    Jung, Kyung-Won; Choi, Brian Hyun; Hwang, Min-Jin; Jeong, Tae-Un; Ahn, Kyu-Hong

    2016-11-01

    Biomass-based granular activated carbon was successfully prepared by entrapping activated carbon powder derived from spent coffee grounds into calcium-alginate beads (SCG-GAC) for the removal of acid orange 7 (AO7) and methylene blue (MB) from aqueous media. The dye adsorption process is highly pH-dependent and essentially independent of ionic effects. The adsorption kinetics was satisfactorily described by the pore diffusion model, which revealed that pore diffusion was the rate-limiting step during the adsorption process. The equilibrium isotherm and isosteric heat of adsorption indicate that SCG-GAC possesses an energetically heterogeneous surface and operates via endothermic process in nature. The maximum adsorption capacities of SCG-GAC for AO7 (pH 3.0) and MB (pH 11.0) adsorption were found to be 665.9 and 986.8mg/g at 30°C, respectively. Lastly, regeneration tests further confirmed that SCG-GAC has promising potential in its reusability, showing removal efficiency of more than 80% even after seven consecutive cycles.

  11. Fabrication of granular activated carbons derived from spent coffee grounds by entrapment in calcium alginate beads for adsorption of acid orange 7 and methylene blue.

    PubMed

    Jung, Kyung-Won; Choi, Brian Hyun; Hwang, Min-Jin; Jeong, Tae-Un; Ahn, Kyu-Hong

    2016-11-01

    Biomass-based granular activated carbon was successfully prepared by entrapping activated carbon powder derived from spent coffee grounds into calcium-alginate beads (SCG-GAC) for the removal of acid orange 7 (AO7) and methylene blue (MB) from aqueous media. The dye adsorption process is highly pH-dependent and essentially independent of ionic effects. The adsorption kinetics was satisfactorily described by the pore diffusion model, which revealed that pore diffusion was the rate-limiting step during the adsorption process. The equilibrium isotherm and isosteric heat of adsorption indicate that SCG-GAC possesses an energetically heterogeneous surface and operates via endothermic process in nature. The maximum adsorption capacities of SCG-GAC for AO7 (pH 3.0) and MB (pH 11.0) adsorption were found to be 665.9 and 986.8mg/g at 30°C, respectively. Lastly, regeneration tests further confirmed that SCG-GAC has promising potential in its reusability, showing removal efficiency of more than 80% even after seven consecutive cycles. PMID:27494099

  12. Taming supersymmetric defects in 3d-3d correspondence

    NASA Astrophysics Data System (ADS)

    Gang, Dongmin; Kim, Nakwoo; Romo, Mauricio; Yamazaki, Masahito

    2016-07-01

    We study knots in 3d Chern-Simons theory with complex gauge group {SL}(N,{{C}}), in the context of its relation with 3d { N }=2 theory (the so-called 3d-3d correspondence). The defect has either co-dimension 2 or co-dimension 4 inside the 6d (2,0) theory, which is compactified on a 3-manifold \\hat{M}. We identify such defects in various corners of the 3d-3d correspondence, namely in 3d {SL}(N,{{C}}) CS theory, in 3d { N }=2 theory, in 5d { N }=2 super Yang-Mills theory, and in the M-theory holographic dual. We can make quantitative checks of the 3d-3d correspondence by computing partition functions at each of these theories. This Letter is a companion to a longer paper [1], which contains more details and more results.

  13. 3D Audio System

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Ames Research Center research into virtual reality led to the development of the Convolvotron, a high speed digital audio processing system that delivers three-dimensional sound over headphones. It consists of a two-card set designed for use with a personal computer. The Convolvotron's primary application is presentation of 3D audio signals over headphones. Four independent sound sources are filtered with large time-varying filters that compensate for motion. The perceived location of the sound remains constant. Possible applications are in air traffic control towers or airplane cockpits, hearing and perception research and virtual reality development.

  14. Medical 3D Printing for the Radiologist.

    PubMed

    Mitsouras, Dimitris; Liacouras, Peter; Imanzadeh, Amir; Giannopoulos, Andreas A; Cai, Tianrun; Kumamaru, Kanako K; George, Elizabeth; Wake, Nicole; Caterson, Edward J; Pomahac, Bohdan; Ho, Vincent B; Grant, Gerald T; Rybicki, Frank J

    2015-01-01

    While use of advanced visualization in radiology is instrumental in diagnosis and communication with referring clinicians, there is an unmet need to render Digital Imaging and Communications in Medicine (DICOM) images as three-dimensional (3D) printed models capable of providing both tactile feedback and tangible depth information about anatomic and pathologic states. Three-dimensional printed models, already entrenched in the nonmedical sciences, are rapidly being embraced in medicine as well as in the lay community. Incorporating 3D printing from images generated and interpreted by radiologists presents particular challenges, including training, materials and equipment, and guidelines. The overall costs of a 3D printing laboratory must be balanced by the clinical benefits. It is expected that the number of 3D-printed models generated from DICOM images for planning interventions and fabricating implants will grow exponentially. Radiologists should at a minimum be familiar with 3D printing as it relates to their field, including types of 3D printing technologies and materials used to create 3D-printed anatomic models, published applications of models to date, and clinical benefits in radiology. Online supplemental material is available for this article.

  15. Medical 3D Printing for the Radiologist.

    PubMed

    Mitsouras, Dimitris; Liacouras, Peter; Imanzadeh, Amir; Giannopoulos, Andreas A; Cai, Tianrun; Kumamaru, Kanako K; George, Elizabeth; Wake, Nicole; Caterson, Edward J; Pomahac, Bohdan; Ho, Vincent B; Grant, Gerald T; Rybicki, Frank J

    2015-01-01

    While use of advanced visualization in radiology is instrumental in diagnosis and communication with referring clinicians, there is an unmet need to render Digital Imaging and Communications in Medicine (DICOM) images as three-dimensional (3D) printed models capable of providing both tactile feedback and tangible depth information about anatomic and pathologic states. Three-dimensional printed models, already entrenched in the nonmedical sciences, are rapidly being embraced in medicine as well as in the lay community. Incorporating 3D printing from images generated and interpreted by radiologists presents particular challenges, including training, materials and equipment, and guidelines. The overall costs of a 3D printing laboratory must be balanced by the clinical benefits. It is expected that the number of 3D-printed models generated from DICOM images for planning interventions and fabricating implants will grow exponentially. Radiologists should at a minimum be familiar with 3D printing as it relates to their field, including types of 3D printing technologies and materials used to create 3D-printed anatomic models, published applications of models to date, and clinical benefits in radiology. Online supplemental material is available for this article. PMID:26562233

  16. Medical 3D Printing for the Radiologist

    PubMed Central

    Mitsouras, Dimitris; Liacouras, Peter; Imanzadeh, Amir; Giannopoulos, Andreas A.; Cai, Tianrun; Kumamaru, Kanako K.; George, Elizabeth; Wake, Nicole; Caterson, Edward J.; Pomahac, Bohdan; Ho, Vincent B.; Grant, Gerald T.

    2015-01-01

    While use of advanced visualization in radiology is instrumental in diagnosis and communication with referring clinicians, there is an unmet need to render Digital Imaging and Communications in Medicine (DICOM) images as three-dimensional (3D) printed models capable of providing both tactile feedback and tangible depth information about anatomic and pathologic states. Three-dimensional printed models, already entrenched in the nonmedical sciences, are rapidly being embraced in medicine as well as in the lay community. Incorporating 3D printing from images generated and interpreted by radiologists presents particular challenges, including training, materials and equipment, and guidelines. The overall costs of a 3D printing laboratory must be balanced by the clinical benefits. It is expected that the number of 3D-printed models generated from DICOM images for planning interventions and fabricating implants will grow exponentially. Radiologists should at a minimum be familiar with 3D printing as it relates to their field, including types of 3D printing technologies and materials used to create 3D-printed anatomic models, published applications of models to date, and clinical benefits in radiology. Online supplemental material is available for this article. ©RSNA, 2015 PMID:26562233

  17. Three-dimensional bioprinting of complex cell laden alginate hydrogel structures.

    PubMed

    Tabriz, Atabak Ghanizadeh; Hermida, Miguel A; Leslie, Nicholas R; Shu, Wenmiao

    2015-01-01

    Different bioprinting techniques have been used to produce cell-laden alginate hydrogel structures, however these approaches have been limited to 2D or simple three-dimension (3D) structures. In this study, a new extrusion based bioprinting technique was developed to produce more complex alginate hydrogel structures. This was achieved by dividing the alginate hydrogel cross-linking process into three stages: primary calcium ion cross-linking for printability of the gel, secondary calcium cross-linking for rigidity of the alginate hydrogel immediately after printing and tertiary barium ion cross-linking for long-term stability of the alginate hydrogel in culture medium. Simple 3D structures including tubes were first printed to ensure the feasibility of the bioprinting technique and then complex 3D structures such as branched vascular structures were successfully printed. The static stiffness of the alginate hydrogel after printing was 20.18 ± 1.62 KPa which was rigid enough to sustain the integrity of the complex 3D alginate hydrogel structure during the printing. The addition of 60 mM barium chloride was found to significantly extend the stability of the cross-linked alginate hydrogel from 3 d to beyond 11 d without compromising the cellular viability. The results based on cell bioprinting suggested that viability of U87-MG cells was 93 ± 0.9% immediately after bioprinting and cell viability maintained above 88% ± 4.3% in the alginate hydrogel over the period of 11 d. PMID:26689257

  18. Three-dimensional bioprinting of complex cell laden alginate hydrogel structures.

    PubMed

    Tabriz, Atabak Ghanizadeh; Hermida, Miguel A; Leslie, Nicholas R; Shu, Wenmiao

    2015-12-21

    Different bioprinting techniques have been used to produce cell-laden alginate hydrogel structures, however these approaches have been limited to 2D or simple three-dimension (3D) structures. In this study, a new extrusion based bioprinting technique was developed to produce more complex alginate hydrogel structures. This was achieved by dividing the alginate hydrogel cross-linking process into three stages: primary calcium ion cross-linking for printability of the gel, secondary calcium cross-linking for rigidity of the alginate hydrogel immediately after printing and tertiary barium ion cross-linking for long-term stability of the alginate hydrogel in culture medium. Simple 3D structures including tubes were first printed to ensure the feasibility of the bioprinting technique and then complex 3D structures such as branched vascular structures were successfully printed. The static stiffness of the alginate hydrogel after printing was 20.18 ± 1.62 KPa which was rigid enough to sustain the integrity of the complex 3D alginate hydrogel structure during the printing. The addition of 60 mM barium chloride was found to significantly extend the stability of the cross-linked alginate hydrogel from 3 d to beyond 11 d without compromising the cellular viability. The results based on cell bioprinting suggested that viability of U87-MG cells was 93 ± 0.9% immediately after bioprinting and cell viability maintained above 88% ± 4.3% in the alginate hydrogel over the period of 11 d.

  19. Fabrication of 3D core-shell multiwalled carbon nanotube@RuO2 lithium-ion battery electrodes through a RuO2 atomic layer deposition process.

    PubMed

    Gregorczyk, Keith E; Kozen, Alexander C; Chen, Xinyi; Schroeder, Marshall A; Noked, Malachi; Cao, Anyuan; Hu, Liangbing; Rubloff, Gary W

    2015-01-27

    Pushing lithium-ion battery (LIB) technology forward to its fundamental scaling limits requires the ability to create designer heterostructured materials and architectures. Atomic layer deposition (ALD) has recently been applied to advanced nanostructured energy storage devices due to the wide range of available materials, angstrom thickness control, and extreme conformality over high aspect ratio nanostructures. A class of materials referred to as conversion electrodes has recently been proposed as high capacity electrodes. RuO2 is considered an ideal conversion material due to its high combined electronic and ionic conductivity and high gravimetric capacity, and as such is an excellent material to explore the behavior of conversion electrodes at nanoscale thicknesses. We report here a fully characterized atomic layer deposition process for RuO2, electrochemical cycling data for ALD RuO2, and the application of the RuO2 to a composite carbon nanotube electrode scaffold with nucleation-controlled RuO2 growth. A growth rate of 0.4 Å/cycle is found between ∼ 210-240 °C. In a planar configuration, the resulting RuO2 films show high first cycle electrochemical capacities of ∼ 1400 mAh/g, but the capacity rapidly degrades with charge/discharge cycling. We also fabricated core/shell MWCNT/RuO2 heterostructured 3D electrodes, which show a 50× increase in the areal capacity over their planar counterparts, with an areal lithium capacity of 1.6 mAh/cm(2).

  20. Bioacetylation of Seaweed Alginate

    PubMed Central

    Lee, J. W.; Day, D. F.

    1995-01-01

    Seaweed alginate was acetylated by intact, resting cells of Pseudomonas syringae ATCC 19304. Maximum acetylation of this polymer occurred at a pH of 6.0 and a temperature of 25 deg C. Aeration and gluconic acid were required for an optimal reaction. A reactor which contained carbon-immobilized cells was constructed to continuously acetylate alginate. The maximal yield of acetylation was about 90%, and the half-life of this system was 6.5 days. PMID:16534934

  1. 3D bioprinting for engineering complex tissues.

    PubMed

    Mandrycky, Christian; Wang, Zongjie; Kim, Keekyoung; Kim, Deok-Ho

    2016-01-01

    Bioprinting is a 3D fabrication technology used to precisely dispense cell-laden biomaterials for the construction of complex 3D functional living tissues or artificial organs. While still in its early stages, bioprinting strategies have demonstrated their potential use in regenerative medicine to generate a variety of transplantable tissues, including skin, cartilage, and bone. However, current bioprinting approaches still have technical challenges in terms of high-resolution cell deposition, controlled cell distributions, vascularization, and innervation within complex 3D tissues. While no one-size-fits-all approach to bioprinting has emerged, it remains an on-demand, versatile fabrication technique that may address the growing organ shortage as well as provide a high-throughput method for cell patterning at the micrometer scale for broad biomedical engineering applications. In this review, we introduce the basic principles, materials, integration strategies and applications of bioprinting. We also discuss the recent developments, current challenges and future prospects of 3D bioprinting for engineering complex tissues. Combined with recent advances in human pluripotent stem cell technologies, 3D-bioprinted tissue models could serve as an enabling platform for high-throughput predictive drug screening and more effective regenerative therapies.

  2. 3D bioprinting for engineering complex tissues.

    PubMed

    Mandrycky, Christian; Wang, Zongjie; Kim, Keekyoung; Kim, Deok-Ho

    2016-01-01

    Bioprinting is a 3D fabrication technology used to precisely dispense cell-laden biomaterials for the construction of complex 3D functional living tissues or artificial organs. While still in its early stages, bioprinting strategies have demonstrated their potential use in regenerative medicine to generate a variety of transplantable tissues, including skin, cartilage, and bone. However, current bioprinting approaches still have technical challenges in terms of high-resolution cell deposition, controlled cell distributions, vascularization, and innervation within complex 3D tissues. While no one-size-fits-all approach to bioprinting has emerged, it remains an on-demand, versatile fabrication technique that may address the growing organ shortage as well as provide a high-throughput method for cell patterning at the micrometer scale for broad biomedical engineering applications. In this review, we introduce the basic principles, materials, integration strategies and applications of bioprinting. We also discuss the recent developments, current challenges and future prospects of 3D bioprinting for engineering complex tissues. Combined with recent advances in human pluripotent stem cell technologies, 3D-bioprinted tissue models could serve as an enabling platform for high-throughput predictive drug screening and more effective regenerative therapies. PMID:26724184

  3. DNA Assembly in 3D Printed Fluidics.

    PubMed

    Patrick, William G; Nielsen, Alec A K; Keating, Steven J; Levy, Taylor J; Wang, Che-Wei; Rivera, Jaime J; Mondragón-Palomino, Octavio; Carr, Peter A; Voigt, Christopher A; Oxman, Neri; Kong, David S

    2015-01-01

    The process of connecting genetic parts-DNA assembly-is a foundational technology for synthetic biology. Microfluidics present an attractive solution for minimizing use of costly reagents, enabling multiplexed reactions, and automating protocols by integrating multiple protocol steps. However, microfluidics fabrication and operation can be expensive and requires expertise, limiting access to the technology. With advances in commodity digital fabrication tools, it is now possible to directly print fluidic devices and supporting hardware. 3D printed micro- and millifluidic devices are inexpensive, easy to make and quick to produce. We demonstrate Golden Gate DNA assembly in 3D-printed fluidics with reaction volumes as small as 490 nL, channel widths as fine as 220 microns, and per unit part costs ranging from $0.61 to $5.71. A 3D-printed syringe pump with an accompanying programmable software interface was designed and fabricated to operate the devices. Quick turnaround and inexpensive materials allowed for rapid exploration of device parameters, demonstrating a manufacturing paradigm for designing and fabricating hardware for synthetic biology. PMID:26716448

  4. DNA Assembly in 3D Printed Fluidics

    PubMed Central

    Patrick, William G.; Nielsen, Alec A. K.; Keating, Steven J.; Levy, Taylor J.; Wang, Che-Wei; Rivera, Jaime J.; Mondragón-Palomino, Octavio; Carr, Peter A.; Voigt, Christopher A.; Oxman, Neri; Kong, David S.

    2015-01-01

    The process of connecting genetic parts—DNA assembly—is a foundational technology for synthetic biology. Microfluidics present an attractive solution for minimizing use of costly reagents, enabling multiplexed reactions, and automating protocols by integrating multiple protocol steps. However, microfluidics fabrication and operation can be expensive and requires expertise, limiting access to the technology. With advances in commodity digital fabrication tools, it is now possible to directly print fluidic devices and supporting hardware. 3D printed micro- and millifluidic devices are inexpensive, easy to make and quick to produce. We demonstrate Golden Gate DNA assembly in 3D-printed fluidics with reaction volumes as small as 490 nL, channel widths as fine as 220 microns, and per unit part costs ranging from $0.61 to $5.71. A 3D-printed syringe pump with an accompanying programmable software interface was designed and fabricated to operate the devices. Quick turnaround and inexpensive materials allowed for rapid exploration of device parameters, demonstrating a manufacturing paradigm for designing and fabricating hardware for synthetic biology. PMID:26716448

  5. Printing 3D dielectric elastomer actuators for soft robotics

    NASA Astrophysics Data System (ADS)

    Rossiter, Jonathan; Walters, Peter; Stoimenov, Boyko

    2009-03-01

    We present a new approach to the fabrication of soft dielectric elastomer actuators using a 3D printing process. Complete actuators including active membranes and support structures can be 3D printed in one go, resulting in a great improvement in fabrication speed and increases in accuracy and consistency. We describe the fabrication process and present force and displacement results for a double-membrane antagonistic actuator. In this structure controlled prestrain is applied by the simple process of pressing together two printed actuator halves. The development of 3D printable soft actuators will have a large impact on many application areas including engineering, medicine and the emerging field of soft robotics.

  6. Prominent rocks - 3D

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Many prominent rocks near the Sagan Memorial Station are featured in this image, taken in stereo by the Imager for Mars Pathfinder (IMP) on Sol 3. 3D glasses are necessary to identify surface detail. Wedge is at lower left; Shark, Half-Dome, and Pumpkin are at center. Flat Top, about four inches high, is at lower right. The horizon in the distance is one to two kilometers away.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

    Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  7. 'Diamond' in 3-D

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This 3-D, microscopic imager mosaic of a target area on a rock called 'Diamond Jenness' was taken after NASA's Mars Exploration Rover Opportunity ground into the surface with its rock abrasion tool for a second time.

    Opportunity has bored nearly a dozen holes into the inner walls of 'Endurance Crater.' On sols 177 and 178 (July 23 and July 24, 2004), the rover worked double-duty on Diamond Jenness. Surface debris and the bumpy shape of the rock resulted in a shallow and irregular hole, only about 2 millimeters (0.08 inch) deep. The final depth was not enough to remove all the bumps and leave a neat hole with a smooth floor. This extremely shallow depression was then examined by the rover's alpha particle X-ray spectrometer.

    On Sol 178, Opportunity's 'robotic rodent' dined on Diamond Jenness once again, grinding almost an additional 5 millimeters (about 0.2 inch). The rover then applied its Moessbauer spectrometer to the deepened hole. This double dose of Diamond Jenness enabled the science team to examine the rock at varying layers. Results from those grindings are currently being analyzed.

    The image mosaic is about 6 centimeters (2.4 inches) across.

  8. Martian terrain - 3D

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This area of terrain near the Sagan Memorial Station was taken on Sol 3 by the Imager for Mars Pathfinder (IMP). 3D glasses are necessary to identify surface detail.

    The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

    Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  9. Factors influencing alginate gel biocompatibility.

    PubMed

    Tam, Susan K; Dusseault, Julie; Bilodeau, Stéphanie; Langlois, Geneviève; Hallé, Jean-Pierre; Yahia, L'Hocine

    2011-07-01

    Alginate remains the most popular polymer used for cell encapsulation, yet its biocompatibility is inconsistent. Two commercially available alginates were compared, one with 71% guluronate (HiG), and the other with 44% (IntG). Both alginates were purified, and their purities were verified. After 2 days in the peritoneal cavity of C57BL/6J mice, barium (Ba)-gel and calcium (Ca)-gel beads of IntG alginate were clean, while host cells were adhered to beads of HiG alginate. IntG gel beads, however, showed fragmentation in vivo while HiG gel beads stayed firm. The physicochemical properties of the sodium alginates and their gels were thoroughly characterized. The intrinsic viscosity of IntG alginate was 2.5-fold higher than that of HiG alginate, suggesting a greater molecular mass. X-ray photoelectron spectroscopy indicated that both alginates were similar in elemental composition, including low levels of counterions in all gels. The wettabilities of the alginates and gels were also identical, as measured by contact angles of water on dry films. Ba-gel beads of HiG alginate resisted swelling and degradation when immersed in water, much more than the other gel beads. These results suggest that the main factors contributing to the biocompatibility of gels of purified alginate are the mannuronate/guluronate content and/or intrinsic viscosity.

  10. 3D Printing of Highly Stretchable and Tough Hydrogels into Complex, Cellularized Structures.

    PubMed

    Hong, Sungmin; Sycks, Dalton; Chan, Hon Fai; Lin, Shaoting; Lopez, Gabriel P; Guilak, Farshid; Leong, Kam W; Zhao, Xuanhe

    2015-07-15

    A 3D printable and highly stretchable tough hydrogel is developed by combining poly(ethylene glycol) and sodium alginate, which synergize to form a hydrogel tougher than natural cartilage. Encapsulated cells maintain high viability over a 7 d culture period and are highly deformed together with the hydrogel. By adding biocompatible nanoclay, the tough hydrogel is 3D printed in various shapes without requiring support material. PMID:26033288

  11. 3D Printing of Highly Stretchable and Tough Hydrogels into Complex, Cellularized Structures.

    PubMed

    Hong, Sungmin; Sycks, Dalton; Chan, Hon Fai; Lin, Shaoting; Lopez, Gabriel P; Guilak, Farshid; Leong, Kam W; Zhao, Xuanhe

    2015-07-15

    A 3D printable and highly stretchable tough hydrogel is developed by combining poly(ethylene glycol) and sodium alginate, which synergize to form a hydrogel tougher than natural cartilage. Encapsulated cells maintain high viability over a 7 d culture period and are highly deformed together with the hydrogel. By adding biocompatible nanoclay, the tough hydrogel is 3D printed in various shapes without requiring support material.

  12. 3D printing of a multifunctional nanocomposite helical liquid sensor

    NASA Astrophysics Data System (ADS)

    Guo, Shuang-Zhuang; Yang, Xuelu; Heuzey, Marie-Claude; Therriault, Daniel

    2015-04-01

    A multifunctional 3D liquid sensor made of a PLA/MWCNT nanocomposite and shaped as a freeform helical structure was fabricated by solvent-cast 3D printing. The 3D liquid sensor featured a relatively high electrical conductivity, the functionality of liquid trapping due to its helical configuration, and an excellent sensitivity and selectivity even for a short immersion into solvents.A multifunctional 3D liquid sensor made of a PLA/MWCNT nanocomposite and shaped as a freeform helical structure was fabricated by solvent-cast 3D printing. The 3D liquid sensor featured a relatively high electrical conductivity, the functionality of liquid trapping due to its helical configuration, and an excellent sensitivity and selectivity even for a short immersion into solvents. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr00278h

  13. 3-D capaciflector

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    1998-01-01

    A capacitive type proximity sensor having improved range and sensitivity between a surface of arbitrary shape and an intruding object in the vicinity of the surface having one or more outer conductors on the surface which serve as capacitive sensing elements shaped to conform to the underlying surface of a machine. Each sensing element is backed by a reflector driven at the same voltage and in phase with the corresponding capacitive sensing element. Each reflector, in turn, serves to reflect the electric field lines of the capacitive sensing element away from the surface of the machine on which the sensor is mounted so as to enhance the component constituted by the capacitance between the sensing element and an intruding object as a fraction of the total capacitance between the sensing element and ground. Each sensing element and corresponding reflecting element are electrically driven in phase, and the capacitance between the sensing elements individually and the sensed object is determined using circuitry known to the art. The reflector may be shaped to shield the sensor and to shape its field of view, in effect providing an electrostatic lensing effect. Sensors and reflectors may be fabricated using a variety of known techniques such as vapor deposition, sputtering, painting, plating, or deformation of flexible films, to provide conformal coverage of surfaces of arbitrary shape.

  14. 3D microfabrication technology

    NASA Astrophysics Data System (ADS)

    Tang, Esheng; FuTing, Yi; Tian, Yangchao; Liang, Jingqiu; Xian, Dingchang

    1998-08-01

    In the late of this century the great success of VSIC impacts into almost every fields of our social. Following this idea people starts to integrate microsensor microprocessor and microactuators into a small space to forming a Micro Electro and Mechanical System. Such small robot parts are applied to including satellites, computer communication, medical, chemical, biological and environment and so on research fields. The development of MEMS would strongly influence industrial revolution in the next century. LIGA technology including X-ray deep etching lithography; electroplating and plastic molding developed by Karlsruhe Nuclear Research Center, Germany since the beginning of 1980. Its advantages are: it could make three-dimensional microstructures with lateral dimension in several micron range and thickness of several hundred microns with sub-micron precision. In principle all kinds of materials such as polymer, metal and ceramic could be used as microcomponents and could be mass- produced by plastic molding to a commercially available fabrication. LIGA process has become one of the most promising Microfabrication technologies for producing micromechanical, microfluid and micro-optical elements. It opens an additional field in the microstructure market.

  15. 3D-printed microfluidic devices.

    PubMed

    Amin, Reza; Knowlton, Stephanie; Hart, Alexander; Yenilmez, Bekir; Ghaderinezhad, Fariba; Katebifar, Sara; Messina, Michael; Khademhosseini, Ali; Tasoglu, Savas

    2016-06-01

    Microfluidics is a flourishing field, enabling a wide range of biochemical and clinical applications such as cancer screening, micro-physiological system engineering, high-throughput drug testing, and point-of-care diagnostics. However, fabrication of microfluidic devices is often complicated, time consuming, and requires expensive equipment and sophisticated cleanroom facilities. Three-dimensional (3D) printing presents a promising alternative to traditional techniques such as lithography and PDMS-glass bonding, not only by enabling rapid design iterations in the development stage, but also by reducing the costs associated with institutional infrastructure, equipment installation, maintenance, and physical space. With the recent advancements in 3D printing technologies, highly complex microfluidic devices can be fabricated via single-step, rapid, and cost-effective protocols, making microfluidics more accessible to users. In this review, we discuss a broad range of approaches for the application of 3D printing technology to fabrication of micro-scale lab-on-a-chip devices. PMID:27321137

  16. Multifunctional, Highly Flexible, Free-Standing 3D Polypyrrole Foam.

    PubMed

    Wang, Chunhui; Ding, Yujie; Yuan, Ye; Cao, Anyuan; He, Xiaodong; Peng, Qingyu; Li, Yibin

    2016-08-01

    Multifunctional, highly flexible 3D polypyrrole (PPy) foam is fabricated via a simple electrodeposition method by using nickel foam as the template. The 3D PPy foam has a unique interior structure and is robust enough to manipulate directly. PMID:27357260

  17. Self assembled structures for 3D integration

    NASA Astrophysics Data System (ADS)

    Rao, Madhav

    Three dimensional (3D) micro-scale structures attached to a silicon substrate have various applications in microelectronics. However, formation of 3D structures using conventional micro-fabrication techniques are not efficient and require precise control of processing parameters. Self assembly is a method for creating 3D structures that takes advantage of surface area minimization phenomena. Solder based self assembly (SBSA), the subject of this dissertation, uses solder as a facilitator in the formation of 3D structures from 2D patterns. Etching a sacrificial layer underneath a portion of the 2D pattern allows the solder reflow step to pull those areas out of the substrate plane resulting in a folded 3D structure. Initial studies using the SBSA method demonstrated low yields in the formation of five different polyhedra. The failures in folding were primarily attributed to nonuniform solder deposition on the underlying metal pads. The dip soldering method was analyzed and subsequently refined. A modified dip soldering process provided improved yield among the polyhedra. Solder bridging referred as joining of solder deposited on different metal patterns in an entity influenced the folding mechanism. In general, design parameters such as small gap-spacings and thick metal pads were found to favor solder bridging for all patterns studied. Two types of soldering: face and edge soldering were analyzed. Face soldering refers to the application of solder on the entire metal face. Edge soldering indicates application of solder only on the edges of the metal face. Mechanical grinding showed that face soldered SBSA structures were void free and robust in nature. In addition, the face soldered 3D structures provide a consistent heat resistant solder standoff height that serve as attachments in the integration of dissimilar electronic technologies. Face soldered 3D structures were developed on the underlying conducting channel to determine the thermo-electric reliability of

  18. 3D Printed Terahertz Diffraction Gratings And Lenses

    NASA Astrophysics Data System (ADS)

    Squires, A. D.; Constable, E.; Lewis, R. A.

    2015-01-01

    3D printing opens up an inexpensive, rapid, and versatile path to the fabrication of optical elements suited to the terahertz regime. The transmission of the plastics used in 3D printers, while generally decreasing with frequency, is usable over the range 0.1-2 THz. We have designed, fabricated, and tested regular and blazed gratings and aspherical lenses for operation at terahertz frequencies. We find that the measured performance matches our theoretical predictions.

  19. 21 CFR 184.1724 - Sodium alginate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium alginate. 184.1724 Section 184.1724 Food... GRAS § 184.1724 Sodium alginate. (a) Sodium alginate (CAS Reg. No. 9005-38-3) is the sodium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Sodium alginate is prepared by...

  20. 21 CFR 184.1724 - Sodium alginate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium alginate. 184.1724 Section 184.1724 Food and... Substances Affirmed as GRAS § 184.1724 Sodium alginate. (a) Sodium alginate (CAS Reg. No. 9005-38-3) is the sodium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Sodium alginate...

  1. 21 CFR 184.1610 - Potassium alginate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium alginate. 184.1610 Section 184.1610 Food... GRAS § 184.1610 Potassium alginate. (a) Potassium alginate (CAS Reg. No. 9005-36-1) is the potassium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Potassium alginate...

  2. 21 CFR 184.1187 - Calcium alginate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Calcium alginate. 184.1187 Section 184.1187 Food... GRAS § 184.1187 Calcium alginate. (a) Calcium alginate (CAS Reg. No. 9005-35-0) is the calcium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Calcium alginate is prepared...

  3. Cell(MC3T3-E1)-printed poly(ϵ-caprolactone)/alginate hybrid scaffolds for tissue regeneration.

    PubMed

    Lee, Hyeongjin; Ahn, SeungHyun; Bonassar, Lawrence J; Kim, GeunHyung

    2013-01-25

    A new cell-printed scaffold consisting of poly(ϵ-caprolactone) (PCL) and cell-embedded alginate struts is designed. The PCL and alginate struts are stacked in an interdigitated pattern in successive layers to acquire a three-dimensional (3D) shape. The hybrid scaffold exhibits a two-phase structure consisting of cell (MC3T3-E1)-laden alginate struts able to support biological activity and PCL struts able to provide controllable mechanical support of the cell-laden alginate struts. The hybrid scaffolds exhibit an impressive increase in tensile modulus and maximum strength compared to pure alginate scaffolds. Laden cells are homogeneously distributed throughout the alginate struts and the entire scaffold, resulting in cell viability of approximately 84%.

  4. 3D Printing of Conductive Complex Structures with In Situ Generation of Silver Nanoparticles.

    PubMed

    Fantino, Erika; Chiappone, Annalisa; Roppolo, Ignazio; Manfredi, Diego; Bongiovanni, Roberta; Pirri, Candido Fabrizio; Calignano, Flaviana

    2016-05-01

    Coupling the photoreduction of a metal precursor with 3D-printing technology is shown to allow the fabrication of conductive 3D hybrid structures consisting of metal nanoparticles and organic polymers shaped in complex multilayered architectures. 3D conductive structures are fabricated incorporating silver nitrate into a photocurable oligomer in the presence of suitable photoinitiators and exposing them to a digital light system.

  5. Dynamic phototuning of 3D hydrogel stiffness

    PubMed Central

    Stowers, Ryan S.; Allen, Shane C.; Suggs, Laura J.

    2015-01-01

    Hydrogels are widely used as in vitro culture models to mimic 3D cellular microenvironments. The stiffness of the extracellular matrix is known to influence cell phenotype, inspiring work toward unraveling the role of stiffness on cell behavior using hydrogels. However, in many biological processes such as embryonic development, wound healing, and tumorigenesis, the microenvironment is highly dynamic, leading to changes in matrix stiffness over a broad range of timescales. To recapitulate dynamic microenvironments, a hydrogel with temporally tunable stiffness is needed. Here, we present a system in which alginate gel stiffness can be temporally modulated by light-triggered release of calcium or a chelator from liposomes. Others have shown softening via photodegradation or stiffening via secondary cross-linking; however, our system is capable of both dynamic stiffening and softening. Dynamic modulation of stiffness can be induced at least 14 d after gelation and can be spatially controlled to produce gradients and patterns. We use this system to investigate the regulation of fibroblast morphology by stiffness in both nondegradable gels and gels with degradable elements. Interestingly, stiffening inhibits fibroblast spreading through either mesenchymal or amoeboid migration modes. We demonstrate this technology can be translated in vivo by using deeply penetrating near-infrared light for transdermal stiffness modulation, enabling external control of gel stiffness. Temporal modulation of hydrogel stiffness is a powerful tool that will enable investigation of the role that dynamic microenvironments play in biological processes both in vitro and in well-controlled in vivo experiments. PMID:25646417

  6. 3D Elevation Program—Virtual USA in 3D

    USGS Publications Warehouse

    Lukas, Vicki; Stoker, J.M.

    2016-01-01

    The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) uses a laser system called ‘lidar’ (light detection and ranging) to create a virtual reality map of the Nation that is very accurate. 3D maps have many uses with new uses being discovered all the time.  

  7. 3D Elevation Program—Virtual USA in 3D

    USGS Publications Warehouse

    Lukas, Vicki; Stoker, J.M.

    2016-04-14

    The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) uses a laser system called ‘lidar’ (light detection and ranging) to create a virtual reality map of the Nation that is very accurate. 3D maps have many uses with new uses being discovered all the time.  

  8. Fabrication

    NASA Astrophysics Data System (ADS)

    Angel, Roger; Helms, Richard; Bilbro, Jim; Brown, Norman; Eng, Sverre; Hinman, Steve; Hull-Allen, Greg; Jacobs, Stephen; Keim, Robert; Ulmer, Melville

    1992-08-01

    What aspects of optical fabrication technology need to be developed so as to facilitate existing planned missions, or enable new ones? Throughout the submillimeter to UV wavelengths, the common goal is to push technology to the limits to make the largest possible apertures that are diffraction limited. At any one wavelength, the accuracy of the surface must be better than lambda/30 (rms error). The wavelength range is huge, covering four orders of magnitude from 1 mm to 100 nm. At the longer wavelengths, diffraction limited surfaces can be shaped with relatively crude techniques. The challenge in their fabrication is to make as large as possible a reflector, given the weight and volume constraints of the launch vehicle. The limited cargo diameter of the shuttle has led in the past to emphasis on deployable or erectable concepts such as the Large Deployable Reflector (LDR), which was studied by NASA for a submillimeter astrophysics mission. Replication techniques that can be used to produce light, low-cost reflecting panels are of great interest for this class of mission. At shorter wavelengths, in the optical and ultraviolet, optical fabrication will tax to the limit the most refined polishing methods. Methods of mechanical and thermal stabilization of the substrate will be severely stressed. In the thermal infrared, the need for large aperture is tempered by the even stronger need to control the telescope's thermal emission by cooled or cryogenic operation. Thus, the SIRTF mirror at 1 meter is not large and does not require unusually high accuracy, but the fabrication process must produce a mirror that is the right shape at a temperature of 4 K. Future large cooled mirrors will present more severe problems, especially if they must also be accurate enough to work at optical wavelengths. At the very shortest wavelengths accessible to reflecting optics, in the x-ray domain, the very low count fluxes of high energy photons place a premium on the collecting area. It is

  9. Fabrication

    NASA Technical Reports Server (NTRS)

    Angel, Roger; Helms, Richard; Bilbro, Jim; Brown, Norman; Eng, Sverre; Hinman, Steve; Hull-Allen, Greg; Jacobs, Stephen; Keim, Robert; Ulmer, Melville

    1992-01-01

    What aspects of optical fabrication technology need to be developed so as to facilitate existing planned missions, or enable new ones? Throughout the submillimeter to UV wavelengths, the common goal is to push technology to the limits to make the largest possible apertures that are diffraction limited. At any one wavelength, the accuracy of the surface must be better than lambda/30 (rms error). The wavelength range is huge, covering four orders of magnitude from 1 mm to 100 nm. At the longer wavelengths, diffraction limited surfaces can be shaped with relatively crude techniques. The challenge in their fabrication is to make as large as possible a reflector, given the weight and volume constraints of the launch vehicle. The limited cargo diameter of the shuttle has led in the past to emphasis on deployable or erectable concepts such as the Large Deployable Reflector (LDR), which was studied by NASA for a submillimeter astrophysics mission. Replication techniques that can be used to produce light, low-cost reflecting panels are of great interest for this class of mission. At shorter wavelengths, in the optical and ultraviolet, optical fabrication will tax to the limit the most refined polishing methods. Methods of mechanical and thermal stabilization of the substrate will be severely stressed. In the thermal infrared, the need for large aperture is tempered by the even stronger need to control the telescope's thermal emission by cooled or cryogenic operation. Thus, the SIRTF mirror at 1 meter is not large and does not require unusually high accuracy, but the fabrication process must produce a mirror that is the right shape at a temperature of 4 K. Future large cooled mirrors will present more severe problems, especially if they must also be accurate enough to work at optical wavelengths. At the very shortest wavelengths accessible to reflecting optics, in the x-ray domain, the very low count fluxes of high energy photons place a premium on the collecting area. It is

  10. 3D grain boundary migration

    NASA Astrophysics Data System (ADS)

    Becker, J. K.; Bons, P. D.

    2009-04-01

    Microstructures of rocks play an important role in determining rheological properties and help to reveal the processes that lead to their formation. Some of these processes change the microstructure significantly and may thus have the opposite effect in obliterating any fabrics indicative of the previous history of the rocks. One of these processes is grain boundary migration (GBM). During static recrystallisation, GBM may produce a foam texture that completely overprints a pre-existing grain boundary network and GBM actively influences the rheology of a rock, via its influence on grain size and lattice defect concentration. We here present a new numerical simulation software that is capable of simulating a whole range of processes on the grain scale (it is not limited to grain boundary migration). The software is polyhedron-based, meaning that each grain (or phase) is represented by a polyhedron that has discrete boundaries. The boundary (the shell) of the polyhedron is defined by a set of facets which in turn is defined by a set of vertices. Each structural entity (polyhedron, facets and vertices) can have an unlimited number of parameters (depending on the process to be modeled) such as surface energy, concentration, etc. which can be used to calculate changes of the microstructre. We use the processes of grain boundary migration of a "regular" and a partially molten rock to demonstrate the software. Since this software is 3D, the formation of melt networks in a partially molten rock can also be studied. The interconnected melt network is of fundamental importance for melt segregation and migration in the crust and mantle and can help to understand the core-mantle differentiation of large terrestrial planets.

  11. 3D Printed Molecules and Extended Solid Models for Teaching Symmetry and Point Groups

    ERIC Educational Resources Information Center

    Scalfani, Vincent F.; Vaid, Thomas P.

    2014-01-01

    Tangible models help students and researchers visualize chemical structures in three dimensions (3D). 3D printing offers a unique and straightforward approach to fabricate plastic 3D models of molecules and extended solids. In this article, we prepared a series of digital 3D design files of molecular structures that will be useful for teaching…

  12. Towards antimicrobial yet bioactive Cu-alginate hydrogels.

    PubMed

    Madzovska-Malagurski, I; Vukasinovic-Sekulic, M; Kostic, D; Levic, S

    2016-06-15

    The simplest approach to enhance alginate hydrogel characteristics and functional properties is to replace the calcium in the process of alginate gelation with other metallic ions which are essential for living systems. Gelling of alginate with other ions and using modern encapsulation techniques can provide new delivery systems with required properties. Hence, in this study Cu-alginate hydrogels in the form of microbeads were produced by electrostatic extrusion using gelling solutions with Cu(II) concentrations in the range 13.5-270 mM and comprehensively characterized in vitro. The variation of gelling solution concentration influenced the microbead Cu(II) content, size, biomechanical properties, Cu(II) release and subsequently potential biomedical application. The formulations chosen for biomedical evaluation showed potential for antimicrobial and tissue engineering applications. Microbeads with higher Cu(II) loading (~100 μmol g(-1)) induced immediate bactericidal effects against Escherichia coli and Staphylococcus aureus. Conversely, Cu(II) release from microbeads with the Cu(II) content of ~60 μmol g(-1) was slower and they were suitable for promoting and maintaining chondrogenic phenotype of bovine calf chondrocytes in 3D culture. Results of this study have shown possibilities for tuning Cu-alginate properties for potential biomedical applications such as antimicrobial wound dressings, tissue engineering scaffolds or articular cartilage implants.

  13. Evaluation of sodium alginate for bone marrow cell tissue engineering.

    PubMed

    Wang, L; Shelton, R M; Cooper, P R; Lawson, M; Triffitt, J T; Barralet, J E

    2003-09-01

    Sodium alginate has applications as a material for the encapsulation and immobilisation of a variety of cell types for immunoisolatory and biochemical processing applications. It forms a biodegradable gel when crosslinked with calcium ions and it has been exploited in cartilage tissue engineering since chondrocytes do not dedifferentiate when immobilised in it. Despite its attractive properties of degradability, ease of processing and cell immobilisation, there is little work demonstrating the efficacy of alginate gel as a substrate for cell proliferation, except when RGD is modified. In this study we investigated the ability of rat bone marrow cells to proliferate and differentiate on alginates of differing composition and purity. The mechanical properties of the gels were investigated. It was found that high purity and high G-type alginate retained 27% of its initial strength after 12 days in culture and that comparable levels of proliferation were observed on this material and tissue culture plastic. Depending on composition, calcium crosslinked alginate can act as a substrate for rat marrow cell proliferation and has potential for use as 3D degradable scaffold.

  14. 3D Printing in Zero-G ISS Technology Demonstration

    NASA Technical Reports Server (NTRS)

    Werkheiser, Niki; Cooper, Kenneth C.; Edmunson, Jennifer E.; Dunn, Jason; Snyder, Michael

    2013-01-01

    The National Aeronautics and Space Administration (NASA) has a long term strategy to fabricate components and equipment on-demand for manned missions to the Moon, Mars, and beyond. To support this strategy, NASA's Marshall Space Fligth Center (MSFC) and Made in Space, Inc. are developing the 3D Printing In Zero-G payload as a Technology Demonstration for the International Space Station (ISS). The 3D Printing In Zero-G experiment ('3D Print') will be the frst machine to perform 3D printing in space.

  15. Fringe projection 3D microscopy with the general imaging model.

    PubMed

    Yin, Yongkai; Wang, Meng; Gao, Bruce Z; Liu, Xiaoli; Peng, Xiang

    2015-03-01

    Three-dimensional (3D) imaging and metrology of microstructures is a critical task for the design, fabrication, and inspection of microelements. Newly developed fringe projection 3D microscopy is presented in this paper. The system is configured according to camera-projector layout and long working distance lenses. The Scheimpflug principle is employed to make full use of the limited depth of field. For such a specific system, the general imaging model is introduced to reach a full 3D reconstruction. A dedicated calibration procedure is developed to realize quantitative 3D imaging. Experiments with a prototype demonstrate the accessibility of the proposed configuration, model, and calibration approach.

  16. Current progress in 3D printing for cardiovascular tissue engineering.

    PubMed

    Mosadegh, Bobak; Xiong, Guanglei; Dunham, Simon; Min, James K

    2015-03-16

    3D printing is a technology that allows the fabrication of structures with arbitrary geometries and heterogeneous material properties. The application of this technology to biological structures that match the complexity of native tissue is of great interest to researchers. This mini-review highlights the current progress of 3D printing for fabricating artificial tissues of the cardiovascular system, specifically the myocardium, heart valves, and coronary arteries. In addition, how 3D printed sensors and actuators can play a role in tissue engineering is discussed. To date, all the work with building 3D cardiac tissues have been proof-of-principle demonstrations, and in most cases, yielded products less effective than other traditional tissue engineering strategies. However, this technology is in its infancy and therefore there is much promise that through collaboration between biologists, engineers and material scientists, 3D bioprinting can make a significant impact on the field of cardiovascular tissue engineering.

  17. Highly compressible 3D periodic graphene aerogel microlattices

    PubMed Central

    Zhu, Cheng; Han, T. Yong-Jin; Duoss, Eric B.; Golobic, Alexandra M.; Kuntz, Joshua D.; Spadaccini, Christopher M.; Worsley, Marcus A.

    2015-01-01

    Graphene is a two-dimensional material that offers a unique combination of low density, exceptional mechanical properties, large surface area and excellent electrical conductivity. Recent progress has produced bulk 3D assemblies of graphene, such as graphene aerogels, but they possess purely stochastic porous networks, which limit their performance compared with the potential of an engineered architecture. Here we report the fabrication of periodic graphene aerogel microlattices, possessing an engineered architecture via a 3D printing technique known as direct ink writing. The 3D printed graphene aerogels are lightweight, highly conductive and exhibit supercompressibility (up to 90% compressive strain). Moreover, the Young's moduli of the 3D printed graphene aerogels show an order of magnitude improvement over bulk graphene materials with comparable geometric density and possess large surface areas. Adapting the 3D printing technique to graphene aerogels realizes the possibility of fabricating a myriad of complex aerogel architectures for a broad range of applications. PMID:25902277

  18. Highly compressible 3D periodic graphene aerogel microlattices

    SciTech Connect

    Zhu, Cheng; Han, T. Yong-Jin; Duoss, Eric B.; Golobic, Alexandra M.; Kuntz, Joshua D.; Spadaccini, Christopher M.; Worsley, Marcus A.

    2015-04-22

    Graphene is a two-dimensional material that offers a unique combination of low density, exceptional mechanical properties, large surface area and excellent electrical conductivity. Recent progress has produced bulk 3D assemblies of graphene, such as graphene aerogels, but they possess purely stochastic porous networks, which limit their performance compared with the potential of an engineered architecture. Here we report the fabrication of periodic graphene aerogel microlattices, possessing an engineered architecture via a 3D printing technique known as direct ink writing. The 3D printed graphene aerogels are lightweight, highly conductive and exhibit supercompressibility (up to 90% compressive strain). Moreover, the Young’s moduli of the 3D printed graphene aerogels show an order of magnitude improvement over bulk graphene materials with comparable geometric density and possess large surface areas. Ultimately, adapting the 3D printing technique to graphene aerogels realizes the possibility of fabricating a myriad of complex aerogel architectures for a broad range of applications.

  19. 3D-printing technologies for electrochemical applications.

    PubMed

    Ambrosi, Adriano; Pumera, Martin

    2016-05-21

    Since its conception during the 80s, 3D-printing, also known as additive manufacturing, has been receiving unprecedented levels of attention and interest from industry and research laboratories. This is in addition to end users, who have benefited from the pervasiveness of desktop-size and relatively cheap printing machines available. 3D-printing enables almost infinite possibilities for rapid prototyping. Therefore, it has been considered for applications in numerous research fields, ranging from mechanical engineering, medicine, and materials science to chemistry. Electrochemistry is another branch of science that can certainly benefit from 3D-printing technologies, paving the way for the design and fabrication of cheaper, higher performing, and ubiquitously available electrochemical devices. Here, we aim to provide a general overview of the most commonly available 3D-printing methods along with a review of recent electrochemistry related studies adopting 3D-printing as a possible rapid prototyping fabrication tool.

  20. 3D-printing technologies for electrochemical applications.

    PubMed

    Ambrosi, Adriano; Pumera, Martin

    2016-05-21

    Since its conception during the 80s, 3D-printing, also known as additive manufacturing, has been receiving unprecedented levels of attention and interest from industry and research laboratories. This is in addition to end users, who have benefited from the pervasiveness of desktop-size and relatively cheap printing machines available. 3D-printing enables almost infinite possibilities for rapid prototyping. Therefore, it has been considered for applications in numerous research fields, ranging from mechanical engineering, medicine, and materials science to chemistry. Electrochemistry is another branch of science that can certainly benefit from 3D-printing technologies, paving the way for the design and fabrication of cheaper, higher performing, and ubiquitously available electrochemical devices. Here, we aim to provide a general overview of the most commonly available 3D-printing methods along with a review of recent electrochemistry related studies adopting 3D-printing as a possible rapid prototyping fabrication tool. PMID:27048921

  1. Highly compressible 3D periodic graphene aerogel microlattices.

    PubMed

    Zhu, Cheng; Han, T Yong-Jin; Duoss, Eric B; Golobic, Alexandra M; Kuntz, Joshua D; Spadaccini, Christopher M; Worsley, Marcus A

    2015-04-22

    Graphene is a two-dimensional material that offers a unique combination of low density, exceptional mechanical properties, large surface area and excellent electrical conductivity. Recent progress has produced bulk 3D assemblies of graphene, such as graphene aerogels, but they possess purely stochastic porous networks, which limit their performance compared with the potential of an engineered architecture. Here we report the fabrication of periodic graphene aerogel microlattices, possessing an engineered architecture via a 3D printing technique known as direct ink writing. The 3D printed graphene aerogels are lightweight, highly conductive and exhibit supercompressibility (up to 90% compressive strain). Moreover, the Young's moduli of the 3D printed graphene aerogels show an order of magnitude improvement over bulk graphene materials with comparable geometric density and possess large surface areas. Adapting the 3D printing technique to graphene aerogels realizes the possibility of fabricating a myriad of complex aerogel architectures for a broad range of applications.

  2. Highly compressible 3D periodic graphene aerogel microlattices

    NASA Astrophysics Data System (ADS)

    Zhu, Cheng; Han, T. Yong-Jin; Duoss, Eric B.; Golobic, Alexandra M.; Kuntz, Joshua D.; Spadaccini, Christopher M.; Worsley, Marcus A.

    2015-04-01

    Graphene is a two-dimensional material that offers a unique combination of low density, exceptional mechanical properties, large surface area and excellent electrical conductivity. Recent progress has produced bulk 3D assemblies of graphene, such as graphene aerogels, but they possess purely stochastic porous networks, which limit their performance compared with the potential of an engineered architecture. Here we report the fabrication of periodic graphene aerogel microlattices, possessing an engineered architecture via a 3D printing technique known as direct ink writing. The 3D printed graphene aerogels are lightweight, highly conductive and exhibit supercompressibility (up to 90% compressive strain). Moreover, the Young's moduli of the 3D printed graphene aerogels show an order of magnitude improvement over bulk graphene materials with comparable geometric density and possess large surface areas. Adapting the 3D printing technique to graphene aerogels realizes the possibility of fabricating a myriad of complex aerogel architectures for a broad range of applications.

  3. Market study: 3-D eyetracker

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A market study of a proposed version of a 3-D eyetracker for initial use at NASA's Ames Research Center was made. The commercialization potential of a simplified, less expensive 3-D eyetracker was ascertained. Primary focus on present and potential users of eyetrackers, as well as present and potential manufacturers has provided an effective means of analyzing the prospects for commercialization.

  4. 3D World Building System

    ScienceCinema

    None

    2016-07-12

    This video provides an overview of the Sandia National Laboratories developed 3-D World Model Building capability that provides users with an immersive, texture rich 3-D model of their environment in minutes using a laptop and color and depth camera.

  5. 3D World Building System

    SciTech Connect

    2013-10-30

    This video provides an overview of the Sandia National Laboratories developed 3-D World Model Building capability that provides users with an immersive, texture rich 3-D model of their environment in minutes using a laptop and color and depth camera.

  6. LLNL-Earth3D

    SciTech Connect

    2013-10-01

    Earth3D is a computer code designed to allow fast calculation of seismic rays and travel times through a 3D model of the Earth. LLNL is using this for earthquake location and global tomography efforts and such codes are of great interest to the Earth Science community.

  7. [3-D ultrasound in gastroenterology].

    PubMed

    Zoller, W G; Liess, H

    1994-06-01

    Three-dimensional (3D) sonography represents a development of noninvasive diagnostic imaging by real-time two-dimensional (2D) sonography. The use of transparent rotating scans, comparable to a block of glass, generates a 3D effect. The objective of the present study was to optimate 3D presentation of abdominal findings. Additional investigations were made with a new volumetric program to determine the volume of selected findings of the liver. The results were compared with the estimated volumes of 2D sonography and 2D computer tomography (CT). For the processing of 3D images, typical parameter constellations were found for the different findings, which facilitated processing of 3D images. In more than 75% of the cases examined we found an optimal 3D presentation of sonographic findings with respect to the evaluation criteria developed by us for the 3D imaging of processed data. Great differences were found for the estimated volumes of the findings of the liver concerning the three different techniques applied. 3D ultrasound represents a valuable method to judge morphological appearance in abdominal findings. The possibility of volumetric measurements enlarges its potential diagnostic significance. Further clinical investigations are necessary to find out if definite differentiation between benign and malign findings is possible.

  8. Emerging Applications of Bedside 3D Printing in Plastic Surgery.

    PubMed

    Chae, Michael P; Rozen, Warren M; McMenamin, Paul G; Findlay, Michael W; Spychal, Robert T; Hunter-Smith, David J

    2015-01-01

    Modern imaging techniques are an essential component of preoperative planning in plastic and reconstructive surgery. However, conventional modalities, including three-dimensional (3D) reconstructions, are limited by their representation on 2D workstations. 3D printing, also known as rapid prototyping or additive manufacturing, was once the province of industry to fabricate models from a computer-aided design (CAD) in a layer-by-layer manner. The early adopters in clinical practice have embraced the medical imaging-guided 3D-printed biomodels for their ability to provide tactile feedback and a superior appreciation of visuospatial relationship between anatomical structures. With increasing accessibility, investigators are able to convert standard imaging data into a CAD file using various 3D reconstruction softwares and ultimately fabricate 3D models using 3D printing techniques, such as stereolithography, multijet modeling, selective laser sintering, binder jet technique, and fused deposition modeling. However, many clinicians have questioned whether the cost-to-benefit ratio justifies its ongoing use. The cost and size of 3D printers have rapidly decreased over the past decade in parallel with the expiration of key 3D printing patents. Significant improvements in clinical imaging and user-friendly 3D software have permitted computer-aided 3D modeling of anatomical structures and implants without outsourcing in many cases. These developments offer immense potential for the application of 3D printing at the bedside for a variety of clinical applications. In this review, existing uses of 3D printing in plastic surgery practice spanning the spectrum from templates for facial transplantation surgery through to the formation of bespoke craniofacial implants to optimize post-operative esthetics are described. Furthermore, we discuss the potential of 3D printing to become an essential office-based tool in plastic surgery to assist in preoperative planning, developing

  9. Emerging Applications of Bedside 3D Printing in Plastic Surgery

    PubMed Central

    Chae, Michael P.; Rozen, Warren M.; McMenamin, Paul G.; Findlay, Michael W.; Spychal, Robert T.; Hunter-Smith, David J.

    2015-01-01

    Modern imaging techniques are an essential component of preoperative planning in plastic and reconstructive surgery. However, conventional modalities, including three-dimensional (3D) reconstructions, are limited by their representation on 2D workstations. 3D printing, also known as rapid prototyping or additive manufacturing, was once the province of industry to fabricate models from a computer-aided design (CAD) in a layer-by-layer manner. The early adopters in clinical practice have embraced the medical imaging-guided 3D-printed biomodels for their ability to provide tactile feedback and a superior appreciation of visuospatial relationship between anatomical structures. With increasing accessibility, investigators are able to convert standard imaging data into a CAD file using various 3D reconstruction softwares and ultimately fabricate 3D models using 3D printing techniques, such as stereolithography, multijet modeling, selective laser sintering, binder jet technique, and fused deposition modeling. However, many clinicians have questioned whether the cost-to-benefit ratio justifies its ongoing use. The cost and size of 3D printers have rapidly decreased over the past decade in parallel with the expiration of key 3D printing patents. Significant improvements in clinical imaging and user-friendly 3D software have permitted computer-aided 3D modeling of anatomical structures and implants without outsourcing in many cases. These developments offer immense potential for the application of 3D printing at the bedside for a variety of clinical applications. In this review, existing uses of 3D printing in plastic surgery practice spanning the spectrum from templates for facial transplantation surgery through to the formation of bespoke craniofacial implants to optimize post-operative esthetics are described. Furthermore, we discuss the potential of 3D printing to become an essential office-based tool in plastic surgery to assist in preoperative planning, developing

  10. Euro3D Science Conference

    NASA Astrophysics Data System (ADS)

    Walsh, J. R.

    2004-02-01

    The Euro3D RTN is an EU funded Research Training Network to foster the exploitation of 3D spectroscopy in Europe. 3D spectroscopy is a general term for spectroscopy of an area of the sky and derives its name from its two spatial + one spectral dimensions. There are an increasing number of instruments which use integral field devices to achieve spectroscopy of an area of the sky, either using lens arrays, optical fibres or image slicers, to pack spectra of multiple pixels on the sky (``spaxels'') onto a 2D detector. On account of the large volume of data and the special methods required to reduce and analyse 3D data, there are only a few centres of expertise and these are mostly involved with instrument developments. There is a perceived lack of expertise in 3D spectroscopy spread though the astronomical community and its use in the armoury of the observational astronomer is viewed as being highly specialised. For precisely this reason the Euro3D RTN was proposed to train young researchers in this area and develop user tools to widen the experience with this particular type of data in Europe. The Euro3D RTN is coordinated by Martin M. Roth (Astrophysikalisches Institut Potsdam) and has been running since July 2002. The first Euro3D science conference was held in Cambridge, UK from 22 to 23 May 2003. The main emphasis of the conference was, in keeping with the RTN, to expose the work of the young post-docs who are funded by the RTN. In addition the team members from the eleven European institutes involved in Euro3D also presented instrumental and observational developments. The conference was organized by Andy Bunker and held at the Institute of Astronomy. There were over thirty participants and 26 talks covered the whole range of application of 3D techniques. The science ranged from Galactic planetary nebulae and globular clusters to kinematics of nearby galaxies out to objects at high redshift. Several talks were devoted to reporting recent observations with newly

  11. PLOT3D user's manual

    NASA Technical Reports Server (NTRS)

    Walatka, Pamela P.; Buning, Pieter G.; Pierce, Larry; Elson, Patricia A.

    1990-01-01

    PLOT3D is a computer graphics program designed to visualize the grids and solutions of computational fluid dynamics. Seventy-four functions are available. Versions are available for many systems. PLOT3D can handle multiple grids with a million or more grid points, and can produce varieties of model renderings, such as wireframe or flat shaded. Output from PLOT3D can be used in animation programs. The first part of this manual is a tutorial that takes the reader, keystroke by keystroke, through a PLOT3D session. The second part of the manual contains reference chapters, including the helpfile, data file formats, advice on changing PLOT3D, and sample command files.

  12. 3D Printed Micro Free-Flow Electrophoresis Device.

    PubMed

    Anciaux, Sarah K; Geiger, Matthew; Bowser, Michael T

    2016-08-01

    The cost, time, and restrictions on creative flexibility associated with current fabrication methods present significant challenges in the development and application of microfluidic devices. Additive manufacturing, also referred to as three-dimensional (3D) printing, provides many advantages over existing methods. With 3D printing, devices can be made in a cost-effective manner with the ability to rapidly prototype new designs. We have fabricated a micro free-flow electrophoresis (μFFE) device using a low-cost, consumer-grade 3D printer. Test prints were performed to determine the minimum feature sizes that could be reproducibly produced using 3D printing fabrication. Microfluidic ridges could be fabricated with dimensions as small as 20 μm high × 640 μm wide. Minimum valley dimensions were 30 μm wide × 130 μm wide. An acetone vapor bath was used to smooth acrylonitrile-butadiene-styrene (ABS) surfaces and facilitate bonding of fully enclosed channels. The surfaces of the 3D-printed features were profiled and compared to a similar device fabricated in a glass substrate. Stable stream profiles were obtained in a 3D-printed μFFE device. Separations of fluorescent dyes in the 3D-printed device and its glass counterpart were comparable. A μFFE separation of myoglobin and cytochrome c was also demonstrated on a 3D-printed device. Limits of detection for rhodamine 110 were determined to be 2 and 0.3 nM for the 3D-printed and glass devices, respectively.

  13. 3D Printed Micro Free-Flow Electrophoresis Device.

    PubMed

    Anciaux, Sarah K; Geiger, Matthew; Bowser, Michael T

    2016-08-01

    The cost, time, and restrictions on creative flexibility associated with current fabrication methods present significant challenges in the development and application of microfluidic devices. Additive manufacturing, also referred to as three-dimensional (3D) printing, provides many advantages over existing methods. With 3D printing, devices can be made in a cost-effective manner with the ability to rapidly prototype new designs. We have fabricated a micro free-flow electrophoresis (μFFE) device using a low-cost, consumer-grade 3D printer. Test prints were performed to determine the minimum feature sizes that could be reproducibly produced using 3D printing fabrication. Microfluidic ridges could be fabricated with dimensions as small as 20 μm high × 640 μm wide. Minimum valley dimensions were 30 μm wide × 130 μm wide. An acetone vapor bath was used to smooth acrylonitrile-butadiene-styrene (ABS) surfaces and facilitate bonding of fully enclosed channels. The surfaces of the 3D-printed features were profiled and compared to a similar device fabricated in a glass substrate. Stable stream profiles were obtained in a 3D-printed μFFE device. Separations of fluorescent dyes in the 3D-printed device and its glass counterpart were comparable. A μFFE separation of myoglobin and cytochrome c was also demonstrated on a 3D-printed device. Limits of detection for rhodamine 110 were determined to be 2 and 0.3 nM for the 3D-printed and glass devices, respectively. PMID:27377354

  14. PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITHOUT TURB3D)

    NASA Technical Reports Server (NTRS)

    Buning, P.

    1994-01-01

    PLOT3D is an interactive graphics program designed to help scientists visualize computational fluid dynamics (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT3D/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT3D, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT3D's interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT3D is part of a computational fluid dynamics software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS3D (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT3D can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT3D's 74 functions are organized into

  15. PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITH TURB3D)

    NASA Technical Reports Server (NTRS)

    Buning, P.

    1994-01-01

    PLOT3D is an interactive graphics program designed to help scientists visualize computational fluid dynamics (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT3D/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT3D, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT3D's interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT3D is part of a computational fluid dynamics software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS3D (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT3D can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT3D's 74 functions are organized into

  16. Unit cell geometry of 3-D braided structures

    NASA Technical Reports Server (NTRS)

    Du, Guang-Wu; Ko, Frank K.

    1993-01-01

    The traditional approach used in modeling of composites reinforced by three-dimensional (3-D) braids is to assume a simple unit cell geometry of a 3-D braided structure with known fiber volume fraction and orientation. In this article, we first examine 3-D braiding methods in the light of braid structures, followed by the development of geometric models for 3-D braids using a unit cell approach. The unit cell geometry of 3-D braids is identified and the relationship of structural parameters such as yarn orientation angle and fiber volume fraction with the key processing parameters established. The limiting geometry has been computed by establishing the point at which yarns jam against each other. Using this factor makes it possible to identify the complete range of allowable geometric arrangements for 3-D braided preforms. This identified unit cell geometry can be translated to mechanical models which relate the geometrical properties of fabric preforms to the mechanical responses of composite systems.

  17. Unassisted 3D camera calibration

    NASA Astrophysics Data System (ADS)

    Atanassov, Kalin; Ramachandra, Vikas; Nash, James; Goma, Sergio R.

    2012-03-01

    With the rapid growth of 3D technology, 3D image capture has become a critical part of the 3D feature set on mobile phones. 3D image quality is affected by the scene geometry as well as on-the-device processing. An automatic 3D system usually assumes known camera poses accomplished by factory calibration using a special chart. In real life settings, pose parameters estimated by factory calibration can be negatively impacted by movements of the lens barrel due to shaking, focusing, or camera drop. If any of these factors displaces the optical axes of either or both cameras, vertical disparity might exceed the maximum tolerable margin and the 3D user may experience eye strain or headaches. To make 3D capture more practical, one needs to consider unassisted (on arbitrary scenes) calibration. In this paper, we propose an algorithm that relies on detection and matching of keypoints between left and right images. Frames containing erroneous matches, along with frames with insufficiently rich keypoint constellations, are detected and discarded. Roll, pitch yaw , and scale differences between left and right frames are then estimated. The algorithm performance is evaluated in terms of the remaining vertical disparity as compared to the maximum tolerable vertical disparity.

  18. Laser printing of 3D metallic interconnects

    NASA Astrophysics Data System (ADS)

    Beniam, Iyoel; Mathews, Scott A.; Charipar, Nicholas A.; Auyeung, Raymond C. Y.; Piqué, Alberto

    2016-04-01

    The use of laser-induced forward transfer (LIFT) techniques for the printing of functional materials has been demonstrated for numerous applications. The printing gives rise to patterns, which can be used to fabricate planar interconnects. More recently, various groups have demonstrated electrical interconnects from laser-printed 3D structures. The laser printing of these interconnects takes place through aggregation of voxels of either molten metal or of pastes containing dispersed metallic particles. However, the generated 3D structures do not posses the same metallic conductivity as a bulk metal interconnect of the same cross-section and length as those formed by wire bonding or tab welding. An alternative is to laser transfer entire 3D structures using a technique known as lase-and-place. Lase-and-place is a LIFT process whereby whole components and parts can be transferred from a donor substrate onto a desired location with one single laser pulse. This paper will describe the use of LIFT to laser print freestanding, solid metal foils or beams precisely over the contact pads of discrete devices to interconnect them into fully functional circuits. Furthermore, this paper will also show how the same laser can be used to bend or fold the bulk metal foils prior to transfer, thus forming compliant 3D structures able to provide strain relief for the circuits under flexing or during motion from thermal mismatch. These interconnect "ridges" can span wide gaps (on the order of a millimeter) and accommodate height differences of tens of microns between adjacent devices. Examples of these laser printed 3D metallic bridges and their role in the development of next generation electronics by additive manufacturing will be presented.

  19. 3D IC for Future HEP Detectors

    SciTech Connect

    Thom, J.; Lipton, R.; Heintz, U.; Johnson, M.; Narain, M.; Badman, R.; Spiegel, L.; Triphati, M.; Deptuch, G.; Kenney, C.; Parker, S.; Ye, Z.; Siddons, D.

    2014-11-07

    Three dimensional integrated circuit technologies offer the possibility of fabricating large area arrays of sensors integrated with complex electronics with minimal dead area, which makes them ideally suited for applications at the LHC upgraded detectors and other future detectors. Here we describe ongoing R&D efforts to demonstrate functionality of components of such detectors. This also includes the study of integrated 3D electronics with active edge sensors to produce "active tiles" which can be tested and assembled into arrays of arbitrary size with high yield.

  20. The upcoming 3D-printing revolution in microfluidics.

    PubMed

    Bhattacharjee, Nirveek; Urrios, Arturo; Kang, Shawn; Folch, Albert

    2016-05-21

    In the last two decades, the vast majority of microfluidic systems have been built in poly(dimethylsiloxane) (PDMS) by soft lithography, a technique based on PDMS micromolding. A long list of key PDMS properties have contributed to the success of soft lithography: PDMS is biocompatible, elastomeric, transparent, gas-permeable, water-impermeable, fairly inexpensive, copyright-free, and rapidly prototyped with high precision using simple procedures. However, the fabrication process typically involves substantial human labor, which tends to make PDMS devices difficult to disseminate outside of research labs, and the layered molding limits the 3D complexity of the devices that can be produced. 3D-printing has recently attracted attention as a way to fabricate microfluidic systems due to its automated, assembly-free 3D fabrication, rapidly decreasing costs, and fast-improving resolution and throughput. Resins with properties approaching those of PDMS are being developed. Here we review past and recent efforts in 3D-printing of microfluidic systems. We compare the salient features of PDMS molding with those of 3D-printing and we give an overview of the critical barriers that have prevented the adoption of 3D-printing by microfluidic developers, namely resolution, throughput, and resin biocompatibility. We also evaluate the various forces that are persuading researchers to abandon PDMS molding in favor of 3D-printing in growing numbers. PMID:27101171

  1. The upcoming 3D-printing revolution in microfluidics.

    PubMed

    Bhattacharjee, Nirveek; Urrios, Arturo; Kang, Shawn; Folch, Albert

    2016-05-21

    In the last two decades, the vast majority of microfluidic systems have been built in poly(dimethylsiloxane) (PDMS) by soft lithography, a technique based on PDMS micromolding. A long list of key PDMS properties have contributed to the success of soft lithography: PDMS is biocompatible, elastomeric, transparent, gas-permeable, water-impermeable, fairly inexpensive, copyright-free, and rapidly prototyped with high precision using simple procedures. However, the fabrication process typically involves substantial human labor, which tends to make PDMS devices difficult to disseminate outside of research labs, and the layered molding limits the 3D complexity of the devices that can be produced. 3D-printing has recently attracted attention as a way to fabricate microfluidic systems due to its automated, assembly-free 3D fabrication, rapidly decreasing costs, and fast-improving resolution and throughput. Resins with properties approaching those of PDMS are being developed. Here we review past and recent efforts in 3D-printing of microfluidic systems. We compare the salient features of PDMS molding with those of 3D-printing and we give an overview of the critical barriers that have prevented the adoption of 3D-printing by microfluidic developers, namely resolution, throughput, and resin biocompatibility. We also evaluate the various forces that are persuading researchers to abandon PDMS molding in favor of 3D-printing in growing numbers.

  2. Spatially resolved 3D noise

    NASA Astrophysics Data System (ADS)

    Haefner, David P.; Preece, Bradley L.; Doe, Joshua M.; Burks, Stephen D.

    2016-05-01

    When evaluated with a spatially uniform irradiance, an imaging sensor exhibits both spatial and temporal variations, which can be described as a three-dimensional (3D) random process considered as noise. In the 1990s, NVESD engineers developed an approximation to the 3D power spectral density (PSD) for noise in imaging systems known as 3D noise. In this correspondence, we describe how the confidence intervals for the 3D noise measurement allows for determination of the sampling necessary to reach a desired precision. We then apply that knowledge to create a smaller cube that can be evaluated spatially across the 2D image giving the noise as a function of position. The method presented here allows for both defective pixel identification and implements the finite sampling correction matrix. In support of the reproducible research effort, the Matlab functions associated with this work can be found on the Mathworks file exchange [1].

  3. Autofocus for 3D imaging

    NASA Astrophysics Data System (ADS)

    Lee-Elkin, Forest

    2008-04-01

    Three dimensional (3D) autofocus remains a significant challenge for the development of practical 3D multipass radar imaging. The current 2D radar autofocus methods are not readily extendable across sensor passes. We propose a general framework that allows a class of data adaptive solutions for 3D auto-focus across passes with minimal constraints on the scene contents. The key enabling assumption is that portions of the scene are sparse in elevation which reduces the number of free variables and results in a system that is simultaneously solved for scatterer heights and autofocus parameters. The proposed method extends 2-pass interferometric synthetic aperture radar (IFSAR) methods to an arbitrary number of passes allowing the consideration of scattering from multiple height locations. A specific case from the proposed autofocus framework is solved and demonstrates autofocus and coherent multipass 3D estimation across the 8 passes of the "Gotcha Volumetric SAR Data Set" X-Band radar data.

  4. Accepting the T3D

    SciTech Connect

    Rich, D.O.; Pope, S.C.; DeLapp, J.G.

    1994-10-01

    In April, a 128 PE Cray T3D was installed at Los Alamos National Laboratory`s Advanced Computing Laboratory as part of the DOE`s High-Performance Parallel Processor Program (H4P). In conjunction with CRI, the authors implemented a 30 day acceptance test. The test was constructed in part to help them understand the strengths and weaknesses of the T3D. In this paper, they briefly describe the H4P and its goals. They discuss the design and implementation of the T3D acceptance test and detail issues that arose during the test. They conclude with a set of system requirements that must be addressed as the T3D system evolves.

  5. Combinatorial 3D Mechanical Metamaterials

    NASA Astrophysics Data System (ADS)

    Coulais, Corentin; Teomy, Eial; de Reus, Koen; Shokef, Yair; van Hecke, Martin

    2015-03-01

    We present a class of elastic structures which exhibit 3D-folding motion. Our structures consist of cubic lattices of anisotropic unit cells that can be tiled in a complex combinatorial fashion. We design and 3d-print this complex ordered mechanism, in which we combine elastic hinges and defects to tailor the mechanics of the material. Finally, we use this large design space to encode smart functionalities such as surface patterning and multistability.

  6. Personalized development of human organs using 3D printing technology.

    PubMed

    Radenkovic, Dina; Solouk, Atefeh; Seifalian, Alexander

    2016-02-01

    3D printing is a technique of fabricating physical models from a 3D volumetric digital image. The image is sliced and printed using a specific material into thin layers, and successive layering of the material produces a 3D model. It has already been used for printing surgical models for preoperative planning and in constructing personalized prostheses for patients. The ultimate goal is to achieve the development of functional human organs and tissues, to overcome limitations of organ transplantation created by the lack of organ donors and life-long immunosuppression. We hypothesized a precision medicine approach to human organ fabrication using 3D printed technology, in which the digital volumetric data would be collected by imaging of a patient, i.e. CT or MRI images followed by mathematical modeling to create a digital 3D image. Then a suitable biocompatible material, with an optimal resolution for cells seeding and maintenance of cell viability during the printing process, would be printed with a compatible printer type and finally implanted into the patient. Life-saving operations with 3D printed implants were already performed in patients. However, several issues need to be addressed before translational application of 3D printing into clinical medicine. These are vascularization, innervation, and financial cost of 3D printing and safety of biomaterials used for the construct. PMID:26826637

  7. Personalized development of human organs using 3D printing technology.

    PubMed

    Radenkovic, Dina; Solouk, Atefeh; Seifalian, Alexander

    2016-02-01

    3D printing is a technique of fabricating physical models from a 3D volumetric digital image. The image is sliced and printed using a specific material into thin layers, and successive layering of the material produces a 3D model. It has already been used for printing surgical models for preoperative planning and in constructing personalized prostheses for patients. The ultimate goal is to achieve the development of functional human organs and tissues, to overcome limitations of organ transplantation created by the lack of organ donors and life-long immunosuppression. We hypothesized a precision medicine approach to human organ fabrication using 3D printed technology, in which the digital volumetric data would be collected by imaging of a patient, i.e. CT or MRI images followed by mathematical modeling to create a digital 3D image. Then a suitable biocompatible material, with an optimal resolution for cells seeding and maintenance of cell viability during the printing process, would be printed with a compatible printer type and finally implanted into the patient. Life-saving operations with 3D printed implants were already performed in patients. However, several issues need to be addressed before translational application of 3D printing into clinical medicine. These are vascularization, innervation, and financial cost of 3D printing and safety of biomaterials used for the construct.

  8. Hepatocyte behavior within three-dimensional porous alginate scaffolds.

    PubMed

    Glicklis, R; Shapiro, L; Agbaria, R; Merchuk, J C; Cohen, S

    2000-02-01

    A potential approach to facilitate the performance of implanted hepatocytes is to enable their aggregation and re-expression of their differentiated function prior to implantation. Here we examined the behavior of freshly isolated rat adult hepatocytes seeded within a novel three-dimensional (3-D) scaffold based on alginate. The attractive features of this scaffold include a highly porous structure (sponge-like) with interconnecting pores, and pore sizes with diameters of 100-150 microm. Due to their hydrophilic nature, seeding hepatocytes onto the alginate sponges was efficient. DNA measurements showed that the total cell number within the sponges did not change over 2 weeks, indicating that hepatocytes do not proliferate under these culture conditions. Nearly all seeded cells maintained viability, according to the MTT assay. Within 24 h post-seeding, small clusters of viable cells, were seen scattered within the sponge. More than 90% of the seeded cells participated in the aggregation; the high efficiency is attributed to the non-adherent nature of alginate. The spheroids had smooth boundaries and by day 4 in culture reached an average diameter of 100 microm, which is at the same magnitude of the sponge pore size. The cells appeared to synthesize fibronectin which was deposited on the spheroids. No laminin or collagen type IV were detected in the deposit. The 3-D arrangement of hepatocytes within the alginate sponges promoted their functional expression; within a week the cells secreted the maximal albumin secretion rate of 60 microg albumin/10(6) cells/day. Urea secretion rate did not depend on cell aggregation and was similar to that obtained when hepatocytes were cultured on collagen type I coated dishes (100 microg/10(6) cells/day). Our studies show that alginate sponges can provide a conducive environment to facilitate the performance of cultured hepatocytes by enhancing their aggregation.

  9. 3D Printing: 3D Printing of Conductive Complex Structures with In Situ Generation of Silver Nanoparticles (Adv. Mater. 19/2016).

    PubMed

    Fantino, Erika; Chiappone, Annalisa; Roppolo, Ignazio; Manfredi, Diego; Bongiovanni, Roberta; Pirri, Candido Fabrizio; Calignano, Flaviana

    2016-05-01

    On page 3712, E. Fantino, A. Chiappone, and co-workers fabricate conductive 3D hybrid structures by coupling the photo-reduction of metal precursors with 3D printing technology. The generated structures consist of metal nanoparticles embedded in a polymer matrix shaped into complex multilayered architectures. 3D conductive structures are fabricated with a digital light-processing printer incorporating silver salt into photocurable formulations. PMID:27167030

  10. 3D Printing: 3D Printing of Conductive Complex Structures with In Situ Generation of Silver Nanoparticles (Adv. Mater. 19/2016).

    PubMed

    Fantino, Erika; Chiappone, Annalisa; Roppolo, Ignazio; Manfredi, Diego; Bongiovanni, Roberta; Pirri, Candido Fabrizio; Calignano, Flaviana

    2016-05-01

    On page 3712, E. Fantino, A. Chiappone, and co-workers fabricate conductive 3D hybrid structures by coupling the photo-reduction of metal precursors with 3D printing technology. The generated structures consist of metal nanoparticles embedded in a polymer matrix shaped into complex multilayered architectures. 3D conductive structures are fabricated with a digital light-processing printer incorporating silver salt into photocurable formulations.

  11. Injectable hydrogels derived from phosphorylated alginic acid calcium complexes.

    PubMed

    Kim, Han-Sem; Song, Minsoo; Lee, Eun-Jung; Shin, Ueon Sang

    2015-06-01

    Phosphorylation of sodium alginate salt (NaAlg) was carried out using H3PO4/P2O5/Et3PO4 followed by acid-base reaction with Ca(OAc)2 to give phosphorylated alginic acid calcium complexes (CaPAlg), as a water dispersible alginic acid derivative. The modified alginate derivatives including phosphorylated alginic acid (PAlg) and CaPAlg were characterized by nuclear magnetic resonance spectroscopy for (1)H, and (31)P nuclei, high resolution inductively coupled plasma optical emission spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. CaPAlg hydrogels were prepared simply by mixing CaPAlg solution (2w/v%) with NaAlg solution (2w/v%) in various ratios (2:8, 4:6, 6:4, 8:2) of volume. No additional calcium salts such as CaSO4 or CaCl2 were added externally. The gelation was completed within about 3-40min indicating a high potential of hydrogel delivery by injection in vivo. Their mechanical properties were tested to be ≤6.7kPa for compressive strength at break and about 8.4kPa/mm for elastic modulus. SEM analysis of the CaPAlg hydrogels showed highly porous morphology with interconnected pores of width in the range of 100-800μm. Cell culture results showed that the injectable hydrogels exhibited comparable properties to the pure alginate hydrogel in terms of cytotoxicity and 3D encapsulation of cells for a short time period. The developed injectable hydrogels showed suitable physicochemical and mechanical properties for injection in vivo, and could therefore be beneficial for the field of soft tissue engineering. PMID:25842118

  12. LASTRAC.3d: Transition Prediction in 3D Boundary Layers

    NASA Technical Reports Server (NTRS)

    Chang, Chau-Lyan

    2004-01-01

    Langley Stability and Transition Analysis Code (LASTRAC) is a general-purpose, physics-based transition prediction code released by NASA for laminar flow control studies and transition research. This paper describes the LASTRAC extension to general three-dimensional (3D) boundary layers such as finite swept wings, cones, or bodies at an angle of attack. The stability problem is formulated by using a body-fitted nonorthogonal curvilinear coordinate system constructed on the body surface. The nonorthogonal coordinate system offers a variety of marching paths and spanwise waveforms. In the extreme case of an infinite swept wing boundary layer, marching with a nonorthogonal coordinate produces identical solutions to those obtained with an orthogonal coordinate system using the earlier release of LASTRAC. Several methods to formulate the 3D parabolized stability equations (PSE) are discussed. A surface-marching procedure akin to that for 3D boundary layer equations may be used to solve the 3D parabolized disturbance equations. On the other hand, the local line-marching PSE method, formulated as an easy extension from its 2D counterpart and capable of handling the spanwise mean flow and disturbance variation, offers an alternative. A linear stability theory or parabolized stability equations based N-factor analysis carried out along the streamline direction with a fixed wavelength and downstream-varying spanwise direction constitutes an efficient engineering approach to study instability wave evolution in a 3D boundary layer. The surface-marching PSE method enables a consistent treatment of the disturbance evolution along both streamwise and spanwise directions but requires more stringent initial conditions. Both PSE methods and the traditional LST approach are implemented in the LASTRAC.3d code. Several test cases for tapered or finite swept wings and cones at an angle of attack are discussed.

  13. From 3D view to 3D print

    NASA Astrophysics Data System (ADS)

    Dima, M.; Farisato, G.; Bergomi, M.; Viotto, V.; Magrin, D.; Greggio, D.; Farinato, J.; Marafatto, L.; Ragazzoni, R.; Piazza, D.

    2014-08-01

    In the last few years 3D printing is getting more and more popular and used in many fields going from manufacturing to industrial design, architecture, medical support and aerospace. 3D printing is an evolution of bi-dimensional printing, which allows to obtain a solid object from a 3D model, realized with a 3D modelling software. The final product is obtained using an additive process, in which successive layers of material are laid down one over the other. A 3D printer allows to realize, in a simple way, very complex shapes, which would be quite difficult to be produced with dedicated conventional facilities. Thanks to the fact that the 3D printing is obtained superposing one layer to the others, it doesn't need any particular work flow and it is sufficient to simply draw the model and send it to print. Many different kinds of 3D printers exist based on the technology and material used for layer deposition. A common material used by the toner is ABS plastics, which is a light and rigid thermoplastic polymer, whose peculiar mechanical properties make it diffusely used in several fields, like pipes production and cars interiors manufacturing. I used this technology to create a 1:1 scale model of the telescope which is the hardware core of the space small mission CHEOPS (CHaracterising ExOPlanets Satellite) by ESA, which aims to characterize EXOplanets via transits observations. The telescope has a Ritchey-Chrétien configuration with a 30cm aperture and the launch is foreseen in 2017. In this paper, I present the different phases for the realization of such a model, focusing onto pros and cons of this kind of technology. For example, because of the finite printable volume (10×10×12 inches in the x, y and z directions respectively), it has been necessary to split the largest parts of the instrument in smaller components to be then reassembled and post-processed. A further issue is the resolution of the printed material, which is expressed in terms of layers

  14. Defining an optimal surface chemistry for pluripotent stem cell culture in 2D and 3D

    NASA Astrophysics Data System (ADS)

    Zonca, Michael R., Jr.

    Surface chemistry is critical for growing pluripotent stem cells in an undifferentiated state. There is great potential to engineer the surface chemistry at the nanoscale level to regulate stem cell adhesion. However, the challenge is to identify the optimal surface chemistry of the substrata for ES cell attachment and maintenance. Using a high-throughput polymerization and screening platform, a chemically defined, synthetic polymer grafted coating that supports strong attachment and high expansion capacity of pluripotent stem cells has been discovered using mouse embryonic stem (ES) cells as a model system. This optimal substrate, N-[3-(Dimethylamino)propyl] methacrylamide (DMAPMA) that is grafted on 2D synthetic poly(ether sulfone) (PES) membrane, sustains the self-renewal of ES cells (up to 7 passages). DMAPMA supports cell attachment of ES cells through integrin beta1 in a RGD-independent manner and is similar to another recently reported polymer surface. Next, DMAPMA has been able to be transferred to 3D by grafting to synthetic, polymeric, PES fibrous matrices through both photo-induced and plasma-induced polymerization. These 3D modified fibers exhibited higher cell proliferation and greater expression of pluripotency markers of mouse ES cells than 2D PES membranes. Our results indicated that desirable surfaces in 2D can be scaled to 3D and that both surface chemistry and structural dimension strongly influence the growth and differentiation of pluripotent stem cells. Lastly, the feasibility of incorporating DMAPMA into a widely used natural polymer, alginate, has been tested. Novel adhesive alginate hydrogels have been successfully synthesized by either direct polymerization of DMAPMA and methacrylic acid blended with alginate, or photo-induced DMAPMA polymerization on alginate nanofibrous hydrogels. In particular, DMAPMA-coated alginate hydrogels support strong ES cell attachment, exhibiting a concentration dependency of DMAPMA. This research provides a

  15. 21 CFR 184.1724 - Sodium alginate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium alginate. 184.1724 Section 184.1724 Food... Specific Substances Affirmed as GRAS § 184.1724 Sodium alginate. (a) Sodium alginate (CAS Reg. No. 9005-38-3) is the sodium salt of alginic acid, a natural polyuronide constituent of certain brown...

  16. 21 CFR 184.1724 - Sodium alginate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium alginate. 184.1724 Section 184.1724 Food... Specific Substances Affirmed as GRAS § 184.1724 Sodium alginate. (a) Sodium alginate (CAS Reg. No. 9005-38-3) is the sodium salt of alginic acid, a natural polyuronide constituent of certain brown...

  17. 21 CFR 184.1724 - Sodium alginate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium alginate. 184.1724 Section 184.1724 Food... Specific Substances Affirmed as GRAS § 184.1724 Sodium alginate. (a) Sodium alginate (CAS Reg. No. 9005-38-3) is the sodium salt of alginic acid, a natural polyuronide constituent of certain brown...

  18. 21 CFR 184.1610 - Potassium alginate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium alginate. 184.1610 Section 184.1610 Food... Specific Substances Affirmed as GRAS § 184.1610 Potassium alginate. (a) Potassium alginate (CAS Reg. No. 9005-36-1) is the potassium salt of alginic acid, a natural polyuronide constituent of certain...

  19. 21 CFR 184.1610 - Potassium alginate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium alginate. 184.1610 Section 184.1610 Food... Specific Substances Affirmed as GRAS § 184.1610 Potassium alginate. (a) Potassium alginate (CAS Reg. No. 9005-36-1) is the potassium salt of alginic acid, a natural polyuronide constituent of certain...

  20. 21 CFR 184.1610 - Potassium alginate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium alginate. 184.1610 Section 184.1610 Food... Specific Substances Affirmed as GRAS § 184.1610 Potassium alginate. (a) Potassium alginate (CAS Reg. No. 9005-36-1) is the potassium salt of alginic acid, a natural polyuronide constituent of certain...

  1. 21 CFR 184.1187 - Calcium alginate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium alginate. 184.1187 Section 184.1187 Food... Specific Substances Affirmed as GRAS § 184.1187 Calcium alginate. (a) Calcium alginate (CAS Reg. No. 9005-35-0) is the calcium salt of alginic acid, a natural polyuronide constituent of certain brown...

  2. 21 CFR 184.1187 - Calcium alginate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Calcium alginate. 184.1187 Section 184.1187 Food... Specific Substances Affirmed as GRAS § 184.1187 Calcium alginate. (a) Calcium alginate (CAS Reg. No. 9005-35-0) is the calcium salt of alginic acid, a natural polyuronide constituent of certain brown...

  3. 21 CFR 184.1187 - Calcium alginate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Calcium alginate. 184.1187 Section 184.1187 Food... Specific Substances Affirmed as GRAS § 184.1187 Calcium alginate. (a) Calcium alginate (CAS Reg. No. 9005-35-0) is the calcium salt of alginic acid, a natural polyuronide constituent of certain brown...

  4. 21 CFR 184.1187 - Calcium alginate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Calcium alginate. 184.1187 Section 184.1187 Food... Specific Substances Affirmed as GRAS § 184.1187 Calcium alginate. (a) Calcium alginate (CAS Reg. No. 9005-35-0) is the calcium salt of alginic acid, a natural polyuronide constituent of certain brown...

  5. 21 CFR 184.1610 - Potassium alginate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium alginate. 184.1610 Section 184.1610 Food... Specific Substances Affirmed as GRAS § 184.1610 Potassium alginate. (a) Potassium alginate (CAS Reg. No. 9005-36-1) is the potassium salt of alginic acid, a natural polyuronide constituent of certain...

  6. Alginate-Iron Speciation and Its Effect on In Vitro Cellular Iron Metabolism

    PubMed Central

    Horniblow, Richard D.; Dowle, Miriam; Iqbal, Tariq H.; Latunde-Dada, Gladys O.; Palmer, Richard E.

    2015-01-01

    Alginates are a class of biopolymers with known iron binding properties which are routinely used in the fabrication of iron-oxide nanoparticles. In addition, alginates have been implicated in influencing human iron absorption. However, the synthesis of iron oxide nanoparticles employs non-physiological pH conditions and whether nanoparticle formation in vivo is responsible for influencing cellular iron metabolism is unclear. Thus the aims of this study were to determine how alginate and iron interact at gastric-comparable pH conditions and how this influences iron metabolism. Employing a range of spectroscopic techniques under physiological conditions alginate-iron complexation was confirmed and, in conjunction with aberration corrected scanning transmission electron microscopy, nanoparticles were observed. The results infer a nucleation-type model of iron binding whereby alginate is templating the condensation of iron-hydroxide complexes to form iron oxide centred nanoparticles. The interaction of alginate and iron at a cellular level was found to decrease cellular iron acquisition by 37% (p < 0.05) and in combination with confocal microscopy the alginate inhibits cellular iron transport through extracellular iron chelation with the resulting complexes not internalised. These results infer alginate as being useful in the chelation of excess iron, especially in the context of inflammatory bowel disease and colorectal cancer where excess unabsorbed luminal iron is thought to be a driver of disease. PMID:26378798

  7. 3-D textile reinforcements in composite materials

    SciTech Connect

    Miravete, A.

    1999-11-01

    Laminated composite materials have been used in structural applications since the 1960s. However, their high cost and inability to accommodate fibers in the laminate`s thickness direction greatly reduce their damage tolerance and impact resistance. The second generation of materials--3-D textile reinforced composites--offers significant cost reduction, and by incorporating reinforcement in the thickness direction, dramatically increases damage tolerance and impact resistance. However, methods for predicting mechanical properties of 3-D textile reinforced composite materials tend to be more complex. These materials also have disadvantages--particularly in regard to crimps in the yarns--that require more research. Textile preforms, micro- and macromechanical modeling, manufacturing processes, and characterization all need further development. As researchers overcome these problems, this new generation of composites will emerge as a highly competitive family of materials. This book provides a state-of-the-art account of this promising technology. In it, top experts describe the manufacturing processes, highlight the advantages, identify the main applications, analyze methods for predicting mechanical properties, and detail various reinforcement strategies, including grid structure, knitted fabric composites, and the braiding technique. Armed with the information in this book, readers will be prepared to better exploit the advantages of 3-D textile reinforced composites, overcome its disadvantages, and contribute to the further development of the technology.

  8. YouDash3D: exploring stereoscopic 3D gaming for 3D movie theaters

    NASA Astrophysics Data System (ADS)

    Schild, Jonas; Seele, Sven; Masuch, Maic

    2012-03-01

    Along with the success of the digitally revived stereoscopic cinema, events beyond 3D movies become attractive for movie theater operators, i.e. interactive 3D games. In this paper, we present a case that explores possible challenges and solutions for interactive 3D games to be played by a movie theater audience. We analyze the setting and showcase current issues related to lighting and interaction. Our second focus is to provide gameplay mechanics that make special use of stereoscopy, especially depth-based game design. Based on these results, we present YouDash3D, a game prototype that explores public stereoscopic gameplay in a reduced kiosk setup. It features live 3D HD video stream of a professional stereo camera rig rendered in a real-time game scene. We use the effect to place the stereoscopic effigies of players into the digital game. The game showcases how stereoscopic vision can provide for a novel depth-based game mechanic. Projected trigger zones and distributed clusters of the audience video allow for easy adaptation to larger audiences and 3D movie theater gaming.

  9. Remote 3D Medical Consultation

    NASA Astrophysics Data System (ADS)

    Welch, Greg; Sonnenwald, Diane H.; Fuchs, Henry; Cairns, Bruce; Mayer-Patel, Ketan; Yang, Ruigang; State, Andrei; Towles, Herman; Ilie, Adrian; Krishnan, Srinivas; Söderholm, Hanna M.

    Two-dimensional (2D) video-based telemedical consultation has been explored widely in the past 15-20 years. Two issues that seem to arise in most relevant case studies are the difficulty associated with obtaining the desired 2D camera views, and poor depth perception. To address these problems we are exploring the use of a small array of cameras to synthesize a spatially continuous range of dynamic three-dimensional (3D) views of a remote environment and events. The 3D views can be sent across wired or wireless networks to remote viewers with fixed displays or mobile devices such as a personal digital assistant (PDA). The viewpoints could be specified manually or automatically via user head or PDA tracking, giving the remote viewer virtual head- or hand-slaved (PDA-based) remote cameras for mono or stereo viewing. We call this idea remote 3D medical consultation (3DMC). In this article we motivate and explain the vision for 3D medical consultation; we describe the relevant computer vision/graphics, display, and networking research; we present a proof-of-concept prototype system; and we present some early experimental results supporting the general hypothesis that 3D remote medical consultation could offer benefits over conventional 2D televideo.

  10. Speaking Volumes About 3-D

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In 1999, Genex submitted a proposal to Stennis Space Center for a volumetric 3-D display technique that would provide multiple users with a 360-degree perspective to simultaneously view and analyze 3-D data. The futuristic capabilities of the VolumeViewer(R) have offered tremendous benefits to commercial users in the fields of medicine and surgery, air traffic control, pilot training and education, computer-aided design/computer-aided manufacturing, and military/battlefield management. The technology has also helped NASA to better analyze and assess the various data collected by its satellite and spacecraft sensors. Genex capitalized on its success with Stennis by introducing two separate products to the commercial market that incorporate key elements of the 3-D display technology designed under an SBIR contract. The company Rainbow 3D(R) imaging camera is a novel, three-dimensional surface profile measurement system that can obtain a full-frame 3-D image in less than 1 second. The third product is the 360-degree OmniEye(R) video system. Ideal for intrusion detection, surveillance, and situation management, this unique camera system offers a continuous, panoramic view of a scene in real time.

  11. 3D-printed microfluidic chips with patterned, cell-laden hydrogel constructs.

    PubMed

    Knowlton, Stephanie; Yu, Chu Hsiang; Ersoy, Fulya; Emadi, Sharareh; Khademhosseini, Ali; Tasoglu, Savas

    2016-06-01

    Three-dimensional (3D) printing offers potential to fabricate high-throughput and low-cost fabrication of microfluidic devices as a promising alternative to traditional techniques which enables efficient design iterations in the development stage. In this study, we demonstrate a single-step fabrication of a 3D transparent microfluidic chip using two alternative techniques: a stereolithography-based desktop 3D printer and a two-step fabrication using an industrial 3D printer based on polyjet technology. This method, compared to conventional fabrication using relatively expensive materials and labor-intensive processes, presents a low-cost, rapid prototyping technique to print functional 3D microfluidic chips. We enhance the capabilities of 3D-printed microfluidic devices by coupling 3D cell encapsulation and spatial patterning within photocrosslinkable gelatin methacryloyl (GelMA). The platform presented here serves as a 3D culture environment for long-term cell culture and growth. Furthermore, we have demonstrated the ability to print complex 3D microfluidic channels to create predictable and controllable fluid flow regimes. Here, we demonstrate the novel use of 3D-printed microfluidic chips as controllable 3D cell culture environments, advancing the applicability of 3D printing to engineering physiological systems for future applications in bioengineering.

  12. 3D-printed microfluidic chips with patterned, cell-laden hydrogel constructs.

    PubMed

    Knowlton, Stephanie; Yu, Chu Hsiang; Ersoy, Fulya; Emadi, Sharareh; Khademhosseini, Ali; Tasoglu, Savas

    2016-06-01

    Three-dimensional (3D) printing offers potential to fabricate high-throughput and low-cost fabrication of microfluidic devices as a promising alternative to traditional techniques which enables efficient design iterations in the development stage. In this study, we demonstrate a single-step fabrication of a 3D transparent microfluidic chip using two alternative techniques: a stereolithography-based desktop 3D printer and a two-step fabrication using an industrial 3D printer based on polyjet technology. This method, compared to conventional fabrication using relatively expensive materials and labor-intensive processes, presents a low-cost, rapid prototyping technique to print functional 3D microfluidic chips. We enhance the capabilities of 3D-printed microfluidic devices by coupling 3D cell encapsulation and spatial patterning within photocrosslinkable gelatin methacryloyl (GelMA). The platform presented here serves as a 3D culture environment for long-term cell culture and growth. Furthermore, we have demonstrated the ability to print complex 3D microfluidic channels to create predictable and controllable fluid flow regimes. Here, we demonstrate the novel use of 3D-printed microfluidic chips as controllable 3D cell culture environments, advancing the applicability of 3D printing to engineering physiological systems for future applications in bioengineering. PMID:27321481

  13. 3D-Printing for Analytical Ultracentrifugation

    PubMed Central

    Desai, Abhiksha; Krynitsky, Jonathan; Pohida, Thomas J.; Zhao, Huaying

    2016-01-01

    Analytical ultracentrifugation (AUC) is a classical technique of physical biochemistry providing information on size, shape, and interactions of macromolecules from the analysis of their migration in centrifugal fields while free in solution. A key mechanical element in AUC is the centerpiece, a component of the sample cell assembly that is mounted between the optical windows to allow imaging and to seal the sample solution column against high vacuum while exposed to gravitational forces in excess of 300,000 g. For sedimentation velocity it needs to be precisely sector-shaped to allow unimpeded radial macromolecular migration. During the history of AUC a great variety of centerpiece designs have been developed for different types of experiments. Here, we report that centerpieces can now be readily fabricated by 3D printing at low cost, from a variety of materials, and with customized designs. The new centerpieces can exhibit sufficient mechanical stability to withstand the gravitational forces at the highest rotor speeds and be sufficiently precise for sedimentation equilibrium and sedimentation velocity experiments. Sedimentation velocity experiments with bovine serum albumin as a reference molecule in 3D printed centerpieces with standard double-sector design result in sedimentation boundaries virtually indistinguishable from those in commercial double-sector epoxy centerpieces, with sedimentation coefficients well within the range of published values. The statistical error of the measurement is slightly above that obtained with commercial epoxy, but still below 1%. Facilitated by modern open-source design and fabrication paradigms, we believe 3D printed centerpieces and AUC accessories can spawn a variety of improvements in AUC experimental design, efficiency and resource allocation. PMID:27525659

  14. 3D-Printing for Analytical Ultracentrifugation.

    PubMed

    Desai, Abhiksha; Krynitsky, Jonathan; Pohida, Thomas J; Zhao, Huaying; Schuck, Peter

    2016-01-01

    Analytical ultracentrifugation (AUC) is a classical technique of physical biochemistry providing information on size, shape, and interactions of macromolecules from the analysis of their migration in centrifugal fields while free in solution. A key mechanical element in AUC is the centerpiece, a component of the sample cell assembly that is mounted between the optical windows to allow imaging and to seal the sample solution column against high vacuum while exposed to gravitational forces in excess of 300,000 g. For sedimentation velocity it needs to be precisely sector-shaped to allow unimpeded radial macromolecular migration. During the history of AUC a great variety of centerpiece designs have been developed for different types of experiments. Here, we report that centerpieces can now be readily fabricated by 3D printing at low cost, from a variety of materials, and with customized designs. The new centerpieces can exhibit sufficient mechanical stability to withstand the gravitational forces at the highest rotor speeds and be sufficiently precise for sedimentation equilibrium and sedimentation velocity experiments. Sedimentation velocity experiments with bovine serum albumin as a reference molecule in 3D printed centerpieces with standard double-sector design result in sedimentation boundaries virtually indistinguishable from those in commercial double-sector epoxy centerpieces, with sedimentation coefficients well within the range of published values. The statistical error of the measurement is slightly above that obtained with commercial epoxy, but still below 1%. Facilitated by modern open-source design and fabrication paradigms, we believe 3D printed centerpieces and AUC accessories can spawn a variety of improvements in AUC experimental design, efficiency and resource allocation.

  15. 3D-Printing for Analytical Ultracentrifugation.

    PubMed

    Desai, Abhiksha; Krynitsky, Jonathan; Pohida, Thomas J; Zhao, Huaying; Schuck, Peter

    2016-01-01

    Analytical ultracentrifugation (AUC) is a classical technique of physical biochemistry providing information on size, shape, and interactions of macromolecules from the analysis of their migration in centrifugal fields while free in solution. A key mechanical element in AUC is the centerpiece, a component of the sample cell assembly that is mounted between the optical windows to allow imaging and to seal the sample solution column against high vacuum while exposed to gravitational forces in excess of 300,000 g. For sedimentation velocity it needs to be precisely sector-shaped to allow unimpeded radial macromolecular migration. During the history of AUC a great variety of centerpiece designs have been developed for different types of experiments. Here, we report that centerpieces can now be readily fabricated by 3D printing at low cost, from a variety of materials, and with customized designs. The new centerpieces can exhibit sufficient mechanical stability to withstand the gravitational forces at the highest rotor speeds and be sufficiently precise for sedimentation equilibrium and sedimentation velocity experiments. Sedimentation velocity experiments with bovine serum albumin as a reference molecule in 3D printed centerpieces with standard double-sector design result in sedimentation boundaries virtually indistinguishable from those in commercial double-sector epoxy centerpieces, with sedimentation coefficients well within the range of published values. The statistical error of the measurement is slightly above that obtained with commercial epoxy, but still below 1%. Facilitated by modern open-source design and fabrication paradigms, we believe 3D printed centerpieces and AUC accessories can spawn a variety of improvements in AUC experimental design, efficiency and resource allocation. PMID:27525659

  16. Alginate electrodeposition onto three-dimensional porous Co-Ni films as drug delivery platforms.

    PubMed

    García-Torres, J; Gispert, C; Gómez, E; Vallés, E

    2015-01-21

    Three-dimensional porous Co-Ni films/alginate hybrid materials have been successfully prepared by electrodeposition to be used as a steerable magnetic device for drug delivery. Firstly, 3D porous Co-Ni films were prepared as substrates for the subsequent electrodeposition of the alginate biopolymer. Cyclic voltammetry, galvanostatic and potentiostatic studies were performed to establish the best conditions to obtain porous Co-Ni films. The electrochemical experiments were carried out in an electrolyte containing the metal salts and ammonium chloride at low pHs. In a second stage, the electrochemical deposition of alginate as a biocompatible polymer drug delivery carrier was performed. The characteristics of the alginate matrix were investigated in terms of electrochemical properties, morphology and drug release. The hybrid material obtained showed soft-magnetic behavior and drug release indicating its suitability to be used as a steerable magnetic drug delivery device.

  17. Mechanically reinforced cell-laden scaffolds formed using alginate-based bioink printed onto the surface of a PCL/alginate mesh structure for regeneration of hard tissue.

    PubMed

    Kim, Yong Bok; Lee, Hyeongjin; Yang, Gi-Hoon; Choi, Chang Hyun; Lee, DaeWeon; Hwang, Heon; Jung, Won-Kyo; Yoon, Hyeon; Kim, Geun Hyung

    2016-01-01

    Cell-printing technology has provided a new paradigm for biofabrication, with potential to overcome several shortcomings of conventional scaffold-based tissue regeneration strategies via controlled delivery of various cell types in well-defined target regions. Here we describe a cell-printing method to obtain mechanically reinforced multi-layered cell-embedded scaffolds, formed of micron-scale poly(ε-caprolactone) (PCL)/alginate struts coated with alginate-based bioink. To compare the physical and cellular activities, we used a scaffold composed of pure alginate (without cells) coated PCL/alginate struts as a control. We systematically varied the ratio of alginate cross-linking agent, and determined the optimal cell-coating conditions to form the PCL/alginate struts. Following fabrication of the cell (MG63)-laden PCL/alginate scaffold, the bioactivity was evaluated in vitro. The laden cells exhibited a substantially more developed cytoskeleton compared with those on a control scaffold consisting of the same material composition. Based on these results, the printed cells exhibited a significantly more homogenous distribution within the scaffold compared with the control. Cell proliferation was determined via MTT assays at 1, 3, 7, and 14 days of culture, and the proliferation of the cell-printed scaffold was substantially in excess (∼2.4-fold) of that on the control. Furthermore, the osteogenic activity such as ALP was measured, and the cell-laden scaffold exhibited significantly greater activity (∼3.2-fold) compared with the control scaffold.

  18. Microbial alginate production, modification and its applications

    PubMed Central

    Hay, Iain D; Rehman, Zahid Ur; Moradali, M Fata; Wang, Yajie; Rehm, Bernd H A

    2013-01-01

    Alginate is an important polysaccharide used widely in the food, textile, printing and pharmaceutical industries for its viscosifying, and gelling properties. All commercially produced alginates are isolated from farmed brown seaweeds. These algal alginates suffer from heterogeneity in composition and material properties. Here, we will discuss alginates produced by bacteria; the molecular mechanisms involved in their biosynthesis; and the potential to utilize these bacterially produced or modified alginates for high-value applications where defined material properties are required. PMID:24034361

  19. 3D Computations and Experiments

    SciTech Connect

    Couch, R; Faux, D; Goto, D; Nikkel, D

    2004-04-05

    This project consists of two activities. Task A, Simulations and Measurements, combines all the material model development and associated numerical work with the materials-oriented experimental activities. The goal of this effort is to provide an improved understanding of dynamic material properties and to provide accurate numerical representations of those properties for use in analysis codes. Task B, ALE3D Development, involves general development activities in the ALE3D code with the focus of improving simulation capabilities for problems of mutual interest to DoD and DOE. Emphasis is on problems involving multi-phase flow, blast loading of structures and system safety/vulnerability studies.

  20. 3D visualization of polymer nanostructure

    SciTech Connect

    Werner, James H

    2009-01-01

    Soft materials and structured polymers are extremely useful nanotechnology building blocks. Block copolymers, in particular, have served as 2D masks for nanolithography and 3D scaffolds for photonic crystals, nanoparticle fabrication, and solar cells. F or many of these applications, the precise 3 dimensional structure and the number and type of defects in the polymer is important for ultimate function. However, directly visualizing the 3D structure of a soft material from the nanometer to millimeter length scales is a significant technical challenge. Here, we propose to develop the instrumentation needed for direct 3D structure determination at near nanometer resolution throughout a nearly millimeter-cubed volume of a soft, potentially heterogeneous, material. This new capability will be a valuable research tool for LANL missions in chemistry, materials science, and nanoscience. Our approach to soft materials visualization builds upon exciting developments in super-resolution optical microscopy that have occurred over the past two years. To date, these new, truly revolutionary, imaging methods have been developed and almost exclusively used for biological applications. However, in addition to biological cells, these super-resolution imaging techniques hold extreme promise for direct visualization of many important nanostructured polymers and other heterogeneous chemical systems. Los Alamos has a unique opportunity to lead the development of these super-resolution imaging methods for problems of chemical rather than biological significance. While these optical methods are limited to systems transparent to visible wavelengths, we stress that many important functional chemicals such as polymers, glasses, sol-gels, aerogels, or colloidal assemblies meet this requirement, with specific examples including materials designed for optical communication, manipulation, or light-harvesting Our Research Goals are: (1) Develop the instrumentation necessary for imaging materials

  1. Hierarchical 3D ZnIn2S4/graphene nano-heterostructures: their in situ fabrication with dual functionality in solar hydrogen production and as anodes for lithium ion batteries.

    PubMed

    Kale, Sayali B; Kalubarme, Ramchandra S; Mahadadalkar, Manjiri A; Jadhav, Harsharaj S; Bhirud, Ashwini P; Ambekar, Jalinder D; Park, Chan-Jin; Kale, Bharat B

    2015-12-21

    Hierarchical 3D ZnIn2S4/graphene (ZnIn2S4/Gr) nano-heterostructures were successfully synthesized using an in-situ hydrothermal method. The dual functionality of these nano-heterostructures i.e. for solar hydrogen production and lithium ion batteries has been demonstrated for the first time. The ZnIn2S4/Gr nano-heterostructures were optimized by varying the concentrations of graphene for utmost hydrogen production. An inspection of the structure shows the existence of layered hexagonal ZnIn2S4 wrapped in graphene. The reduction of graphene oxide (GO) to graphene was confirmed by Raman and XPS analyses. The morphological analysis demonstrated that ultrathin ZnIn2S4 nanopetals are dispersed on graphene sheets. The optical study reveals the extended absorption edge to the visible region due to the presence of graphene and hence is used as a photocatalyst to transform H2S into eco-friendly hydrogen using solar light. The ZnIn2S4/Gr nano-heterostructure that is comprised of graphene and ZnIn2S4 in a weight ratio of 1 : 99 exhibits enhanced photocatalytically stable hydrogen production i.e. ∼6365 μmole h(-1) under visible light irradiation using just 0.2 g of nano-heterostructure, which is much higher as compared to bare hierarchical 3D ZnIn2S4. The heightened photocatalytic activity is attributed to the enhanced charge carrier separation due to graphene which acts as an excellent electron collector and transporter. Furthermore, the usage of nano-heterostructures and pristine ZnIn2S4 as anodes in lithium ion batteries confers the charge capacities of 590 and 320 mA h g(-1) after 220 cycles as compared to their initial reversible capacities of 645 and 523 mA h g(-1), respectively. These nano-heterostructures show high reversible capacity, excellent cycling stability, and high-rate capability indicating their potential as promising anode materials for LIBs. The excellent performance is due to the nanostructuring of ZnIn2S4 and the presence of a graphene layer, which

  2. Hierarchical 3D ZnIn2S4/graphene nano-heterostructures: their in situ fabrication with dual functionality in solar hydrogen production and as anodes for lithium ion batteries.

    PubMed

    Kale, Sayali B; Kalubarme, Ramchandra S; Mahadadalkar, Manjiri A; Jadhav, Harsharaj S; Bhirud, Ashwini P; Ambekar, Jalinder D; Park, Chan-Jin; Kale, Bharat B

    2015-12-21

    Hierarchical 3D ZnIn2S4/graphene (ZnIn2S4/Gr) nano-heterostructures were successfully synthesized using an in-situ hydrothermal method. The dual functionality of these nano-heterostructures i.e. for solar hydrogen production and lithium ion batteries has been demonstrated for the first time. The ZnIn2S4/Gr nano-heterostructures were optimized by varying the concentrations of graphene for utmost hydrogen production. An inspection of the structure shows the existence of layered hexagonal ZnIn2S4 wrapped in graphene. The reduction of graphene oxide (GO) to graphene was confirmed by Raman and XPS analyses. The morphological analysis demonstrated that ultrathin ZnIn2S4 nanopetals are dispersed on graphene sheets. The optical study reveals the extended absorption edge to the visible region due to the presence of graphene and hence is used as a photocatalyst to transform H2S into eco-friendly hydrogen using solar light. The ZnIn2S4/Gr nano-heterostructure that is comprised of graphene and ZnIn2S4 in a weight ratio of 1 : 99 exhibits enhanced photocatalytically stable hydrogen production i.e. ∼6365 μmole h(-1) under visible light irradiation using just 0.2 g of nano-heterostructure, which is much higher as compared to bare hierarchical 3D ZnIn2S4. The heightened photocatalytic activity is attributed to the enhanced charge carrier separation due to graphene which acts as an excellent electron collector and transporter. Furthermore, the usage of nano-heterostructures and pristine ZnIn2S4 as anodes in lithium ion batteries confers the charge capacities of 590 and 320 mA h g(-1) after 220 cycles as compared to their initial reversible capacities of 645 and 523 mA h g(-1), respectively. These nano-heterostructures show high reversible capacity, excellent cycling stability, and high-rate capability indicating their potential as promising anode materials for LIBs. The excellent performance is due to the nanostructuring of ZnIn2S4 and the presence of a graphene layer, which

  3. 3D printed impedance elements by micro-dispensing

    NASA Astrophysics Data System (ADS)

    Robles Dominguez, Ubaldo

    Micro-dispensing allows electric circuits to be "3D printed," which can be used to give 3D printed systems electronic and electromagnetic functionality. The focus of this thesis is using micro-dispensing to fabricate capacitors and inductors. 3D printed impedance elements are capable of being more easily embedded, can be used to create structural electronics, and will have extensive applications in antennas, metamaterials, frequency selective surfaces, and more. This is the first known effort to print and measure impedance elements by micro-dispensing which holds great potential for manufacturing multi-material devices.