Towards a Standard Mixed-Signal Parallel Processing Architecture for Miniature and Microrobotics.

PubMed

Sadler, Brian M; Hoyos, Sebastian

2014-01-01

The conventional analog-to-digital conversion (ADC) and digital signal processing (DSP) architecture has led to major advances in miniature and micro-systems technology over the past several decades. The outlook for these systems is significantly enhanced by advances in sensing, signal processing, communications and control, and the combination of these technologies enables autonomous robotics on the miniature to micro scales. In this article we look at trends in the combination of analog and digital (mixed-signal) processing, and consider a generalized sampling architecture. Employing a parallel analog basis expansion of the input signal, this scalable approach is adaptable and reconfigurable, and is suitable for a large variety of current and future applications in networking, perception, cognition, and control.

Towards a Standard Mixed-Signal Parallel Processing Architecture for Miniature and Microrobotics

PubMed Central

Sadler, Brian M; Hoyos, Sebastian

2014-01-01

The conventional analog-to-digital conversion (ADC) and digital signal processing (DSP) architecture has led to major advances in miniature and micro-systems technology over the past several decades. The outlook for these systems is significantly enhanced by advances in sensing, signal processing, communications and control, and the combination of these technologies enables autonomous robotics on the miniature to micro scales. In this article we look at trends in the combination of analog and digital (mixed-signal) processing, and consider a generalized sampling architecture. Employing a parallel analog basis expansion of the input signal, this scalable approach is adaptable and reconfigurable, and is suitable for a large variety of current and future applications in networking, perception, cognition, and control. PMID:26601042

Robust Bioinformatics Recognition with VLSI Biochip Microsystem

NASA Technical Reports Server (NTRS)

Lue, Jaw-Chyng L.; Fang, Wai-Chi

2006-01-01

A microsystem architecture for real-time, on-site, robust bioinformatic patterns recognition and analysis has been proposed. This system is compatible with on-chip DNA analysis means such as polymerase chain reaction (PCR)amplification. A corresponding novel artificial neural network (ANN) learning algorithm using new sigmoid-logarithmic transfer function based on error backpropagation (EBP) algorithm is invented. Our results show the trained new ANN can recognize low fluorescence patterns better than the conventional sigmoidal ANN does. A differential logarithmic imaging chip is designed for calculating logarithm of relative intensities of fluorescence signals. The single-rail logarithmic circuit and a prototype ANN chip are designed, fabricated and characterized.

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.

High-accuracy microassembly by intelligent vision systems and smart sensor integration

NASA Astrophysics Data System (ADS)

Schilp, Johannes; Harfensteller, Mark; Jacob, Dirk; Schilp, Michael

2003-10-01

Innovative production processes and strategies from batch production to high volume scale are playing a decisive role in generating microsystems economically. In particular assembly processes are crucial operations during the production of microsystems. Due to large batch sizes many microsystems can be produced economically by conventional assembly techniques using specialized and highly automated assembly systems. At laboratory stage microsystems are mostly assembled by hand. Between these extremes there is a wide field of small and middle sized batch production wherefore common automated solutions rarely are profitable. For assembly processes at these batch sizes a flexible automated assembly system has been developed at the iwb. It is based on a modular design. Actuators like grippers, dispensers or other process tools can easily be attached due to a special tool changing system. Therefore new joining techniques can easily be implemented. A force-sensor and a vision system are integrated into the tool head. The automated assembly processes are based on different optical sensors and smart actuators like high-accuracy robots or linear-motors. A fiber optic sensor is integrated in the dispensing module to measure contactless the clearance between the dispense needle and the substrate. Robot vision systems using the strategy of optical pattern recognition are also implemented as modules. In combination with relative positioning strategies, an assembly accuracy of the assembly system of less than 3 μm can be realized. A laser system is used for manufacturing processes like soldering.

Microsystems Research in Japan

DTIC Science & Technology

2003-09-01

microsystems applications, like microfluidic systems, will require more than planar lithography -based fabrication processes. The committee was impressed by the...United States focused on exploiting silicon planar lithography as the core technology for microstructure fabrication, whereas Japan explored a wide...including LIGA and its extensions, micro-stereolithography, and e-beam lithography . The range of materials seen in Japan was broader than in the

Building a Gateway for the CD-ROM Network: A Step toward the Virtual Library with the Virtual Microsystems V-Server.

ERIC Educational Resources Information Center

Sylvia, Margaret

1993-01-01

Describes one college library's experience with a gateway for dial-in access to its CD-ROM network to increase access to automated index searching for students off-campus. Hardware and software choices are discussed in terms of access, reliability, affordability, and ease of use. Installation problems are discussed, and an appendix lists product…

[Research advances in water quality monitoring technology based on UV-Vis spectrum analysis].

PubMed

Wei, Kang-Lin; Wen, Zhi-yu; Wu, Xin; Zhang, Zhong-Wei; Zeng, Tian-Ling

2011-04-01

The application of spectral analysis to water quality monitoring is an important developing trend in the field of modern environment monitoring technology. The principle and characteristic of water quality monitoring technology based on UV-Vis spectrum analysis are briefly reviewed. And the research status and advances are introduced from two aspects, on-line monitoring and in-situ monitoring. Moreover, the existent key technical problems are put forward. Finally, the technology trends of multi-parameter water quality monitoring microsystem and microsystem networks based on microspectrometer are prospected, which has certain reference value for the research and development of environmental monitoring technology and modern scientific instrument in the authors' country.

An Implementation Plan for NFS at NASA's NAS Facility

NASA Technical Reports Server (NTRS)

Lam, Terance L.; Kutler, Paul (Technical Monitor)

1998-01-01

This document discusses how NASA's NAS can benefit from the Sun Microsystems' Network File System (NFS). A case study is presented to demonstrate the effects of NFS on the NAS supercomputing environment. Potential problems are addressed and an implementation strategy is proposed.

Rapid prototyping of multi-scale biomedical microdevices by combining additive manufacturing technologies.

PubMed

Hengsbach, Stefan; Lantada, Andrés Díaz

2014-08-01

The possibility of designing and manufacturing biomedical microdevices with multiple length-scale geometries can help to promote special interactions both with their environment and with surrounding biological systems. These interactions aim to enhance biocompatibility and overall performance by using biomimetic approaches. In this paper, we present a design and manufacturing procedure for obtaining multi-scale biomedical microsystems based on the combination of two additive manufacturing processes: a conventional laser writer to manufacture the overall device structure, and a direct-laser writer based on two-photon polymerization to yield finer details. The process excels for its versatility, accuracy and manufacturing speed and allows for the manufacture of microsystems and implants with overall sizes up to several millimeters and with details down to sub-micrometric structures. As an application example we have focused on manufacturing a biomedical microsystem to analyze the impact of microtextured surfaces on cell motility. This process yielded a relevant increase in precision and manufacturing speed when compared with more conventional rapid prototyping procedures.

Potentiometric analytical microsystem based on the integration of a gas-diffusion step for on-line ammonium determination in water recycling processes in manned space missions.

PubMed

Calvo-López, Antonio; Ymbern, Oriol; Puyol, Mar; Casalta, Joan Manel; Alonso-Chamarro, Julián

2015-05-18

The design, construction and evaluation of a versatile cyclic olefin copolymer (COC)-based continuous flow potentiometric microanalyzer to monitor the presence of ammonium ion in recycling water processes for future manned space missions is presented. The microsystem integrates microfluidics, a gas-diffusion module and a detection system in a single substrate. The gas-diffusion module was integrated by a hydrophobic polyvinylidene fluoride (PVDF) membrane. The potentiometric detection system is based on an all-solid state ammonium selective electrode and a screen-printed Ag/AgCl reference electrode. The analytical features provided by the analytical microsystem after the optimization process were a linear range from 0.15 to 500 mg L(-1) and a detection limit of 0.07 ± 0.01 mg L(-1). Nevertheless, the operational features can be easily adapted to other applications through the modification of the hydrodynamic variables of the microfluidic platform. Copyright © 2014 Elsevier B.V. All rights reserved.

Bronfenbrenner's Bioecological Theory Revision: Moving Culture From the Macro Into the Micro.

PubMed

Vélez-Agosto, Nicole M; Soto-Crespo, José G; Vizcarrondo-Oppenheimer, Mónica; Vega-Molina, Stephanie; García Coll, Cynthia

2017-09-01

Bronfenbrenner's bioecological theory of human development is one of the most widely known theoretical frameworks in human development. In spite of its popularity, the notion of culture within the macrosystem, as a separate entity of everyday practices and therefore microsystems, is problematic. Using the theoretical and empirical work of Rogoff and Weisner, and influenced as they are by Vygotsky's sociocultural perspective, we reconceptualize Bronfenbrenner's model by placing culture as an intricate part of proximal development processes. In our model, culture has the role of defining and organizing microsystems and therefore becomes part of the central processes of human development. Culture is an ever changing system composed of the daily practices of social communities (families, schools, neighborhoods, etc.) and the interpretation of those practices through language and communication. It also comprises tools and signs that are part of the historical legacy of those communities, and thus diversity is an integral part of the child's microsystems, leading to culturally defined acceptable developmental processes and outcomes.

Boundary conditioning of capacitive MEMS devices through fabrication methods and operating environments

NASA Astrophysics Data System (ADS)

Muthukumaran, Packirisamy; Stiharu, Ion G.; Bhat, Rama B.

2003-10-01

This paper presents and applies the concept of micro-boundary conditioning to the design synthesis of microsystems in order to quantify the influence of inherent limitations of the fabrication process and the operating conditions on both static and dynamic behavior of microsystems. The predicted results on the static and dynamic behavior of a capacitive MEMS device, fabricated through MUMPs process, under the influence of the fabrication limitation and operating environment are presented along with the test results. The comparison between the predicted and experimental results shows a good agreement.

Preliminary Thermal Characterization of a Fully-Passive Wireless Backscattering Neuro-Recording Microsystem

NASA Technical Reports Server (NTRS)

Schwerdt, H. N.; Xu, W.; Shekhar, S.; Chae, J.; Miranda, F. A.

2011-01-01

We present analytical and experimental thermal characteristics of a battery-less, fully-passive wireless backscattering microsystem for recording of neuropotentials. A major challenge for cortically implantable microsystems involves minimizing the heat dissipated by on-chip circuitry, which can lead to permanent brain damage. Therefore, knowledge of temperature changes induced by implantable microsystems while in operation is of utmost importance. In this work, a discrete diode appended to the neuro-recording microsystem has been used to indirectly monitor the aforesaid temperature changes. Using this technique, the maximum temperature rise measured for the microsystem while in operation was 0.15 +/- 0.1 C, which is significantly less than current safety guidelines. Specific absorption ratio (SAR) due to the microsystem was also computed to further demonstrate fully-passive functionality of the neuro-recording microsystem.

Microsystems: from technologies to products

NASA Astrophysics Data System (ADS)

Ryser, Peter

2003-10-01

In this paper, we outline the process leading from technologies to successful products in the MEMS (Microelectromechanical Systems) and MST (Microsystems Technology) field. The development of new products involves a lot of factors, such as mature technologies, interdisciplinary team, identifying the right business potential and long term oriented investors. The paper summarizes a survey of different technologies and point out that packaging, test and calibration are still major shortcomings for the concerned industries.

A Differential Monolithically Integrated Inductive Linear Displacement Measurement Microsystem

PubMed Central

Podhraški, Matija; Trontelj, Janez

2016-01-01

An inductive linear displacement measurement microsystem realized as a monolithic Application-Specific Integrated Circuit (ASIC) is presented. The system comprises integrated microtransformers as sensing elements, and analog front-end electronics for signal processing and demodulation, both jointly fabricated in a conventional commercially available four-metal 350-nm CMOS process. The key novelty of the presented system is its full integration, straightforward fabrication, and ease of application, requiring no external light or magnetic field source. Such systems therefore have the possibility of substituting certain conventional position encoder types. The microtransformers are excited by an AC signal in MHz range. The displacement information is modulated into the AC signal by a metal grating scale placed over the microsystem, employing a differential measurement principle. Homodyne mixing is used for the demodulation of the scale displacement information, returned by the ASIC as a DC signal in two quadrature channels allowing the determination of linear position of the target scale. The microsystem design, simulations, and characterization are presented. Various system operating conditions such as frequency, phase, target scale material and distance have been experimentally evaluated. The best results have been achieved at 4 MHz, demonstrating a linear resolution of 20 µm with steel and copper scale, having respective sensitivities of 0.71 V/mm and 0.99 V/mm. PMID:26999146

A Differential Monolithically Integrated Inductive Linear Displacement Measurement Microsystem.

PubMed

Podhraški, Matija; Trontelj, Janez

2016-03-17

An inductive linear displacement measurement microsystem realized as a monolithic Application-Specific Integrated Circuit (ASIC) is presented. The system comprises integrated microtransformers as sensing elements, and analog front-end electronics for signal processing and demodulation, both jointly fabricated in a conventional commercially available four-metal 350-nm CMOS process. The key novelty of the presented system is its full integration, straightforward fabrication, and ease of application, requiring no external light or magnetic field source. Such systems therefore have the possibility of substituting certain conventional position encoder types. The microtransformers are excited by an AC signal in MHz range. The displacement information is modulated into the AC signal by a metal grating scale placed over the microsystem, employing a differential measurement principle. Homodyne mixing is used for the demodulation of the scale displacement information, returned by the ASIC as a DC signal in two quadrature channels allowing the determination of linear position of the target scale. The microsystem design, simulations, and characterization are presented. Various system operating conditions such as frequency, phase, target scale material and distance have been experimentally evaluated. The best results have been achieved at 4 MHz, demonstrating a linear resolution of 20 µm with steel and copper scale, having respective sensitivities of 0.71 V/mm and 0.99 V/mm.

Smart sensors development based on a distributed bus for microsystems applications

NASA Astrophysics Data System (ADS)

Ferrer, Carles; Lorente, Bibiana

2003-04-01

Our main objective in this work has been to develop a comunication system applicable between sensors and actuators and the data processing circuitry inside the microsystem in order to develop a flexible and modular architecture. This communication system is based on the use of a dedicated sensor bus composed by only two wires (a bidirectional data line and a clock line for sincronization). The basic philosophy of this development has been to create an IP model with VHDL for the bus driver that can be added to the sensor or the actuator to create an smart device that could be easily plugged with the other componets of the microsystem architecture. This methodology can be applied to a high integrated microsystem based on an extensively use of microelectronics technologies (ASICs, SoCs & MCMs). The reduced number of wires is an extraordinary advatage because produce a minimal interconnection between all the components and as a consequence the size of the microinstrument becomes smaller. The second aspect that we have considered in this development has been to reach a communication protocol that permits to built-up a very simple but robust bus driver interface that minimize the circuit overhead. This interconnection system has been applied to biomedical and aerospatial microsystems applications.

Light-Induced Temperature Transitions in Biodegradable Polymer and Nanorod Composites**

PubMed Central

Hribar, Kolin C.; Metter, Robert B.; Ifkovits, Jamie L.; Troxler, Thomas

2010-01-01

Shape-memory materials (including polymers, metals, and ceramics) are those that are processed into a temporary shape and respond to some external stimuli (e.g., temperature) to undergo a transition back to a permanent shape.[1, 2] Shape memory polymers are finding use in a range of applications from aerospace to fabrics, to biomedical devices and microsystem components.[3–5] For many applications, it would be beneficial to initiate heating with an external trigger (e.g., transdermal light exposure). In this work, we formulated composites of gold nanorods (<1% by volume) and biodegradable networks, where exposure to infrared light induced heating and consequently, shape transitions. The heating is repeatable and tunable based on nanorod concentration and light intensity and the nanorods did not alter the cytotoxicity or in vivo tissue response to the networks. PMID:19408258

A modular assembling platform for manufacturing of microsystems by optical tweezers

NASA Astrophysics Data System (ADS)

Ksouri, Sarah Isabelle; Aumann, Andreas; Ghadiri, Reza; Prüfer, Michael; Baer, Sebastian; Ostendorf, Andreas

2013-09-01

Due to the increased complexity in terms of materials and geometries for microsystems new assembling techniques are required. Assembling techniques from the semiconductor industry are often very specific and cannot fulfill all specifications in more complex microsystems. Therefore, holographic optical tweezers are applied to manipulate structures in micrometer range with highest flexibility and precision. As is well known non-spherical assemblies can be trapped and controlled by laser light and assembled with an additional light modulator application, where the incident laser beam is rearranged into flexible light patterns in order to generate multiple spots. The complementary building blocks are generated by a two-photon-polymerization process. The possibilities of manufacturing arbitrary microstructures and the potential of optical tweezers lead to the idea of combining manufacturing techniques with manipulation processes to "microrobotic" processes. This work presents the manipulation of generated complex microstructures with optical tools as well as a storage solution for 2PP assemblies. A sample holder has been developed for the manual feeding of 2PP building blocks. Furthermore, a modular assembling platform has been constructed for an `all-in-one' 2PP manufacturing process as a dedicated storage system. The long-term objective is the automation process of feeding and storage of several different 2PP micro-assemblies to realize an automated assembly process.

Microfabrication of microsystem-enabled photovoltaic (MEPV) cells

NASA Astrophysics Data System (ADS)

Nielson, Gregory N.; Okandan, Murat; Cruz-Campa, Jose L.; Resnick, Paul J.; Wanlass, Mark W.; Clews, Peggy J.; Pluym, Tammy C.; Sanchez, Carlos A.; Gupta, Vipin P.

2011-02-01

Microsystem-Enabled Photovoltaic (MEPV) cells allow solar PV systems to take advantage of scaling benefits that occur as solar cells are reduced in size. We have developed MEPV cells that are 5 to 20 microns thick and down to 250 microns across. We have developed and demonstrated crystalline silicon (c-Si) cells with solar conversion efficiencies of 14.9%, and gallium arsenide (GaAs) cells with a conversion efficiency of 11.36%. In pursuing this work, we have identified over twenty scaling benefits that reduce PV system cost, improve performance, or allow new functionality. To create these cells, we have combined microfabrication techniques from various microsystem technologies. We have focused our development efforts on creating a process flow that uses standard equipment and standard wafer thicknesses, allows all high-temperature processing to be performed prior to release, and allows the remaining post-release wafer to be reprocessed and reused. The c-Si cell junctions are created using a backside point-contact PV cell process. The GaAs cells have an epitaxially grown junction. Despite the horizontal junction, these cells also are backside contacted. We provide recent developments and details for all steps of the process including junction creation, surface passivation, metallization, and release.

A low power flash-FPGA based brain implant micro-system of PID control.

PubMed

Lijuan Xia; Fattah, Nabeel; Soltan, Ahmed; Jackson, Andrew; Chester, Graeme; Degenaar, Patrick

2017-07-01

In this paper, we demonstrate that a low power flash FPGA based micro-system can provide a low power programmable interface for closed-loop brain implant inter- faces. The proposed micro-system receives recording local field potential (LFP) signals from an implanted probe, performs closed-loop control using a first order control system, then converts the signal into an optogenetic control stimulus pattern. Stimulus can be implemented through optoelectronic probes. The long term target is for both fundamental neuroscience applications and for clinical use in treating epilepsy. Utilizing our device, closed-loop processing consumes only 14nJ of power per PID cycle compared to 1.52μJ per cycle for a micro-controller implementation. Compared to an application specific digital integrated circuit, flash FPGA's are inherently programmable.

Macro-meso-microsystems integration in LTCC : LDRD report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Smet, Dennis J.; Nordquist, Christopher Daniel; Turner, Timothy Shawn

2007-03-01

Low Temperature Cofired Ceramic (LTCC) has proven to be an enabling medium for microsystem technologies, because of its desirable electrical, physical, and chemical properties coupled with its capability for rapid prototyping and scalable manufacturing of components. LTCC is viewed as an extension of hybrid microcircuits, and in that function it enables development, testing, and deployment of silicon microsystems. However, its versatility has allowed it to succeed as a microsystem medium in its own right, with applications in non-microelectronic meso-scale devices and in a range of sensor devices. Applications include silicon microfluidic ''chip-and-wire'' systems and fluid grid array (FGA)/microfluidic multichip modulesmore » using embedded channels in LTCC, and cofired electro-mechanical systems with moving parts. Both the microfluidic and mechanical system applications are enabled by sacrificial volume materials (SVM), which serve to create and maintain cavities and separation gaps during the lamination and cofiring process. SVMs consisting of thermally fugitive or partially inert materials are easily incorporated. Recognizing the premium on devices that are cofired rather than assembled, we report on functional-as-released and functional-as-fired moving parts. Additional applications for cofired transparent windows, some as small as an optical fiber, are also described. The applications described help pave the way for widespread application of LTCC to biomedical, control, analysis, characterization, and radio frequency (RF) functions for macro-meso-microsystems.« less

Inversion Concept of the Origin of Life

NASA Astrophysics Data System (ADS)

Kompanichenko, V. N.

2012-06-01

The essence of the inversion concept of the origin of life can be narrowed down to the following theses: 1) thermodynamic inversion is the key transformation of prebiotic microsystems leading to their transition into primary forms of life; 2) this transformation might occur only in the microsystems oscillating around the bifurcation point under far-from-equilibrium conditions. The transformation consists in the inversion of the balance "free energy contribution / entropy contribution", from negative to positive values. At the inversion moment the microsystem radically reorganizes in accordance with the new negentropy (i.e. biological) way of organization. According to this approach, the origin-of-life process on the early Earth took place in the fluctuating hydrothermal medium. The process occurred in two successive stages: a) spontaneous self-assembly of initial three-dimensional prebiotic microsystems composed mainly of hydrocarbons, lipids and simple amino acids, or their precursors, within the temperature interval of 100-300°C (prebiotic stage); b) non-spontaneous synthesis of sugars, ATP and nucleic acids started at the inversion moment under the temperature 70-100°C (biotic stage). Macro- and microfluctuations of thermodynamic and physico-chemical parameters able to sustain this way of chemical conversion have been detected in several contemporary hydrothermal systems. A minimal self-sufficient unit of life on the early Earth was a community of simplest microorganisms (not a separate microorganism).

Management and development of local area network upgrade prototype

NASA Technical Reports Server (NTRS)

Fouser, T. J.

1981-01-01

Given the situation of having management and development users accessing a central computing facility and given the fact that these same users have the need for local computation and storage, the utilization of a commercially available networking system such as CP/NET from Digital Research provides the building blocks for communicating intelligent microsystems to file and print services. The major problems to be overcome in the implementation of such a network are the dearth of intelligent communication front-ends for the microcomputers and the lack of a rich set of management and software development tools.

Separation and preconcentration of actinides from concentrated nitric acid by extraction chromatography in microsystems.

PubMed

Losno, Marion; Pellé, Julien; Marie, Mylène; Ferrante, Ivan; Brennetot, René; Descroix, Stéphanie; Mariet, Clarisse

2018-08-01

An original method of monolith impregnation in microsystem for the analysis of radionuclides in nitric acid is reported. Three microcolumns made of monolith poly(AMA-co-EDMA) were impregnated in COC microsystems. The robustness of the microsystems in nitric acid media until 8 M was demonstrated. High exchange capacity and affinity for tetravalent and hexavalent actinides in concentrated nitric media were obtained. The retention characteristics of the microcolumns impregnated by TBP, TBP-CMPO and DAAP were compared with those of the equivalent commercial particulate resins TBP™, TRU™ and UTEVA™ respectively. The separation of U, Th and Eu was validated in a classical microsystem and a procedure is proposed in a centrifugal microsystem. Copyright © 2018. Published by Elsevier B.V.

Microassembly of Heterogeneous Materials using Transfer Printing and Thermal Processing

PubMed Central

Keum, Hohyun; Yang, Zining; Han, Kewen; Handler, Drew E.; Nguyen, Thong Nhu; Schutt-Aine, Jose; Bahl, Gaurav; Kim, Seok

2016-01-01

Enabling unique architectures and functionalities of microsystems for numerous applications in electronics, photonics and other areas often requires microassembly of separately prepared heterogeneous materials instead of monolithic microfabrication. However, microassembly of dissimilar materials while ensuring high structural integrity has been challenging in the context of deterministic transferring and joining of materials at the microscale where surface adhesion is far more dominant than body weight. Here we present an approach to assembling microsystems with microscale building blocks of four disparate classes of device-grade materials including semiconductors, metals, dielectrics, and polymers. This approach uniquely utilizes reversible adhesion-based transfer printing for material transferring and thermal processing for material joining at the microscale. The interfacial joining characteristics between materials assembled by this approach are systematically investigated upon different joining mechanisms using blister tests. The device level capabilities of this approach are further demonstrated through assembling and testing of a microtoroid resonator and a radio frequency (RF) microelectromechanical systems (MEMS) switch that involve optical and electrical functionalities with mechanical motion. This work opens up a unique route towards 3D heterogeneous material integration to fabricate microsystems. PMID:27427243

Platelet Lysate-Modified Porous Silicon Microparticles for Enhanced Cell Proliferation in Wound Healing Applications.

PubMed

Fontana, Flavia; Mori, Michela; Riva, Federica; Mäkilä, Ermei; Liu, Dongfei; Salonen, Jarno; Nicoletti, Giovanni; Hirvonen, Jouni; Caramella, Carla; Santos, Hélder A

2016-01-13

The new frontier in the treatment of chronic nonhealing wounds is the use of micro- and nanoparticles to deliver drugs or growth factors into the wound. Here, we used platelet lysate (PL), a hemoderivative of platelets, consisting of a multifactorial cocktail of growth factors, to modify porous silicon (PSi) microparticles and assessed both in vitro and ex vivo the properties of the developed microsystem. PL-modified PSi was assessed for its potential to induce proliferation of fibroblasts. The wound closure-promoting properties of the microsystem were then assessed in an in vitro wound healing assay. Finally, the PL-modified PSi microparticles were evaluated in an ex vivo experiment over human skin. It was shown that PL-modified PSi microparticles were cytocompatible and enhanced the cell proliferation in different experimental settings. In addition, this microsystem promoted the closure of the gap between the fibroblast cells in the wound healing assay, in periods of time comparable with the positive control, and induced a proliferation and regeneration process onto the human skin in an ex vivo experiment. Overall, our results show that PL-modified PSi microparticles are suitable microsystems for further development toward applications in the treatment of chronic nonhealing wounds.

Through-wafer interrogation of microstructure motion for MEMS feedback control

NASA Astrophysics Data System (ADS)

Dawson, Jeremy M.; Chen, Jingdong; Brown, Kolin S.; Famouri, Parviz F.; Hornak, Lawrence A.

1999-09-01

Closed-loop MEMS control enables mechanical microsystems to adapt to the demands of the environment which they are actuating opening a new window of opportunity for future MEMS applications. Planar diffractive optical microsystems have the potential to enable the integrated optical interrogation of MEMS microstructure position fully decoupled from the means of mechanical actuation which is central to realization of feedback control. This paper presents the results of initial research evaluating through-wafer optical microsystems for MEMS integrated optical monitoring. Positional monitoring results obtained from a 1.3 micrometer wavelength through- wafer free-space optical probe of a lateral comb resonator fabricated using the Multi-User MEMS Process Service (MUMPS) are presented. Given the availability of positional information via probe signal feedback, a simulation of the application of nonlinear sliding control is presented illustrating position control of the lateral comb resonator structure.

Microsystems for the Capture of Low-Abundance Cells

NASA Astrophysics Data System (ADS)

Dharmasiri, Udara; Witek, Małgorzata A.; Adams, Andre A.; Soper, Steven A.

2010-07-01

Efficient selection and enumeration of low-abundance biological cells are highly important in a variety of applications. For example, the clinical utility of circulating tumor cells (CTCs) in peripheral blood is recognized as a viable biomarker for the management of various cancers, in which the clinically relevant number of CTCs per 7.5 ml of blood is two to five. Although there are several methods for isolating rare cells from a variety of heterogeneous samples, such as immunomagnetic-assisted cell sorting and fluorescence-activated cell sorting, they are fraught with challenges. Microsystem-based technologies are providing new opportunities for selecting and isolating rare cells from complex, heterogeneous samples. Such approaches involve reductions in target-cell loss, process automation, and minimization of contamination issues. In this review, we introduce different application areas requiring rare cell analysis, conventional techniques for their selection, and finally microsystem approaches for low-abundance-cell isolation and enumeration.

How many theories for the origin of /proto/life

NASA Technical Reports Server (NTRS)

Fox, S. W.

1980-01-01

The sequence of primordial chemical events leading to contemporary metabolism is considered, taking into account primordial reactants, amino acids, proteinoid, protocells, ATP, polynucleotides, and protein. The right kind of matter, thermal copolyamino acids, can organize itself into cell-like structures, in the absence of discrete lipid, when triggered to do so by water. Another unpredicted result of examination of the microsystems formed was the step-by-step realization that the component processes of a primitive form of replication were latent in the proteinoid microsystems. At the present time, four modes of primitive replication of proteinoid microsystems have been identified, plus one that has the appearance of protosexual reproduction. Two main conceptual pathways have received attention. One is the proteinoid theory, derived from experiments. The other is the DNA-first theory, for which attempts at conceptual construction and experimental support continue to be sought.

Clinical microsystems, Part 3. Transformation of two hospitals using microsystem, mesosystem, and macrosystem strategies.

PubMed

Godfrey, Marjorie M; Melin, Craig N; Muething, Stephen E; Batalden, Paul B; Nelson, Eugene C

2008-10-01

Two hospitals-a large, urban academic medical center and a rural, community hospital-have each chosen a similar microsystem-based approach to improvement, customizing the engagement of the micro-, meso-, and macrosystems and the improvement targets on the basis of an understanding of the local context. CINCINNATI CHILDREN'S HOSPITAL MEDICAL CENTER (CCHMC): Since 2004, strategic changes have been developed to support microsystems and their leaders through (1) ongoing improvement training for all macro-, meso-, and microsystem leaders; (2) financial support for physicians who are serving as co-leaders of clinical microsystems; (3) increased emphasis on aligning academic pursuits with improvement work at the clinical front lines; (4) microsystem leaders' continuous access to unit-level data through the organization's intranet; and (5) encouragement of unit leaders to share outcomes data with families. CDH has moved from near closure to a survival-turnaround focus, significant engagement in quality and finally, a complete reframing of a quality focus in 2004. Since then, it has deployed the clinical microsystems approach in one pilot care unit (West 2, a medical surgery unit), broadened it to two, then six more, and is now spreading it organizationwide. In "2+2 Charters," interdisciplinary teams address two strategic goals set by senior leadership and two goals set by frontline microsystem leaders and staff CCHMC and CDH have had a clear focus on developing alignment, capability, and accountability to fuse together the work at all levels of the hospital, unifying the macrosystem with the mesosystem and microsystem. Their improvement experience suggests tips and actions at all levels of the organization that could be adapted with specific context knowledge by others.

Analyzing crime scene videos

NASA Astrophysics Data System (ADS)

Cunningham, Cindy C.; Peloquin, Tracy D.

1999-02-01

Since late 1996 the Forensic Identification Services Section of the Ontario Provincial Police has been actively involved in state-of-the-art image capture and the processing of video images extracted from crime scene videos. The benefits and problems of this technology for video analysis are discussed. All analysis is being conducted on SUN Microsystems UNIX computers, networked to a digital disk recorder that is used for video capture. The primary advantage of this system over traditional frame grabber technology is reviewed. Examples from actual cases are presented and the successes and limitations of this approach are explored. Suggestions to companies implementing security technology plans for various organizations (banks, stores, restaurants, etc.) will be made. Future directions for this work and new technologies are also discussed.

Sandia National Laboratories: Exceptional Service in the National Interest

Science.gov Websites

Electromagnetics Engineering Science Geoscience Materials Science Nanodevices & Microsystems Radiation Effects Electromagnetics Engineering Science Geoscience Materials Science Nanodevices & Microsystems Radiation Effects Geoscience Materials Science Nanodevices & Microsystems Radiation Effects & High Energy Density

Transforming Social Regularities in a Multicomponent Community-Based Intervention: A Case Study of Professionals' Adaptability to Better Support Parents to Meet Their Children's Needs.

PubMed

Quiroz Saavedra, Rodrigo; Brunson, Liesette; Bigras, Nathalie

2017-06-01

This paper presents an in-depth case study of the dynamic processes of mutual adjustment that occurred between two professional teams participating in a multicomponent community-based intervention (CBI). Drawing on the concept of social regularities, we focus on patterns of social interaction within and across the two microsystems involved in delivering the intervention. Two research strategies, narrative analysis and structural network analysis, were used to reveal the social regularities linking the two microsystems. Results document strategies and actions undertaken by the professionals responsible for the intervention to modify intersetting social regularities to deal with a problem situation that arose during the course of one intervention cycle. The results illustrate how key social regularities were modified in order to resolve the problem situation and allow the intervention to continue to function smoothly. We propose that these changes represent a transition to a new state of the ecological intervention system. This transformation appeared to be the result of certain key intervening mechanisms: changing key role relationships, boundary spanning, and synergy. The transformation also appeared to be linked to positive setting-level and individual-level outcomes: confidence of key team members, joint planning, decision-making and intervention activities, and the achievement of desired intervention objectives. © Society for Community Research and Action 2017.

An analysis of microsystems development at Sandia National Laboratories

NASA Astrophysics Data System (ADS)

Herrera, Gilbert V.; Myers, David R.

2011-06-01

While Sandia initially was motivated to investigate emergent microsystem technology to miniaturize existing macroscale structures, present designs embody innovative approaches that directly exploit the fundamentally different material properties of a new technology at the micro- and nano-scale. Direct, hands-on experience with the emerging technology gave Sandia engineers insights that not only guided the evolution of the technology but also enabled them to address new applications that enlarged the customer base for the new technology. Sandia's early commitment to develop complex microsystems demonstrated the advantages that early adopters gain by developing an extensive design and process tool kit and a shared awareness of multiple approaches to achieve the multiple goals. As with any emergent technology, Sandia's program benefited from interactions with the larger technical community. However, custom development followed a spiral path of direct trial-and-error experience, analysis, quantification of materials properties at the micro- and nano-scale, evolution of design tools and process recipes, and an understanding of reliability factors and failure mechanisms even in extreme environments. The microsystems capability at Sandia relied on three key elements. The first was people: a mix of mechanical and semiconductor engineers, chemists, physical scientists, designers, and numerical analysts. The second was a unique facility that enabled the development of custom technologies without contaminating mainline product deliveries. The third was the arrival of specialized equipment as part of a Cooperative Research And Development Agreement (CRADA) enabled by the National Competitiveness Technology Transfer Act of 1989. Underpinning all these, the program was guided and sustained through the research and development phases by accomplishing intermediate milestones addressing direct mission needs.

A bioanalytical microsystem for protein and DNA sensing based on a monolithic silicon optoelectronic transducer

NASA Astrophysics Data System (ADS)

Misiakos, K.; Petrou, P. S.; Kakabakos, S. E.; Ruf, H. H.; Ehrentreich-Förster, E.; Bier, F. F.

2005-01-01

A bioanalytical microsystem that is based on a monolithic silicon optical transducer and a microfluidic module and it is appropriate for real-time sensing of either DNA or protein analytes is presented. The optical transducer monolithically integrates silicon avalanche diodes as light sources, silicon nitride optical fibers and detectors and efficiently intercouples these optical elements through a self-alignment technique. After hydrophilization and silanization of the transducer surface, the biomolecular probes are immobilized through physical adsorption. Detection is performed through reaction of the immobilized biomolecules with gold nanoparticle labeled counterpart molecules. The binding of these molecules within the evanescent field at the surface of the optical fiber cause attenuated total reflection of the waveguided modes and reduction of the detector photocurrent. Using the developed microsystem, determination of single nucleotide polymorphism (SNP) in the gene of the human phenol sulfotransferase SULT1A1 was achieved. Full-matching hybrid resulted in 4-5 times higher signals compared to the mismatched hybrid after hybridization and dissociation processes. The protein sensing abilities of the developed microsystem were also investigated through a non-competitive assay for the determination of the MB isoform of creatine kinase enzyme (CK-MB) that is a widely used cardiac marker.

A new construction of measurement system based on specialized microsystem design for laryngological application

NASA Astrophysics Data System (ADS)

Paczesny, Daniel; Mikłaszewicz, Franciszek

2013-10-01

This article describes the design, construction and parameters of diagnostic medical system for air humidity measurement which can be proceeded in various places of human nasal cavities and also human throat. The system can measure dynamic changes of dew point temperature (absolute value of humidity) of inspired and expired air in different places of human upper airways. During regular respiration process dew point temperature is measured in nasal cavity, middle part cavity and nasopharynx. The presented system is the next step in construction of measurement system based on specialized microsystem for laryngological application. The microsystem fabricated on silicon substrate includes microheater, microthermoresistor and interdigitated electrodes. In comparison with previously built measurement system with current version some system functionalities and measurement parameters were improved. Additionally 3D printing technology was applied for rapid prototyping a measurement system housing. Presented measurement system is set of microprocessor module with signal conditioning circuits; heated measurement head based on specialized microsystem with disposable heated pipe for air sucking from various places of upper airways; power supplier and computer application for monitoring all system parameters and presenting on-line and off-line measured results. Some example results of constructed measurement system and dew point temperature measurements during respiration cycle are presented.

Biochip microsystem for bioinformatics recognition and analysis

NASA Technical Reports Server (NTRS)

Lue, Jaw-Chyng (Inventor); Fang, Wai-Chi (Inventor)

2011-01-01

A system with applications in pattern recognition, or classification, of DNA assay samples. Because DNA reference and sample material in wells of an assay may be caused to fluoresce depending upon dye added to the material, the resulting light may be imaged onto an embodiment comprising an array of photodetectors and an adaptive neural network, with applications to DNA analysis. Other embodiments are described and claimed.

Sandia National Laboratories: Research: Research Foundations

Science.gov Websites

Materials Science Nanodevices & Microsystems Radiation Effects & High Energy Density Science Science Geoscience Materials Science Nanodevices and Microsystems Radiation Effects and High Energy Nanodevices and Microsystems Radiation Effects and High Energy Density Science Exceptional service in the

Microsystems Enabled Photovoltaics

ScienceCinema

Gupta, Vipin; Nielson, Greg; Okandan, Murat, Granata, Jennifer; Nelson, Jeff; Haney, Mike; Cruz-Campa, Jose Luiz

2018-06-07

Sandia's microsystems enabled photovoltaic advances combine mature technology and tools currently used in microsystem production with groundbreaking advances in photovoltaics cell design, decreasing production and system costs while improving energy conversion efficiency. The technology has potential applications in buildings, houses, clothing, portable electronics, vehicles, and other contoured structures.

Microsystem Cooler Concept Developed and Being Fabricated

NASA Technical Reports Server (NTRS)

Moran, Matthew E.

2005-01-01

A patented microsystem cooler concept has been developed by the NASA Glenn Research Center. It incorporates diaphragm actuators to produce the Stirling refrigeration cycle within a planar configuration compatible with the thermal management of electronics, sensors, optical and radiofrequency systems, microarrays, and other microsystems. The microsystem cooler is most suited to volume-limited applications that require cooling below the ambient or sink temperature. Johns Hopkins University Applied Physics Laboratory is conducting development testing and fabrication of a prototype under a grant from Glenn.

Wafer-scale integrated micro-supercapacitors on an ultrathin and highly flexible biomedical platform.

PubMed

Maeng, Jimin; Meng, Chuizhou; Irazoqui, Pedro P

2015-02-01

We present wafer-scale integrated micro-supercapacitors on an ultrathin and highly flexible parylene platform, as progress toward sustainably powering biomedical microsystems suitable for implantable and wearable applications. All-solid-state, low-profile (<30 μm), and high-density (up to ~500 μF/mm(2)) micro-supercapacitors are formed on an ultrathin (~20 μm) freestanding parylene film by a wafer-scale parylene packaging process in combination with a polyaniline (PANI) nanowire growth technique assisted by surface plasma treatment. These micro-supercapacitors are highly flexible and shown to be resilient toward flexural stress. Further, direct integration of micro-supercapacitors into a radio frequency (RF) rectifying circuit is achieved on a single parylene platform, yielding a complete RF energy harvesting microsystem. The system discharging rate is shown to improve by ~17 times in the presence of the integrated micro-supercapacitors. This result suggests that the integrated micro-supercapacitor technology described herein is a promising strategy for sustainably powering biomedical microsystems dedicated to implantable and wearable applications.

Synthesis of Biofluidic Microsystems (SYNBIOSYS)

DTIC Science & Technology

2007-10-01

reaction system. 58 FIGURE 41. The micro reactor is represented by a PFR network model. The calculation of reaction and convection is conducted in...one column of PFRs and the calculation of diffusional mixing is conducted between two columns of PFRs. 59 FIGURE 42. Apply the numerical method of...lines to calculate the diffusion in the channel width direction. Here, we take 10 discretized concentration points in the channel: ci1 - ci10. Points

EDITORIAL: Special section: Selected papers from OMS'05, the 1st Topical Meeting of the European Optical Society on Optical Microsystems (OMS)

NASA Astrophysics Data System (ADS)

Rendina, Ivo; Fazio, Eugenio; Ferraro, Pietro

2006-07-01

OMS'05 is the first international conference wholly dedicated to optical microsystems. It was organized by the European Optical Society (EOS) in the frame of its international topical meeting activity and was held in Italy, September 2005, amidst the wonderful scenery of the Island of Capri. A possible definition of an optical microsystem is a complex system, able to perform one or more sensing and actuation functions, where optical devices are integrated in a smart way with electronic, mechanical and sensing components by taking advantage of the progress in micro- and nano-technologies. The increasing interest in this field arises from the expected applications that would significantly improve the quality of life. The list of possibilities offered by the optical microsystem enabling technologies is very long and seems to increase day by day. We are not only thinking about the next generation of optical telecommunication networks and computers, but also about low-cost, compact microsystems for environmental monitoring, in order to improve safety in the avionic and automotive fields, medical diagnostics and proteomic/genomic studies, or just finding general applications in several industrial fields. The goal of the conference was to involve scientists and young researchers from the main public and private laboratories, giving them the opportunity to present new scientific results and compare their know-how in the exciting and emerging field of optical microsystems. We believe that we succeeded in this. More than 200 scientists from all over the world attended the conference. We had more than 100 oral presentations and approximately 20 from the keynote lectures and invited speeches. It was an opportunity to define the most recent progress carried out in the field and to outline the possible road-map leading to the expected results in the industrial and social fields. We strongly believe that research and technology are closely interconnected at present and cannot move forward separately. Thus, we wanted the meeting to encourage the cross-fertilization of ideas of all the people involved and active in the areas of optics, photonics, microelectronics and materials, by gathering together theoreticians, experimentalists and those interested in industrial applications. For these reasons the conference programme focused on fundamental as well as more applied topics. Photonic crystals, non-linear and quantum optics in micro-devices, nanophotonic-based devices, silicon-based optoelectronics and MOEMS, microsensors, biochips and the new characterization methods for materials and devices were among the hot topics of the conference. Special emphasis was also given to industrial applications and to technologies enabling the production of microsytems and their sub-components. In this special section of Journal of Optics A: Pure and Applied Optics, a series of interesting papers has been collected, reporting progress in the different aspects of microsystems design, production, characterization and testing. The papers embrace most of the various topics that were debated during the conference. We hope that these papers will not only report the most up-to-date research progress made in this field, but will also involve and stimulate everyone working in these areas to continue in the effort of developing more and better optical microsystems in the future. We would like to thank all the members of the Scientific and Industrial Committees for the high scientific content of the meeting and the European Optical Society for its support of the conference organization.

Evaluation of Knowledge Development in a Healthcare Setting

NASA Astrophysics Data System (ADS)

Schaffer, Scott P.

Healthcare organizations worldwide have recently increased efforts to improve performance, quality, and knowledge transfer using information and communication technologies. Evaluation of the effectiveness and quality of such efforts is challenging. A macro and micro-level system evaluation conducted with a 14000 member US hospital administrative services organization examined the appropriateness of a blended face-to-face and technology-enabled performance improvement and knowledge development system. Furthermore, a successful team or microsystem in a high performing hospital was studied in-depth. Several types of data methods including interview, observation, and questionnaire were used to address evaluation questions within a knowledge development framework created for the study. Results of this preliminary study focus on how this organization attempted to organize clinical improvement efforts around quality and performance improvement processes supported by networked technologies.

Microelectromechanical System (MEMS) Device Being Developed for Active Cooling and Temperature Control

NASA Technical Reports Server (NTRS)

Beach, Duane E.

2003-01-01

High-capacity cooling options remain limited for many small-scale applications such as microelectronic components, miniature sensors, and microsystems. A microelectromechanical system (MEMS) using a Stirling thermodynamic cycle to provide cooling or heating directly to a thermally loaded surface is being developed at the NASA Glenn Research Center to meet this need. The device can be used strictly in the cooling mode or can be switched between cooling and heating modes in milliseconds for precise temperature control. Fabrication and assembly employ techniques routinely used in the semiconductor processing industry. Benefits of the MEMS cooler include scalability to fractions of a millimeter, modularity for increased capacity and staging to low temperatures, simple interfaces, limited failure modes, and minimal induced vibration. The MEMS cooler has potential applications across a broad range of industries such as the biomedical, computer, automotive, and aerospace industries. The basic capabilities it provides can be categorized into four key areas: 1) Extended environmental temperature range in harsh environments; 2) Lower operating temperatures for electronics and other components; 3) Precision spatial and temporal thermal control for temperature-sensitive devices; and 4) The enabling of microsystem devices that require active cooling and/or temperature control. The rapidly expanding capabilities of semiconductor processing in general, and microsystems packaging in particular, present a new opportunity to extend Stirling-cycle cooling to the MEMS domain. The comparatively high capacity and efficiency possible with a MEMS Stirling cooler provides a level of active cooling that is impossible at the microscale with current state-of-the-art techniques. The MEMS cooler technology builds on decades of research at Glenn on Stirling-cycle machines, and capitalizes on Glenn s emerging microsystems capabilities.

75 FR 43555 - Hewlett Packard; Hewlett Packard-Enterprise Business Services Formerly Known as Electronic Data...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-26

... Workers From Sun Microsystems, Inc., Dell Computer Corp., EMC Corp., EMC Corp. Total, Cisco Systems Capital Corporation, Microsoft Corp., Symantec Corp., Xerox Corp., Vmware, Inc., Sun Microsystems Federal... known as Electronic Data Systems, including on- site leased workers from Sun Microsystems, Inc., Dell...

An integrated microsystem with dielectrophoresis enrichment and impedance detection for detection of Escherichia coli

USDA-ARS?s Scientific Manuscript database

An integrated microsystem device with matched interdigitated microelectrode chip was fabricated for enrichment and detection of Escherichia coli O157:H7. The microsystem has integrated with positive dielectrophoresis (pDEP) enrichment and in situ impedance detection, whose total volume is only 3.0 ×...

Advanced Microsystems for Automotive Applications 2005

NASA Astrophysics Data System (ADS)

Valldorf, Jürgen; Gessner, Wolfgang

Since 1995 the annual international forum on Advanced Microsystems for Automotive Applications (AMAA) has been held in Berlin. The event offers a unique opportunity for microsystems component developers, system suppliers and car manufacturers to show and to discuss competing technological approaches of microsystems based solutions in vehicles. The book accompanying the event has demonstrated to be an efficient instrument for the diffusion of new concepts and technology results. The present volume including the papers of the AMAA 2005 gives an overview on the state-of-the-art and outlines imminent and mid-term R&D perspectives.

Heterogeneously integrated microsystem-on-a-chip

DOEpatents

Chanchani, Rajen [Albuquerque, NM

2008-02-26

A microsystem-on-a-chip comprises a bottom wafer of normal thickness and a series of thinned wafers can be stacked on the bottom wafer, glued and electrically interconnected. The interconnection layer comprises a compliant dielectric material, an interconnect structure, and can include embedded passives. The stacked wafer technology provides a heterogeneously integrated, ultra-miniaturized, higher performing, robust and cost-effective microsystem package. The highly integrated microsystem package, comprising electronics, sensors, optics, and MEMS, can be miniaturized both in volume and footprint to the size of a bottle-cap or less.

A programmable microsystem using system-on-chip for real-time biotelemetry.

PubMed

Wang, Lei; Johannessen, Erik A; Hammond, Paul A; Cui, Li; Reid, Stuart W J; Cooper, Jonathan M; Cumming, David R S

2005-07-01

A telemetry microsystem, including multiple sensors, integrated instrumentation and a wireless interface has been implemented. We have employed a methodology akin to that for System-on-Chip microelectronics to design an integrated circuit instrument containing several "intellectual property" blocks that will enable convenient reuse of modules in future projects. The present system was optimized for low-power and included mixed-signal sensor circuits, a programmable digital system, a feedback clock control loop and RF circuits integrated on a 5 mm x 5 mm silicon chip using a 0.6 microm, 3.3 V CMOS process. Undesirable signal coupling between circuit components has been investigated and current injection into sensitive instrumentation nodes was minimized by careful floor-planning. The chip, the sensors, a magnetic induction-based transmitter and two silver oxide cells were packaged into a 36 mm x 12 mm capsule format. A base station was built in order to retrieve the data from the microsystem in real-time. The base station was designed to be adaptive and timing tolerant since the microsystem design was simplified to reduce power consumption and size. The telemetry system was found to have a packet error rate of 10(-3) using an asynchronous simplex link. Trials in animal carcasses were carried out to show that the transmitter was as effective as a conventional RF device whilst consuming less power.

Epoxy Chip-in-Carrier Integration and Screen-Printed Metalization for Multichannel Microfluidic Lab-on-CMOS Microsystems.

PubMed

Li, Lin; Yin, Heyu; Mason, Andrew J

2018-04-01

The integration of biosensors, microfluidics, and CMOS instrumentation provides a compact lab-on-CMOS microsystem well suited for high throughput measurement. This paper describes a new epoxy chip-in-carrier integration process and two planar metalization techniques for lab-on-CMOS that enable on-CMOS electrochemical measurement with multichannel microfluidics. Several design approaches with different fabrication steps and materials were experimentally analyzed to identify an ideal process that can achieve desired capability with high yield and low material and tool cost. On-chip electrochemical measurements of the integrated assembly were performed to verify the functionality of the chip-in-carrier packaging and its capability for microfluidic integration. The newly developed CMOS-compatible epoxy chip-in-carrier process paves the way for full implementation of many lab-on-CMOS applications with CMOS ICs as core electronic instruments.

New EUROPRACTICE microsystem design and foundry services

NASA Astrophysics Data System (ADS)

Salomon, Patric R.; Beernaert, Dirk; Turner, Rob

2000-08-01

The microsystems market for MST is predicted to grow to 38 billion dollars by the year 2002, with systems containing these components generating even higher revenues and growth. One of the barriers to successful exploitation of this technology has been the lack of access to industrial foundries capable of producing certified microsystems devices in commercial quantities. To overcome this problem, the European Commission has started the EUROPRACTICE program in 1996 with the installation of manufacturing clusters and demonstration activities to provide access to microsystems foundry services for European small and medium sized companies (SMEs). Since 1996, there has been a shift form providing 'broad technology offers' and 'raising awareness fro microsystem capabilities' to 'direct support of design needs' and 'focused services' which allow SMEs to use even complex microsystems technologies to implement their products, The third phase of EUROPRACTICE has just been launched, and contains 5 Manufacturing Clusters, 12 Designs Houses, and 7 Competence Centers, each working in different application/technology areas. The EUROPRACTICE program will be presented together with a detail description of the capabilities of the participants and information on how to access their services.

Biodriven microsystem for treatment of hydrocephalus

NASA Astrophysics Data System (ADS)

Joswig, Jurgen; Oswald, Jens; Seifert, Steffen

1995-09-01

A microvalve system made of silicon for use in hydrocephalus therapy is presented, which will provide an excellent intracranial pressure stabilization. Design and processing are described. Testing results (in vitro) are presented.

Integrating patient safety into the clinical microsystem

PubMed Central

Mohr, J; Batalden, P; Barach, P

2004-01-01

Healthcare institutions continue to face challenges in providing safe patient care in increasingly complex organisational and regulatory environments while striving to maintain financial viability. The clinical microsystem provides a conceptual and practical framework for approaching organisational learning and delivery of care. Tensions exist between the conceptual theory and the daily practical applications of providing safe and effective care within healthcare systems. Healthcare organisations are often complex, disorganised, and opaque systems to their users and their patients. This disorganisation may lead to patient discomfort and harm as well as much waste. Healthcare organisations are in some sense conglomerates of smaller systems, not coherent monolithic organisations. The microsystem unit allows organisational leaders to embed quality and safety into a microsystem's developmental journey. Leaders can set the stage for making safety a priority for the organisation while allowing individual microsystems to create innovative strategies for improvement. PMID:15576690

Wireless Performance of a Fully Passive Neurorecording Microsystem Embedded in Dispersive Human Head Phantom

NASA Technical Reports Server (NTRS)

Schwerdt, Helen N.; Chae, Junseok; Miranda, Felix A.

2012-01-01

This paper reports the wireless performance of a biocompatible fully passive microsystem implanted in phantom media simulating the dispersive dielectric properties of the human head, for potential application in recording cortical neuropotentials. Fully passive wireless operation is achieved by means of backscattering electromagnetic (EM) waves carrying 3rd order harmonic mixing products (2f(sub 0) plus or minus f(sub m)=4.4-4.9 GHZ) containing targeted neuropotential signals (fm approximately equal to 1-1000 Hz). The microsystem is enclosed in 4 micrometer thick parylene-C for biocompatibility and has a footprint of 4 millimeters x 12 millimeters x 500 micrometers. Preliminary testing of the microsystem implanted in the lossy biological simulating media results in signal-to-noise ratio's (SNR) near 22 (SNR approximately equal to 38 in free space) for millivolt level neuropotentials, demonstrating the potential for fully passive wireless microsystems in implantable medical applications.

Single-mode glass waveguide technology for optical interchip communication on board level

NASA Astrophysics Data System (ADS)

Brusberg, Lars; Neitz, Marcel; Schröder, Henning

2012-01-01

The large bandwidth demand in long-distance telecom networks lead to single-mode fiber interconnects as result of low dispersion, low loss and dense wavelength multiplexing possibilities. In contrast, multi-mode interconnects are suitable for much shorter lengths up to 300 meters and are promising for optical links between racks and on board level. Active optical cables based on multi-mode fiber links are at the market and research in multi-mode waveguide integration on board level is still going on. Compared to multi-mode, a single-mode waveguide has much more integration potential because of core diameters of around 20% of a multi-mode waveguide by a much larger bandwidth. But light coupling in single-mode waveguides is much more challenging because of lower coupling tolerances. Together with the silicon photonics technology, a single-mode waveguide technology on board-level will be the straight forward development goal for chip-to-chip optical interconnects integration. Such a hybrid packaging platform providing 3D optical single-mode links bridges the gap between novel photonic integrated circuits and the glass fiber based long-distance telecom networks. Following we introduce our 3D photonic packaging approach based on thin glass substrates with planar integrated optical single-mode waveguides for fiber-to-chip and chip-to-chip interconnects. This novel packaging approach merges micro-system packaging and glass integrated optics. It consists of a thin glass substrate with planar integrated singlemode waveguide circuits, optical mirrors and lenses providing an integration platform for photonic IC assembly and optical fiber interconnect. Thin glass is commercially available in panel and wafer formats and characterizes excellent optical and high-frequency properties. That makes it perfect for microsystem packaging. The paper presents recent results in single-mode waveguide technology on wafer level and waveguide characterization. Furthermore the integration in a hybrid packaging process and design issues are discussed.

Command and Control in Virtual Environments: Using Contingency Theory to Understand Organization in Virtual Worlds

DTIC Science & Technology

2010-10-01

organization in the WoW virtual world. Unlike the real world guilds of olden days (e.g., stone masons, leather workers, apothecaries) and unions of current...oriented sports teams (e.g., football, hockey, rugby ). This is the case in particular with player-vs- player combat. Fourth, organizational learning is...Microsystems  Telecom Italia  Telus Mobility  Text 100  Toyota  Trades Union Congress  Union Network International  New Unionism

LIGA-based microsystem manufacturing:the electrochemistry of through-mold depostion and material properties.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelly, James J.; Goods, Steven Howard

2005-06-01

The report presented below is to appear in ''Electrochemistry at the Nanoscale'', Patrik Schmuki, Ed. Springer-Verlag, (ca. 2005). The history of the LIGA process, used for fabricating dimensional precise structures for microsystem applications, is briefly reviewed, as are the basic elements of the technology. The principal focus however, is on the unique aspects of the electrochemistry of LIGA through-mask metal deposition and the generation of the fine and uniform microstructures necessary to ensure proper functionality of LIGA components. We draw from both previously published work by external researchers in the field as well as from published and unpublished studies frommore » within Sandia.« less

Dielectrophoresis-Assisted Integration of 1024 Carbon Nanotube Sensors into a CMOS Microsystem.

PubMed

Seichepine, Florent; Rothe, Jörg; Dudina, Alexandra; Hierlemann, Andreas; Frey, Urs

2017-05-01

Carbon-nanotube (CNT)-based sensors offer the potential to detect single-molecule events and picomolar analyte concentrations. An important step toward applications of such nanosensors is their integration in large arrays. The availability of large arrays would enable multiplexed and parallel sensing, and the simultaneously obtained sensor signals would facilitate statistical analysis. A reliable method to fabricate an array of 1024 CNT-based sensors on a fully processed complementary-metal-oxide-semiconductor microsystem is presented. A high-yield process for the deposition of CNTs from a suspension by means of liquid-coupled floating-electrode dielectrophoresis (DEP), which yielded 80% of the sensor devices featuring between one and five CNTs, is developed. The mechanism of floating-electrode DEP on full arrays and individual devices to understand its self-limiting behavior is studied. The resistance distributions across the array of CNT devices with respect to different DEP parameters are characterized. The CNT devices are then operated as liquid-gated CNT field-effect-transistors (LG-CNTFET) in liquid environment. Current dependency to the gate voltage of up to two orders of magnitude is recorded. Finally, the sensors are validated by studying the pH dependency of the LG-CNTFET conductance and it is demonstrated that 73% of the CNT sensors of a given microsystem show a resistance decrease upon increasing the pH value. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

pH-Taxis of Biohybrid Microsystems

NASA Astrophysics Data System (ADS)

Zhuang, Jiang; Wright Carlsen, Rika; Sitti, Metin

2015-06-01

The last decade has seen an increasing number of studies developing bacteria and other cell-integrated biohybrid microsystems. However, the highly stochastic motion of these microsystems severely limits their potential use. Here, we present a method that exploits the pH sensing of flagellated bacteria to realize robust drift control of multi-bacteria propelled microrobots. Under three specifically configured pH gradients, we demonstrate that the microrobots exhibit both unidirectional and bidirectional pH-tactic behaviors, which are also observed in free-swimming bacteria. From trajectory analysis, we find that the swimming direction and speed biases are two major factors that contribute to their tactic drift motion. The motion analysis of microrobots also sheds light on the propulsion dynamics of the flagellated bacteria as bioactuators. It is expected that similar driving mechanisms are shared among pH-taxis, chemotaxis, and thermotaxis. By identifying the mechanism that drives the tactic behavior of bacteria-propelled microsystems, this study opens up an avenue towards improving the control of biohybrid microsystems. Furthermore, assuming that it is possible to tune the preferred pH of bioactuators by genetic engineering, these biohybrid microsystems could potentially be applied to sense the pH gradient induced by cancerous cells in stagnant fluids inside human body and realize targeted drug delivery.

Building information for systematic improvement of the prevention of hospital-acquired pressure ulcers with statistical process control charts and regression.

PubMed

Padula, William V; Mishra, Manish K; Weaver, Christopher D; Yilmaz, Taygan; Splaine, Mark E

2012-06-01

To demonstrate complementary results of regression and statistical process control (SPC) chart analyses for hospital-acquired pressure ulcers (HAPUs), and identify possible links between changes and opportunities for improvement between hospital microsystems and macrosystems. Ordinary least squares and panel data regression of retrospective hospital billing data, and SPC charts of prospective patient records for a US tertiary-care facility (2004-2007). A prospective cohort of hospital inpatients at risk for HAPUs was the study population. There were 337 HAPU incidences hospital wide among 43 844 inpatients. A probit regression model predicted the correlation of age, gender and length of stay on HAPU incidence (pseudo R(2)=0.096). Panel data analysis determined that for each additional day in the hospital, there was a 0.28% increase in the likelihood of HAPU incidence. A p-chart of HAPU incidence showed a mean incidence rate of 1.17% remaining in statistical control. A t-chart showed the average time between events for the last 25 HAPUs was 13.25 days. There was one 57-day period between two incidences during the observation period. A p-chart addressing Braden scale assessments showed that 40.5% of all patients were risk stratified for HAPUs upon admission. SPC charts complement standard regression analysis. SPC amplifies patient outcomes at the microsystem level and is useful for guiding quality improvement. Macrosystems should monitor effective quality improvement initiatives in microsystems and aid the spread of successful initiatives to other microsystems, followed by system-wide analysis with regression. Although HAPU incidence in this study is below the national mean, there is still room to improve HAPU incidence in this hospital setting since 0% incidence is theoretically achievable. Further assessment of pressure ulcer incidence could illustrate improvement in the quality of care and prevent HAPUs.

Health care applications based on mobile phone centric smart sensor network.

PubMed

Quero, J M; Tarrida, C L; Santana, J J; Ermolov, V; Jantunen, I; Laine, H; Eichholz, J

2007-01-01

This paper presents the MIMOSA architecture and development platform to create Ambient Intelligence applications. MIMOSA achieves this objective by developing a personal mobile-device centric architecture and open technology platform where microsystem technology is the key enabling technology for their realization due to its low-cost, low power consumption, and small size. This paper focuses the demonstration activities carried out in the field of health care. MIMOSA project is a European level initiative involving 15 enterprises and research institutions and universities.

Improvement Research Priorities: USA Survey and Expert Consensus

PubMed Central

Stevens, Kathleen R.; Ovretveit, John

2013-01-01

The purpose of this study was to identify stakeholder views about national priorities for improvement science and build agreement for action in a national improvement and implementation research network in the USA. This was accomplished using three stages of identification and consensus. (1) Topics were identified through a multipronged environmental scan of the literature and initiatives. (2) Based on this scan, a survey was developed, and stakeholders (n = 2,777) were invited to rate the resulting 33-topic, 9-category list, via an online survey. Data from 560 respondents (20% response) were analyzed. (3) An expert panel used survey results to further refine the research priorities through a Rand Delphi process. Priorities identified were within four categories: care coordination and transitions, high-performing clinical systems and microsystems improvement approaches, implementation of evidence-based improvements and best practices, and culture of quality and safety. The priorities identified were adopted by the improvement science research network as the research agenda to guide strategy. The process and conclusions may be of value to quality improvement research funding agencies, governments, and research units seeking to concentrate their resources on improvement topics where research is capable of yielding timely and actionable answers as well as contributing to the knowledge base for improvement. PMID:24024029

Capillary electrophoresis-electrochemistry microfluidic system for the determination of organic peroxides

NASA Technical Reports Server (NTRS)

Wang, Joseph; Escarpa, Alberto; Pumera, Martin; Feldman, Jason; Svehla, D. (Principal Investigator)

2002-01-01

A microfluidic analytical system for the separation and detection of organic peroxides, based on a microchip capillary electrophoresis device with an integrated amperometric detector, was developed. The new microsystem relies on the reductive detection of both organic acid peroxides and hydroperoxides at -700 mV (vs. Ag wire/AgCl). Factors influencing the separation and detection processes were examined and optimized. The integrated microsystem offers rapid measurements (within 130 s) of these organic-peroxide compounds, down to micromolar levels. A highly stable response for repetitive injections (RSD 0.35-3.12%; n = 12) reflects the negligible electrode passivation. Such a "lab-on-a-chip" device should be attractive for on-site analysis of organic peroxides, as desired for environmental screening and industrial monitoring.

Recent Advances in Fluorescence Lifetime Analytical Microsystems: Contact Optics and CMOS Time-Resolved Electronics.

PubMed

Wei, Liping; Yan, Wenrong; Ho, Derek

2017-12-04

Fluorescence spectroscopy has become a prominent research tool with wide applications in medical diagnostics and bio-imaging. However, the realization of combined high-performance, portable, and low-cost spectroscopic sensors still remains a challenge, which has limited the technique to the laboratories. A fluorescence lifetime measurement seeks to obtain the characteristic lifetime from the fluorescence decay profile. Time-correlated single photon counting (TCSPC) and time-gated techniques are two key variations of time-resolved measurements. However, commercial time-resolved analysis systems typically contain complex optics and discrete electronic components, which lead to bulkiness and a high cost. These two limitations can be significantly mitigated using contact sensing and complementary metal-oxide-semiconductor (CMOS) implementation. Contact sensing simplifies the optics, whereas CMOS technology enables on-chip, arrayed detection and signal processing, significantly reducing size and power consumption. This paper examines recent advances in contact sensing and CMOS time-resolved circuits for the realization of fully integrated fluorescence lifetime measurement microsystems. The high level of performance from recently reported prototypes suggests that the CMOS-based contact sensing microsystems are emerging as sound technologies for application-specific, low-cost, and portable time-resolved diagnostic devices.

Recent Advances in Fluorescence Lifetime Analytical Microsystems: Contact Optics and CMOS Time-Resolved Electronics

PubMed Central

Yan, Wenrong; Ho, Derek

2017-01-01

Fluorescence spectroscopy has become a prominent research tool with wide applications in medical diagnostics and bio-imaging. However, the realization of combined high-performance, portable, and low-cost spectroscopic sensors still remains a challenge, which has limited the technique to the laboratories. A fluorescence lifetime measurement seeks to obtain the characteristic lifetime from the fluorescence decay profile. Time-correlated single photon counting (TCSPC) and time-gated techniques are two key variations of time-resolved measurements. However, commercial time-resolved analysis systems typically contain complex optics and discrete electronic components, which lead to bulkiness and a high cost. These two limitations can be significantly mitigated using contact sensing and complementary metal-oxide-semiconductor (CMOS) implementation. Contact sensing simplifies the optics, whereas CMOS technology enables on-chip, arrayed detection and signal processing, significantly reducing size and power consumption. This paper examines recent advances in contact sensing and CMOS time-resolved circuits for the realization of fully integrated fluorescence lifetime measurement microsystems. The high level of performance from recently reported prototypes suggests that the CMOS-based contact sensing microsystems are emerging as sound technologies for application-specific, low-cost, and portable time-resolved diagnostic devices. PMID:29207568

Responsive hydrogels--structurally and dimensionally optimized smart frameworks for applications in catalysis, micro-system technology and material science.

PubMed

Döring, Artjom; Birnbaum, Wolfgang; Kuckling, Dirk

2013-09-07

Although the technological and scientific importance of functional polymers has been well established over the last few decades, the most recent focus that has attracted much attention has been on stimuli-responsive polymers. This group of materials is of particular interest due to its ability to respond to internal and/or external chemico-physical stimuli, which is often manifested as large macroscopic responses. Aside from scientific challenges of designing stimuli-responsive polymers, the main technological interest lies in their numerous applications ranging from catalysis through microsystem technology and chemomechanical actuators to sensors that have been extensively explored. Since the phase transition phenomenon of hydrogels is theoretically well understood advanced materials based on the predictions can be prepared. Since the volume phase transition of hydrogels is a diffusion-limited process the size of the synthesized hydrogels is an important factor. Consistent downscaling of the gel size will result in fast smart gels with sufficient response times. In order to apply smart gels in microsystems and sensors, new preparation techniques for hydrogels have to be developed. For the up-coming nanotechnology, nano-sized gels as actuating materials would be of great interest.

[The design and experiment of multi-parameter water quality monitoring microsystem based on MOEMS microspectrometer].

PubMed

Wei, Kang-Lin; Wen, Zhi-Yu; Guo, Jian; Chen, Song-Bo

2012-07-01

Aiming at the monitoring and protecting of water resource environment, a multi-parameter water quality monitoring microsystem based on microspectrometer was put forward in the present paper. The microsystem is mainly composed of MOEMS microspectrometer, flow paths system and embedded measuring & controlling system. It has the functions of self-injecting samples and detection regents, automatic constant temperature, self -stirring, self- cleaning and samples' spectrum detection. The principle prototype machine of the microsystem was developed, and its structure principle was introduced in the paper. Through experiment research, it was proved that the principle prototype machine can rapidly detect quite a few water quality parameters and can meet the demands of on-line water quality monitoring, moreover, the principle prototype machine has strong function expansibility.

Three-Dimensional Nanobiocomputing Architectures With Neuronal Hypercells

DTIC Science & Technology

2007-06-01

Neumann architectures, and CMOS fabrication. Novel solutions of massive parallel distributed computing and processing (pipelined due to systolic... and processing platforms utilizing molecular hardware within an enabling organization and architecture. The design technology is based on utilizing a...Microsystems and Nanotechnologies investigated a novel 3D3 (Hardware Software Nanotechnology) technology to design super-high performance computing

MEMS and MOEMS for national security applications

NASA Astrophysics Data System (ADS)

Scott, Marion W.

2003-01-01

Major opportunities for microsystem insertion into commercial applications, such as telecommunications and medical prosthesis, are well known. Less well known are applications that ensure the security of our nation, the protection of its armed forces, and the safety of its citizens. Microsystems enable entirely new possibilities to meet National Security needs, which can be classed along three lines: anticipating security needs and threats, deterring the efficacy of identified threats, and defending against the application of these threats. In each of these areas, specific products that are enabled by MEMS and MOEMS are discussed. In the area of anticipating needs and threats, sensored microsystems designed for chem/bio/nuclear threats, and sensors for border and asset protection can significantly secure our borders, ports, and transportation systems. Key features for these applications include adaptive optics and spectroscopic capabilities. Microsystems to monitor soil and water quality can be used to secure critical infrastructure, food safety can be improved by in-situ identification of pathogens, and sensored buildings can ensure the architectural safety of our homes and workplaces. A challenge to commercializing these opportunities, and thus making them available for National Security needs, is developing predictable markets and predictable technology roadmaps. The integrated circuit manufacturing industry provides an example of predictable technology maturation and market insertion, primarily due to the existence of a "unit cell" that allows volume manufacturing. It is not clear that microsystems can follow an analogous path. The possible paths to affordable low-volume production, as well as the prospects of a microsystems unit cell, are discussed.

Survey of Media Forms and Information Flow Models in Microsystems Companies

NASA Astrophysics Data System (ADS)

Durugbo, Christopher; Tiwari, Ashutosh; Alcock, Jeffery R.

The paper presents the findings of a survey of 40 microsystems companies that was carried out to determine the use and the purpose of use of media forms and information flow models within these companies. These companies as 'product-service systems' delivered integrated products and services to realise customer solutions. Data collection was carried out by means of an online survey over 3 months. The survey revealed that 42.5% of respondents made use of data flow diagrams and 10% made use of design structure matrices. The survey also suggests that a majority of companies (75%) made use of textual and diagrammatic media forms for communication, analysis, documentation and representation during design and development processes. The paper also discusses the implications of the survey findings to product-service systems.

Review: Semiconductor Piezoresistance for Microsystems.

PubMed

Barlian, A Alvin; Park, Woo-Tae; Mallon, Joseph R; Rastegar, Ali J; Pruitt, Beth L

2009-01-01

Piezoresistive sensors are among the earliest micromachined silicon devices. The need for smaller, less expensive, higher performance sensors helped drive early micromachining technology, a precursor to microsystems or microelectromechanical systems (MEMS). The effect of stress on doped silicon and germanium has been known since the work of Smith at Bell Laboratories in 1954. Since then, researchers have extensively reported on microscale, piezoresistive strain gauges, pressure sensors, accelerometers, and cantilever force/displacement sensors, including many commercially successful devices. In this paper, we review the history of piezoresistance, its physics and related fabrication techniques. We also discuss electrical noise in piezoresistors, device examples and design considerations, and alternative materials. This paper provides a comprehensive overview of integrated piezoresistor technology with an introduction to the physics of piezoresistivity, process and material selection and design guidance useful to researchers and device engineers.

Detailed study of scratch drive actuator characteristics using high-speed imaging

NASA Astrophysics Data System (ADS)

Li, Lijie; Brown, James G.; Uttamchandani, Deepak G.

2001-10-01

Microactuators are one of the key components in MEMS and Microsystems technology, and various designs have been realized through different fabrication processes. One type of microactuator commonly used is the scratch drive actuator (SDA) that is frequently fabricated by surface micromachining processes. An experimental investigation has been conducted on the characteristics of SDAs fabricated using the Cronos Microsystems MUMPs process. The motivation is to compare the response of SDAs located on the same die, and SDAs located on the different dies from the same fabrication batch. A high-speed imaging camera has been used to precisely determine important SDA characteristics such as step size, velocity, maximum velocity, and acceleration over long travel distance. These measurements are important from a repeatability point of view, and in order to fully exploit the potential of the SDA as a precise positioning mechanism. 2- and 3-stage SDAs have been designed and fabricated for these experiments. Typical step sizes varying from 7 nm at a driving voltage of 60 V to 23 nm at 290 V have been obtained.

A Fully-Passive Wireless Microsystem for Recording of Neuropotentials using RF Backscattering Methods

PubMed Central

Xu, Wencheng; Shekhar, Sameer; Abbaspour-Tamijani, Abbas; Towe, Bruce C.; Miranda, Félix A.; Chae, Junseok

2011-01-01

The ability to safely monitor neuropotentials is essential in establishing methods to study the brain. Current research focuses on the wireless telemetry aspect of implantable sensors in order to make these devices ubiquitous and safe. Chronic implants necessitate superior reliability and durability of the integrated electronics. The power consumption of implanted electronics must also be limited to within several milliwatts to microwatts to minimize heat trauma in the human body. In order to address these severe requirements, we developed an entirely passive and wireless microsystem for recording neuropotentials. An external interrogator supplies a fundamental microwave carrier to the microsystem. The microsystem comprises varactors that perform nonlinear mixing of neuropotential and fundamental carrier signals. The varactors generate third-order mixing products that are wirelessly backscattered to the external interrogator where the original neuropotential signals are recovered. Performance of the neuro-recording microsystem was demonstrated by wireless recording of emulated and in vivo neuropotentials. The obtained results were wireless recovery of neuropotentials as low as approximately 500 microvolts peak-to-peak (μVpp) with a bandwidth of 10 Hz to 3 kHz (for emulated signals) and with 128 epoch signal averaging of repetitive signals (for in vivo signals). PMID:22267898

Mechanics of Multifunctional Materials and Microsystems

DTIC Science & Technology

2013-03-07

unlimited 46  Successfully processed the 1st self-healing prepreg in continuous production mode SEM image of E-glass fiber tow (200 count) with 3.3...healing composite with well dispersed microcapsules were fabricated from prepreg . E-glass fiber/epoxy resin Matrix: EPON862/EPIKURE3274

Fully-Polymeric pH Sensor Realized by Means of a Single-Step Soft Embossing Technique

PubMed Central

Fanzio, Paola; Chang, Chi-Tung; Skolimowski, Maciej; Tanzi, Simone; Sasso, Luigi

2017-01-01

We present here an electrochemical sensor microsystem for the monitoring of pH. The all-polymeric device is comprised of a cyclic olefin copolymer substrate, a 200 nm-thin patterned layer of conductive polymer (PEDOT), and a 70 nm electropolymerized layer of a pH sensitive conductive polymer (polyaniline). The patterning of the fluidic (microfluidic channels) and conductive (wiring and electrodes) functional elements was achieved with a single soft PDMS mold via a single embossing step process. A post-processing treatment with ethylene glycol assured the functional enhancement of the electrodes, as demonstrated via an electrical and electrochemical characterization. A surface modification of the electrodes was carried out, based on voltammetric electropolymerization, to obtain a thin layer of polyaniline. The mechanism for pH sensing is based on the redox reactions of the polyaniline layer caused by protonation. The sensing performance of the microsystem was finally validated by monitoring its potentiometric response upon exposure to a relevant range of pH. PMID:28531106

Biparametric potentiometric analytical microsystem for nitrate and potassium monitoring in water recycling processes for manned space missions.

PubMed

Calvo-López, Antonio; Arasa-Puig, Eva; Puyol, Mar; Casalta, Joan Manel; Alonso-Chamarro, Julián

2013-12-04

The construction and evaluation of a Low Temperature Co-fired Ceramics (LTCC)-based continuous flow potentiometric microanalyzer prototype to simultaneously monitor the presence of two ions (potassium and nitrate) in samples from the water recycling process for future manned space missions is presented. The microsystem integrates microfluidics and the detection system in a single substrate and it is smaller than a credit card. The detection system is based on two ion-selective electrodes (ISEs), which are built using all-solid state nitrate and potassium polymeric membranes, and a screen-printed Ag/AgCl reference electrode. The obtained analytical features after the optimization of the microfluidic design and hydrodynamics are a linear range from 10 to 1000 mg L(-1) and from 1.9 to 155 mg L(-1) and a detection limit of 9.56 mg L(-1) and 0.81 mg L(-1) for nitrate and potassium ions respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

Fully-Polymeric pH Sensor Realized by Means of a Single-Step Soft Embossing Technique.

PubMed

Fanzio, Paola; Chang, Chi-Tung; Skolimowski, Maciej; Tanzi, Simone; Sasso, Luigi

2017-05-20

We present here an electrochemical sensor microsystem for the monitoring of pH. The all-polymeric device is comprised of a cyclic olefin copolymer substrate, a 200 nm-thin patterned layer of conductive polymer (PEDOT), and a 70 nm electropolymerized layer of a pH sensitive conductive polymer (polyaniline). The patterning of the fluidic (microfluidic channels) and conductive (wiring and electrodes) functional elements was achieved with a single soft PDMS mold via a single embossing step process. A post-processing treatment with ethylene glycol assured the functional enhancement of the electrodes, as demonstrated via an electrical and electrochemical characterization. A surface modification of the electrodes was carried out, based on voltammetric electropolymerization, to obtain a thin layer of polyaniline. The mechanism for pH sensing is based on the redox reactions of the polyaniline layer caused by protonation. The sensing performance of the microsystem was finally validated by monitoring its potentiometric response upon exposure to a relevant range of pH.

Ultra-low-power and robust digital-signal-processing hardware for implantable neural interface microsystems.

PubMed

Narasimhan, S; Chiel, H J; Bhunia, S

2011-04-01

Implantable microsystems for monitoring or manipulating brain activity typically require on-chip real-time processing of multichannel neural data using ultra low-power, miniaturized electronics. In this paper, we propose an integrated-circuit/architecture-level hardware design framework for neural signal processing that exploits the nature of the signal-processing algorithm. First, we consider different power reduction techniques and compare the energy efficiency between the ultra-low frequency subthreshold and conventional superthreshold design. We show that the superthreshold design operating at a much higher frequency can achieve comparable energy dissipation by taking advantage of extensive power gating. It also provides significantly higher robustness of operation and yield under large process variations. Next, we propose an architecture level preferential design approach for further energy reduction by isolating the critical computation blocks (with respect to the quality of the output signal) and assigning them higher delay margins compared to the noncritical ones. Possible delay failures under parameter variations are confined to the noncritical components, allowing graceful degradation in quality under voltage scaling. Simulation results using prerecorded neural data from the sea-slug (Aplysia californica) show that the application of the proposed design approach can lead to significant improvement in total energy, without compromising the output signal quality under process variations, compared to conventional design approaches.

Assessment of nanosystems for space applications

NASA Astrophysics Data System (ADS)

Bilhaut, Lise; Duraffourg, Laurent

2009-11-01

This paper first gives an overview of the applications of micro-electro-mechanical systems (MEMS) in space. Microsystems are advertised for their extremely low size and mass, along with their low power consumption and in some case their improved performances. Examples of actual flown MEMS and future missions relying on MEMS are given. Microsystems are now enjoying a dynamic and expanding interest in the space community. This paper intends to give an idea about the next step in miniaturization, since the microelectronic industry is already looking at nano-electro-mechanical systems (NEMS) driven by the more-than-Moore philosophy. We show that the impact of nanosystems should not be reduced at a homothecy in size, weight and power consumption. New forces appear at this scale (Casimir force…) which have to be considered in the system design. The example of a nano-mechanical memory is developed. We also show that performances of nanosystems are not systematically better than their microscopic counterparts through the study of the impact of dimension reduction on an accelerometer resolution and sensitivity. We conclude with the idea that nanosystems will find their greatest applications in distributed intelligent networks that will allow new mission concepts for space exploration.

The risk and protective functions of perceived family and peer microsystems among urban adolescents in poverty.

PubMed

Seidman, E; Chesir-Teran, D; Friedman, J L; Yoshikawa, H; Allen, L; Roberts, A; Aber, J L

1999-04-01

Utilized a pattern-based approach to discover the different constellations of perceived social transactions separately for family and peer systems and explored the risk and protective functions of these microsystem profiles for both depression and antisocial behavior among a sample of ethnically and racially diverse urban adolescents living in poverty. Measures of perceived social support, involvement and hassles with family and peers, as well as perceived social acceptance and peers' values were entered into two sets of iterative cluster analyses to identify distinct profiles of family and peer transactions. From each of the perceived family and peer transactional analyses, six replicated profiles emerged. Several of the profiles were consistent with expectations from prior literature such as Enmeshing families and Rejecting peer networks, while others were novel and intriguing such as Entangling peers. Family profiles were consistent in their risk and protective associations for both depression and antisocial behavior, while the peer profiles varied in their effects for each developmental outcome. For example, the Rejecting peer profile placed adolescents at increased risk for depression but protected them from antisocial behavior. Implications for future research and preventive intervention are discussed.

Sandia National Laboratories: Research: Research Foundations: Radiation

Science.gov Websites

Effects and High Energy Density Science Sandia National Laboratories Exceptional service in the Engineering Science Geoscience Materials Science Nanodevices & Microsystems Radiation Effects & High Science Geoscience Materials Science Nanodevices and Microsystems Radiation Effects and High Energy

Sandia National Laboratories: Research: Research Foundations: Geoscience

Science.gov Websites

Materials Science Nanodevices & Microsystems Radiation Effects & High Energy Density Science Engineering Science Geoscience Materials Science Nanodevices and Microsystems Radiation Effects and High variety of scales, including mechanical, thermal, and chemical effects Improve the understanding of

Review: Semiconductor Piezoresistance for Microsystems

PubMed Central

Barlian, A. Alvin; Park, Woo-Tae; Mallon, Joseph R.; Rastegar, Ali J.; Pruitt, Beth L.

2010-01-01

Piezoresistive sensors are among the earliest micromachined silicon devices. The need for smaller, less expensive, higher performance sensors helped drive early micromachining technology, a precursor to microsystems or microelectromechanical systems (MEMS). The effect of stress on doped silicon and germanium has been known since the work of Smith at Bell Laboratories in 1954. Since then, researchers have extensively reported on microscale, piezoresistive strain gauges, pressure sensors, accelerometers, and cantilever force/displacement sensors, including many commercially successful devices. In this paper, we review the history of piezoresistance, its physics and related fabrication techniques. We also discuss electrical noise in piezoresistors, device examples and design considerations, and alternative materials. This paper provides a comprehensive overview of integrated piezoresistor technology with an introduction to the physics of piezoresistivity, process and material selection and design guidance useful to researchers and device engineers. PMID:20198118

Implementing Simulation Design of Experiments and Remote Execution on a High Performance Computing Cluster

DTIC Science & Technology

2007-09-01

example, an application developed in Sun’s Netbeans [2007] integrated development environment (IDE) uses Swing class object for graphical user... Netbeans Version 5.5.1 [Computer Software]. Santa Clara, CA: Sun Microsystems. Process Modeler Version 7.0 [Computer Software]. Santa Clara, Ca

Conductive inks for metalization in integrated polymer microsystems

DOEpatents

Davidson, James Courtney [Livermore, CA; Krulevitch, Peter A [Pleasanton, CA; Maghribi, Mariam N [Livermore, CA; Benett, William J [Livermore, CA; Hamilton, Julie K [Tracy, CA; Tovar, Armando R [San Antonio, TX

2006-02-28

A system of metalization in an integrated polymer microsystem. A flexible polymer substrate is provided and conductive ink is applied to the substrate. In one embodiment the flexible polymer substrate is silicone. In another embodiment the flexible polymer substrate comprises poly(dimethylsiloxane).

Internet Use and Child Development: The Techno-Microsystem

ERIC Educational Resources Information Center

Johnson, Genevieve Marie

2010-01-01

Ecological systems theory assumes that child development is the consequence of ongoing reciprocal and spiraling interactions between the child and his/her microsystem (immediate home, school, and community environments). The increasing presence of digital technologies in children's immediate environments suggests the need for the proposed…

Java: An Explosion on the Internet.

ERIC Educational Resources Information Center

Read, Tim; Hall, Hazel

Summer 1995 saw the release, with considerable media attention, of draft versions of Sun Microsystems' Java computer programming language and the HotJava browser. Java has been heralded as the latest "killer" technology in the Internet explosion. Sun Microsystems and numerous companies including Microsoft, IBM, and Netscape have agreed…

A ceramic microreactor for the synthesis of water soluble CdS and CdS/ZnS nanocrystals with on-line optical characterization

NASA Astrophysics Data System (ADS)

Pedro, Sara Gómez-De; Puyol, Mar; Izquierdo, David; Salinas, Iñigo; de La Fuente, J. M.; Alonso-Chamarro, Julián

2012-02-01

In this paper, a computer controlled microreactor to synthesize water soluble CdS and CdS/ZnS nanocrystals with in situ monitoring of the reaction progress is developed. It is based on ceramic tapes and the Low-Temperature Co-fired Ceramics technology (LTCC). As well the microsystem set-up, the microreactor fluidic design has also been thoroughly optimized. The final device is based on a hydrodynamic focusing of the reagents followed by a three-dimensional micromixer. This generates monodispersed and stable CdS and core-shell CdS/ZnS nanocrystals of 4.5 and 4.2 nm, respectively, with reproducible optical properties in terms of fluorescence emission wavelengths, bandwidth, and quantum yields, which is a key requirement for their future analytical applications. The synthetic process is also controlled in real time with the integration of an optical detection system for absorbance and fluorescence measurements based on commercial miniaturized optical components. This makes possible the efficient managing of the hydrodynamic variables to obtain the desired colloidal suspension. As a result, a simple, economic, robust and portable microsystem for the well controlled synthesis of CdS and CdS/ZnS nanocrystals is presented. Moreover, the reaction takes place in aqueous medium, thus allowing the direct modular integration of this microreactor in specific analytical microsystems, which require the use of such quantum dots as labels.

Between War and Peace: Interactional Patterns of Couples under Prolonged Uncertainty.

ERIC Educational Resources Information Center

Ben-David, Amith; Lavee, Yoav

1996-01-01

Explores how global and political issues affect microsystems like the marital unit. A variety of interactional patterns emerged in the observation of 30 couples marital interactions during a prolonged stressful situation. Couples reporting a deterioration of their relationship had more disagreements regarding the meaning of a peace process and its…

Opportunity NYC-Family Rewards: An Embedded Child and Family Study of Conditional Cash Transfers

ERIC Educational Resources Information Center

Morris, Pamela; Aber, J. Lawrence; Wolf, Sharon; Berg, Juliette

2011-01-01

This study builds on and informs ecological theory (Bronfenbrenner & Morris, 2006) by focusing on the contextual processes by which individual developmental trajectories can be altered. Ecological theory posits that children are embedded in a nested and interactive set of interrelated contexts beginning with the micro-system (the most…

Applications of laser ablation to microengineering

NASA Astrophysics Data System (ADS)

Gower, Malcolm C.; Rizvi, Nadeem H.

2000-08-01

Applications of pulsed laser ablation to the manufacture of micro- electro-mechanical systems (MEMS) and micro-opto-electro-mechanical systems (MOEMS) devices are presented. Laser ablative processes used to manufacture a variety of microsystems technology (MST) components in the computer peripheral, sensing and biomedical industries are described together with a view of some future developments.

Neighborhood Social Capital, Poor Physical Conditions, and School Achievement

ERIC Educational Resources Information Center

Woolley, Michael E.; Grogan-Kaylor, Andrew; Gilster, Megan E.; Karb, Rebecca A.; Gant, Larry M.; Reischl, Thomas M.; Alaimo, Katherine

2008-01-01

Success in school is a vital developmental outcome for children. In recent decades, it has been shown that school outcomes are influenced by a variety of environments and social processes in the lives of children, both within and across the central microsystems of family, school, and neighborhood. The current study used a multilevel analytic…

FERMI: a digital Front End and Readout MIcrosystem for high resolution calorimetry

NASA Astrophysics Data System (ADS)

Alexanian, H.; Appelquist, G.; Bailly, P.; Benetta, R.; Berglund, S.; Bezamat, J.; Blouzon, F.; Bohm, C.; Breveglieri, L.; Brigati, S.; Cattaneo, P. W.; Dadda, L.; David, J.; Engström, M.; Genat, J. F.; Givoletti, M.; Goggi, V. G.; Gong, S.; Grieco, G. M.; Hansen, M.; Hentzell, H.; Holmberg, T.; Höglund, I.; Inkinen, S. J.; Kerek, A.; Landi, C.; Ledortz, O.; Lippi, M.; Lofstedt, B.; Lund-Jensen, B.; Maloberti, F.; Mutz, S.; Nayman, P.; Piuri, V.; Polesello, G.; Sami, M.; Savoy-Navarro, A.; Schwemling, P.; Stefanelli, R.; Sundblad, R.; Svensson, C.; Torelli, G.; Vanuxem, J. P.; Yamdagni, N.; Yuan, J.; Ödmark, A.; Fermi Collaboration

1995-02-01

We present a digital solution for the front-end electronics of high resolution calorimeters at future colliders. It is based on analogue signal compression, high speed {A}/{D} converters, a fully programmable pipeline and a digital signal processing (DSP) chain with local intelligence and system supervision. This digital solution is aimed at providing maximal front-end processing power by performing waveform analysis using DSP methods. For the system integration of the multichannel device a multi-chip, silicon-on-silicon multi-chip module (MCM) has been adopted. This solution allows a high level of integration of complex analogue and digital functions, with excellent flexibility in mixing technologies for the different functional blocks. This type of multichip integration provides a high degree of reliability and programmability at both the function and the system level, with the additional possibility of customising the microsystem to detector-specific requirements. For enhanced reliability in high radiation environments, fault tolerance strategies, i.e. redundancy, reconfigurability, majority voting and coding for error detection and correction, are integrated into the design.

Thin glass based packaging and photonic single-mode waveguide integration by ion-exchange technology on board and module level

NASA Astrophysics Data System (ADS)

Brusberg, Lars; Lang, Günter; Schröder, Henning

2011-01-01

The proposed novel packaging approach merges micro-system packaging and glass integrated optics. It provides 3D optical single-mode intra system links to bridge the gap between novel photonic integrated circuits and the glass fibers for inter system interconnects. We introduce our hybrid 3D photonic packaging approach based on thin glass substrates with planar integrated optical single-mode waveguides for fiber-to-chip and chip-to-chip links. Optical mirrors and lenses provide optical mode matching for photonic IC assemblies and optical fiber interconnects. Thin glass is commercially available in panel and wafer formats and characterizes excellent optical and high-frequency properties as reviewed in the paper. That makes it perfect for micro-system packaging. The adopted planar waveguide process based on ion-exchange technology is capable for high-volume manufacturing. This ion-exchange process and the optical propagation are described in detail for thin glass substrates. An extensive characterization of all basic circuit elements like straight and curved waveguides, couplers and crosses proves the low attenuation of the optical circuit elements.

Design and fabrication of vertically-integrated CMOS image sensors.

PubMed

Skorka, Orit; Joseph, Dileepan

2011-01-01

Technologies to fabricate integrated circuits (IC) with 3D structures are an emerging trend in IC design. They are based on vertical stacking of active components to form heterogeneous microsystems. Electronic image sensors will benefit from these technologies because they allow increased pixel-level data processing and device optimization. This paper covers general principles in the design of vertically-integrated (VI) CMOS image sensors that are fabricated by flip-chip bonding. These sensors are composed of a CMOS die and a photodetector die. As a specific example, the paper presents a VI-CMOS image sensor that was designed at the University of Alberta, and fabricated with the help of CMC Microsystems and Micralyne Inc. To realize prototypes, CMOS dies with logarithmic active pixels were prepared in a commercial process, and photodetector dies with metal-semiconductor-metal devices were prepared in a custom process using hydrogenated amorphous silicon. The paper also describes a digital camera that was developed to test the prototype. In this camera, scenes captured by the image sensor are read using an FPGA board, and sent in real time to a PC over USB for data processing and display. Experimental results show that the VI-CMOS prototype has a higher dynamic range and a lower dark limit than conventional electronic image sensors.

Design and Fabrication of Vertically-Integrated CMOS Image Sensors

PubMed Central

Skorka, Orit; Joseph, Dileepan

2011-01-01

Technologies to fabricate integrated circuits (IC) with 3D structures are an emerging trend in IC design. They are based on vertical stacking of active components to form heterogeneous microsystems. Electronic image sensors will benefit from these technologies because they allow increased pixel-level data processing and device optimization. This paper covers general principles in the design of vertically-integrated (VI) CMOS image sensors that are fabricated by flip-chip bonding. These sensors are composed of a CMOS die and a photodetector die. As a specific example, the paper presents a VI-CMOS image sensor that was designed at the University of Alberta, and fabricated with the help of CMC Microsystems and Micralyne Inc. To realize prototypes, CMOS dies with logarithmic active pixels were prepared in a commercial process, and photodetector dies with metal-semiconductor-metal devices were prepared in a custom process using hydrogenated amorphous silicon. The paper also describes a digital camera that was developed to test the prototype. In this camera, scenes captured by the image sensor are read using an FPGA board, and sent in real time to a PC over USB for data processing and display. Experimental results show that the VI-CMOS prototype has a higher dynamic range and a lower dark limit than conventional electronic image sensors. PMID:22163860

A μ analysis-based, controller-synthesis framework for robust bioinspired visual navigation in less-structured environments.

PubMed

Keshavan, J; Gremillion, G; Escobar-Alvarez, H; Humbert, J S

2014-06-01

Safe, autonomous navigation by aerial microsystems in less-structured environments is a difficult challenge to overcome with current technology. This paper presents a novel visual-navigation approach that combines bioinspired wide-field processing of optic flow information with control-theoretic tools for synthesis of closed loop systems, resulting in robustness and performance guarantees. Structured singular value analysis is used to synthesize a dynamic controller that provides good tracking performance in uncertain environments without resorting to explicit pose estimation or extraction of a detailed environmental depth map. Experimental results with a quadrotor demonstrate the vehicle's robust obstacle-avoidance behaviour in a straight line corridor, an S-shaped corridor and a corridor with obstacles distributed in the vehicle's path. The computational efficiency and simplicity of the current approach offers a promising alternative to satisfying the payload, power and bandwidth constraints imposed by aerial microsystems.

Microsystems and Nanoscience for Biomedical Applications: A View to the Future

ERIC Educational Resources Information Center

Pilarski, Linda M.; Mehta, Michael D.; Caulfield, Timothy; Kaler, Karan V. I. S.; Backhouse, Christopher J.

2004-01-01

At present there is an enormous discrepancy between our nanotechnological capabilities (particularly our nanobiotechnologies), our social wisdom, and consensus on how to apply them. To date, cost considerations have greatly constrained our application of nanotechnologies. However, novel advances in microsystem platform technologies are about to…

Loran-C flight test software

NASA Technical Reports Server (NTRS)

Nickum, J. D.

1978-01-01

The software package developed for the KIM-1 Micro-System and the Mini-L PLL receiver to simplify taking flight test data is described along with the address and data bus buffers used in the KIM-1 Micro-system. The interface hardware and timing are also presented to describe completely the software programs.

75 FR 63509 - Hewlett Packard, Hewlett Packard-Enterprise Business Services, Formerly Known as Electronic Data...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-15

... Workers From Sun Microsystems, Inc., Dell Computer Corp., EMC Corp., EMC Corp. Total, Cisco Systems Capital Corporation, Microsoft Corp., Symantec Corp., Xerox Corp., VMWare, Inc., Sun Microsystems Federal...-- Services, formerly known as Electronic Data Systems, including on- site leased workers from Sun...

Smart image sensors: an emerging key technology for advanced optical measurement and microsystems

NASA Astrophysics Data System (ADS)

Seitz, Peter

1996-08-01

Optical microsystems typically include photosensitive devices, analog preprocessing circuitry and digital signal processing electronics. The advances in semiconductor technology have made it possible today to integrate all photosensitive and electronical devices on one 'smart image sensor' or photo-ASIC (application-specific integrated circuits containing photosensitive elements). It is even possible to provide each 'smart pixel' with additional photoelectronic functionality, without compromising the fill factor substantially. This technological capability is the basis for advanced cameras and optical microsystems showing novel on-chip functionality: Single-chip cameras with on- chip analog-to-digital converters for less than $10 are advertised; image sensors have been developed including novel functionality such as real-time selectable pixel size and shape, the capability of performing arbitrary convolutions simultaneously with the exposure, as well as variable, programmable offset and sensitivity of the pixels leading to image sensors with a dynamic range exceeding 150 dB. Smart image sensors have been demonstrated offering synchronous detection and demodulation capabilities in each pixel (lock-in CCD), and conventional image sensors are combined with an on-chip digital processor for complete, single-chip image acquisition and processing systems. Technological problems of the monolithic integration of smart image sensors include offset non-uniformities, temperature variations of electronic properties, imperfect matching of circuit parameters, etc. These problems can often be overcome either by designing additional compensation circuitry or by providing digital correction routines. Where necessary for technological or economic reasons, smart image sensors can also be combined with or realized as hybrids, making use of commercially available electronic components. It is concluded that the possibilities offered by custom smart image sensors will influence the design and the performance of future electronic imaging systems in many disciplines, reaching from optical metrology to machine vision on the factory floor and in robotics applications.

The logic of relations and the logic of management.

PubMed

Buntinx, W

2008-07-01

Increasing emphasis on financial and administrative control processes is affecting service culture in support organisations for persons with intellectual disability. This phenomenon is currently obvious in Dutch service organisations that find themselves in transition towards more community care and at the same time under pressure from new administrative and funding managerial bureaucracy. As a result, the logic of management is becoming more dominant in direct support settings and risk to overshadow the logic of relationships between staff and clients. The article presents a reflection on this phenomenon, starting from a description of service team characteristics as found in the literature. Next, findings about direct support staff (DSS) continuity are summarised from four Dutch studies. Following up these findings, the concept of 'microsystems' is explored as a possible answer to the organisational challenges demonstrated in the studies. Team characteristics, especially team size and membership continuity for DSS, appear relevant factors for assuring supportive relationships and service quality in direct support teams. The structure of the primary support team shows to be of special interest. The organisational concept of 'microsystems' is explored with respect to transcending the present conflict between bureaucratic managerial pressure and the need for supportive relationships. Service organisations need to create structural conditions for the efficacy of direct support teams in terms of client relationships and relevant client outcomes. At the same time, the need for administrative and control processes can not be denied. The concept of 'microsystems', application of a Quality of Life framework and the use of new instruments, such as the Supports Intensity Scale, can contribute to an organisational solution for the present conflicting logic of relations and management.

77 FR 19745 - Angstrom Microsystems Corp., Bedminster National Corp., Brake Headquarters U.S.A., Inc., and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-02

... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] Angstrom Microsystems Corp., Bedminster National Corp., Brake Headquarters U.S.A., Inc., and BrandPartners Group, Inc.; Order of Suspension of... BrandPartners Group, Inc. because it has not filed any periodic reports since the period ended September...

Microfabrication techniques for integrated sensors and microsystems.

PubMed

Wise, K D; Najafi, K

1991-11-29

Integrated sensors and actuators are rapidly evolving to provide an important link between very large scale integrated circuits and nonelectronic monitoring and control applications ranging from biomedicine to automated manufacturing. As they continue to expand, entire microsystems merging electrical, mechanical, thermal, optical, magnetic, and perhaps chemical components should be possible on a common substrate.

Superamphiphobic Silicon-Nanowire-Embedded Microsystem and In-Contact Flow Performance of Gas and Liquid Streams.

PubMed

Ko, Dong-Hyeon; Ren, Wurong; Kim, Jin-Oh; Wang, Jun; Wang, Hao; Sharma, Siddharth; Faustini, Marco; Kim, Dong-Pyo

2016-01-26

Gas and liquid streams are invariably separated either by a solid wall or by a membrane for heat or mass transfer between the gas and liquid streams. Without the separating wall, the gas phase is present as bubbles in liquid or, in a microsystem, as gas plugs between slugs of liquid. Continuous and direct contact between the two moving streams of gas and liquid is quite an efficient way of achieving heat or mass transfer between the two phases. Here, we report a silicon nanowire built-in microsystem in which a liquid stream flows in contact with an underlying gas stream. The upper liquid stream does not penetrate into the lower gas stream due to the superamphiphobic nature of the silicon nanowires built into the bottom wall, thereby preserving the integrity of continuous gas and liquid streams, although they are flowing in contact. Due to the superamphiphobic nature of silicon nanowires, the microsystem provides the best possible interfacial mass transfer known to date between flowing gas and liquid phases, which can achieve excellent chemical performance in two-phase organic syntheses.

Network dynamics of 3D engineered neuronal cultures: a new experimental model for in-vitro electrophysiology.

PubMed

Frega, Monica; Tedesco, Mariateresa; Massobrio, Paolo; Pesce, Mattia; Martinoia, Sergio

2014-06-30

Despite the extensive use of in-vitro models for neuroscientific investigations and notwithstanding the growing field of network electrophysiology, all studies on cultured cells devoted to elucidate neurophysiological mechanisms and computational properties, are based on 2D neuronal networks. These networks are usually grown onto specific rigid substrates (also with embedded electrodes) and lack of most of the constituents of the in-vivo like environment: cell morphology, cell-to-cell interaction and neuritic outgrowth in all directions. Cells in a brain region develop in a 3D space and interact with a complex multi-cellular environment and extracellular matrix. Under this perspective, 3D networks coupled to micro-transducer arrays, represent a new and powerful in-vitro model capable of better emulating in-vivo physiology. In this work, we present a new experimental paradigm constituted by 3D hippocampal networks coupled to Micro-Electrode-Arrays (MEAs) and we show how the features of the recorded network dynamics differ from the corresponding 2D network model. Further development of the proposed 3D in-vitro model by adding embedded functionalized scaffolds might open new prospects for manipulating, stimulating and recording the neuronal activity to elucidate neurophysiological mechanisms and to design bio-hybrid microsystems.

Network dynamics of 3D engineered neuronal cultures: a new experimental model for in-vitro electrophysiology

PubMed Central

Frega, Monica; Tedesco, Mariateresa; Massobrio, Paolo; Pesce, Mattia; Martinoia, Sergio

2014-01-01

Despite the extensive use of in-vitro models for neuroscientific investigations and notwithstanding the growing field of network electrophysiology, all studies on cultured cells devoted to elucidate neurophysiological mechanisms and computational properties, are based on 2D neuronal networks. These networks are usually grown onto specific rigid substrates (also with embedded electrodes) and lack of most of the constituents of the in-vivo like environment: cell morphology, cell-to-cell interaction and neuritic outgrowth in all directions. Cells in a brain region develop in a 3D space and interact with a complex multi-cellular environment and extracellular matrix. Under this perspective, 3D networks coupled to micro-transducer arrays, represent a new and powerful in-vitro model capable of better emulating in-vivo physiology. In this work, we present a new experimental paradigm constituted by 3D hippocampal networks coupled to Micro-Electrode-Arrays (MEAs) and we show how the features of the recorded network dynamics differ from the corresponding 2D network model. Further development of the proposed 3D in-vitro model by adding embedded functionalized scaffolds might open new prospects for manipulating, stimulating and recording the neuronal activity to elucidate neurophysiological mechanisms and to design bio-hybrid microsystems. PMID:24976386

A FPGA embedded web server for remote monitoring and control of smart sensors networks.

PubMed

Magdaleno, Eduardo; Rodríguez, Manuel; Pérez, Fernando; Hernández, David; García, Enrique

2013-12-27

This article describes the implementation of a web server using an embedded Altera NIOS II IP core, a general purpose and configurable RISC processor which is embedded in a Cyclone FPGA. The processor uses the μCLinux operating system to support a Boa web server of dynamic pages using Common Gateway Interface (CGI). The FPGA is configured to act like the master node of a network, and also to control and monitor a network of smart sensors or instruments. In order to develop a totally functional system, the FPGA also includes an implementation of the time-triggered protocol (TTP/A). Thus, the implemented master node has two interfaces, the webserver that acts as an Internet interface and the other to control the network. This protocol is widely used to connecting smart sensors and actuators and microsystems in embedded real-time systems in different application domains, e.g., industrial, automotive, domotic, etc., although this protocol can be easily replaced by any other because of the inherent characteristics of the FPGA-based technology.

A FPGA Embedded Web Server for Remote Monitoring and Control of Smart Sensors Networks

PubMed Central

Magdaleno, Eduardo; Rodríguez, Manuel; Pérez, Fernando; Hernández, David; García, Enrique

2014-01-01

This article describes the implementation of a web server using an embedded Altera NIOS II IP core, a general purpose and configurable RISC processor which is embedded in a Cyclone FPGA. The processor uses the μCLinux operating system to support a Boa web server of dynamic pages using Common Gateway Interface (CGI). The FPGA is configured to act like the master node of a network, and also to control and monitor a network of smart sensors or instruments. In order to develop a totally functional system, the FPGA also includes an implementation of the time-triggered protocol (TTP/A). Thus, the implemented master node has two interfaces, the webserver that acts as an Internet interface and the other to control the network. This protocol is widely used to connecting smart sensors and actuators and microsystems in embedded real-time systems in different application domains, e.g., industrial, automotive, domotic, etc., although this protocol can be easily replaced by any other because of the inherent characteristics of the FPGA-based technology. PMID:24379047

Implantable Biomedical Microsystems: A New Graduate Course in Biomedical Circuits and Systems

ERIC Educational Resources Information Center

Sodagar, Amir M.

2014-01-01

After more than two decades of research on the design and development of implantable biomedical microsystems, it is time now to organize research achievements in this area in a consolidated and pedagogical form. This paper introduces a new graduate course in advanced biomedical circuits and systems. Designed for graduate students with electrical…

A digital front-end and readout microsystem for calorimetry at LHC

NASA Astrophysics Data System (ADS)

Alippi, C.; Appelquist, G.; Berglund, S.; Bohm, C.; Breveglieri, L.; Brigati, S.; Carlson, P.; Cattaneo, P.; Dadda, L.; David, J.; Del Buono, L.; Dell'Acqua, A.; Engström, M.; Fumagalli, G.; Gatti, U.; Genat, J. F.; Goggi, G.; Hansen, M.; Hentzell, H.; Höglund, I.; Inkinen, S.; Kerek, A.; Lebbolo, H.; LeDortz, O.; Lofstedt, B.; Maloberti, F.; Nayman, P.; Persson, S.-T.; Piuri, V.; Salice, F.; Sami, M.; Savoy-Navarro, A.; Stefanelli, R.; Sundblad, R.; Svensson, C.; Torelli, G.; Vanuxem, J. P.; Yamdagni, N.; Yuan, J.; Zitoun, R.

1994-04-01

A digital solution to the front-end electronics for calorimetric detectors at future supercolliders is presented. The solution is based on high speed {A}/{D} converters, a fully programmable pipeline/digital filter chain and local intelligence. Questions of error correction, fault-tolerance and system redundancy are also being considered. A system integration of a multichannel device in a multichip, Silicon-on-Silicon Microsystem hybrid, is used. This solution allows a new level of integration of complex analogue and digital functions, with an excellent flexibility in mixing technologies for the different functional blocks. It also allows a high degree of programmability at both the function and the system level, and offers the possibility of customising the microsystem with detector-specific functions.

MOEM systems in Europe

NASA Astrophysics Data System (ADS)

Salomon, Patric R.; Parriaux, Olivier M.

1997-04-01

This is a brief summary of the talk given at Photonics West, San Jose, on 10 February 1997. The description made hereafter of the strategic problematics in Europe in the domain of microsystems results from a free and extensive reading of the literature made available by the EC programs in particular through EUROPRACTICE and NEXUS. What follows expresses personal views and does not reflect any official position. Most of the information material can be found in the mst news journal edited by VDI/VDE-IT. This talk was an attempt to extract the essentials of what is going on in European Microsystem Technologies (MST) from the numerous programs, projects schemes, and initiatives which have been announced, and to position the Opto-Electro-Mechanical Microsystem sin the MST framework.

Comparison of inkjet-printed silver conductors on different microsystem substrates

NASA Astrophysics Data System (ADS)

Kruger, Jené; Bezuidenhout, Petroné H.; Joubert, Trudi-Heleen

2016-02-01

Applications for diagnostic and environmental point-of-need require processes and building blocks to add smart features to disposable biosensors on low-cost substrates. A novel method for producing such biosensors is printing electronics using additive technologies. This work contributes to the toolbox of processes, materials and components for printed electronics manufacturing - as well as rapid prototyping - of circuits. Printing protocols were developed to facilitate successful inkjet printing of nanosilver ink (Harima NPS-JL) onto different microsystem substrates using a functional printer (Dimatix DMP-3281). Photo paper is a standard inkjet substrate, which were compared with glass, polycarbonate (PC), plastic projector transparency foil, and polydimethylsiloxane (PDMS). Comparison attributes include physical and electrical properties. The layout design comprised dogbone elements of 8 mm length, and widths varying between 100 μm and 2 mm. All printed features were thermally cured for 1 hour at 120 °C. The physical characteristics were measured with a laser scanning microscope (Zeiss LSM-5) to determine the width, thickness and surface roughness of the printed features. An LCR meter (GW-Instek 8110) was used to measure the printed structures' electrical characteristics (resistance, capacitance and inductance). A lumped element model and layout design rules were extracted to assist in standardized design procedures. The model incorporates prediction of the bandwidth attainable with these structures. The layer thickness on all substrates is larger than the 1 μm on photo paper, and varies between 1.6 μm (PC) and 7 μm (PDMS). The spreading for PDMS is similar to photo paper, but since for the other substrates it is between 5 (glass) and 10 (PC) times larger than for photo paper, the layout design rules require large spacing, leading to larger area networks. Electrical probing on the PDMS is not consistent and results are inconclusive. For the other substrates, the comparative dogbone resistance (100 μm width) is significantly larger than the 2 Ω standard, varying from 12.6 Ω (PC) to 19.3 Ω (glass). The bandwidth relative to photo paper is smaller by a factor of between 6 (PC) and 9.5 (glass).

Arrays of High-Aspect Ratio Microchannels for High-Throughput Isolation of Circulating Tumor Cells (CTCs).

PubMed

Hupert, Mateusz L; Jackson, Joshua M; Wang, Hong; Witek, Małgorzata A; Kamande, Joyce; Milowsky, Matthew I; Whang, Young E; Soper, Steven A

2014-10-01

Microsystem-based technologies are providing new opportunities in the area of in vitro diagnostics due to their ability to provide process automation enabling point-of-care operation. As an example, microsystems used for the isolation and analysis of circulating tumor cells (CTCs) from complex, heterogeneous samples in an automated fashion with improved recoveries and selectivity are providing new opportunities for this important biomarker. Unfortunately, many of the existing microfluidic systems lack the throughput capabilities and/or are too expensive to manufacture to warrant their widespread use in clinical testing scenarios. Here, we describe a disposable, all-polymer, microfluidic system for the high-throughput (HT) isolation of CTCs directly from whole blood inputs. The device employs an array of high aspect ratio (HAR), parallel, sinusoidal microchannels (25 µm × 150 µm; W × D; AR = 6.0) with walls covalently decorated with anti-EpCAM antibodies to provide affinity-based isolation of CTCs. Channel width, which is similar to an average CTC diameter (12-25 µm), plays a critical role in maximizing the probability of cell/wall interactions and allows for achieving high CTC recovery. The extended channel depth allows for increased throughput at the optimized flow velocity (2 mm/s in a microchannel); maximizes cell recovery, and prevents clogging of the microfluidic channels during blood processing. Fluidic addressing of the microchannel array with a minimal device footprint is provided by large cross-sectional area feed and exit channels poised orthogonal to the network of the sinusoidal capillary channels (so-called Z-geometry). Computational modeling was used to confirm uniform addressing of the channels in the isolation bed. Devices with various numbers of parallel microchannels ranging from 50 to 320 have been successfully constructed. Cyclic olefin copolymer (COC) was chosen as the substrate material due to its superior properties during UV-activation of the HAR microchannels surfaces prior to antibody attachment. Operation of the HT-CTC device has been validated by isolation of CTCs directly from blood secured from patients with metastatic prostate cancer. High CTC sample purities (low number of contaminating white blood cells, WBCs) allowed for direct lysis and molecular profiling of isolated CTCs.

A ceramic microreactor for the synthesis of water soluble CdS and CdS/ZnS nanocrystals with on-line optical characterization.

PubMed

Gómez-de Pedro, Sara; Puyol, Mar; Izquierdo, David; Salinas, Iñigo; de la Fuente, J M; Alonso-Chamarro, Julián

2012-02-21

In this paper, a computer controlled microreactor to synthesize water soluble CdS and CdS/ZnS nanocrystals with in situ monitoring of the reaction progress is developed. It is based on ceramic tapes and the Low-Temperature Co-fired Ceramics technology (LTCC). As well the microsystem set-up, the microreactor fluidic design has also been thoroughly optimized. The final device is based on a hydrodynamic focusing of the reagents followed by a three-dimensional micromixer. This generates monodispersed and stable CdS and core-shell CdS/ZnS nanocrystals of 4.5 and 4.2 nm, respectively, with reproducible optical properties in terms of fluorescence emission wavelengths, bandwidth, and quantum yields, which is a key requirement for their future analytical applications. The synthetic process is also controlled in real time with the integration of an optical detection system for absorbance and fluorescence measurements based on commercial miniaturized optical components. This makes possible the efficient managing of the hydrodynamic variables to obtain the desired colloidal suspension. As a result, a simple, economic, robust and portable microsystem for the well controlled synthesis of CdS and CdS/ZnS nanocrystals is presented. Moreover, the reaction takes place in aqueous medium, thus allowing the direct modular integration of this microreactor in specific analytical microsystems, which require the use of such quantum dots as labels. This journal is © The Royal Society of Chemistry 2012

Microinverters for employment in connection with photovoltaic modules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lentine, Anthony L.; Nielson, Gregory N.; Okandan, Murat

2015-09-22

Microinverters useable in association with photovoltaic modules are described. A three phase-microinverter receives direct current output generated by a microsystems-enabled photovoltaic cell and converts such direct current output into three-phase alternating current out. The three-phase microinverter is interleaved with other three-phase-microinverters, wherein such microinverters are integrated in a photovoltaic module with the microsystems-enabled photovoltaic cell.

An Implantable Neural Sensing Microsystem with Fiber-Optic Data Transmission and Power Delivery

PubMed Central

Park, Sunmee; Borton, David A.; Kang, Mingyu; Nurmikko, Arto V.; Song, Yoon-Kyu

2013-01-01

We have developed a prototype cortical neural sensing microsystem for brain implantable neuroengineering applications. Its key feature is that both the transmission of broadband, multichannel neural data and power required for the embedded microelectronics are provided by optical fiber access. The fiber-optic system is aimed at enabling neural recording from rodents and primates by converting cortical signals to a digital stream of infrared light pulses. In the full microsystem whose performance is summarized in this paper, an analog-to-digital converter and a low power digital controller IC have been integrated with a low threshold, semiconductor laser to extract the digitized neural signals optically from the implantable unit. The microsystem also acquires electrical power and synchronization clocks via optical fibers from an external laser by using a highly efficient photovoltaic cell on board. The implantable unit employs a flexible polymer substrate to integrate analog and digital microelectronics and on-chip optoelectronic components, while adapting to the anatomical and physiological constraints of the environment. A low power analog CMOS chip, which includes preamplifier and multiplexing circuitry, is directly flip-chip bonded to the microelectrode array to form the cortical neurosensor device. PMID:23666130

Action Research as Professional Development: Its Role in Education Reform in the United Arab Emirates

ERIC Educational Resources Information Center

Hathorn, Conley; Dillon, Anna Marie

2018-01-01

This paper is concerned with exploring the microsystem of teachers' experiences with education reform within the action research (AR) model for professional development (PD). Within the macrosystem of current major education reform in the UAE, it is timely to explore teachers' experiences of AR as PD to improve pedagogy. The process of engaging in…

Cu Pillar Low Temperature Bonding and Interconnection Technology of for 3D RF Microsystem

NASA Astrophysics Data System (ADS)

Shi, G. X.; Qian, K. Q.; Huang, M.; Yu, Y. W.; Zhu, J.

2018-03-01

In this paper 3D interconnects technologies used Cu pillars are discussed with respect to RF microsystem. While 2.5D Si interposer and 3D packaging seem to rely to cu pillars for the coming years, RF microsystem used the heterogeneous chip such as GaAs integration with Si interposers should be at low temperature. The pillars were constituted by Cu (2 micron) -Ni (2 micron) -Cu (3 micron) -Sn (1 micron) multilayer metal and total height is 8 micron on the front-side of the wafer by using electroplating. The wafer backside Cu pillar is obtained by temporary bonding, thinning and silicon surface etching. The RF interposers are stacked by Cu-Sn eutectic bonding at 260 °C. Analyzed the reliability of different pillar bonding structure.

A CMOS Time-Resolved Fluorescence Lifetime Analysis Micro-System

PubMed Central

Rae, Bruce R.; Muir, Keith R.; Gong, Zheng; McKendry, Jonathan; Girkin, John M.; Gu, Erdan; Renshaw, David; Dawson, Martin D.; Henderson, Robert K.

2009-01-01

We describe a CMOS-based micro-system for time-resolved fluorescence lifetime analysis. It comprises a 16 × 4 array of single-photon avalanche diodes (SPADs) fabricated in 0.35 μm high-voltage CMOS technology with in-pixel time-gated photon counting circuitry and a second device incorporating an 8 × 8 AlInGaN blue micro-pixellated light-emitting diode (micro-LED) array bump-bonded to an equivalent array of LED drivers realized in a standard low-voltage 0.35 μm CMOS technology, capable of producing excitation pulses with a width of 777 ps (FWHM). This system replaces instrumentation based on lasers, photomultiplier tubes, bulk optics and discrete electronics with a PC-based micro-system. Demonstrator lifetime measurements of colloidal quantum dot and Rhodamine samples are presented. PMID:22291564

Emergence of biological organization through thermodynamic inversion.

PubMed

Kompanichenko, Vladimir

2014-01-01

Biological organization arises under thermodynamic inversion in prebiotic systems that provide the prevalence of free energy and information contribution over the entropy contribution. The inversion might occur under specific far-from-equilibrium conditions in prebiotic systems oscillating around the bifurcation point. At the inversion moment, (physical) information characteristic of non-biological systems acquires the new features: functionality, purposefulness, and control over the life processes, which transform it into biological information. Random sequences of amino acids and nucleotides, spontaneously synthesized in the prebiotic microsystem, in the primary living unit (probiont) re-assemble into functional sequences, involved into bioinformation circulation through nucleoprotein interaction, resulted in the genetic code emergence. According to the proposed concept, oscillating three-dimensional prebiotic microsystems transformed into probionts in the changeable hydrothermal medium of the early Earth. The inversion concept states that spontaneous (accidental, random) transformations in prebiotic systems cannot produce life; it is only non-spontaneous (perspective, purposeful) transformations, which are the result of thermodynamic inversion, that lead to the negentropy conversion of prebiotic systems into initial living units.

Mixed-Dimensionality VLSI-Type Configurable Tools for Virtual Prototyping of Biomicrofluidic Devices and Integrated Systems

NASA Astrophysics Data System (ADS)

Makhijani, Vinod B.; Przekwas, Andrzej J.

2002-10-01

This report presents results of a DARPA/MTO Composite CAD Project aimed to develop a comprehensive microsystem CAD environment, CFD-ACE+ Multiphysics, for bio and microfluidic devices and complete microsystems. The project began in July 1998, and was a three-year team effort between CFD Research Corporation, California Institute of Technology (CalTech), University of California, Berkeley (UCB), and Tanner Research, with Mr. Don Verlee from Abbott Labs participating as a consultant on the project. The overall objective of this project was to develop, validate and demonstrate several applications of a user-configurable VLSI-type mixed-dimensionality software tool for design of biomicrofluidics devices and integrated systems. The developed tool would provide high fidelity 3-D multiphysics modeling capability, l-D fluidic circuits modeling, and SPICE interface for system level simulations, and mixed-dimensionality design. It would combine tools for layouts and process fabrication, geometric modeling, and automated grid generation, and interfaces to EDA tools (e.g. Cadence) and MCAD tools (e.g. ProE).

Microsystem technology as a road from macro to nanoworld.

PubMed

Grabiec, Piotr; Domański, Krzysztof; Janus, Paweł; Zaborowski, Michał; Jaroszewicz, Bogdan

2005-04-01

Tremendous progress of microelectronic technology observed within last 40 years is closely related to even more remarkable progress of technological tools. It is important to note however, that these new tools may be used for fabrication of diverse multifunctional structures as well. Such devices, called MEMS (Micro-Electro-Mechanical-System) and MOEMS (Micro-Electro-Opto-Mechanical-System) integrate microelectronic and micromechanical structures in one system enabling interdisciplinary application, with most interesting and prospective being bio-medical investigations. Development of these applications requires however cooperation of multidisciplinary team of specialists, covering broad range of physics, (bio) chemistry and electronics, not mentioning medical doctors and other medical specialists. Thus, dissemination, of knowledge about existing processing capabilities is of key importance. In this paper, examples of various applications of microelectronic technology for fabrication of Microsystems which may be used for medicine and chemistry, will be presented. Besides, information concerning a design and technology potential available in poland and new, emerging opportunities will be given.

Nanothermite-Based Microsystem for Drug Delivery and Cell Transfection

DTIC Science & Technology

2008-12-01

micropyrotechnic-based system in which a nanothermite energy source is coupled to a biological target for gene transfer and drug delivery ... delivery of particulate vaccines and drugs to human skin with a practical, hand-held shock tube-based system . Shock Waves, 12, 23-30. Kodama, T., M...1 NANOTHERMITE-BASED MICROSYSTEM FOR DRUG DELIVERY AND CELL TRANSFECTION S. Apperson, R. Thiruvengadathan, A. Bezmelnitsyn, K. Gangopadhyay, S

Droplet size prediction in the production of drug delivery microsystems by ultrasonic atomization

PubMed Central

Dalmoro, Annalisa; d’Amore, Matteo; Barba, Anna Angela

Microencapsulation processes of drugs or other functional molecules are of great interest in pharmaceutical production fields. Ultrasonic assisted atomization is a new technique to produce microencapsulated systems by mechanical approach. It seems to offer several advantages (low level of mechanical stress in materials, reduced energy request, reduced apparatuses size) with respect to more conventional techniques. In this paper the groundwork of atomization is briefly introduced and correlations to predict droplet size starting from process parameters and material properties are presented. PMID:24251250

Petabyte Class Storage at Jefferson Lab (CEBAF)

NASA Technical Reports Server (NTRS)

Chambers, Rita; Davis, Mark

1996-01-01

By 1997, the Thomas Jefferson National Accelerator Facility will collect over one Terabyte of raw information per day of Accelerator operation from three concurrently operating Experimental Halls. When post-processing is included, roughly 250 TB of raw and formatted experimental data will be generated each year. By the year 2000, a total of one Petabyte will be stored on-line. Critical to the experimental program at Jefferson Lab (JLab) is the networking and computational capability to collect, store, retrieve, and reconstruct data on this scale. The design criteria include support of a raw data stream of 10-12 MB/second from Experimental Hall B, which will operate the CEBAF (Continuous Electron Beam Accelerator Facility) Large Acceptance Spectrometer (CLAS). Keeping up with this data stream implies design strategies that provide storage guarantees during accelerator operation, minimize the number of times data is buffered allow seamless access to specific data sets for the researcher, synchronize data retrievals with the scheduling of postprocessing calculations on the data reconstruction CPU farms, as well as support the site capability to perform data reconstruction and reduction at the same overall rate at which new data is being collected. The current implementation employs state-of-the-art StorageTek Redwood tape drives and robotics library integrated with the Open Storage Manager (OSM) Hierarchical Storage Management software (Computer Associates, International), the use of Fibre Channel RAID disks dual-ported between Sun Microsystems SMP servers, and a network-based interface to a 10,000 SPECint92 data processing CPU farm. Issues of efficiency, scalability, and manageability will become critical to meet the year 2000 requirements for a Petabyte of near-line storage interfaced to over 30,000 SPECint92 of data processing power.

Silicon technology-based micro-systems for atomic force microscopy/photon scanning tunnelling microscopy.

PubMed

Gall-Borrut, P; Belier, B; Falgayrettes, P; Castagne, M; Bergaud, C; Temple-Boyer, P

2001-04-01

We developed silicon nitride cantilevers integrating a probe tip and a wave guide that is prolonged on the silicon holder with one or two guides. A micro-system is bonded to a photodetector. The resulting hybrid system enables us to obtain simultaneously topographic and optical near-field images. Examples of images obtained on a longitudinal cross-section of an optical fibre are shown.

Mid-IR Lasers: Challenges Imposed by the Population Dynamics of the Gain System

DTIC Science & Technology

2010-09-01

MicroSystems (IOMS) Central-Field Approximation: Perturbations 1. a) Non-centrosymmetric splitting (Coulomb interaction) ⇒ total orbital angular momentum b...Accordingly: ⇒ total electron-spin momentum 2. Spin-orbit coupling (“LS” coupling) ⇒ total angular momentum lanthanides: intermediate coupling (LS / jj) 3...MicroSystems (IOMS) Luminescence Decay Curves Rate-equation for decay: Solution ( Bernoulli -Eq.): Linearized solution: T. Jensen, Ph.D. Thesis, Univ. Hamburg

Generic controller dedicated to telemetry-controlled microsystems.

PubMed

Sodagar, Amir M; Wise, Kensall D; Najafi, Khalil

2006-01-01

This paper introduces a generic controller designed for telemetry-controlled microsystems. This controller receives a data packet through a serial link carrying a command word and the associated data, and is capable of generating a variety of control/timing signals according to the definition of the received command. The flexible microprogrammed architecture of the controller allows for defining the commands functions in an on-chip mask-programmable read-only memory.

Microsystem Cooler Development

NASA Technical Reports Server (NTRS)

Moran, Matthew E.; Wesolek, Danielle M.; Berhane, Bruk T.; Rebello, Keith J.

2004-01-01

A patented microsystem Stirling cooler is under development with potential application to electronics, sensors, optical and radio frequency (RF) systems, microarrays, and other microsystems. The microsystem Stirling cooler is most suited to volume-limited applications that require cooling below the ambient or sink temperature. Primary components of the planar device include: two diaphragm actuators that replace the pistons found in traditional-scale Stirling machines; and a micro-regenerator that stores and releases thermal energy to the working gas during the Stirling cycle. The use of diaphragms eliminates frictional losses and bypass leakage concerns associated with pistons, while permitting reversal of the hot and cold sides of the device during operation to allow precise temperature control. Three candidate microregenerators were custom fabricated for initial evaluation: two constructed of porous ceramic, and one made of multiple layers of nickel and photoresist in an offset grating pattern. An additional regenerator was prepared with a random stainless steel fiber matrix commonly used in existing Stirling machines for comparison to the custom fabricated regenerators. The candidate regenerators were tested in a piezoelectric-actuated test apparatus designed to simulate the Stirling refrigeration cycle. In parallel with the regenerator testing, electrostatically-driven comb-drive diaphragm actuators for the prototype device have been designed for deep reactive ion etching (DRIE) fabrication.

A wireless batteryless in vivo EKG and core body temperature sensing microsystem with 60 Hz suppression technique for untethered genetically engineered mice real-time monitoring.

PubMed

Chaimanonart, Nattapon; Young, Darrin J

2009-01-01

A wireless, batteryless, and implantable EKG and core body temperature sensing microsystem with adaptive RF powering for untethered genetically engineered mice real-time monitoring is designed, implemented, and in vivo characterized. A packaged microsystem, exhibiting a total size of 9 mm x 7 mm x 3 mm with a weight of 400 mg including a pair of stainless-steel EKG electrodes, is implanted in a mouse abdomen for real-time monitoring. A low power 2 mm x 2 mm ASIC, consisting of an EKG amplifier, a proportional-to-absolute-temperature (PTAT)-based temperature sensor, an RF power sensing circuit, an RF-DC power converter, an 8-bit ADC, digital control circuitry, and a 433 MHz FSK transmitter, is powered by an adaptively controlled external RF energy source at 4 MHz to ensure a stable 2V supply with 156microA current driving capability for the overall microsystem. An electrical model for analyzing 60 Hz interference based on 2-electrode and 3-electrode configurations is proposed and compared with in vivo evaluation results. Due to the small laboratory animal chest area, a 60 Hz suppression technique by employing input termination resistors is chosen for two-EKG-electrode implant configuration.

Flexible distributed architecture for semiconductor process control and experimentation

NASA Astrophysics Data System (ADS)

Gower, Aaron E.; Boning, Duane S.; McIlrath, Michael B.

1997-01-01

Semiconductor fabrication requires an increasingly expensive and integrated set of tightly controlled processes, driving the need for a fabrication facility with fully computerized, networked processing equipment. We describe an integrated, open system architecture enabling distributed experimentation and process control for plasma etching. The system was developed at MIT's Microsystems Technology Laboratories and employs in-situ CCD interferometry based analysis in the sensor-feedback control of an Applied Materials Precision 5000 Plasma Etcher (AME5000). Our system supports accelerated, advanced research involving feedback control algorithms, and includes a distributed interface that utilizes the internet to make these fabrication capabilities available to remote users. The system architecture is both distributed and modular: specific implementation of any one task does not restrict the implementation of another. The low level architectural components include a host controller that communicates with the AME5000 equipment via SECS-II, and a host controller for the acquisition and analysis of the CCD sensor images. A cell controller (CC) manages communications between these equipment and sensor controllers. The CC is also responsible for process control decisions; algorithmic controllers may be integrated locally or via remote communications. Finally, a system server images connections from internet/intranet (web) based clients and uses a direct link with the CC to access the system. Each component communicates via a predefined set of TCP/IP socket based messages. This flexible architecture makes integration easier and more robust, and enables separate software components to run on the same or different computers independent of hardware or software platform.

A stable wireless energy transmission system for gastrointestinal microsystems.

PubMed

Xin, W H; Yan, G Z; Wang, W X

2010-01-01

A wireless energy transmission system using a Helmholtz primary coil outside and a 3-dimensional secondary coil inside the body is introduced. It is designed to transmit stable power to a gastrointestinal microsystem regardless of its position and orientation when working in the gastric tract. Up to 310 mW of usable DC power can be delivered under worst-case geometrical conditions. Measured data of the system performance are presented and evaluated.

Recent advances in microparticle continuous separation.

PubMed

Kersaudy-Kerhoas, M; Dhariwal, R; Desmulliez, M P Y

2008-03-01

Recent advances in microparticle separation in continuous flow are presented. It is intended for scientists in the field of separation science in biology, chemistry and microsystems engineering. Recent techniques of micron-sized particle separation within microsystems are described with emphasis on five different categories: optical, magnetic, fluidic-only, electrical and minor separation methods. Examples from the growing literature are explained with insights on separation efficiency and microengineering challenges. Current applications of the techniques are discussed.

Applicability of Time-Averaged Holography for Micro-Electro-Mechanical System Performing Non-Linear Oscillations

PubMed Central

Palevicius, Paulius; Ragulskis, Minvydas; Palevicius, Arvydas; Ostasevicius, Vytautas

2014-01-01

Optical investigation of movable microsystem components using time-averaged holography is investigated in this paper. It is shown that even a harmonic excitation of a non-linear microsystem may result in an unpredictable chaotic motion. Analytical results between parameters of the chaotic oscillations and the formation of time-averaged fringes provide a deeper insight into computational and experimental interpretation of time-averaged MEMS holograms. PMID:24451467

Characterization Techniques for a MEMS Electric-Field Sensor in Vacuum

DTIC Science & Technology

2012-01-01

nected so that the noise contributions of the transimpedance amplifier and the digitizer may be determined. The raw voltage data, after processing...of Vrms/rtHz. The noise may be seen in terms of the device trans- duction physics, signal conditioning ( transimpedance amp), and DAQ. (right) Field...Sensor using Thermal Actua- tors with Mechanically Amplified Response,” Solid-State Sensors, Actuators and Microsystems Confer- ence, 2007. TRANSDUCERS

PREFACE: The Second Conference on Microelectronics, Microsystems and Nanotechnology

NASA Astrophysics Data System (ADS)

Nassiopoulou, Androula G.; Papanikolaou, Nikos; Tsamis, Christos

2005-01-01

The Second Conference on Microelectronics, Microsystems and Nanotechnology took place at the National Centre for Scientific Research `Demokritos', in Athens, Greece, between 14 and 17 November 2004. The conference was organized by the Institute of Microelectronics (IMEL) with the aim to bring together scientists and engineers working in the above exciting fields in an interactive forum. The conference included 45 oral presentations with 9 invited papers and was attended by 146 participants from 16 countries. The topics covered were nanotechnologies, quantum devices, sensors, micro- and nano-systems, semiconductor devices, C-MOS fabrication and characterization techniques, new materials, and IC design. Quantum devices and nanostructured materials attracted considerable attention. Both theoretical and experimental studies of metallic and semiconducting quantum systems were presented, with emphasis on their applications in electronics, optoelectronics, and nanocrystal memory devices. Another exciting topic was the recent developments in biocompatible lithographic processes for applications in biosensors. In particular novel processes for bio-friendly lithography, together with innovations in Si sensors for applications in medicine and food industry were presented. Recent developments and perspectives in CMOS technology towards the ultimate limit were also discussed. The conference covered issues and concepts of IC design with two invited talks on RF design and cryptography.The conference included presentations from several companies active in the field of microelectronics and systems in Greece.

Intelligent agents: adaptation of autonomous bimodal microsystems

NASA Astrophysics Data System (ADS)

Smith, Patrice; Terry, Theodore B.

2014-03-01

Autonomous bimodal microsystems exhibiting survivability behaviors and characteristics are able to adapt dynamically in any given environment. Equipped with a background blending exoskeleton it will have the capability to stealthily detect and observe a self-chosen viewing area while exercising some measurable form of selfpreservation by either flying or crawling away from a potential adversary. The robotic agent in this capacity activates a walk-fly algorithm, which uses a built in multi-sensor processing and navigation subsystem or algorithm for visual guidance and best walk-fly path trajectory to evade capture or annihilation. The research detailed in this paper describes the theoretical walk-fly algorithm, which broadens the scope of spatial and temporal learning, locomotion, and navigational performances based on optical flow signals necessary for flight dynamics and walking stabilities. By observing a fly's travel and avoidance behaviors; and, understanding the reverse bioengineering research efforts of others, we were able to conceptualize an algorithm, which works in conjunction with decisionmaking functions, sensory processing, and sensorimotor integration. Our findings suggest that this highly complex decentralized algorithm promotes inflight or terrain travel mobile stability which is highly suitable for nonaggressive micro platforms supporting search and rescue (SAR), and chemical and explosive detection (CED) purposes; a necessity in turbulent, non-violent structured or unstructured environments.

Inverse problem analysis for identification of reaction kinetics constants in microreactors for biodiesel synthesis

NASA Astrophysics Data System (ADS)

Pontes, P. C.; Naveira-Cotta, C. P.

2016-09-01

The theoretical analysis for the design of microreactors in biodiesel production is a complicated task due to the complex liquid-liquid flow and mass transfer processes, and the transesterification reaction that takes place within these microsystems. Thus, computational simulation is an important tool that aids in understanding the physical-chemical phenomenon and, consequently, in determining the suitable conditions that maximize the conversion of triglycerides during the biodiesel synthesis. A diffusive-convective-reactive coupled nonlinear mathematical model, that governs the mass transfer process during the transesterification reaction in parallel plates microreactors, under isothermal conditions, is here described. A hybrid numerical-analytical solution via the Generalized Integral Transform Technique (GITT) for this partial differential system is developed and the eigenfunction expansions convergence rates are extensively analyzed and illustrated. The heuristic method of Particle Swarm Optimization (PSO) is applied in the inverse analysis of the proposed direct problem, to estimate the reaction kinetics constants, which is a critical step in the design of such microsystems. The results present a good agreement with the limited experimental data in the literature, but indicate that the GITT methodology combined with the PSO approach provide a reliable computational algorithm for direct-inverse analysis in such reactive mass transfer problems.

Polyimide as a versatile enabling material for microsystems fabrication: surface micromachining and electrodeposited nanowires integration

NASA Astrophysics Data System (ADS)

Walewyns, Thomas; Reckinger, Nicolas; Ryelandt, Sophie; Pardoen, Thomas; Raskin, Jean-Pierre; Francis, Laurent A.

2013-09-01

The interest of using polyimide as a sacrificial and anchoring layer is demonstrated for post-processing surface micromachining and for the incorporation of metallic nanowires into microsystems. In addition to properties like a high planarization factor, a good resistance to most non-oxidizing acids and bases, and CMOS compatibility, polyimide can also be used as a mold for nanostructures after ion track-etching. Moreover, specific polyimide grades, such as PI-2611 from HD Microsystems™, involve a thermal expansion coefficient similar to silicon and low internal stress. The process developed in this study permits higher gaps compared to the state-of-the-art, limits stiction problems with the substrate and is adapted to various top-layer materials. Most metals, semiconductors or ceramics will not be affected by the oxygen plasma required for polyimide etching. Released structures with vertical gaps from one to several tens of μm have been obtained, possibly using multiple layers of polyimide. Furthermore, patterned freestanding nanowires have been synthesized with diameters from 20 to 60 nm and up to 3 μm in length. These results have been applied to the fabrication of two specific devices: a generic nanomechanical testing lab-on-chip platform and a miniaturized ionization sensor.

TOPICAL REVIEW: Microsystem technologies for implantable applications

NASA Astrophysics Data System (ADS)

Receveur, Rogier A. M.; Lindemans, Fred W.; de Rooij, Nicolaas F.

2007-05-01

Microsystem technologies (MST) have become the basis of a large industry. The advantages of MST compared to other technologies provide opportunities for application in implantable biomedical devices. This paper presents a general and broad literature review of MST for implantable applications focused on the technical domain. A classification scheme is introduced to order the examples, basic technological building blocks relevant for implantable applications are described and finally a case study on the role of microsystems for one clinical condition is presented. We observe that the microfabricated parts span a wide range for implantable applications in various clinical areas. There are 94 active and 67 commercial 'end items' out of a total of 142. End item refers to the total concept, of which the microsystem may only be a part. From the 105 active end items 18 (13% of total number of end items) are classified as products. From these 18 products, there are only two for chronic use. The number of active end items in clinical, animal and proto phase for chronic use is 17, 13 and 20, respectively. The average year of first publication of chronic end items that are still in the animal or clinical phase is 1994 (n = 7) and 1993 (n = 11), respectively. The major technology market combinations are sensors for cardiovascular, drug delivery for drug delivery and electrodes for neurology and ophthalmology. Together these form 51% of all end items. Pressure sensors form the majority of sensors and there is just one product (considered to be an implantable microsystem) in the neurological area. Micro-machined ceramic packages, glass sealed packages and polymer encapsulations are used. Glass to metal seals are used for feedthroughs. Interconnection techniques such as flip chip, wirebonding or conductive epoxy as used in the semiconductor packaging and assembly industry are also used for manufacturing of implantable devices. Coatings are polymers or metal. As an alternative to implantable primary batteries, rechargeable batteries were introduced or concepts in which energy is provided from the outside based on inductive coupling. Long-term developments aiming at autonomous power are, for example, based on electrostatic conversion of mechanical vibrations. Communication with the implantable device is usually done using an inductive link. A large range of materials commonly used in microfabrication are also used for implantable microsystems.

Optofluidic Microsystems for Chemical and Biological Analysis

PubMed Central

Fan, Xudong; White, Ian M.

2011-01-01

Optofluidics – the synergistic integration of photonics and microfluidics – has recently emerged as a new analytical field that provides a number of unique characteristics for enhanced sensing performance and simplification of microsystems. In this review, we describe various optofluidic architectures developed in the past five years, emphasize the mechanisms by which optofluidics enhances bio/chemical analysis capabilities, including sensing and the precise control of biological micro/nanoparticles, and envision new research directions to which optofluidics leads. PMID:22059090

Dual-polarized light-field imaging micro-system via a liquid-crystal microlens array for direct three-dimensional observation.

PubMed

Xin, Zhaowei; Wei, Dong; Xie, Xingwang; Chen, Mingce; Zhang, Xinyu; Liao, Jing; Wang, Haiwei; Xie, Changsheng

2018-02-19

Light-field imaging is a crucial and straightforward way of measuring and analyzing surrounding light worlds. In this paper, a dual-polarized light-field imaging micro-system based on a twisted nematic liquid-crystal microlens array (TN-LCMLA) for direct three-dimensional (3D) observation is fabricated and demonstrated. The prototyped camera has been constructed by integrating a TN-LCMLA with a common CMOS sensor array. By switching the working state of the TN-LCMLA, two orthogonally polarized light-field images can be remapped through the functioned imaging sensors. The imaging micro-system in conjunction with the electric-optical microstructure can be used to perform polarization and light-field imaging, simultaneously. Compared with conventional plenoptic cameras using liquid-crystal microlens array, the polarization-independent light-field images with a high image quality can be obtained in the arbitrary polarization state selected. We experimentally demonstrate characters including a relatively wide operation range in the manipulation of incident beams and the multiple imaging modes, such as conventional two-dimensional imaging, light-field imaging, and polarization imaging. Considering the obvious features of the TN-LCMLA, such as very low power consumption, providing multiple imaging modes mentioned, simple and low-cost manufacturing, the imaging micro-system integrated with this kind of liquid-crystal microstructure driven electrically presents the potential capability of directly observing a 3D object in typical scattering media.

Pressure activated interconnection of micro transfer printed components

NASA Astrophysics Data System (ADS)

Prevatte, Carl; Guven, Ibrahim; Ghosal, Kanchan; Gomez, David; Moore, Tanya; Bonafede, Salvatore; Raymond, Brook; Trindade, António Jose; Fecioru, Alin; Kneeburg, David; Meitl, Matthew A.; Bower, Christopher A.

2016-05-01

Micro transfer printing and other forms of micro assembly deterministically produce heterogeneously integrated systems of miniaturized components on non-native substrates. Most micro assembled systems include electrical interconnections to the miniaturized components, typically accomplished by metal wires formed on the non-native substrate after the assembly operation. An alternative scheme establishing interconnections during the assembly operation is a cost-effective manufacturing method for producing heterogeneous microsystems, and facilitates the repair of integrated microsystems, such as displays, by ex post facto addition of components to correct defects after system-level tests. This letter describes pressure-concentrating conductor structures formed on silicon (1 0 0) wafers to establish connections to preexisting conductive traces on glass and plastic substrates during micro transfer printing with an elastomer stamp. The pressure concentrators penetrate a polymer layer to form the connection, and reflow of the polymer layer bonds the components securely to the target substrate. The experimental yield of series-connected test systems with >1000 electrical connections demonstrates the suitability of the process for manufacturing, and robustness of the test systems against exposure to thermal shock, damp heat, and mechanical flexure shows reliability of the resulting bonds.

Towards an implantable bio-sensor platform for continuous real-time monitoring of anti-epileptic drugs.

PubMed

Hammoud, Abbas; Chamseddine, Ahmad; Nguyen, Dang K; Sawan, Mohamad

2016-08-01

The need of continuous real-time monitoring device for in-vivo drug level detection has been widely articulated lately. Such monitoring could guide drug posology and timing of intake, detect low or high drug levels, in order to take adequate measures, and give clinicians a valuable window into patients' health and their response to therapeutics. This paper presents a novel implantable bio-sensor based on impedance measurement capable of continuously monitoring various antiepileptic drug levels. This portable point-of-care microsystem replaces large and stationary conventional macrosystems, and is a one of a kind system designed with an array of electrodes to monitor various anti-epileptic drugs rather than one drug. The micro-system consists of (i) the front-end circuit including an inductive coil to receive energy from an external base station, and to exchange data with the latter; (ii) the power management block; (iii) the readout and control block; and (iv) the biosensor array. The electrical circuitry was designed using the 0.18-um CMOS process technology intended to be miniature and consume ultra-low power.

A 4 μW/Ch analog front-end module with moderate inversion and power-scalable sampling operation for 3-D neural microsystems.

PubMed

Al-Ashmouny, Khaled M; Chang, Sun-Il; Yoon, Euisik

2012-10-01

We report an analog front-end prototype designed in 0.25 μm CMOS process for hybrid integration into 3-D neural recording microsystems. For scaling towards massive parallel neural recording, the prototype has investigated some critical circuit challenges in power, area, interface, and modularity. We achieved extremely low power consumption of 4 μW/channel, optimized energy efficiency using moderate inversion in low-noise amplifiers (K of 5.98 × 10⁸ or NEF of 2.9), and minimized asynchronous interface (only 2 per 16 channels) for command and data capturing. We also implemented adaptable operations including programmable-gain amplification, power-scalable sampling (up to 50 kS/s/channel), wide configuration range (9-bit) for programmable gain and bandwidth, and 5-bit site selection capability (selecting 16 out of 128 sites). The implemented front-end module has achieved a reduction in noise-energy-area product by a factor of 5-25 times as compared to the state-of-the-art analog front-end approaches reported to date.

Medical capability team: the clinical microsystem for combat healthcare delivery in counterinsurgency operations.

PubMed

Clark, Susz; Van Steenvort, Jon K

2008-01-01

Today's operational environment in the support of counterinsurgency operations requires greater tactical and operational flexibility and diverse medical capabilities. The skills and organizations required for full spectrum medical operations are different from those of the past. Combat healthcare demands agility and the capacity for rapid change in clinical systems and processes to better support the counterinsurgency environment. This article proposes the Army Medical Department (AMEDD) develop and implement the medical capability team (MCT) for combat healthcare delivery. It discusses using the concept of the brigade combat team to develop medical capability teams as the unit of effectiveness to transform frontline care; provides a theoretical overview of the MCT as a "clinical microsystem"; discusses MCT leadership, training, and organizational support, and the deployment and employment of the MCT in a counterinsurgency environment. Additionally, this article proposes that the AMEDD initiate the development of an AMEDD Combat Training Center of Excellence to train and validate the MCTs. The complexity of combat healthcare demands an agile and campaign quality AMEDD with joint expeditionary capability in order to promote the best patient outcomes in a counterinsurgency environment.

3D packaging of a microfluidic system with sensory applications

NASA Astrophysics Data System (ADS)

Morrissey, Anthony; Kelly, Gerard; Alderman, John C.

1997-09-01

Among the main benefits of microsystem technology are its contributions to cost reductio, reliability and improved performance. however, the packaging of microsystems, and particularly microsensor, has proven to be one of the biggest limitations to their commercialization and the packaging of silicon sensor devices can be the most costly part of their fabrication. This paper describes the integration of 3D packaging of a microsystem. Central to the operation of the 3D demonstrator is a micromachined silicon membrane pump to supply fluids to a sensing chamber constructed about the active area of a sensor chip. This chip carries ISFET based chemical sensors, pressure sensors and thermal sensors. The electronics required for controlling and regulating the activity of the various sensors ar also available on this chip and as other chips in the 3D assembly. The demonstrator also contains a power supply module with optical fiber interconnections. All of these modules are integrated into a single plastic- encapsulated 3D vertical multichip module. The reliability of such a structure, initially proposed by Val was demonstrated by Barrett et al. An additional module available for inclusion in some of our assemblies is a test chip capable of measuring the packaging-induced stress experienced during and after assembly. The packaging process described produces a module with very high density and utilizes standard off-the-shelf components to minimize costs. As the sensor chip and micropump include micromachined silicon membranes and microvalves, the packaging of such structures has to allow consideration for the minimization of the packaging-induced stresses. With this in mind, low stress techniques, including the use of soft glob-top materials, were employed.

Testing a bioecological model to examine social support in postpartum adolescents.

PubMed

Logsdon, M Cynthia; Ziegler, Craig; Hertweck, Paige; Pinto-Foltz, Melissa

2008-01-01

The purpose was twofold and included examining a bioecological model as a framework to describe social support in postpartum adolescents. The second purpose was to determine the relationship between a comprehensive view of the context of social support and symptoms of depression. Cross-sectional design with convenience sampling (n=85) of adolescents at 4-6 weeks postpartum, recruited from two community hospitals. Approval was received from the university's IRB (institutional review board), each recruitment site, the adolescent mothers, and their parents or guardians. Data were collected by a research assistant during home visits using a battery of self-report instruments to measure macro, meso, and microsystems of social support. Demographics, exposure to community violence (macrosystem), social support, social network (mesosystem), and perceived stress, mastery, and self-esteem (microsystem) were predictor variables. Depressive symptoms were measured by using the Center for Epidemiologic Studies of Depression (CES-D) Scale. Variables from each system were significant predictors of depressive symptoms but perceived stress was the strongest predictor. Many postpartum adolescents reported that they had been victims of violence. Significant symptoms of depression were identified in 37% of the postpartum adolescents. Context is important to consider in comparing international studies of social support. Researchers and clinicians should investigate variables associated with the low incidence of treatment for depressive symptoms in postpartum adolescents. Feelings of high self-esteem and mastery should be fostered in nursing interventions with postpartum adolescents and routine screening for symptoms of depression should be considered in relevant healthcare settings.

General order of the origin of life in the Universe

NASA Astrophysics Data System (ADS)

Kompanichenko, V. N.

2007-08-01

The principal succession of transformations of organic matter leading to its transition into the primary living units is theoretically substantiated in the framework of the systemic approach to the origin of life (Kompanichenko, 2004). The succession is conditionally divided into three stages. For 1st stage significant change of conditions in the host aquatic medium constrains an organic prebiotic microsystem to leave the current stable state with the following transition into a new stable state through the unstable critical (bifurcation) point. At the critical point the microsystem acquires the original properties without of which life cannot exist (self-maintaining heterogeneous structure, incessant fluctuations and rearrangement of molecules, exchange with the surroundings by matter and energy, etc.). During 2nd stage its unstable (nonequilibrium) state relatively stabilizes by means of the balanced oscillations around the bifurcation point (there appears the paradoxical state "stabilized instability"). In this way the microsystem keeps the original critical properties and acquires biforked structure. This rare and unusual type of natural systems was called a bistate system. 3rd stage is characterized with the radical turn in the network of chemical reactions (from in Vitro into in Vivo): the free energy contribution begins to prevail over entropy contribution. As a result, constructive transformations proceed faster than destructive ones. Just at this stage the key properties of biological organization appeared: the ability to concentrate free energy and information, ability for intensified counteraction to external influences, expedient behaviour, persistent self-renovating. In accordance with the conception, on the early Earth such successive transformation of organic matter occurred in the changeable conditions of hydrothermal medium. Most of the scientific knowledge that was put in background of the elaborated systemic conception of the origin of life covers not only to Earth, but to processes in the vast explored Universe too. The used key notions "free energy" and "entropy" are universal and characterize ability or disability of a natural system to carry out work elsewhere. For instance, outbreak of ash by active volcanoes on Earth and Jupiter's satellite Io is the same kind of work that can be approximately evaluated in terms of the spent free energy. The opposite spontaneous and non-spontaneous processes are universal as well. They are described the transition of a natural system to more or less probable state correspondingly. Cooling of a lava flow on Earth and cooling of the entire Mars planet are similar processes related with the spontaneous process - heat conductivity. All stars, planets and other space bodies in the Universe are composed of about one hundred elements systematized in the Periodic Table. In this context behaviour of chemical systems elsewhere in the explored Universe should comply with the fundamental laws determined on Earth, in particular with the Le Chatelier principle, Onsager theorem and the theory of dissipative structures used in this work. For example, outflow of matter from a star occurs simultaneously with outflow of heat energy (i.e. they are interdependent processes) as it follows of the Onsager theorem. The organic microsystems, which are considered as prebiotic for the early Earth, composed of diverse organic compounds that were detected in the space and meteorites (from simple hydrocarbons up to amino acids). Taking these reasons into account, the distinguished three stages in principle can be considered in the context of a general scenario of the origin of life in the Universe. Some new ways of the experimental research in the origin of life field are suggested. The first of them is laboratory experimental research of diverse prebiotic models at the state of bifurcate transition and under oscillating conditions in the experimental chamber. The goal of the experiments is to corroborate or demolish the thesis about real existence of the bistate type of natural systems, including its "prebiotic version" useful to evolve to life. One more way consists in natural experimental exploration of changeability of the thermodynamic and physic-chemical parameters (pressure, temperature, concentrations of compounds, pH, Eh) in submarine and terrestrial hydrothermal systems, including amplitudes, frequencies, and periods of the oscillations. Also it is important to determine how the hydrothermal oscillations depend on the close volcanic and tectonic (seismic) events. The events were much more intensive on the early Earth, and might significantly influence a scale of the fluctuations. These investigations are aimed to characterize the probable geological Cradle of life with the following using the obtained data to conduct laboratory experiments. This information can be important for evaluation of possible life arising on other Earth-like planets at the early stage of their geological evolution, including the extrasolar planet Gliese 581 C discovered just recently. Reference. Kompanichenko V.N. (2004) Systemic approach to the origin of life. Frontier Perspectives, 13/1, 22-40.

Electronics for better healthcare.

PubMed

Wolf, Bernhard; Herzog, Karolin

2013-06-01

Microelectronics and microsystem technology have changed our daily lives considerably in the past 50 years. Countless everyday objects contain microelectronic components. In healthcare up to the present, however, it has not been possible to make major alterations in introducing electronics and information technology that would lead to innovative improvements and greater transparency. This paper describes initial steps in diagnostics and oncological therapy including telematic healthcare systems which can, for example, assist patients with cardiovascular diseases and shows, through these areas, how electronics and microsystems technology can contribute to better healthcare.

Micro-System Technology for X-ray Astronomy

NASA Technical Reports Server (NTRS)

Schattenburg, Mark L.

2002-01-01

This research investigation was devoted to developing micro-system and nanotechnology for x-ray astronomy optics. The goal was to develop and demonstrate new types of lightweight, high accuracy x-ray optics for future high throughput, high resolution x-ray telescopes such as Constellation X (Con-X) and MAXIM. A number of significant accomplishments were reported under this program, which are summarized below. Most of this work has been reported in journal and conference proceedings and in presentations to NASA and at international meeting (see Bibliography).

Optimized microsystems-enabled photovoltaics

DOEpatents

Cruz-Campa, Jose Luis; Nielson, Gregory N.; Young, Ralph W.; Resnick, Paul J.; Okandan, Murat; Gupta, Vipin P.

2015-09-22

Technologies pertaining to designing microsystems-enabled photovoltaic (MEPV) cells are described herein. A first restriction for a first parameter of an MEPV cell is received. Subsequently, a selection of a second parameter of the MEPV cell is received. Values for a plurality of parameters of the MEPV cell are computed such that the MEPV cell is optimized with respect to the second parameter, wherein the values for the plurality of parameters are computed based at least in part upon the restriction for the first parameter.

Development and Packaging of Microsystems Using Foundry Services

DTIC Science & Technology

1998-06-01

DEVELOPMENT AND PACKAGING OF MICROSYSTEMS USING FOUNDRY SERVICES Jeffrey T. Butler, BSEE, MSEE Captain, USAF Approved: Paul H . Ostdiek, PhD, Lt...structural polysilicon layers. CMOS Device Area Micromechanical Device Area arsenic-daped epitaxial layer >J1M* ’ MM t° H 0J n-type ailioon...Ö ♦ * ♦ m B 1 —i ft H 035 0.045 0.055 0.065 0.075 Power Applied to Driver (W) (b) Figure 4-4. (a) Driver output loading

X-ray photonic microsystems for the manipulation of synchrotron light

DOE PAGES

Mukhopadhyay, D.; Walko, D. A.; Jung, I. W.; ...

2015-05-05

In this study, photonic microsystems played an essential role in the development of integrated photonic devices, thanks to their unique spatiotemporal control and spectral shaping capabilities. Similar capabilities to markedly control and manipulate X-ray radiation are highly desirable but practically impossible due to the massive size of the silicon single-crystal optics currently used. Here we show that micromechanical systems can be used as X-ray optics to create and preserve the spatial, temporal and spectral correlation of the X-rays. We demonstrate that, as X-ray reflective optics they can maintain the wavefront properties with nearly 100% reflectivity, and as a dynamic diffractivemore » optics they can generate nanosecond time windows with over 100-kHz repetition rates. Since X-ray photonic microsystems can be easily incorporated into lab-based and next-generation synchrotron X-ray sources, they bring unprecedented design flexibility for future dynamic and miniature X-ray optics for focusing, wavefront manipulation, multicolour dispersion, and pulse slicing.« less

Improving chemotherapy for patients with advanced non-small cell lung cancer.

PubMed

von Plessen, Christian

2011-01-01

Lung cancer is the third most common mortal disease in industrialised countries and the prognosis has been slow to improve. The largest subgroup has locally advanced or metastatic non-small cell lung cancer (NSCLC). Unfortunately, these patients can usually not be cured and the main treatment option is palliative chemotherapy. Given the palliative intention of the chemotherapy, it is clinically highly relevant to establish the optimal treatment duration. While chemotherapy prolongs survival and improves quality of life (QoL), it also has side effects and only a minority of patients achieve an objective treatment response. Clinicians need guidance on treatment duration from controlled trials to balance these aspects. Improvements of the conditions under which chemotherapy is given can increase patient and staff satisfaction and increase system performance. This is especially relevant to incurable patients who spend a lot of their limited time at oncology outpatient clinics. Staffing, infrastructure and organisation of these units are often suboptimal to serve patients with palliative needs and reports of improvement projects can inspire and guide clinicians in improving their microsystems of care. Clinicians, health care administrators and the public need knowledge about the outcomes of palliative chemotherapy in unselected patient populations. The efficacy of palliative chemotherapy for advanced NSCLC has been amply documented in controlled clinical trials. Meanwhile, the elderly and patients with higher performance status have usually been under-represented in these trials and population studies of the effectiveness of chemotherapy are needed. (i) To establish the optimal duration of platinum-based first line chemotherapy for advanced NSCLC; (ii) To improve the care processes at an oncology outpatient clinical microsystem; (iii) To describe the use of chemotherapy in a national population and investigate associations between chemotherapy use and survival; and (iv) To explore approaches to improve the system of chemotherapy from the macro perspective of a whole country. The thesis combines methods from different knowledge domains. In a randomised trial, we compared three with six courses of platinum-based chemotherapy for advanced NSCLC. In a quality improvement study, we used logistic improvement tools, qualitative and quantitative patient and staff satisfaction measurements. Finally using data from the Norwegian cancer and chemotherapy registries, we investigated temporary and geographical variations of chemotherapy use and correlations with the survival of patients with advanced NSCLC. Methods and findings from the three studies were explored to inform a national improvement strategy for the chemotherapy of advanced NSCLC. Survival and QoL were equal with three or six courses of chemotherapy for advanced NSCLC. Systematic process changes at the outpatient clinic led to increased patient and staff satisfaction. Furthermore, the study illustrates the application of established process improvement and evaluation tools in a clinical microsystem. In the registry study, we found delays of the introduction of palliative chemotherapy in Norway and significant associations between the use of chemotherapy and the survival of patients with advanced NSCLC. The general section of the thesis describes approaches to system-wide improvements and introduces a quality improvement matrix. We conclude from our randomised trial and related research that chemotherapy beyond three courses is not beneficial for patients with advanced NSCLC. The report from the oncology outpatient clinic illustrates the value of the clinical microsystem approach for quality improvement at the front line of care. Patient feedback through a focus group, simple methods of assessing and simplifying processes of care, as well as measuring results over time were effective tools in our project. The description of the experiences can serve as an example for the improvement of microsystems in settings with similar problems. Finally, in the registry study of Norwegian patients with lung cancer, we found significant geographical and temporal variations of the utilisation of chemotherapy that were related to survival. Potential areas of improvement in the system of care for lung cancer are recruitment of patients in clinical studies, standardisation of the processes of care in outpatient clinics, definition of strategic aims of quality, development of balanced quality indicators, as well as measuring and reporting of outcomes by means of a quality registry. © 2010 Blackwell Publishing Ltd.

A Distributed Prognostic Health Management Architecture

NASA Technical Reports Server (NTRS)

Bhaskar, Saha; Saha, Sankalita; Goebel, Kai

2009-01-01

This paper introduces a generic distributed prognostic health management (PHM) architecture with specific application to the electrical power systems domain. Current state-of-the-art PHM systems are mostly centralized in nature, where all the processing is reliant on a single processor. This can lead to loss of functionality in case of a crash of the central processor or monitor. Furthermore, with increases in the volume of sensor data as well as the complexity of algorithms, traditional centralized systems become unsuitable for successful deployment, and efficient distributed architectures are required. A distributed architecture though, is not effective unless there is an algorithmic framework to take advantage of its unique abilities. The health management paradigm envisaged here incorporates a heterogeneous set of system components monitored by a varied suite of sensors and a particle filtering (PF) framework that has the power and the flexibility to adapt to the different diagnostic and prognostic needs. Both the diagnostic and prognostic tasks are formulated as a particle filtering problem in order to explicitly represent and manage uncertainties; however, typically the complexity of the prognostic routine is higher than the computational power of one computational element ( CE). Individual CEs run diagnostic routines until the system variable being monitored crosses beyond a nominal threshold, upon which it coordinates with other networked CEs to run the prognostic routine in a distributed fashion. Implementation results from a network of distributed embedded devices monitoring a prototypical aircraft electrical power system are presented, where the CEs are Sun Microsystems Small Programmable Object Technology (SPOT) devices.

A front-end wafer-level microsystem packaging technique with micro-cap array

NASA Astrophysics Data System (ADS)

Chiang, Yuh-Min

2002-09-01

The back-end packaging process is the remaining challenge for the micromachining industry to commercialize microsystem technology (MST) devices at low cost. This dissertation presents a novel wafer level protection technique as a final step of the front-end fabrication process for MSTs. It facilitates improved manufacturing throughput and automation in package assembly, wafer level testing of devices, and enhanced device performance. The method involves the use of a wafer-sized micro-cap array, which consists of an assortment of small caps micro-molded onto a material with adjustable shapes and sizes to serve as protective structures against the hostile environments during packaging. The micro-cap array is first constructed by a micromachining process with micro-molding technique, then sealed to the device wafer at wafer level. Epoxy-based wafer-level micro cap array has been successfully fabricated and showed good compatibility with conventional back-end packaging processes. An adhesive transfer technique was demonstrated to seal the micro cap array with a MEMS device wafer. No damage or gross leak was observed while wafer dicing or later during a gross leak test. Applications of the micro cap array are demonstrated on MEMS, microactuators fabricated using CRONOS MUMPS process. Depending on the application needs, the micro-molded cap can be designed and modified to facilitate additional component functions, such as optical, electrical, mechanical, and chemical functions, which are not easily achieved in the device by traditional means. Successful fabrication of a micro cap array comprised with microlenses can provide active functions as well as passive protection. An optical tweezer array could be one possibility for applications of a micro cap with microlenses. The micro cap itself could serve as micro well for DNA or bacteria amplification as well.

Microfluidic devices with thick-film electrochemical detection

DOEpatents

Wang, Joseph; Tian, Baomin; Sahlin, Eskil

2005-04-12

An apparatus for conducting a microfluidic process and analysis, including at least one elongated microfluidic channel, fluidic transport means for transport of fluids through the microfluidic channel, and at least one thick-film electrode in fluidic connection with the outlet end of the microfluidic channel. The present invention includes an integrated on-chip combination reaction, separation and thick-film electrochemical detection microsystem, for use in detection of a wide range of analytes, and methods for the use thereof.

CMOS Time-Resolved, Contact, and Multispectral Fluorescence Imaging for DNA Molecular Diagnostics

PubMed Central

Guo, Nan; Cheung, Ka Wai; Wong, Hiu Tung; Ho, Derek

2014-01-01

Instrumental limitations such as bulkiness and high cost prevent the fluorescence technique from becoming ubiquitous for point-of-care deoxyribonucleic acid (DNA) detection and other in-field molecular diagnostics applications. The complimentary metal-oxide-semiconductor (CMOS) technology, as benefited from process scaling, provides several advanced capabilities such as high integration density, high-resolution signal processing, and low power consumption, enabling sensitive, integrated, and low-cost fluorescence analytical platforms. In this paper, CMOS time-resolved, contact, and multispectral imaging are reviewed. Recently reported CMOS fluorescence analysis microsystem prototypes are surveyed to highlight the present state of the art. PMID:25365460

Optical microsystem for analyzing engine lubricants

NASA Astrophysics Data System (ADS)

Scott, Andrew J.; Mabesa, Jose R., Jr.; Gorsich, David; Rathgeb, Brian; Said, Ali A.; Dugan, Mark; Haddock, Tom F.; Bado, Philippe W.

2004-12-01

It is possible to dramatically improve the performance, reliability, and maintainability of vehicles and other similarly complex equipment if improved sensing and diagnostics systems are available. Each year military and commercial maintenance personnel unnecessarily replace, at scheduled intervals, significant amounts of lubricant fluids in vehicles, weapon systems, and supporting equipment. Personnel draw samples of fluids and send them to test labs for analysis to determine if replacement is necessary. Systematic use of either on-board (embedded) lubricant quality analysis capabilities will save millions of dollars each year in avoided fluid changes, saved labor, prevented damage to mechanical components while providing associated environmental benefits. This paper discusses the design, the manufacturing, and the evaluation of robust optical sensors designed to monitor the condition of industrial fluids. The sensors reported are manufactured from bulk fused silica substrates. They incorporate three-dimensional micro fluidic circuitry side-by-side with three-dimensional wave guided optical networks. The manufacturing of the optical waveguides are completed using a direct-write process based on the use of femtosecond laser pulses to locally alter the structure of the glass substrate at the nano-level. The microfluidic circuitry is produced using the same femtosecond laser based process, followed by an anisotropic wet chemical etching step. Data will be presented regarding the use of these sensors to monitor the quality of engine oil and possibly some other vehicle lubricants such as hydraulic oil.

Packaging Technology Designed, Fabricated, and Assembled for High-Temperature SiC Microsystems

NASA Technical Reports Server (NTRS)

Chen, Liang-Yu

2003-01-01

A series of ceramic substrates and thick-film metalization-based prototype microsystem packages designed for silicon carbide (SiC) high-temperature microsystems have been developed for operation in 500 C harsh environments. These prototype packages were designed, fabricated, and assembled at the NASA Glenn Research Center. Both the electrical interconnection system and the die-attach scheme for this packaging system have been tested extensively at high temperatures. Printed circuit boards used to interconnect these chip-level packages and passive components also are being fabricated and tested. NASA space and aeronautical missions need harsh-environment, especially high-temperature, operable microsystems for probing the inner solar planets and for in situ monitoring and control of next-generation aeronautical engines. Various SiC high-temperature-operable microelectromechanical system (MEMS) sensors, actuators, and electronics have been demonstrated at temperatures as high as 600 C, but most of these devices were demonstrated only in the laboratory environment partially because systematic packaging technology for supporting these devices at temperatures of 500 C and beyond was not available. Thus, the development of a systematic high-temperature packaging technology is essential for both in situ testing and the commercialization of high-temperature SiC MEMS. Researchers at Glenn developed new prototype packages for high-temperature microsystems using ceramic substrates (aluminum nitride and 96- and 90-wt% aluminum oxides) and gold (Au) thick-film metalization. Packaging components, which include a thick-film metalization-based wirebond interconnection system and a low-electrical-resistance SiC die-attachment scheme, have been tested at temperatures up to 500 C. The interconnection system composed of Au thick-film printed wire and 1-mil Au wire bond was tested in 500 C oxidizing air with and without 50-mA direct current for over 5000 hr. The Au thick-film metalization-based wirebond electrical interconnection system was also tested in an extremely dynamic thermal environment to assess thermal reliability. The I-V curve1 of a SiC high-temperature diode was measured in oxidizing air at 500 C for 1000 hr to electrically test the Au thick-film material-based die-attach assembly.

A CMOS-MEMS clamped–clamped beam displacement amplifier for resonant switch applications

NASA Astrophysics Data System (ADS)

Liu, Jia-Ren; Lu, Shih-Chuan; Tsai, Chun-Pu; Li, Wei-Chang

2018-06-01

This paper presents a micromechanical clamped–clamped beam (CC-beam) displacement amplifier based on a CMOS-MEMS fabrication process platform. In particular, a 2.0 MHz resonant displacement amplifier composed of two identical CC-beams coupled by a mechanical beam at locations where the two beams have mismatched velocities exhibits a larger displacement, up to 9.96×, on one beam than that of the other. The displacement amplification prevents unwanted input impacting—the structure switches only to the output but not the input—required by resonant switch-based mechanical circuits (Kim et al 2009 22nd IEEE Int. Conf. on Micro Electro Mechanical Systems; Lin et al 2009 15th Int. Conf. on Solid-State Sensors, Actuators, & Microsystems (TRANSDUCERS’09) Li et al 2013 17th Int. Conf. on Solid-State Sensors, Actuators, & Microsystems (TRANSDUCERS’13)). Compared to a single CC-beam displacement amplifier, theory predicts that the displacement amplifying CC-beam array yields a larger overall output displacement for displacement gain beyond 1.13 thanks to the preserved input driving force. A complete analytical model predicts the resultant stiffness and displacement gain of the coupled CC-beam displacement amplifier that match well with finite element analysis (FEA) prediction and measured results.

Through-wafer optical probe characterization for microelectromechanical systems positional state monitoring and feedback control

NASA Astrophysics Data System (ADS)

Dawson, Jeremy M.; Chen, Jingdong; Brown, Kolin S.; Famouri, Parviz F.; Hornak, Lawrence A.

2000-12-01

Implementation of closed-loop microelectromechanical system (MEMS) control enables mechanical microsystems to adapt to the demands of the environment that they are actuating, opening a broad range of new opportunities for future MEMS applications. Integrated optical microsystems have the potential to enable continuous in situ optical interrogation of MEMS microstructure position fully decoupled from the means of mechanical actuation that is necessary for realization of feedback control. We present the results of initial research evaluating through-wafer optical microprobes for surface micromachined MEMS integrated optical position monitoring. Results from the through-wafer free-space optical probe of a lateral comb resonator fabricated using the multiuser MEMS process service (MUMPS) indicate significant positional information content with an achievable return probe signal dynamic range of up to 80% arising from film transmission contrast. Static and dynamic deflection analysis and experimental results indicate a through-wafer probe positional signal sensitivity of 40 mV/micrometers for the present setup or 10% signal change per micrometer. A simulation of the application of nonlinear sliding control is presented illustrating position control of the lateral comb resonator structure given the availability of positional state information.

Autonomous Microsystems for Downhole Applications: Design Challenges, Current State, and Initial Test Results

PubMed Central

Choi, Myungjoon; Sui, Yu; Lee, In Hee; Meredith, Ryan; Ma, Yushu; Kim, Gyouho; Blaauw, David; Gianchandani, Yogesh B.; Li, Tao

2017-01-01

This paper describes two platforms for autonomous sensing microsystems that are intended for deployment in chemically corrosive environments at elevated temperatures and pressures. Following the deployment period, the microsystems are retrieved, recharged, and interrogated wirelessly at close proximity. The first platform is the Michigan Micro Mote for High Temperature (M3HT), a chip stack 2.9 × 1.1 × 1.5 mm3 in size. It uses RF communications to support pre-deployment and post-retrieval functions, and it uses customized electronics to achieve ultralow power consumption, permitting the use of a chip-scale battery. The second platform is the Environmental Logging Microsystem (ELM). This system, which is 6.5 × 6.3 × 4.5 mm3 in size, uses the smallest suitable off-the-shelf electronic and battery components that are compatible with assembly on a flexible printed circuit board. Data are stored in non-volatile memory, permitting retrieval even after total power loss. Pre-deployment and post-retrieval functions are supported by optical communication. Two types of encapsulation methods are used to withstand high pressure and corrosive environments: an epoxy filled volume is used for the M3HT, and a hollow stainless-steel shell with a sapphire lid is used for both the M3HT and ELM. The encapsulated systems were successfully tested at temperature and pressure reaching 150 °C and 10,000 psi, in environments of concentrated brine, oil, and cement slurry. At elevated temperatures, the limited lifetimes of available batteries constrain the active deployment period to several hours. PMID:28946614

Design and manufacturing challenges of optogenetic neural interfaces: a review

NASA Astrophysics Data System (ADS)

Goncalves, S. B.; Ribeiro, J. F.; Silva, A. F.; Costa, R. M.; Correia, J. H.

2017-08-01

Optogenetics is a relatively new technology to achieve cell-type specific neuromodulation with millisecond-scale temporal precision. Optogenetic tools are being developed to address neuroscience challenges, and to improve the knowledge about brain networks, with the ultimate aim of catalyzing new treatments for brain disorders and diseases. To reach this ambitious goal the implementation of mature and reliable engineered tools is required. The success of optogenetics relies on optical tools that can deliver light into the neural tissue. Objective/Approach: Here, the design and manufacturing approaches available to the scientific community are reviewed, and current challenges to accomplish appropriate scalable, multimodal and wireless optical devices are discussed. Significance: Overall, this review aims at presenting a helpful guidance to the engineering and design of optical microsystems for optogenetic applications.

Application of Electro Chemical Machining for materials used in extreme conditions

NASA Astrophysics Data System (ADS)

Pandilov, Z.

2018-03-01

Electro-Chemical Machining (ECM) is the generic term for a variety of electrochemical processes. ECM is used to machine work pieces from metal and metal alloys irrespective of their hardness, strength or thermal properties, through the anodic dissolution, in aerospace, automotive, construction, medical equipment, micro-systems and power supply industries. The Electro Chemical Machining is extremely suitable for machining of materials used in extreme conditions. General overview of the Electro-Chemical Machining and its application for different materials used in extreme conditions is presented.

Uncooled Cantilever Microbolometer Focal Plane Arrays with mK Temperature Resolution: Engineering Mechanics for the Next Generation

DTIC Science & Technology

2009-11-25

34Nanoindentation Stress-Strain Curves of Plasma Enhanced Chemical Vapor Deposited Silicon Oxide Thin Films," Thin Solid Films, 516 (8) (2008) 1941-1951. 9. S...1604. 5. Z. Cao* and X. Zhang, "Measurement of Stress-Strain Curves of PECVD Silicon Oxide Thin Films by Means of Nanoindentation," in Processing...Microsystems (Transducers 󈧋), Lyon, France, June 10-14, 2007. 9. Z. Cao* and X. Zhang, “Measurement of Stress-strain Curves of PECVD Silicon Oxide

Deep Etching Process Developed for the Fabrication of Silicon Carbide Microsystems

NASA Technical Reports Server (NTRS)

Beheim, Glenn M.

2000-01-01

Silicon carbide (SiC), because of its superior electrical and mechanical properties at elevated temperatures, is a nearly ideal material for the microminiature sensors and actuators that are used in harsh environments where temperatures may reach 600 C or greater. Deep etching using plasma methods is one of the key processes used to fabricate silicon microsystems for more benign environments, but SiC has proven to be a more difficult material to etch, and etch depths in SiC have been limited to several micrometers. Recently, the Sensors and Electronics Technology Branch at the NASA Glenn Research Center at Lewis Field developed a plasma etching process that was shown to be capable of etching SiC to a depth of 60 mm. Deep etching of SiC is achieved by inductive coupling of radiofrequency electrical energy to a sulfur hexafluoride (SF6) plasma to direct a high flux of energetic ions and reactive fluorine atoms to the SiC surface. The plasma etch is performed at a low pressure, 5 mtorr, which together with a high gas throughput, provides for rapid removal of the gaseous etch products. The lateral topology of the SiC microstructure is defined by a thin film of etch-resistant material, such as indium-tin-oxide, which is patterned using conventional photolithographic processes. Ions from the plasma bombard the exposed SiC surfaces and supply the energy needed to initiate a reaction between SiC and atomic fluorine. In the absence of ion bombardment, no reaction occurs, so surfaces perpendicular to the wafer surface (the etch sidewalls) are etched slowly, yielding the desired vertical sidewalls.

Final report on LDRD project : narrow-linewidth VCSELs for atomic microsystems.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chow, Weng Wah; Geib, Kent Martin; Peake, Gregory Merwin

2011-09-01

Vertical-cavity surface-emitting lasers (VCSELs) are well suited for emerging photonic microsystems due to their low power consumption, ease of integration with other optical components, and single frequency operation. However, the typical VCSEL linewidth of 100 MHz is approximately ten times wider than the natural linewidth of atoms used in atomic beam clocks and trapped atom research, which degrades or completely destroys performance in those systems. This report documents our efforts to reduce VCSEL linewidths below 10 MHz to meet the needs of advanced sub-Doppler atomic microsystems, such as cold-atom traps. We have investigated two complementary approaches to reduce VCSEL linewidth:more » (A) increasing the laser-cavity quality factor, and (B) decreasing the linewidth enhancement factor (alpha) of the optical gain medium. We have developed two new VCSEL devices that achieved increased cavity quality factors: (1) all-semiconductor extended-cavity VCSELs, and (2) micro-external-cavity surface-emitting lasers (MECSELs). These new VCSEL devices have demonstrated linewidths below 10 MHz, and linewidths below 1 MHz seem feasible with further optimization.« less

A comparative framework for maneuverability and gust tolerance of aerial microsystems

NASA Astrophysics Data System (ADS)

Campbell, Renee

Aerial microsystems have the potential of navigating low-altitude, cluttered environments such as urban corridors and building interiors. Reliable systems require both agility and tolerance to gusts. While many platform designs are under development, no framework currently exists to quantitatively assess these inherent bare airframe characteristics which are independent of closed loop controllers. This research develops a method to quantify the maneuverability and gust tolerance of vehicles using reachability and disturbance sensitivity sets. The method is applied to a stable flybar helicopter and an unstable flybarless helicopter, whose state space models were formed through system identification. Model-based static H∞ controllers were also implemented on the vehicles and tested in the lab using fan-generated gusts. It is shown that the flybar restricts the bare airframe's ability to maneuver in translational velocity directions. As such, the flybarless helicopter proved more maneuverable and gust tolerant than the flybar helicopter. This approach was specifically applied here to compare stable and unstable helicopter platforms; however, the framework may be used to assess a broad range of aerial microsystems.

Separation and sorting of cells in microsystems using physical principles

NASA Astrophysics Data System (ADS)

Lee, Gi-Hun; Kim, Sung-Hwan; Ahn, Kihoon; Lee, Sang-Hoon; Park, Joong Yull

2016-01-01

In the last decade, microfabrication techniques have been combined with microfluidics and applied to cell biology. Utilizing such new techniques, various cell studies have been performed for the research of stem cells, immune cells, cancer, neurons, etc. Among the various biological applications of microtechnology-based platforms, cell separation technology has been highly regarded in biological and clinical fields for sorting different types of cells, finding circulating tumor cells (CTCs), and blood cell separation, amongst other things. Many cell separation methods have been created using various physical principles. Representatively, these include hydrodynamic, acoustic, dielectrophoretic, magnetic, optical, and filtering methods. In this review, each of these methods will be introduced, and their physical principles and sample applications described. Each physical principle has its own advantages and disadvantages. The engineers who design the systems and the biologists who use them should understand the pros and cons of each method or principle, to broaden the use of microsystems for cell separation. Continuous development of microsystems for cell separation will lead to new opportunities for diagnosing CTCs and cancer metastasis, as well as other elements in the bloodstream.

Interdisciplinary collaboration: the role of the clinical nurse leader.

PubMed

Bender, Miriam; Connelly, Cynthia D; Brown, Caroline

2013-01-01

  To explore the feasibility and acceptability of a clinical nurse leader (CNL) role to improve interdisciplinary collaboration (IC) within a fragmented acute-care microsystem.   Fragmented patient care is associated with preventable adverse healthcare outcomes. IC decreases fragmentation and improves patient care quality. The CNL role is theorized to provide the necessary leadership and competency skill base to impact IC at the optimal organizational level, the point of care where most healthcare decisions are made.   This study used a descriptive non-experimental design. CNL daily workflow was developed to target empirical determinants of IC. Descriptive data were collected from multiple stakeholders using an investigator-developed survey.   Findings indicate the integration of the role is feasible and acceptable to the microsystem healthcare team.   Preliminary evidence suggests the CNL role may be an effective intervention to facilitate IC. More research is needed to support the CNL role's association with microsystem IC.   The CNL role presents an innovative opportunity for clinical and administrative leadership to partner together to redesign a healthcare delivery system and improve patient care quality. © 2012 Blackwell Publishing Ltd.

Chalk-calcite-microfluidic experiments: construction and flooding of microsystems with reactive fluids

NASA Astrophysics Data System (ADS)

Neuville, Amélie; Thuy Luu, Thi; Dysthe, Dag Kristian; Vinningland, Jan Ludvig; Hiorth, Aksel

2015-04-01

Direct in situ observation of the pore structure changes that occur when chalk is flooded with brines could resolve many of the open questions that remain about the interactions between mineralogical alterations and oil-liberating mechanisms. Experiments on core scale and field tests that have been carried out the last decade have clearly shown that water chemistry affects the final oil recovery. However, there is generally no consensus in the scientific community of why additional oil is released. In this work, our aim is to focus on in-situ observations of single phase flow and interactions at the pore scale. To do so, we create several types of custom-made microsystems with chalk and calcite crystals. We then do experiments with reacting fluids in these microsystems. During these experiments, we realize in-situ observations (geometrical characteristics, reaction rate) using microsopy techniques (white light vertical/phase shift interferometric microscopy, and classical microscopy), and show how they vary as function as the water chemistry. In simple systems made of calcite, we obtain reactive rates that are coherent with the litterature and with numerical simulations based on Lattice-Boltzmann methods.

Laser processing for strengthening of the self-restoring metal-elastomer interface on a silicone sheet

NASA Astrophysics Data System (ADS)

Yasuda, Kiyokazu

2012-08-01

A self-restoring microsystem is a unique concept which realizes the sensing functionality and robust interface which mechanically and electrically connects a deformable object such as a human body with printed electronic devices. For this purpose, the formation of conductive wiring on an elastomer substrate was attempted using the nickel ink printing process. Before the wiring process, surface patterning of a silicone sheet by a galvano-scanned infrared laser was conducted for the enhancement of interface adhesion of the metal deposit and polymer. Characterization of the fabricated pattern was conducted by optical microscopy. The novel method was successfully demonstrated as a fabrication of selective patterns of metal particles on self-restoring MEMS.

LTCC Thick Film Process Characterization

DOE PAGES

Girardi, M. A.; Peterson, K. A.; Vianco, P. T.

2016-05-01

Low temperature cofired ceramic (LTCC) technology has proven itself in military/space electronics, wireless communication, microsystems, medical and automotive electronics, and sensors. The use of LTCC for high frequency applications is appealing due to its low losses, design flexibility and packaging and integration capability. Moreover, we summarize the LTCC thick film process including some unconventional process steps such as feature machining in the unfired state and thin film definition of outer layer conductors. The LTCC thick film process was characterized to optimize process yields by focusing on these factors: 1) Print location, 2) Print thickness, 3) Drying of tapes and panels,more » 4) Shrinkage upon firing, and 5) Via topography. Statistical methods were used to analyze critical process and product characteristics in the determination towards that optimization goal.« less

Development of polypyrrole based solid-state on-chip microactuators using photolithography

NASA Astrophysics Data System (ADS)

Zhong, Yong; Lundemo, Staffan; Jager, Edwin W. H.

2018-07-01

There is a need for soft microactuators, especially for biomedical applications. We have developed a microfabrication process to create such soft, on-chip polymer based microactuators that can operate in air. The on-chip microactuators were fabricated using standard photolithographic techniques and wet etching, combined with special designed process to micropattern the electroactive polymer polypyrrole that drives the microactuators. By immobilizing a UV-patternable gel containing a liquid electrolyte on top of the electroactive polypyrrole layer, actuation in air was achieved although with reduced movement. Further optimization of the processing is currently on-going. The result shows the possibility to batch fabricate complex microsystems such as microrobotics and micromanipulators based on these solid-state on-chip microactuators using microfabrication methods including standard photolithographic processes.

Microsystems in medicine.

PubMed

Wallrabe, U; Ruther, P; Schaller, T; Schomburg, W K

1998-03-01

The complexity of modern surgical and analytical methods requires the miniaturisation of many medical devices. The LIGA technique and also mechanical microengineering are well known for the batch fabrication of microsystems. Actuators and sensors are developed based on these techniques. The hydraulic actuation principle is advantageous for medical applications since the energy may be supplied by pressurised balanced salt solution. Some examples are turbines, pumps and valves. In addition, optical sensors and components are useful for analysis and inspection as represented by microspectrometers and spherical lenses. Finally, plastic containers with microporous bottoms allow a 3-dimensional growth of cell culture systems.

A Brief Overview of NASA Glenn Research Center Sensor and Electronics Activities

NASA Technical Reports Server (NTRS)

Hunter, Gary W.

2012-01-01

Aerospace applications require a range of sensing technologies. There is a range of sensor and sensor system technologies being developed using microfabrication and micromachining technology to form smart sensor systems and intelligent microsystems. Drive system intelligence to the local (sensor) level -- distributed smart sensor systems. Sensor and sensor system development examples: (1) Thin-film physical sensors (2) High temperature electronics and wireless (3) "lick and stick" technology. NASA GRC is a world leader in aerospace sensor technology with a broad range of development and application experience. Core microsystems technology applicable to a range of application environmentS.

The Search for Perpetual Motion: Fatigue, Friction, and Drag in Quality Improvement.

PubMed

Cumbler, Ethan; Pierce, Read

Most people who have worked on continuous quality improvement (QI) with teams in the clinical microsystem have experienced "change fatigue." Application of the "Limit-to-Growth" system archetype to QI teams within health care can be used to understand negative feedback loops generated by successful QI that can limit future progress. Awareness of these factors can result in actions designed to reduce drag on forward momentum. Leaders in health care QI can anticipate and minimize negative feedback loops that accumulate to slow subsequent progress of highly functioning improvement teams within clinical microsystems.

Power Management and SRAM for Energy-Autonomous and Low-Power Systems

NASA Astrophysics Data System (ADS)

Chen, Gregory K.

We demonstrate the two first-known, complete, self-powered millimeter-scale computer systems. These microsystems achieve zero-net-energy operation using solar energy harvesting and ultra-low-power circuits. A medical implant for monitoring intraocular pressure (IOP) is presented as part of a treatment for glaucoma. The 1.5mm3 IOP monitor is easily implantable because of its small size and measures IOP with 0.5mmHg accuracy. It wirelessly transmits data to an external wand while consuming 4.70nJ/bit. This provides rapid feedback about treatment efficacies to decrease physician response time and potentially prevent unnecessary vision loss. A nearly-perpetual temperature sensor is presented that processes data using a 2.1muW near-threshold ARMRTM Cortex-M3(TM) muP that provides a widely-used and trusted programming platform. Energy harvesting and power management techniques for these two microsystems enable energy-autonomous operation. The IOP monitor harvests 80nW of solar power while consuming only 5.3nW, extending lifetime indefinitely. This allows the device to provide medical information for extended periods of time, giving doctors time to converge upon the best glaucoma treatment. The temperature sensor uses on-demand power delivery to improve low-load dc-dc voltage conversion efficiency by 4.75x. It also performs linear regulation to deliver power with low noise, improved load regulation, and tight line regulation. Low-power high-throughput SRAM techniques help millimeter-scale microsystems meet stringent power budgets. VDD scaling in memory decreases energy per access, but also decreases stability margins. These margins can be improved using sizing, VTH selection, and assist circuits, as well as new bitcell designs. Adaptive Crosshairs modulation of SRAM power supplies fixes 70% of parametric failures. Half-differential SRAM design improves stability, reducing VMIN by 72mV. The circuit techniques for energy autonomy presented in this dissertation enable millimeter-scale microsystems for medical implants, such as blood pressure and glucose sensors, as well as non-medical applications, such as supply chain and infrastructure monitoring. These pervasive sensors represent the continuation of Bell's Law, which accurately traces the evolution of computers as they have become smaller, more numerous, and more powerful. The development of millimeter-scale massively-deployed ubiquitous computers ensures the continued expansion and profitability of the semiconductor industry. NanoWatt circuit techniques will allow us to meet this next frontier in IC design.

New integrated silicon-PDMS process for compliant micro-mechanisms

NASA Astrophysics Data System (ADS)

Haouas, Wissem; Dahmouche, Redwan; Agnus, Joël; Le Fort-Piat, Nadine; Laurent, Guillaume J.

2017-12-01

Polydimethylsiloxane (PDMS) elastomers are used for many applications, such as microfluidics and micro-engineering. This paper presents a new process of integrating soft elastomers into a silicon structure without any assembly steps. The novelty of this process is the use of only one deep reactive ion etch (DRIE) instead of two or more as developed in previous works. Thus, this fabrication process allows the use of elastomers that are usually not compatible with some fabrication processes. Compliant flexures with different interference shapes have been designed, simulated, fabricated, and characterized for generic use and notably for micro-robot joints and compliant micro-systems. The experimental results show that the 400 μm  ×  400 μm cross-sectional area samples can be bended more than 60\\circ without delamination.

Materials integrity in microsystems: a framework for a petascale predictive-science-based multiscale modeling and simulation system

NASA Astrophysics Data System (ADS)

To, Albert C.; Liu, Wing Kam; Olson, Gregory B.; Belytschko, Ted; Chen, Wei; Shephard, Mark S.; Chung, Yip-Wah; Ghanem, Roger; Voorhees, Peter W.; Seidman, David N.; Wolverton, Chris; Chen, J. S.; Moran, Brian; Freeman, Arthur J.; Tian, Rong; Luo, Xiaojuan; Lautenschlager, Eric; Challoner, A. Dorian

2008-09-01

Microsystems have become an integral part of our lives and can be found in homeland security, medical science, aerospace applications and beyond. Many critical microsystem applications are in harsh environments, in which long-term reliability needs to be guaranteed and repair is not feasible. For example, gyroscope microsystems on satellites need to function for over 20 years under severe radiation, thermal cycling, and shock loading. Hence a predictive-science-based, verified and validated computational models and algorithms to predict the performance and materials integrity of microsystems in these situations is needed. Confidence in these predictions is improved by quantifying uncertainties and approximation errors. With no full system testing and limited sub-system testings, petascale computing is certainly necessary to span both time and space scales and to reduce the uncertainty in the prediction of long-term reliability. This paper presents the necessary steps to develop predictive-science-based multiscale modeling and simulation system. The development of this system will be focused on the prediction of the long-term performance of a gyroscope microsystem. The environmental effects to be considered include radiation, thermo-mechanical cycling and shock. Since there will be many material performance issues, attention is restricted to creep resulting from thermal aging and radiation-enhanced mass diffusion, material instability due to radiation and thermo-mechanical cycling and damage and fracture due to shock. To meet these challenges, we aim to develop an integrated multiscale software analysis system that spans the length scales from the atomistic scale to the scale of the device. The proposed software system will include molecular mechanics, phase field evolution, micromechanics and continuum mechanics software, and the state-of-the-art model identification strategies where atomistic properties are calibrated by quantum calculations. We aim to predict the long-term (in excess of 20 years) integrity of the resonator, electrode base, multilayer metallic bonding pads, and vacuum seals in a prescribed mission. Although multiscale simulations are efficient in the sense that they focus the most computationally intensive models and methods on only the portions of the space time domain needed, the execution of the multiscale simulations associated with evaluating materials and device integrity for aerospace microsystems will require the application of petascale computing. A component-based software strategy will be used in the development of our massively parallel multiscale simulation system. This approach will allow us to take full advantage of existing single scale modeling components. An extensive, pervasive thrust in the software system development is verification, validation, and uncertainty quantification (UQ). Each component and the integrated software system need to be carefully verified. An UQ methodology that determines the quality of predictive information available from experimental measurements and packages the information in a form suitable for UQ at various scales needs to be developed. Experiments to validate the model at the nanoscale, microscale, and macroscale are proposed. The development of a petascale predictive-science-based multiscale modeling and simulation system will advance the field of predictive multiscale science so that it can be used to reliably analyze problems of unprecedented complexity, where limited testing resources can be adequately replaced by petascale computational power, advanced verification, validation, and UQ methodologies.

Multilevel risk factors and developmental assets for internalizing symptoms and self-esteem in disadvantaged adolescents: modeling longitudinal trajectories from the Rural Adaptation Project.

PubMed

Smokowski, Paul R; Guo, Shenyang; Rose, Roderick; Evans, Caroline B R; Cotter, Katie L; Bacallao, Martica

2014-11-01

The current study filled significant gaps in our knowledge of developmental psychopathology by examining the influence of multilevel risk factors and developmental assets on longitudinal trajectories of internalizing symptoms and self-esteem in an exceptionally culturally diverse sample of rural adolescents. Integrating ecological and social capital theories, we explored if positive microsystem transactions are associated with self-esteem while negative microsystem transactions increase the chances of internalizing problems. Data came from the Rural Adaptation Project, a 5-year longitudinal panel study of more than 4,000 middle school students from 28 public schools in two rural, disadvantaged counties in North Carolina. Three-level hierarchical linear modeling models were estimated to predict internalizing symptoms (e.g., depression, anxiety) and self-esteem. Relative to other students, risk for internalizing problems and low self-esteem was elevated for aggressive adolescents, students who were hassled or bullied at school, and those who were rejected by peers or in conflict with their parents. Internalizing problems were also more common among adolescents from socioeconomically disadvantaged families and neighborhoods, among those in schools with more suspensions, in students who reported being pressured by peers, and in youth who required more teacher support. It is likely that these experiences left adolescents disengaged from developing social capital from ecological microsystems (e.g., family, school, peers). On the positive side, support from parents and friends and optimism about the future were key assets associated with lower internalizing symptoms and higher self-esteem. Self-esteem was also positively related to religious orientation, school satisfaction, and future optimism. These variables show active engagement with ecological microsystems. The implications and limitations were discussed.

An exploratory analysis of the model for understanding success in quality.

PubMed

Kaplan, Heather C; Froehle, Craig M; Cassedy, Amy; Provost, Lloyd P; Margolis, Peter A

2013-01-01

Experience suggests that differences in context produce variability in the effectiveness of quality improvement (QI) interventions. However, little is known about which contextual factors affect success or how they exert influence. Using the Model for Understanding Success in Quality (MUSIQ), we perform exploratory quantitative tests of the role of context in QI success. We used a cross-sectional design to survey individuals participating in QI projects in three settings: a pediatric hospital, hospitals affiliated with a state QI collaborative, and organizations sponsoring participants in an improvement advisor training program. Individuals participating in QI projects completed a questionnaire assessing contextual factors included in MUSIQ and measures of perceived success. Path analysis was used to test the direct, indirect, and total effects of context variables on QI success as hypothesized in MUSIQ. In the 74 projects studied, most contextual factors in MUSIQ were found to be significantly related to at least one QI project performance outcome. Contextual factors exhibiting significant effects on two measures of perceived QI success included resource availability, QI team leadership, team QI skills, microsystem motivation, microsystem QI culture, and microsystem QI capability. There was weaker evidence for effects of senior leader project sponsors, organizational QI culture, QI team decision-making, and microsystem QI leadership. These initial tests add to the validity of MUSIQ as a tool for identifying which contextual factors affect improvement success and understanding how they exert influence. Using MUSIQ, managers and QI practitioners can begin to identify aspects of context that must be addressed before or during the execution of QI projects and plan strategies to modify context for increased success. Additional work by QI researchers to improve the theory, refine measurement approaches, and validate MUSIQ as a predictive tool in a wider range of QI efforts is necessary.

Microsystems Technology for Retinal Implants

NASA Astrophysics Data System (ADS)

Weiland, James

2005-03-01

The retinal prosthesis is targeted to treat age-related macular degeneration, retinitis pigmentosa, and other outer retinal degenerations. Simulations of artificial vision have predicted that 600-1000 individual pixels will be needed if a retinal prosthesis is to restore function such as reading large print and face recognition. An implantable device with this many electrode contacts will require microsystems technology as part of its design. An implantable retinal prosthesis will consist of several subsystems including an electrode array and hermetic packaging. Microsystems and microtechnology approaches are being investigated as possible solutions for these design problems. Flexible polydimethylsiloxane (PDMS) substrate electrode arrays and silicon micromachined electrode arrays are under development. Inactive PDMS electrodes have been implanted in 3 dogs to assess mechanical biocompatibility. 3 dogs were followed for 6 months. The implanted was securely fastened to the retina with a single retinal tack. No post-operative complications were evident. The array remained within 100 microns of the retinal surface. Histological evaluation showed a well preserved retina underneath the electrode array. A silicon device with electrodes suspended on micromachined springs has been implanted in 4 dogs (2 acute implants, 2 chronic implants). The device, though large, could be inserted into the eye and positioned on the retina. Histological analysis of the retina from the spring electrode implants showed that spring mounted posts penetrated the retina, thus the device will be redesigned to reduce the strength of the springs. These initial implants will provide information for the designers to make the next generation silicon device. We conclude that microsystems technology has the potential to make possible a retinal prosthesis with 1000 individual contacts in close proximity to the retina.

Wireless, High-Bandwidth Recordings from Non-Human Primate Motor Cortex using a Scalable 16-Ch Implantable Microsystem

PubMed Central

Borton, David A.; Song, Yoon-Kyu; Patterson, William R.; Bull, Christopher W.; Park, Sunmee; Laiwalla, Farah; Donoghue, John P.; Nurmikko, Arto V.

2013-01-01

A multitude of neuroengineering challenges exist today in creating practical, chronic multichannel neural recording systems for primate research and human clinical application. Specifically, a) the persistent wired connections limit patient mobility from the recording system, b) the transfer of high bandwidth signals to external (even distant) electronics normally forces premature data reduction, and c) the chronic susceptibility to infection due to the percutaneous nature of the implants all severely hinder the success of neural prosthetic systems. Here we detail one approach to overcome these limitations: an entirely implantable, wirelessly communicating, integrated neural recording microsystem, dubbed the Brain Implantable Chip (BIC). PMID:19964128

An optical microsystem based on vertical silicon-air Bragg mirror for liquid substances monitoring

NASA Astrophysics Data System (ADS)

De Stefano, Luca; Rendina, Ivo; Rea, Ilaria; Rotiroti, Lucia; De Tommasi, Edoardo; Barillaro, Giuseppe

2007-05-01

In this work, an integrated optical microsystems for the continuous detection of flammable liquids has been fabricated and characterized. The proposed system is composed of a the transducer element, which is a vertical silicon/air Bragg mirror fabricated by silicon electrochemical micromachining, sealed with a cover glass anodically bonded on its top. The device has been optically characterized in presence of liquid substances of environmental interest, such as ethanol and isopropanol. The preliminary experimental results are in good agreement with the theoretical calculations and show the possibility to use the device as an optical sensor based on the change of its reflectivity spectrum.

Microfluidic diffusion diluter: bulging of PDMS microchannels under pressure-driven flow

NASA Astrophysics Data System (ADS)

Holden, Matthew A.; Kumar, Saurabh; Beskok, Ali; Cremer, Paul S.

2003-05-01

The bulging of microfluidic systems during pressure-driven flow is potentially a major consideration for polydimethylsiloxane (PDMS)-based devices. Microchannel cross-sectional areas can change drastically as a function of flow rate and downstream microchannel position. Such geometrical flexibility leads to difficulties in predicting convective/diffusive transport for these systems. We have previously introduced a non-dimensional parameter, kappa, for characterizing convection and diffusion behavior for pressure-driven flow in rigid all-glass systems. This paper describes a modification of that concept for application to non-rigid systems, which is accomplished by incorporating an experimental step to account for the bulging in PDMS/glass microsystems. Specifically, an experimental measurement of channel height by fluorescence microscopy is combined with the aforementioned theory to characterize convective/diffusive behavior at a single location in the device. This allowed the parameter kappa to be determined at that point and applied to predict fluid flow in the subsequent portion of the PDMS microsystem. This procedure was applied to a PDMS/glass microfluidic diffusion dilution (muDD) device designed for generating concentration gradients. Theoretically predicted and experimentally measured distributions of concentrations within the microsystem matched well.

Integration of electrochemistry in micro-total analysis systems for biochemical assays: recent developments.

PubMed

Xu, Xiaoli; Zhang, Song; Chen, Hui; Kong, Jilie

2009-11-15

Micro-total analysis systems (microTAS) integrate different analytical operations like sample preparation, separation and detection into a single microfabricated device. With the outstanding advantages of low cost, satisfactory analytical efficiency and flexibility in design, highly integrated and miniaturized devices from the concept of microTAS have gained widespread applications, especially in biochemical assays. Electrochemistry is shown to be quite compatible with microanalytical systems for biochemical assays, because of its attractive merits such as simplicity, rapidity, high sensitivity, reduced power consumption, and sample/reagent economy. This review presents recent developments in the integration of electrochemistry in microdevices for biochemical assays. Ingenious microelectrode design and fabrication methods, and versatility of electrochemical techniques are involved. Practical applications of such integrated microsystem in biochemical assays are focused on in situ analysis, point-of-care testing and portable devices. Electrochemical techniques are apparently suited to microsystems, since easy microfabrication of electrochemical elements and a high degree of integration with multi-analytical functions can be achieved at low cost. Such integrated microsystems will play an increasingly important role for analysis of small volume biochemical samples. Work is in progress toward new microdevice design and applications.

Wireless and batteryless biomedical microsystem for neural recording and epilepsy suppression based on brain focal cooling.

PubMed

Hou, K-C; Chang, C-W; Chiou, J-C; Huang, Y-H; Shaw, F-Z

2011-12-01

This work presents a biomedical microsystem with a wireless radiofrequency (RF)-powered electronics and versatile sensors/actuators for use in nanomedicinal diagnosis and therapy. The cooling of brain tissue has the potential to reduce the frequency and severity of epilepsy. Miniaturised spiral coils as a wireless power module with low-dropout linear regulator circuit convert RF signals into a DC voltage, can be implanted without a battery in monitoring free behaviour. A thermoelectric (TE) cooler is an actuator that is employed to cool down brain tissue to suppress epilepsy. Electroencephalogram (EEG) electrodes and TE coolers are integrated to form module that is placed inside the head of a rat and fastened with a bio-compatible material. EEG signals are used to identify waveforms associated with epilepsy and are measured using readout circuits. The wireless part of the presented design achieves a low quiescent current and line/load regulation and high antenna/current efficiency with thermal protection to avoid damage to the implanted tissue. Epilepsy is suppressed by reducing the temperature to reduce the duration of this epileptic episode. Related characterisations demonstrate that the proposed design can be adopted in an effective nanomedicine microsystem.

Practice-based learning for improvement: the pursuit of clinical excellence.

PubMed

Staker, L V

2000-10-01

Physicians often seem to be paralyzed waiting for a health plan, a health maintenance organization, or an integrated health care system to bring about change or improvement in health care. But small changes in individual practices (microsystems) can have a profound impact on outcomes in an organization (microsystem). With simple graphical measurement tools, physicians can teach patients to measure and empower themselves to learn to improve both their health and their health care. At the same time, physicians can learn a great deal from their patient population data. When these measurement tools and a well-known and widely accepted method for clinical practice improvement called rapid cycle testing were used in a population of patients with diabetes, the average fasting blood sugar changed from 187 to 110 and the average hemoglobin A1c from 10.5 to 7.2. This article shows that measurement using specification charts and control charts in patient care can have a profound impact on patients, physicians, and organizations. Understanding these principles and using time-sequence measurement with graphical data feedback, physicians can engage in practice-based learning and can participate in improvement in the microsystems over which they have control.

A MEMS approach to determine the biochemical oxygen demand (BOD) of wastewaters

NASA Astrophysics Data System (ADS)

Recoules, L.; Migaou, A.; Dollat, X.; Thouand, G.; Gue, A. M.; Boukabache, A.

2017-07-01

A MEMS approach to obtain an efficient tool for the evaluation of the biochemical oxygen demand (BOD) of wastewaters is introduced. Its operating principle is based on the measurement of oxygen concentration in water samples containing organic pollutants and specific bacteria. The microsystem has been designed to perform multiple and parallel measurements in a poly-wells microfluidic device. The monitoring of the bacterial activity is ensured by optical sensors incorporated in each well of the fluidic network. By using an optode sensor, it is hereby demonstrated that this approach is efficient to measure organic pollutants by testing different Luria Bertani buffer dilutions. These results also show that it is possible to reduce the duration of measurements from 5 d (BOD5) of the standard approach to few hours, typically 3 h-5 h.

CMOS-micromachined, two-dimenisional transistor arrays for neural recording and stimulation.

PubMed

Lin, J S; Chang, S R; Chang, C H; Lu, S C; Chen, H

2007-01-01

In-plane microelectrode arrays have proven to be useful tools for studying the connectivities and the functions of neural tissues. However, seldom microelectrode arrays are monolithically-integrated with signal-processing circuits, without which the maximum number of electrodes is limited by the compromise with routing complexity and interferences. This paper proposes a CMOS-compatible, two-dimensional array of oxide-semiconductor field-effect transistors(OSFETs), capable of both recording and stimulating neuronal activities. The fabrication of the OSFETs not only requires simply die-level, post-CMOS micromachining process, but also retains metal layers for monolithic integration with signal-processing circuits. A CMOS microsystem containing the OSFET arrays and gain-programmable recording circuits has been fabricated and tested. The preliminary testing results are presented and discussed.

2004 research briefs :Materials and Process Sciences Center.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cieslak, Michael J.

2004-01-01

This report is the latest in a continuing series that highlights the recent technical accomplishments associated with the work being performed within the Materials and Process Sciences Center. Our research and development activities primarily address the materials-engineering needs of Sandia's Nuclear-Weapons (NW) program. In addition, we have significant efforts that support programs managed by the other laboratory business units. Our wide range of activities occurs within six thematic areas: Materials Aging and Reliability, Scientifically Engineered Materials, Materials Processing, Materials Characterization, Materials for Microsystems, and Materials Modeling and Simulation. We believe these highlights collectively demonstrate the importance that a strong materials-sciencemore » base has on the ultimate success of the NW program and the overall DOE technology portfolio.« less

An active locking mechanism for assembling 3D micro structures

NASA Astrophysics Data System (ADS)

Zhang, Ping; Mayyas, Mohammad; Lee, Woo Ho; Popa, Dan; Shiakolas, Panos; Stephanou, Harry; Chiao, J. C.

2007-01-01

Microassembly is an enabling technology to build 3D microsystems consisting of microparts made of different materials and processes. Multiple microparts can be connected together to construct complicated in-plane and out-of-plane microsystems by using compliant mechanical structures such as micro hinges and snap fasteners. This paper presents design, fabrication, and assembly of an active locking mechanism that provides mechanical and electrical interconnections between mating microparts. The active locking mechanism is composed of thermally actuated Chevron beams and sockets. Assembly by means of an active locking mechanism offers more flexibility in designing microgrippers as it reduces or minimizes mating force, which is one of the main reasons causing fractures in a microgripper during microassembly operation. Microgrippers, microparts, and active locking mechanisms were fabricated on a silicon substrate using the deep reactive ion etching (DRIE) processes with 100-um thick silicon on insulator (SOI) wafers. A precision robotic assembly platform with a dual microscope vision system was used to automate the manipulation and assembly processes of microparts. The assembly sequence includes (1) tether breaking and picking up of a micropart by using an electrothermally actuated microgripper, (2) opening of a socket area for zero-force insertion, (3) a series of translation and rotation of a mating micropart to align it onto the socket, (4) insertion of a micropart into the socket, and (5) deactivation and releasing of locking fingers. As a result, the micropart was held vertically to the substrate and locked by the compliance of Chevron beams. Microparts were successfully assembled using the active locking mechanism and the measured normal angle was 89.2°. This active locking mechanism provides mechanical and electrical interconnections, and it can potentially be used to implement a reconfigurable microrobot that requires complex assembly of multiple links and joints.

Engineering micro-supercapacitors of graphene nanowalls/Ni heterostructure based on microfabrication technology

NASA Astrophysics Data System (ADS)

Li, Jinhua; Zhu, Minjie; Wang, Zhuqing; Ono, Takahito

2016-10-01

Heterostructure of graphene nanowalls (GNW) supported Ni thin-layer was fabricated to form an on-chip pseudocapacitor via a standard microelectromechanical system process. Beyond a high-rate capability of the micro-supercapacitors, a large specific energy density of 2.1 mW h cm-3 and power density up to 5.91 W cm-3 have been achieved, which are two orders of magnitude higher than those commercial electrolytic capacitors and thin-film batteries, respectively. Rational analysis revealed a rapid GNW growth originated from the Pt current collector embedment by catalyzing hydrocarbon dissociating. The unique concept in our design includes that Ni was evaporated onto GNW to serve as both the shadow mask for microelectrode patterning and subsequently a precursor to be in-situ electrochemically converted into pseudo-capacitive Ni(OH)2 for capacitance enhancing. Addressing the challenge to uniformly coat in complex nanoporous structures, this strategy renders a conformal deposition of pseudo-capacitive material on individual graphene nanoflakes, leading to efficient merits harnessing of huge accessible surfaces from the conductive GNW networks and great capacitance of the Ni-based active materials for high performance delivery. The proof of concept can be potentially extended to other transition metals and paves the way to further apply GNW hybrids in diverse microsystems.

Pyroelectric Applications of the VDF-TrFE Copolymer

NASA Technical Reports Server (NTRS)

Simonne, J. J.; Bauer, Ph.; Audaire, L.; Bauer, F.

1995-01-01

VDF/TrFe pyroelectric sensors have now definitely reached the level of a product. Based on a bidimensional staring array, it can be considered as a whole system with a monolithic technology processed on a silicon substrate provided with the integrated read out circuit. The paper will describe the main procedure dealing with the elaboration of a 32 x 32 focal plane array developed, in the context of the PROMETHEUS PROCHIP European Program (EUREKA), as a passive infrared obstacle detection applied to automotive. Additional experimental data suggest that this microsystem could operate in space environment.

Wireless multichannel biopotential recording using an integrated FM telemetry circuit.

PubMed

Mohseni, Pedram; Najafi, Khalil; Eliades, Steven J; Wang, Xiaoqin

2005-09-01

This paper presents a four-channel telemetric microsystem featuring on-chip alternating current amplification, direct current baseline stabilization, clock generation, time-division multiplexing, and wireless frequency-modulation transmission of microvolt- and millivolt-range input biopotentials in the very high frequency band of 94-98 MHz over a distance of approximately 0.5 m. It consists of a 4.84-mm2 integrated circuit, fabricated using a 1.5-microm double-poly double-metal n-well standard complementary metal-oxide semiconductor process, interfaced with only three off-chip components on a custom-designed printed-circuit board that measures 1.7 x 1.2 x 0.16 cm3, and weighs 1.1 g including two miniature 1.5-V batteries. We characterize the microsystem performance, operating in a truly wireless fashion in single-channel and multichannel operation modes, via extensive benchtop and in vitro tests in saline utilizing two different micromachined neural recording microelectrodes, while dissipating approximately 2.2 mW from a 3-V power supply. Moreover, we demonstrate successful wireless in vivo recording of spontaneous neural activity at 96.2 MHz from the auditory cortex of an awake marmoset monkey at several transmission distances ranging from 10 to 50 cm with signal-to-noise ratios in the range of 8.4-9.5 dB.

Smart single-chip gas sensor microsystem

NASA Astrophysics Data System (ADS)

Hagleitner, C.; Hierlemann, A.; Lange, D.; Kummer, A.; Kerness, N.; Brand, O.; Baltes, H.

2001-11-01

Research activity in chemical gas sensing is currently directed towards the search for highly selective (bio)chemical layer materials, and to the design of arrays consisting of different partially selective sensors that permit subsequent pattern recognition and multi-component analysis. Simultaneous use of various transduction platforms has been demonstrated, and the rapid development of integrated-circuit technology has facilitated the fabrication of planar chemical sensors and sensors based on three-dimensional microelectromechanical systems. Complementary metal-oxide silicon processes have previously been used to develop gas sensors based on metal oxides and acoustic-wave-based sensor devices. Here we combine several of these developments to fabricate a smart single-chip chemical microsensor system that incorporates three different transducers (mass-sensitive, capacitive and calorimetric), all of which rely on sensitive polymeric layers to detect airborne volatile organic compounds. Full integration of the microelectronic and micromechanical components on one chip permits control and monitoring of the sensor functions, and enables on-chip signal amplification and conditioning that notably improves the overall sensor performance. The circuitry also includes analog-to-digital converters, and an on-chip interface to transmit the data to off-chip recording units. We expect that our approach will provide a basis for the further development and optimization of gas microsystems.

A selective nanosensor device for exhaled breath analysis.

PubMed

Gouma, P; Prasad, A; Stanacevic, S

2011-09-01

This paper describes a novel concept of a three-nanosensor array microsystem that may potentially serve as a coarse diagnostic tool handheld breath analyzer to provide a first detection device. The specification and performance of a simple metal oxide nanosensor operating between three distinct temperatures are discussed, focusing on the need for a noninvasive blood cholesterol monitor. Interfacing the sensor array to an integrated circuit for electrical readout and temperature control provides a complete microsystem capable of capturing a single exhaled breath and analyzing it with respect to the relative content of isoprene, carbon dioxide and ammonia gas. This inexpensive sensor technology may be used as a personalized medical diagnostics tool in the near future.

REVIEW ARTICLE: Medical implants based on microsystems

NASA Astrophysics Data System (ADS)

Mokwa, W.

2007-05-01

The fast development of CMOS technologies to smaller dimensions led to very high integration densities with complex circuitry on very small chip areas. In 2006 Intel fabricated the first products in a 65 nm technology. The cointegration of microsensors or actuators together with the very low power consumption of the CMOS circuitry is very well suited for use in implanted systems. Applications like intracranial or intraocular pressure measurements have become possible. This review presents an overview over actual applications and developments of sensor/actuator-based microsystems for medical implants. It concentrates on the technical part of these investigations. It will mainly review work on systems measuring pressure in blood vessels and on systems for ophthalmic applications.

Preventing cerebral palsy in preterm labour: a multiorganisational quality improvement approach to the adoption and spread of magnesium sulphate for neuroprotection

PubMed Central

Burhouse, Anna; Lea, Charlotte; Ray, Stephen; Bailey, Hannah; Davies, Ruth; Harding, Hannah; Howard, Rachel; Jordan, Sharon; Menzies, Noshin; White, Sarah; Phillips, Kathryn; Luyt, Karent

2017-01-01

Magnesium sulphate has been demonstrated to be an effective neuroprotectant for babies delivered prematurely (under 37 weeks’ gestational age). Antenatal administration reduces infant mortality and cerebral palsy (CP); however, uptake in the UK has been significantly lower than other countries. A quality improvement (QI) project (PReventing Cerebral palsy in Pre Term labour (PReCePT)) was carried out in the West of England, UK, to raise awareness of evidence and to improve the uptake of magnesium sulphate as neuroprotectant in preterm deliveries. Five National Health Service (NHS) Trusts and the West of England Academic Health Science Network participated in the QI project. The project was underpinned by a multifaceted QI approach that included: patient and clinical coproduction of resources; recruitment of clinical champions to support the local microsystems and create a stimulating/supporting environment for change; Plan, Do, Study, Act cycles; training for over 600 NHS staff and awareness raising and strategic influencing of key leaders. A baseline audit and regular measurement of the number of eligible women receiving magnesium sulphate was undertaken at each hospital site, and the overall programme was evaluated using data from an international benchmarking organisation for neonatal care outcomes—the Vermont Oxford Network. During the project 664 staff received magnesium sulphate training. The use of magnesium sulphate increased across the West of England from an average baseline of 21% over the 2 years preceding the project to 88% by the conclusion of the project. The project was also able to influence the development of a national data collection process for benchmarking the use of magnesium sulphate for neuroprotection in preterm deliveries in the U.K. PReCePT appears to have had a favourable effect on the uptake of magnesium sulphate across the West of England. The project has also provided learning about how to stimulate adoption and spread of evidence using a QI approach across a network. PMID:29450301

Clinical Nurse Leader Integration Into Practice: Developing Theory To Guide Best Practice.

PubMed

Bender, Miriam

2016-01-01

Numerous policy bodies have identified the clinical nurse leader (CNL) as an innovative new role for meeting higher health care quality standards. Although there is growing evidence of improved care environment and patient safety and quality outcomes after redesigning care delivery microsystems to integrate CNL practice, significant variation in CNL implementation has been noted across reports, making it difficult to causally link CNL practice to reported outcomes. This variability reflects the overall absence in the literature of a well-defined CNL theoretical framework to help guide standardized application in practice. To address this knowledge gap, an interpretive synthesis with a grounded theory analysis of CNL narratives was conducted to develop a theoretical model for CNL practice. The model clarifies CNL practice domains and proposes mechanisms by which CNL-integrated care delivery microsystems improve health care quality. The model highlights the need for a systematic approach to CNL implementation including a well-thought out strategy for care delivery redesign; a consistent, competency-based CNL workflow; and sustained macro-to-micro system leadership support. CNL practice can be considered an effective approach to organizing nursing care that maximizes the scope of nursing to influence the ways care is delivered by all professions within a clinical microsystem. Copyright © 2016 Elsevier Inc. All rights reserved.

Portable microsystem integrates multifunctional dielectrophoresis manipulations and a surface stress biosensor to detect red blood cells for hemolytic anemia.

PubMed

Sang, Shengbo; Feng, Qiliang; Jian, Aoqun; Li, Huiming; Ji, Jianlong; Duan, Qianqian; Zhang, Wendong; Wang, Tao

2016-09-20

Hemolytic anemia intensity has been suggested as a vital factor for the growth of certain clinical complications of sickle cell disease. However, there is no effective and rapid diagnostic method. As a powerful platform for bio-particles testing, biosensors integrated with microfluidics offer great potential for a new generation of portable point of care systems. In this paper, we describe a novel portable microsystem consisting of a multifunctional dielectrophoresis manipulations (MDM) device and a surface stress biosensor to separate and detect red blood cells (RBCs) for diagnosis of hemolytic anemia. The peripheral circuit to power the interdigitated electrode array of the MDM device and the surface stress biosensor test platform were integrated into a portable signal system. The MDM includes a preparing region, a focusing region, and a sorting region. Simulation and experimental results show the RBCs trajectories when they are subjected to the positive DEP force, allowing the successful sorting of living/dead RBCs. Separated RBCs are then transported to the biosensor and the capacitance values resulting from the variation of surface stress were measured. The diagnosis of hemolytic anemia can be realized by detecting RBCs and the portable microsystem provides the assessment to the hemolytic anemia patient.

Barriers and facilitators for breastfeeding among working women in the United States.

PubMed

Johnston, Marina L; Esposito, Noreen

2007-01-01

To review the literature and describe the barriers and facilitators to the continuation of breastfeeding for at least 6 months by working women in the United States. A search of PubMed, CINAHL, Sociological Abstracts, ISI, PsychInfo, and ProQuest. Twenty studies based on the inclusion criteria and published between January 1, 1995, and January 2006. An ecologic framework, which includes the individual (microsystem), social support and relationships (mesosystem), and the workplace environment (exosystem). When working mothers possess certain personal characteristics and develop a strategic plan, breastfeeding is promoted. When social support is available and when support groups are utilized, lactation is also facilitated. Part-time work, lack of long mother-infant separations, supportive work environments and facilities, and child care options facilitate breastfeeding. Health care providers can use the findings of this review to promote breastfeeding among working women by using tactics geared toward the mother, her social network, and the entire community.

Multi-parametric polymer-based potentiometric analytical microsystem for future manned space missions.

PubMed

Calvo-López, Antonio; Puyol, Mar; Casalta, Joan Manel; Alonso-Chamarro, Julián

2017-12-01

The construction and evaluation of a Cyclic Olefin Copolymer (COC)-based continuous flow potentiometric microanalyzer to simultaneously monitor potassium, chloride and nitrate ions in samples from an on-board water recycling process expected to be installed in future manned space missions is presented. The main goals accomplished in this work address the specific required characteristics for a miniaturized on-line monitoring system to control water quality in such missions. To begin with, the integration of three ion-selective electrodes (ISEs) and a reference electrode in a compact microfluidic platform that incorporates a simple automatic autocalibration process allows obtaining information about the concentration of the three ions with optimal analytical response characteristics, but moreover with low reagents consumption and therefore with few waste generation, which is critical for this specific application. By a simple signal processing (signal removal) the chloride ion interference on the nitrate electrode response can be eliminated. Furthermore, all fluidics management is performed by computer-controlled microvalves and micropumps, so no manual intervention of the crew is necessary. The analytical features provided by the microsystem after the optimization process were a linear range from 6.3 to 630 mg L -1 and a detection limit of 0.51 mg L -1 for the potassium electrode, a linear range from 10 to 1000 mg L -1 and a detection limit of 1.58 mg L -1 for the chloride electrode and a linear range from 10 to 1000 mg L -1 and a detection limit of 3.37 mg L -1 for the nitrate electrode with a reproducibility (RSD) of 4%, 2% and 3% respectively. Sample throughput was 12 h -1 with a reagent consumptions lower than 2 mL per analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Limiting factors in the production of deep microstructures

NASA Astrophysics Data System (ADS)

Tolfree, David W. L.; O'Neill, William; Tunna, Leslie; Sutcliffe, Christopher

1999-10-01

Microsystems increasingly require precision deep microstructures that can be cost-effectively designed and manufactured. New products must be able to meet the demands of the rapidly growing markets for microfluidic, micro- optical and micromechanical devices in industrial sectors which include chemicals, pharmaceuticals, biosciences, medicine and food. The realization of such products, first requires an effective process to design and manufacture prototypes. Two process methods used for the fabrication of high aspect-ratio microstructures are based on X-ray beam lithography with electroforming processes and direct micromachining with a frequency multiplied Nd:YAG laser using nanosecond pulse widths. Factors which limit the efficiency and precision obtainable using such processes are important parameters when deciding on the best fabrication method to use. A basic microstructure with narrow channels suitable for a microfluidic mixer have been fabricated using both these techniques and comparisons made of the limitations and suitability of the processes in respect of fast prototyping and manufacture or working devices.

Sol-gel layers for ceramic microsystems application

NASA Astrophysics Data System (ADS)

Czok, Mateusz; Golonka, Leszek

2016-11-01

This paper describes research on sol-gel solutions preparation process. Utilize of a sol-gel layers in the LTCC technology for reduction of surface roughness and influence on the ceramics properties is examined and described. The influence of sol-gel layer on possible sedimentation of dyes or biological substances in channels, mixers or chambers of ceramic microfluidic structures was investigated. Moreover, properties of sol-gel coated surfaces have been precisely examined and described. Finally, positive results of conducted experiments made it possible to design and manufacture a simple microfluidic ceramic structure, with embedded protective layer of sol-gel, for fluorescence measurements.

Microsystems, Space Qualified Electronics and Mobile Sensor Platforms for Harsh Environment Applications and Planetary Exploration

NASA Technical Reports Server (NTRS)

Hunter, Gary W.; Okojie, Robert S.; Krasowski, Michael J.; Beheim, Glenn M.; Fralick, Gustave C.; Wrbanek, John D.; Greenberg, Paul S.; Xu, Jennifer

2007-01-01

NASA Glenn Research Center is presently developing and applying a range of sensor and electronic technologies that can enable future planetary missions. These include space qualified instruments and electronics, high temperature sensors for Venus missions, mobile sensor platforms, and Microsystems for detection of a range of chemical species and particulates. A discussion of each technology area and its level of maturity is given. It is concluded that there is a strong need for low power devices which can be mobile and provide substantial characterization of the planetary environment where and when needed. While a given mission will require tailoring of the technology for the application, basic tools which can enable new planetary missions are being developed.

On-chip micro-power: three-dimensional structures for micro-batteries and micro-supercapacitors

NASA Astrophysics Data System (ADS)

Beidaghi, Majid; Wang, Chunlei

2010-04-01

With the miniaturization of portable electronic devices, there is a demand for micro-power source which can be integrated on the semiconductor chips. Various micro-batteries have been developed in recent years to generate or store the energy that is needed by microsystems. Micro-supercapacitors are also developed recently to couple with microbatteries and energy harvesting microsystems and provide the peak power. Increasing the capacity per footprint area of micro-batteries and micro-supercapacitors is a great challenge. One promising route is the manufacturing of three dimensional (3D) structures for these micro-devices. In this paper, the recent advances in fabrication of 3D structure for micro-batteries and micro-supercapacitors are briefly reviewed.

Autonomous microsystems for ground observation (AMIGO)

NASA Astrophysics Data System (ADS)

Laou, Philips

2005-05-01

This paper reports the development of a prototype autonomous surveillance microsystem AMIGO that can be used for remote surveillance. Each AMIGO unit is equipped with various sensors and electronics. These include passive infrared motion sensor, acoustic sensor, uncooled IR camera, electronic compass, global positioning system (GPS), and spread spectrum wireless transceiver. The AMIGO unit was configured to multipoint (AMIGO units) to point (base station) communication mode. In addition, field trials were conducted with AMIGO in various scenarios. These scenarios include personnel and vehicle intrusion detection (motion or sound) and target imaging; determination of target GPS position by triangulation; GPS position real time tracking; entrance event counting; indoor surveillance; and aerial surveillance on a radio controlled model plane. The architecture and test results of AMIGO will be presented.

Design and Analysis of a Preconcentrator for the ChemLab

DOE Office of Scientific and Technical Information (OSTI.GOV)

WONG,CHUNGNIN C.; FLEMMING,JEB H.; MANGINELL,RONALD P.

2000-07-17

Preconcentration is a critical analytical procedure when designing a microsystem for trace chemical detection, because it can purify a sample mixture and boost the small analyte concentration to a much higher level allowing a better analysis. This paper describes the development of a micro-fabricated planar preconcentrator for the {mu}ChemLab{trademark} at Sandia. To guide the design, an analytical model to predict the analyte transport, adsorption and resorption process in the preconcentrator has been developed. Experiments have also been conducted to analyze the adsorption and resorption process and to validate the model. This combined effort of modeling, simulation, and testing has ledmore » us to build a reliable, efficient preconcentrator with good performance.« less

LGBTQ Experiences in Curricular Contexts

ERIC Educational Resources Information Center

Linley, Jodi L.; Nguyen, David J.

2015-01-01

This chapter examines curricula as important microsystems for LGBTQ college students. The authors explore sociocultural influences on curricula and discuss strategies for creating positive curricular experiences for LGBTQ students.

Rapid Prototyping of Patterned Multifunctional Nanostructures

DOE Office of Scientific and Technical Information (OSTI.GOV)

FAN,HONGYOU; LU,YUNFENG; LOPEZ,GABRIEL P.

2000-07-18

The ability to engineer ordered arrays of objects on multiple length scales has potential for applications such as microelectronics, sensors, wave guides, and photonic lattices with tunable band gaps. Since the invention of surfactant templated mesoporous sieves in 1992, great progress has been made in controlling different mesophases in the form of powders, particles, fibers, and films. To date, although there have been several reports of patterned mesostructures, materials prepared have been limited to metal oxides with no specific functionality. For many of the envisioned applications of hierarchical materials in micro-systems, sensors, waveguides, photonics, and electronics, it is necessary tomore » define both form and function on several length scales. In addition, the patterning strategies utilized so far require hours or even days for completion. Such slow processes are inherently difficult to implement in commercial environments. The authors present a series of new methods of producing patterns within seconds. Combining sol-gel chemistry, Evaporation-Induced Self-Assembly (EISA), and rapid prototyping techniques like pen lithography, ink-jet printing, and dip-coating on micro-contact printed substrates, they form hierarchically organized silica structures that exhibit order and function on multiple scales: on the molecular scale, functional organic moieties are positioned on pore surfaces, on the mesoscale, mono-sized pores are organized into 1-, 2-, or 3-dimensional networks, providing size-selective accessibility from the gas or liquid phase, and on the macroscale, 2-dimensional arrays and fluidic or photonic systems may be defined. These rapid patterning techniques establish for the first time a link between computer-aided design and rapid processing of self-assembled nanostructures.« less

Study of scratch drive actuator force characteristics

NASA Astrophysics Data System (ADS)

Li, Lijie; Brown, J. Gordon; Uttamchandani, Deepak

2002-11-01

Microactuators are one of the key components in MEMS technology, and various designs have been realized through different fabrication processes. One type of microactuator commonly used is the scratch drive actuator (SDA) that is frequently fabricated by surface micromachining processes. An experimental investigation has been conducted on the force characteristics of SDAs fabricated using the JDSU Microsystems MUMPs process. One-, two-, three- and four-plate SDAs connected to box-springs have been designed and fabricated for these experiments using MUMPs run 44. The spring constant for the box-springs has been calculated by FEM using ANSYS software. The product of the spring constant and spring extension is used to measure the forces produced by these SDAs. It is estimated that the forces produced exceed 250 μN from a one-plate SDA and 850 μN from a four-plate SDA.

Multiscale analysis of the correlation of processing parameters on viscidity of composites fabricated by automated fiber placement

NASA Astrophysics Data System (ADS)

Han, Zhenyu; Sun, Shouzheng; Fu, Yunzhong; Fu, Hongya

2017-10-01

Viscidity is an important physical indicator for assessing fluidity of resin that is beneficial to contact resin with the fibers effectively and reduce manufacturing defects during automated fiber placement (AFP) process. However, the effect of processing parameters on viscidity evolution is rarely studied during AFP process. In this paper, viscidities under different scales are analyzed based on multi-scale analysis method. Firstly, viscous dissipation energy (VDE) within meso-unit under different processing parameters is assessed by using finite element method (FEM). According to multi-scale energy transfer model, meso-unit energy is used as the boundary condition for microscopic analysis. Furthermore, molecular structure of micro-system is built by molecular dynamics (MD) method. And viscosity curves are then obtained by integrating stress autocorrelation function (SACF) with time. Finally, the correlation characteristics of processing parameters to viscosity are revealed by using gray relational analysis method (GRAM). A group of processing parameters is found out to achieve the stability of viscosity and better fluidity of resin.

High-precision and high-speed laser microjoining for electronics and microsystems

NASA Astrophysics Data System (ADS)

Gillner, Arnold; Olowinsky, Alexander; Klages, Kilian; Gedicke, Jens; Sari, Fahri

2006-02-01

The joining processes in electronic device manufacturing are today still dominated by conventional joining techniques like press fitting, crimping and resistance welding. Laser beam joining techniques have been under intensive investigations and subsequently new processes for mass manufacturing and high accuracy assembling were established. With the newly developed SHADOW (R) welding technology technical aspects such as tensile strength, geometry and precision of the weld could be improved. This technology provides highest flexibility in weld geometry with a minimum welding time as well as new possibilities in using application adapted materials. Different parts and even different metals can be joined by a non-contact process. The application of a relative movement between the laser beam and the part to be joined at feed rates of up to 60 m/min produces weld seams with a length from 0.6 mm to 15.7 mm using a pulsed Nd:YAG laser with a pulse duration of up to 50 ms. Due to the low energy input, typically 1 J to 6 J, a weld width as small as 50 μm and a weld depth as small as 20 pm have been attained. This results in low distortion of the joined watch components. Within this paper this new welding process will be explained and several examples of joined components will be presented with respect to fundamentals and the sustainable implementation of the SHADOW (R) welding technique into watch manufacturing and electronic industry. For microsystem applications the laser joining technology is modified to join even silicon and glass parts without any melting based on the formation of a thermally induced oxygen bond. New fields of applications for joining different materials such as steel to brass or steel to copper for electrical interconnects will be discussed. Here the SHADOW (R) welding technique offers new possibilities for the combination of good electrical properties of copper with high mechanical stiffness of steel. The paper will give a closer look to microjoining applications especially using the SHADOW (R) welding technique. Basics of the process as well as its application on dedicated examples will be shown for small parts such as axis-wheel combinations and electrical connectors.

Developing Implantable Neuroprosthetics: a New Model in Pig

PubMed Central

Yin, Ming; Aceros, Juan; Agha, Naubahar; Minxha, Juri; Komar, Jacob; Patterson, William; Bull, Christopher; Nurmikko, Arto

2014-01-01

A new model has been established in the domestic pig for neural prosthetic device development and testing. To this end, we report on a complete neural prosthetic developmental system using a wireless sensor as the implant, a pig as the animal model, and a novel data acquisition paradigm for actuator control. A new type of stereotactic frame with clinically-inspired fixations pins that place the pig brain in standard surgical plane was developed and tested with success during the implantation of the microsystem. The microsystem implanted was an ultralow power (12.5mW) 16-channel intracortical/epicranial device transmitting broadband (40kS/s) data over a wireless infrared telemetric link. Pigs were implanted and neural data was collected over a period of 5 weeks, clearly showing single unit spiking activity. PMID:22254977

Developing implantable neuroprosthetics: a new model in pig.

PubMed

Borton, David; Yin, Ming; Aceros, Juan; Agha, Naubahar; Minxha, Juri; Komar, Jacob; Patterson, William; Bull, Christopher; Nurmikko, Arto

2011-01-01

A new model has been established in the domestic pig for neural prosthetic device development and testing. To this end, we report on a complete neural prosthetic developmental system using a wireless sensor as the implant, a pig as the animal model, and a novel data acquisition paradigm for actuator control. A new type of stereotactic frame with clinically-inspired fixations pins that place the pig brain in standard surgical plane was developed and tested with success during the implantation of the microsystem. The microsystem implanted was an ultra-low power (12.5 mW) 16-channel intracortical/epicranial device transmitting broadband (40 kS/s) data over a wireless infrared telemetric link. Pigs were implanted and neural data was collected over a period of 5 weeks, clearly showing single unit spiking activity.

Top-down Approach for the Direct Synthesis, Patterning, and Operation of Artificial Micromuscles on Flexible Substrates.

PubMed

Maziz, Ali; Plesse, Cédric; Soyer, Caroline; Cattan, Eric; Vidal, Frédéric

2016-01-27

Recent progress in the field of microsystems on flexible substrates raises the need for alternatives to the stiffness of classical actuation technologies. This paper reports a top-down process to microfabricate soft conducting polymer actuators on substrates on which they ultimately operate. The bending microactuators were fabricated by sequentially stacking layers using a layer polymerization by layer polymerization of conducting polymer electrodes and a solid polymer electrolyte. Standalone microbeams thinner than 10 μm were fabricated on SU-8 substrates associated with a bottom gold electrical contact. The operation of microactuators was demonstrated in air and at low voltage (±4 V).

Smart integrated microsystems: the energy efficiency challenge (Conference Presentation) (Plenary Presentation)

NASA Astrophysics Data System (ADS)

Benini, Luca

2017-06-01

The "internet of everything" envisions trillions of connected objects loaded with high-bandwidth sensors requiring massive amounts of local signal processing, fusion, pattern extraction and classification. From the computational viewpoint, the challenge is formidable and can be addressed only by pushing computing fabrics toward massive parallelism and brain-like energy efficiency levels. CMOS technology can still take us a long way toward this goal, but technology scaling is losing steam. Energy efficiency improvement will increasingly hinge on architecture, circuits, design techniques such as heterogeneous 3D integration, mixed-signal preprocessing, event-based approximate computing and non-Von-Neumann architectures for scalable acceleration.

Fabrication of Fresnel micro lens array in borosilicate glass by F2-laser ablation for glass interposer application

NASA Astrophysics Data System (ADS)

Brusberg, Lars; Neitz, Marcel; Schröder, Henning; Fricke-Begemann, Thomas; Ihlemann, Jürgen

2014-03-01

The future need for more bandwidth forces the development of optical transmission solutions for rack-to-rack, boardto- board and chip-to-chip interconnects. The goals are significant reduction of power consumption, highest density and potential for bandwidth scalability to overcome the limitations of the systems today with mostly copper based interconnects. For system integration the enabling of thin glass as a substrate material for electro-optical components with integrated micro-optics for efficient light coupling to integrated optical waveguides or fibers is becoming important. Our glass based packaging approach merges micro-system packaging and glass integrated optics. This kind of packaging consists of a thin glass substrate with integrated micro lenses providing a platform for photonic component assembly and optical fiber or waveguide interconnection. Thin glass is commercially available in panel and wafer size and characterizes excellent optical and high frequency properties. That makes it perfect for microsystem packaging. A suitable micro lens approach has to be comparable with different commercial glasses and withstand post-processing like soldering. A benefit of using laser ablated Fresnel lenses is the planar integration capability in the substrate for highest integration density. In the paper we introduce our glass based packaging concept and the Fresnel lens design for different scenarios like chip-to-fiber, chip-to-optical-printed-circuit-board coupling. Based on the design the Fresnel lenses were fabricated by using a 157 nm fluorine laser ablation system.

Review of the potential of a wireless MEMS and TFT microsystems for the measurement of pressure in the GI tract.

PubMed

Arshak, A; Arshak, K; Waldron, D; Morris, D; Korostynska, O; Jafer, E; Lyons, G

2005-06-01

Telemetry capsules have existed since the 1950s and were used to measure temperature, pH or pressure inside the gastrointestinal (GI) tract. It was hoped that these capsules would replace invasive techniques in the diagnosis of function disorders in the GI tract. However, problems such as signal loss and uncertainty of the pills position limited their use in a clinical setting. In this paper, a review of the capabilities of MicroElectroMechanical Systems (MEMS) and thick film technology (TFT) for the fabrication of a wireless pressure sensing microsystem is presented. The circuit requirements and methods of data transfer are examined. The available fabrication methods for MEMS sensors are also discussed and examples of wireless sensors are given. Finally the limitations of each technology are examined.

European MEMS foundries

NASA Astrophysics Data System (ADS)

Salomon, Patric R.

2003-01-01

According to the latest release of the NEXUS market study, the market for MEMS or Microsystems Technology (MST) is predicted to grow to $68B by the year 2005, with systems containing these components generating even higher revenues and growth. The latest advances in MST/MEMS technology have enabled the design of a new generation of microsystems that are smaller, cheaper, more reliable, and consume less power. These integrated systems bring together numerous analog/mixed signal microelectronics blocks and MEMS functions on a single chip or on two or more chips assembled within an integrated package. In spite of all these advances in technology and manufacturing, a system manufacturer either faces a substantial up-front R&D investment to create his own infrastructure and expertise, or he can use design and foundry services to get the initial product into the marketplace fast and with an affordable investment. Once he has a viable product, he can still think about his own manufacturing efforts and investments to obtain an optimized high volume manufacturing for the specific product. One of the barriers to successful exploitation of MEMS/MST technology has been the lack of access to industrial foundries capable of producing certified microsystems devices in commercial quantities, including packaging and test. This paper discusses Multi-project wafer (MPW) runs, requirements for foundries and gives some examples of foundry business models. Furthermore, this paper will give an overview on MST/MEMS services that are available in Europe, including pure commercial activities, European project activities (e.g. Europractice), and some academic services.

Preface

NASA Astrophysics Data System (ADS)

Dascalu, Dan; Muller, Alexandru

2003-07-01

It is a great pleasure for us to introduce this special issue featuring selected papers from the 13th European Micromechanics Workshop, MME'02, organized by the National Institute for R&D in Microtechnologies (IMT Bucharest). The conference was held in the beautiful mountain resort Sinaia, a former Romanian royal residence, 120 km north of Bucharest. In 1989 the first MME workshop was held in Twente, since then it has traveled from one Western European country to another. MME'02 is the first workshop to have been held in Eastern Europe. MEMS consolidated as an exciting field for research and development over the past decade and the MEMS industry is now a substantial presence. Commercial applications of MEMS technology now include pressure, chemical, acceleration, rotation rate sensors, microphones, microdevices in microfluidic systems for bio-engineering, RF switches and fiber optic networks (optical switches), etc. Microtechnology is one of the major growth markets of the 21st century. Microsystems are now key products in information and communication technology, automotive engineering and are also increasing in the fields of chemistry and life sciences. The 6th Framework Programme, already underway, promotes long-term initiatives in this area of research. After reviewing 72 high-quality abstracts submitted for the conference, the programme organizers selected 68 for presentation during the one and half days of the workshop. There were 62 papers from Europe and six papers from outside Europe (USA, Canada and Singapore). The papers covered materials, processing, modeling and applications of micromachining and micromachined devices. Following the tradition of the MME workshops, non-invited papers were discussed at poster sessions after a short oral presentation. This formula was again highly appreciated and stimulated much discussion between scientists. Five invited papers were also presented orally. These invited talks reviewed the latest technological developments in MEMS topics. This year special attention was devoted to the emerging RF MEMS technology. In addition, a presentation of `Microsystems in FP6' was held as a special invited talk at the end of the conference. The selection of papers for inclusion in this issue was difficult, due to the high quality of the papers of the workshop. The final content is a result of the collaboration of the programme committee and Institute of Physics Publishing staff. We wish to thank our colleagues from the MME'02 programme committee: A G R Evans (Southampton University), M Hill (Cork Institute of Technology) and R Wolffenbuttel (Delft University of Technology). We are grateful to all participants for making the workshop a very stimulating meeting place for the MEMS community in Europe.

Packaging Technology Developed for High-Temperature Silicon Carbide Microsystems

NASA Technical Reports Server (NTRS)

Chen, Liang-Yu; Hunter, Gary W.; Neudeck, Philip G.

2001-01-01

High-temperature electronics and sensors are necessary for harsh-environment space and aeronautical applications, such as sensors and electronics for space missions to the inner solar system, sensors for in situ combustion and emission monitoring, and electronics for combustion control for aeronautical and automotive engines. However, these devices cannot be used until they can be packaged in appropriate forms for specific applications. Suitable packaging technology for operation temperatures up to 500 C and beyond is not commercially available. Thus, the development of a systematic high-temperature packaging technology for SiC-based microsystems is essential for both in situ testing and commercializing high-temperature SiC sensors and electronics. In response to these needs, researchers at Glenn innovatively designed, fabricated, and assembled a new prototype electronic package for high-temperature electronic microsystems using ceramic substrates (aluminum nitride and aluminum oxide) and gold (Au) thick-film metallization. Packaging components include a ceramic packaging frame, thick-film metallization-based interconnection system, and a low electrical resistance SiC die-attachment scheme. Both the materials and fabrication process of the basic packaging components have been tested with an in-house-fabricated SiC semiconductor test chip in an oxidizing environment at temperatures from room temperature to 500 C for more than 1000 hr. These test results set lifetime records for both high-temperature electronic packaging and high-temperature electronic device testing. As required, the thick-film-based interconnection system demonstrated low (2.5 times of the room-temperature resistance of the Au conductor) and stable (decreased 3 percent in 1500 hr of continuous testing) electrical resistance at 500 C in an oxidizing environment. Also as required, the electrical isolation impedance between printed wires that were not electrically joined by a wire bond remained high (greater than 0.4 GW) at 500 C in air. The attached SiC diode demonstrated low (less than 3.8 W/mm2) and relatively consistent dynamic resistance from room temperature to 500 C. These results indicate that the prototype package and the compatible die-attach scheme meet the initial design standards for high-temperature, low-power, and long-term operation. This technology will be further developed and evaluated, especially with more mechanical tests of each packaging element for operation at higher temperatures and longer lifetimes.

A method for compression of intra-cortically-recorded neural signals dedicated to implantable brain-machine interfaces.

PubMed

Shaeri, Mohammad Ali; Sodagar, Amir M

2015-05-01

This paper proposes an efficient data compression technique dedicated to implantable intra-cortical neural recording devices. The proposed technique benefits from processing neural signals in the Discrete Haar Wavelet Transform space, a new spike extraction approach, and a novel data framing scheme to telemeter the recorded neural information to the outside world. Based on the proposed technique, a 64-channel neural signal processor was designed and prototyped as a part of a wireless implantable extra-cellular neural recording microsystem. Designed in a 0.13- μ m standard CMOS process, the 64-channel neural signal processor reported in this paper occupies ∼ 0.206 mm(2) of silicon area, and consumes 94.18 μW when operating under a 1.2-V supply voltage at a master clock frequency of 1.28 MHz.

Fabrication of 3D solenoid microcoils in silica glass by femtosecond laser wet etch and microsolidics

NASA Astrophysics Data System (ADS)

Meng, Xiangwei; Yang, Qing; Chen, Feng; Shan, Chao; Liu, Keyin; Li, Yanyang; Bian, Hao; Du, Guangqing; Hou, Xun

2015-02-01

This paper reports a flexible fabrication method for 3D solenoid microcoils in silica glass. The method consists of femtosecond laser wet etching (FLWE) and microsolidics process. The 3D microchannel with high aspect ratio is fabricated by an improved FLWE method. In the microsolidics process, an alloy was chosen as the conductive metal. The microwires are achieved by injecting liquid alloy into the microchannel, and allowing the alloy to cool and solidify. The alloy microwires with high melting point can overcome the limitation of working temperature and improve the electrical property. The geometry, the height and diameter of microcoils were flexibly fabricated by the pre-designed laser writing path, the laser power and etching time. The 3D microcoils can provide uniform magnetic field and be widely integrated in many magnetic microsystems.

Transient nanobubbles in short-time electrolysis

NASA Astrophysics Data System (ADS)

Svetovoy, Vitaly B.; Sanders, Remco G. P.; Elwenspoek, Miko C.

2013-05-01

Water electrolysis in a microsystem is observed and analyzed on a short-time scale of ∼10 μs. The very unusual properties of the process are stressed. An extremely high current density is observed because the process is not limited by the diffusion of electroactive species. The high current is accompanied by a high relative supersaturation, S > 1000, that results in homogeneous nucleation of bubbles. On the short-time scale only nanobubbles can be formed. These nanobubbles densely cover the electrodes and aggregate at a later time to microbubbles. The effect is significantly intensified with a small increase of temperature. Application of alternating polarity voltage pulses produces bubbles containing a mixture of hydrogen and oxygen. Spontaneous reaction between gases is observed for stoichiometric bubbles with sizes smaller than ∼150 nm. Such bubbles disintegrate violently affecting the surfaces of the electrodes.

Synthesis of branched polymers under continuous-flow microprocess: an improvement of the control of macromolecular architectures.

PubMed

Bally, Florence; Serra, Christophe A; Brochon, Cyril; Hadziioannou, Georges

2011-11-15

Polymerization reactions can benefit from continuous-flow microprocess in terms of kinetics control, reactants mixing or simply efficiency when high-throughput screening experiments are carried out. In this work, we perform for the first time the synthesis of branched macromolecular architecture through a controlled/'living' polymerization technique, in tubular microreactor. Just by tuning process parameters, such as flow rates of the reactants, we manage to generate a library of polymers with various macromolecular characteristics. Compared to conventional batch process, polymerization kinetics shows a faster initiation step and more interestingly an improved branching efficiency. Due to reduced diffusion pathway, a characteristic of microsystems, it is thus possible to reach branched polymers exhibiting a denser architecture, and potentially a higher functionality for later applications. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CMOS Electrochemical Instrumentation for Biosensor Microsystems: A Review.

PubMed

Li, Haitao; Liu, Xiaowen; Li, Lin; Mu, Xiaoyi; Genov, Roman; Mason, Andrew J

2016-12-31

Modern biosensors play a critical role in healthcare and have a quickly growing commercial market. Compared to traditional optical-based sensing, electrochemical biosensors are attractive due to superior performance in response time, cost, complexity and potential for miniaturization. To address the shortcomings of traditional benchtop electrochemical instruments, in recent years, many complementary metal oxide semiconductor (CMOS) instrumentation circuits have been reported for electrochemical biosensors. This paper provides a review and analysis of CMOS electrochemical instrumentation circuits. First, important concepts in electrochemical sensing are presented from an instrumentation point of view. Then, electrochemical instrumentation circuits are organized into functional classes, and reported CMOS circuits are reviewed and analyzed to illuminate design options and performance tradeoffs. Finally, recent trends and challenges toward on-CMOS sensor integration that could enable highly miniaturized electrochemical biosensor microsystems are discussed. The information in the paper can guide next generation electrochemical sensor design.

Microsystem enabled photovoltaic modules and systems

DOEpatents

Nielson, Gregory N; Sweatt, William C; Okandan, Murat

2015-05-12

A microsystem enabled photovoltaic (MEPV) module including: an absorber layer; a fixed optic layer coupled to the absorber layer; a translatable optic layer; a translation stage coupled between the fixed and translatable optic layers; and a motion processor electrically coupled to the translation stage to controls motion of the translatable optic layer relative to the fixed optic layer. The absorber layer includes an array of photovoltaic (PV) elements. The fixed optic layer includes an array of quasi-collimating (QC) micro-optical elements designed and arranged to couple incident radiation from an intermediate image formed by the translatable optic layer into one of the PV elements such that it is quasi-collimated. The translatable optic layer includes an array of focusing micro-optical elements corresponding to the QC micro-optical element array. Each focusing micro-optical element is designed to produce a quasi-telecentric intermediate image from substantially collimated radiation incident within a predetermined field of view.

Micro-gas analysis system for measurement of nitric oxide and nitrogen dioxide: respiratory treatment and environmental mobile monitoring.

PubMed

Toda, Kei; Hato, Yuki; Ohira, Shin-ichi; Namihira, Takao

2007-11-05

In this paper, novel microsystems for gas analysis and gas generation are described. The same microchannel devices covered with a gas permeable membrane were used for both the gas collection and the gas generation. For the first time, a dual liquid flow system was utilized in a micro-gas analysis system. Even though micropumps are utilized in the dual line microsystem, a good baseline was obtained in the NO2 measurement with Griess-Saltzman chemistry. The system was developed for on-site measurements in medical treatment; the treatment is of respiratory disease syndrome by NO inhalation and the monitoring is of the product NO and the harmful byproduct NO2. The system was also applied to mobile atmospheric monitoring. Chemical NO generation using the microchannel device was investigated for safe NO inhalation as an alternative to a NO generator based on pulsed arc discharge.

From microsystems technology to the Saenger II space transportation system

NASA Astrophysics Data System (ADS)

Vogels, Hanns Arnt

The role of space projects as drivers and catalysts of technology advances is discussed and illustrated from the perspective of the West German aerospace industry, summarizing a talk presented at the 1986 meeting of the German aerospace society DGLR. The history of space-transportation-system (STS) technology since the 1950s is traced, emphasizing the needs for greater payload weights and lower costs, and the design concept of Saenger II, a proposed two-stage ESA STS employing a hypersonic jet transport aircraft as its first stage, is outlined. It is argued that experience gained in developing the rocket-launched Hermes STS will be applicable to the second stage of Saenger II. Recent developments in microsystems (combining microelectronics, micromechanics, and microoptics), advanced materials (fiber-reinforced plastics, metals, and ceramics), and energy technology (hydrogen-based systems and solar cells) are surveyed, and their applicability to STSs is considered.

Active Microelectronic Neurosensor Arrays for Implantable Brain Communication Interfaces

PubMed Central

Song, Y.-K.; Borton, D. A.; Park, S.; Patterson, W. R.; Bull, C. W.; Laiwalla, F.; Mislow, J.; Simeral, J. D.; Donoghue, J. P.; Nurmikko, A. V.

2010-01-01

We have built a wireless implantable microelectronic device for transmitting cortical signals transcutaneously. The device is aimed at interfacing a microelectrode array cortical to an external computer for neural control applications. Our implantable microsystem enables presently 16-channel broadband neural recording in a non-human primate brain by converting these signals to a digital stream of infrared light pulses for transmission through the skin. The implantable unit employs a flexible polymer substrate onto which we have integrated ultra-low power amplification with analog multiplexing, an analog-to-digital converter, a low power digital controller chip, and infrared telemetry. The scalable 16-channel microsystem can employ any of several modalities of power supply, including via radio frequency by induction, or infrared light via a photovoltaic converter. As of today, the implant has been tested as a sub-chronic unit in non-human primates (~ 1 month), yielding robust spike and broadband neural data on all available channels. PMID:19502132

Photoelectrochemically driven self-assembly method

DOEpatents

Nielson, Gregory N.; Okandan, Murat

2017-01-17

Various technologies described herein pertain to assembling electronic devices into a microsystem. The electronic devices are disposed in a solution. Light can be applied to the electronic devices in the solution. The electronic devices can generate currents responsive to the light applied to the electronic devices in the solution, and the currents can cause electrochemical reactions that functionalize regions on surfaces of the electronic devices. Additionally or alternatively, the light applied to the electronic devices in the solution can cause the electronic devices to generate electric fields, which can orient the electronic devices and/or induce movement of the electronic devices with respect to a receiving substrate. Further, electrodes on a receiving substrate can be biased to attract and form connections with the electronic devices having the functionalized regions on the surfaces. The microsystem can include the receiving substrate and the electronic devices connected to the receiving substrate.

CMOS Electrochemical Instrumentation for Biosensor Microsystems: A Review

PubMed Central

Li, Haitao; Liu, Xiaowen; Li, Lin; Mu, Xiaoyi; Genov, Roman; Mason, Andrew J.

2016-01-01

Modern biosensors play a critical role in healthcare and have a quickly growing commercial market. Compared to traditional optical-based sensing, electrochemical biosensors are attractive due to superior performance in response time, cost, complexity and potential for miniaturization. To address the shortcomings of traditional benchtop electrochemical instruments, in recent years, many complementary metal oxide semiconductor (CMOS) instrumentation circuits have been reported for electrochemical biosensors. This paper provides a review and analysis of CMOS electrochemical instrumentation circuits. First, important concepts in electrochemical sensing are presented from an instrumentation point of view. Then, electrochemical instrumentation circuits are organized into functional classes, and reported CMOS circuits are reviewed and analyzed to illuminate design options and performance tradeoffs. Finally, recent trends and challenges toward on-CMOS sensor integration that could enable highly miniaturized electrochemical biosensor microsystems are discussed. The information in the paper can guide next generation electrochemical sensor design. PMID:28042860

The Development of Metal Oxide Chemical Sensing Nanostructures

NASA Technical Reports Server (NTRS)

Hunter, G. W.; VanderWal,R. L.; Xu, J. C.; Evans, L. J.; Berger, G. M.; Kulis, M. J.

2008-01-01

This paper discusses sensor development based on metal oxide nanostructures and microsystems technology. While nanostructures such as nanowires show significant potential as enabling materials for chemical sensors, a number of significant technical challenges remain. This paper discusses development to address each of these technical barriers: 1) Improved contact and integration of the nanostructured materials with microsystems in a sensor structure; 2) Control of nanostructure crystallinity to allow control of the detection mechanism; and 3) Widening the range of gases that can be detected by fabricating multiple nanostructured materials. A sensor structure composed of three nanostructured oxides aligned on a single microsensor has been fabricated and tested. Results of this testing are discussed and future development approaches are suggested. It is concluded that while this work lays the foundation for further development, these are the beginning steps towards realization of repeatable, controlled sensor systems using oxide based nanostructures.

Optofluidic opportunities in global health, food, water and energy

NASA Astrophysics Data System (ADS)

Chen, Yih-Fan; JiangLj, Mm, Aj,; Vo Contributed Equally To This Paper., Li; Mancuso, Matthew; Jain, Aadhar; Oncescu, Vlad; Erickson, David

2012-07-01

Optofluidics is a rapidly advancing field that utilizes the integration of optics and microfluidics to provide a number of novel functionalities in microsystems. In this review, we discuss how this approach can potentially be applied to address some of the greatest challenges facing both the developing and developed world, including healthcare, food shortages, malnutrition, water purification, and energy. While medical diagnostics has received most of the attention to date, here we show that some other areas can also potentially benefit from optofluidic technology. Whenever possible we briefly describe how microsystems are currently used to address these problems and then explain why and how optofluidics can provide better solutions. The focus of the article is on the applications of optofluidic techniques in low-resource settings, but we also emphasize that some of these techniques, such as those related to food production, food safety assessment, nutrition monitoring, and energy production, could be very useful in well-developed areas as well.

The BioSentinel Bioanalytical Microsystem: Characterizing DNA Radiation Damage in Living Organisms Beyond Earth Orbit

NASA Technical Reports Server (NTRS)

Ricco, A. J.; Hanel, R.; Bhattacharya, S.; Boone, T.; Tan, M.; Mousavi, A.; Rademacher, A.; Schooley, A.; Klamm, B.; Benton, J.;

Operating principles of an electrothermal vibrometer for optical switching applications

NASA Astrophysics Data System (ADS)

Pai, Min-fan; Tien, Norman C.

1999-09-01

A compact polysilicon surface-micromachined microactuator designed for optical switching applications is described. This actuator is fabricated using the foundry MUMPs process provided by Cronos Integrated Microsystems Inc. Actuated electrothermally, the microactuator allows fast switching speeds and can be operated with a low voltage square-wave signal. The design, operation mechanisms for this long-range and high frequency thermal actuation are described. A vertical micromirror integrated with this actuator can be operated with a 10.5 V, 20 kHz 15% duty-cycle pulse signal, achieving a lateral moving speed higher than 15.6 mm/sec. The optical switch has been operated to frequencies as high as 30 kHz.

Electrically Isolating Subsystems in SOAC Technologies

NASA Technical Reports Server (NTRS)

Boyd, R. M.; Mojarradi, M. M.; Kuhn, W. B.; Shumaker, E. A.

2001-01-01

Integrated circuit fabrication technology has evolved to the point that it is possible to construct complete systems, including power, data processing, and communications, on a single chip. Such System-on-a-chip (SOAC) technologies can enable drastic reductions in spacecraft size and weight, lowering the cost of missions and presenting new mission opportunities. This paper overviews some key enabling technologies unique to the needs of spacecraft for outer-planet exploration and missions requiring extreme resistance to radiation such as Europa orbiters and Europa Landers. The work is being carried out by Kansas State University (KSU) under direction of the Center for Integrated Space Microsystems (CISM) at NASA's Jet Propulsion Laboratory. Additional information is contained in the original extended abstract.

Combining clinical microsystems and an experiential quality improvement curriculum to improve residency education in internal medicine.

PubMed

Tess, Anjala V; Yang, Julius J; Smith, C Christopher; Fawcett, Caitlin M; Bates, Carol K; Reynolds, Eileen E

2009-03-01

Beth Israel Deaconess Medical Center's internal medicine residency program was admitted to the new Education Innovation Project accreditation pathway of the Accreditation Council of Graduate Medical Education to begin in July 2006. The authors restructured the inpatient medical service to create clinical microsystems in which residents practice throughout residency. Program leadership then mandated an active curriculum in quality improvement based in those microsystems. To provide the experience to every graduating resident, a core faculty in patient safety was trained in the basics of quality improvement. The authors hypothesized that such changes would increase the number of residents participating in quality improvement projects, improve house officer engagement in quality improvement work, enhance the culture of safety the residents perceive in their training environment, improve work flow on the general medicine ward rotations, and improve the overall educational experience for the residents on ward rotations.The authors describe the first 18 months of the intervention (July 2006 to January 2008). The authors assessed attitudes and the educational experience with surveys and evaluation forms. After the intervention, the authors documented residents' participation in projects that overlapped with hospital priorities. More residents reported roles in designing and implementing quality improvement changes. Residents also noted greater satisfaction with the quality of care they deliver. Fewer residents agreed or strongly agreed that the new admitting system interfered with communication. Ongoing residency program assessment showed an improved perception of workload, and educational ratings of rotations improved. The changes required few resources and can be transported to other settings.

MEMS for medical technology applications

NASA Astrophysics Data System (ADS)

Frisk, Thomas; Roxhed, Niclas; Stemme, Göran

2007-01-01

This paper gives an in-depth description of two recent projects at the Royal Institute of Technology (KTH) which utilize MEMS and microsystem technology for realization of components intended for specific applications in medical technology and diagnostic instrumentation. By novel use of the DRIE fabrication technology we have developed side-opened out-of-plane silicon microneedles intended for use in transdermal drug delivery applications. The side opening reduces clogging probability during penetration into the skin and increases the up-take area of the liquid in the tissue. These microneedles offer about 200µm deep and pain-free skin penetration. We have been able to combine the microneedle chip with an electrically and heat controlled liquid actuator device where expandable microspheres are used to push doses of drug liquids into the skin. The entire unit is made of low cost materials in the form of a square one cm-sized patch. Finally, the design, fabrication and evaluation of an integrated miniaturized Quartz Crystal Microbalance (QCM) based "electronic nose" microsystem for detection of narcotics is described. The work integrates a novel environment-to-chip sample interface with the sensor element. The choice of multifunctional materials and the geometric features of a four-component microsystem allow a functional integration of a QCM crystal, electrical contacts, fluidic contacts and a sample interface in a single system with minimal assembly effort, a potential for low-cost manufacturing, and a few orders of magnitude reduced in system size (12*12*4 mm 3) and weight compared to commercially available instruments. The sensor chip was successfully used it for the detection of 200 ng of narcotics sample.

Cooperative Microsystems and Neural Interfaces

DTIC Science & Technology

2009-03-04

polyimide coil for wireless power/data transfer F. Solzbacher, University of Utah – K. Shenoy, Stanford • Demonstrated wireless operation of implanted...Approach: Collapse cable into a single biocompatible optical fiber. Challenge: develop and demonstrate low power multi-channel data acquisition chip

Nickel hydrogen battery expert system

NASA Technical Reports Server (NTRS)

Shiva, Sajjan G.

1991-01-01

The Hubble Telescope Battery Testbed at MSFC uses the Nickel Cadmium (NiCd) Battery Expert System (NICBES-2) which supports the evaluation of performance of Hubble Telescope spacecraft batteries and provides alarm diagnosis and action advice. NICBES-2 provides a reasoning system along with a battery domain knowledge base to achieve this battery health management function. An effort is summarized which was used to modify NICBES-2 to accommodate Nickel Hydrogen (NiH2) battery environment now in MSFC testbed. The NICBES-2 is implemented on a Sun Microsystem and is written in SunOS C and Quintus Prolog. The system now operates in a multitasking environment. NICBES-2 spawns three processes: serial port process (SPP); data handler process (DHP); and the expert system process (ESP) in order to process the telemetry data and provide the status and action advice. NICBES-2 performs orbit data gathering, data evaluation, alarm diagnosis and action advice and status and history display functions. The adaptation of NICBES-2 to work with NiH2 battery environment required modification to all of the three component processes.

Corti's organ physiology-based cochlear model: a microelectronic prosthetic implant

NASA Astrophysics Data System (ADS)

Rios, Francisco; Fernandez-Ramos, Raquel; Romero-Sanchez, Jorge; Martin, Jose Francisco

2003-04-01

Corti"s Organ is an Electro-Mechanical transducer that allows the energy coupling between acoustical stimuli and auditory nerve. Although the structure and funtionality of this organ are complex, state of the art models have been currently developed and tested. Cochlea model presented in this paper is based on the theories of Bekesy and others and concerns on the behaviour of auditory system on frequency-place domain and mechanisms of lateral inhibition. At the same time, present state of technology will permit us developing a microsystem that reproduce this phenomena applied to hearing aid prosthesis. Corti"s Organ is composed of more than 20.000 cilia excited by mean of travelling waves. These waves produce relative pressures distributed along the cochlea, exciting an specific number of cilia in a local way. Nonlinear mechanisms of local adaptation to the intensity (external cilia cells) and lateral inhibition (internal cilia cells) allow the selection of very few elements excited. These transmit a very precise intensity and frequency information. These signals are the only ones coupled to the auditory nerve. Distribution of pressure waves matches a quasilogaritmic law due to Cochlea morphology. Microsystem presented in this paper takes Bark"s law as an approximation to this behaviour consisting on grouped arbitrary elements composed of a set of selective coupled exciters (bank of filters according to Patterson"s model).These sets apply the intensity adaptation principles and lateral inhibition. Elements excited during the process generate a bioelectric signal in the same way than cilia cell. A microelectronic solution is presented for the development of an implantable prosthesis device.

Design and validation of a microfluidic device for blood-brain barrier monitoring and transport studies

NASA Astrophysics Data System (ADS)

Ugolini, Giovanni Stefano; Occhetta, Paola; Saccani, Alessandra; Re, Francesca; Krol, Silke; Rasponi, Marco; Redaelli, Alberto

2018-04-01

In vitro blood-brain barrier models are highly relevant for drug screening and drug development studies, due to the challenging task of understanding the transport mechanism of drug molecules through the blood-brain barrier towards the brain tissue. In this respect, microfluidics holds potential for providing microsystems that require low amounts of cells and reagent and can be potentially multiplexed for increasing the ease and throughput of the drug screening process. We here describe the design, development and validation of a microfluidic device for endothelial blood-brain barrier cell transport studies. The device comprises of two microstructured layers (top culture chamber and bottom collection chamber) sandwiching a porous membrane for the cell culture. Microstructured layers include two pairs of physical electrodes, embedded into the device layers by geometrically defined guiding channels with computationally optimized positions. These electrodes allow the use of commercial electrical measurement systems for monitoring trans-endothelial electrical resistance (TEER). We employed the designed device for performing preliminary assessment of endothelial barrier formation with murine brain endothelial cells (Br-bEnd5). Results demonstrate that cellular junctional complexes effectively form in the cultures (expression of VE-Cadherin and ZO-1) and that the TEER monitoring systems effectively detects an increase of resistance of the cultured cell layers indicative of tight junction formation. Finally, we validate the use of the described microsystem for drug transport studies demonstrating that Br-bEnd5 cells significantly hinder the transport of molecules (40 kDa and 4 kDa dextran) from the top culture chamber to the bottom collection chamber.

Sandia National Laboratories: 100 Resilient Cities

Science.gov Websites

Materials Science Nanodevices & Microsystems Radiation Effects & High Energy Density Science front of monitors Emergency Response Cognitive testing Psychological/ Cognitive Effects The Rockefeller Body's Systems - 100 Resilient Cities Blog News Releases City resilience: Sandia analyzes effects of

Sandia National Laboratories: Microsystems Science & Technology Center

Science.gov Websites

Programs Nuclear Weapons About Nuclear Weapons Safety & Security Weapons Science & Technology Robotics R&D 100 Awards Laboratory Directed Research & Development Technology Deployment Centers Audit Sandia's Economic Impact Licensing & Technology Transfer Browse Technology Portfolios

EDITORIAL: The Fourth International Workshop on Microfactories (IWMF'04)

NASA Astrophysics Data System (ADS)

Chu, Jiaru; Maeda, Ryutaro

2005-10-01

This special section of Journal of Micromechanics and Microengineering is devoted to the fourth International Workshop on Microfactories. After the first three successful Workshops, which took place in Tsukuba, Japan in 1998, Fribourg, Switzerland in 2000 and Minneapolis, USA in 2002, the fourth (IWMF'04) was held in Shanghai, China on 15-17 October 2004. The concept of the `microfactory' and miniaturized production systems was first proposed by the Mechanical Engineering Laboratory in Japan who demonstrated the feasibility of downsizing energy-saving, distributed and eventually environmentally conscious manufacturing systems. There is incredible potential in reducing the physical scale of numerous processes related to the manufacture of many forms of future dense `mechatronic' products and in the manipulation of microscopic and nanoscopic objects and materials for the benefit of mankind. Small systems capable of these operations can be referred to as `microfactories'. A worldwide effort is currently underway to bring such microfactories to fruition. MEMS, MST and micromachines are regarded as synonyms, but they do not necessarily have the same meaning. In particular, differences can be found in their technological approaches. Roughly speaking, research and development in the USA is based primarily on surface or bulk silicon micromachining processes, and the ideal realization of MEMS seems to be the monolithic device. The European approach also focuses on integration between electronics and mechanics but, especially in connection with the development of `µTAS', it also demands the integration of non-mechanical components into the system. In Japan the approaches for MST are said to be rather less focused. Besides the above-mentioned `classical' microsystem technologies, down-scaling of conventional manufacturing methods, or non-silicon based device processing within this field, completely new technological methods are also considered as `microsystem technologies'. Out of more than 150 submitted abstracts, 138 papers were accepted for presentation at the workshop. Of these, a selection of seven high-quality papers have been chosen for presentation in this special section. We would like to express our appreciation of the outstanding efforts made by all involved in the workshop, especially the local committee for all the detailed planning required to make it an interesting meeting.

Socioecological factors influencing women's HIV risk in the United States: qualitative findings from the women's HIV SeroIncidence study (HPTN 064).

PubMed

Frew, Paula M; Parker, Kimberly; Vo, Linda; Haley, Danielle; O'Leary, Ann; Diallo, Dazon Dixon; Golin, Carol E; Kuo, Irene; Soto-Torres, Lydia; Wang, Jing; Adimora, Adaora A; Randall, Laura A; Del Rio, Carlos; Hodder, Sally

2016-08-17

We sought to understand the multilevel syndemic factors that are concurrently contributing to the HIV epidemic among women living in the US. We specifically examined community, network, dyadic, and individual factors to explain HIV vulnerability within a socioecological framework. We gathered qualitative data (120 interviews and 31 focus groups) from a subset of women ages 18-44 years (N = 2,099) enrolled in the HPTN 064 HIV seroincidence estimation study across 10 US communities. We analyzed data from 4 diverse locations: Atlanta, New York City (the Bronx), Raleigh, and Washington, DC. Data were thematically coded using grounded theory methodology. Intercoder reliability was assessed to evaluate consistency of team-based coding practices. The following themes were identified at 4 levels including 1) exosystem (community): poverty prevalence, discrimination, gender imbalances, community violence, and housing challenges; 2) mesosystem (network): organizational social support and sexual concurrency; 3) microsystem (dyadic): sex exchange, interpersonal social support, intimate partner violence; and 4) individual: HIV/STI awareness, risk taking, and substance use. A strong theme emerged with over 80 % of responses linked to the fundamental role of financial insecurity underlying risk-taking behavioral pathways. Multilevel syndemic factors contribute to women's vulnerability to HIV in the US. Financial insecurity is a predominant theme, suggesting the need for tailored programming for women to reduce HIV risk. Clinicaltrials.gov, NCT00995176.

Novel strategies for the formulation and processing of poorly water-soluble drugs.

PubMed

Göke, Katrin; Lorenz, Thomas; Repanas, Alexandros; Schneider, Frederic; Steiner, Denise; Baumann, Knut; Bunjes, Heike; Dietzel, Andreas; Finke, Jan H; Glasmacher, Birgit; Kwade, Arno

2018-05-01

Low aqueous solubility of active pharmaceutical ingredients presents a serious challenge in the development process of new drug products. This article provides an overview on some of the current approaches for the formulation of poorly water-soluble drugs with a special focus on strategies pursued at the Center of Pharmaceutical Engineering of the TU Braunschweig. These comprise formulation in lipid-based colloidal drug delivery systems and experimental as well as computational approaches towards the efficient identification of the most suitable carrier systems. For less lipophilic substances the preparation of drug nanoparticles by milling and precipitation is investigated for instance by means of microsystem-based manufacturing techniques and with special regard to the preparation of individualized dosage forms. Another option to overcome issues with poor drug solubility is the incorporation into nanospun fibers. Copyright © 2017 Elsevier B.V. All rights reserved.

Investigation of improved designs for rotational micromirrors using multiuser MEMS processes

NASA Astrophysics Data System (ADS)

Lin, Julianna E.; Michael, Feras S. J.; Kirk, Andrew G.

2001-04-01

In recent years, the design of rotational micromirrors for use in optical cross connects has received much attention. Although several companies have already produced and marketed a number of torsional mirror devices, more work is still needed to determine how these mirrors can be integrated into optical systems to form compact optical switches. However, recently several commercial MEMS foundry services have become available. Thus, due to the low cost of these prototyping services, new devices can be fabricated in short amounts of time and the designs adapted to meet the needs of different applications. The purpose of this work is to investigate the fabrication of new micromirror designs using the Multi-User MEMS Processes (MUMPs) foundry service available from Cronos Integrated Microsystems, located in North Carolina, USA). Several sets of mirror designs were submitted for fabrication and the resulting structures characterized using a phase-shifting Mirau interferometer. The results of these devices are presented.

A Microsystem Based on Porous Silicon-Glass Anodic Bonding for Gas and Liquid Optical Sensing

PubMed Central

De Stefano, Luca; Malecki, Krzysztof; Della Corte, Francesco G.; Moretti, Luigi; Rea, Ilaria; Rotiroti, Lucia; Rendina, Ivo

2006-01-01

We have recently presented an integrated silicon-glass opto-chemical sensor for lab-on-chip applications, based on porous silicon and anodic bonding technologies. In this work, we have optically characterized the sensor response on exposure to vapors of several organic compounds by means of reflectivity measurements. The interaction between the porous silicon, which acts as transducer layer, and the organic vapors fluxed into the glass sealed microchamber, is preserved by the fabrication process, resulting in optical path increase, due to the capillary condensation of the vapors into the pores. Using the Bruggemann theory, we have calculated the filled pores volume for each substance. The sensor dynamic has been described by time-resolved measurements: due to the analysis chamber miniaturization, the response time is only of 2 s. All these results have been compared with data acquired on the same PSi structure before the anodic bonding process.

Field-temperature phase diagrams of freestanding and substrate-constrained epitaxial Ni-Mn-Ga-Co films for magnetocaloric applications

NASA Astrophysics Data System (ADS)

Diestel, A.; Niemann, R.; Schleicher, B.; Schwabe, S.; Schultz, L.; Fähler, S.

2015-07-01

Ferroic cooling processes that rely on field-induced first-order transformations of solid materials are a promising step towards a more energy-efficient refrigeration technology. In particular, thin films are discussed for their fast heat transfer and possible applications in microsystems. Substrate-constrained films are not useful since their substrates act as a heat sink. In this article, we examine a substrate-constrained and a freestanding epitaxial film of magnetocaloric Ni-Mn-Ga-Co. We compare phase diagrams and entropy changes obtained by magnetic field and temperature scans, which differ. We observe an asymmetry of the hysteresis between heating and cooling branch, which vanishes at high magnetic fields. These effects are discussed with respect to the vector character of a magnetic field, which acts differently on the nucleation and growth processes compared to the scalar character of the temperature.

Development and implementation of a low cost micro computer system for LANDSAT analysis and geographic data base applications

NASA Technical Reports Server (NTRS)

Faust, N.; Jordon, L.

1981-01-01

Since the implementation of the GRID and IMGRID computer programs for multivariate spatial analysis in the early 1970's, geographic data analysis subsequently moved from large computers to minicomputers and now to microcomputers with radical reduction in the costs associated with planning analyses. Programs designed to process LANDSAT data to be used as one element in a geographic data base were used once NIMGRID (new IMGRID), a raster oriented geographic information system, was implemented on the microcomputer. Programs for training field selection, supervised and unsupervised classification, and image enhancement were added. Enhancements to the color graphics capabilities of the microsystem allow display of three channels of LANDSAT data in color infrared format. The basic microcomputer hardware needed to perform NIMGRID and most LANDSAT analyses is listed as well as the software available for LANDSAT processing.

Smart Microsystems with Photonic Element and Their Applications to Aerospace Platforms

NASA Technical Reports Server (NTRS)

Adamovsky, G.; Lekki, J.; Sutter, J. K.; Sarkisov, S. S.; Curley, M. J.; Martin, C. E.

2000-01-01

The need to make manufacturing, operation, and support of airborne vehicles safer and more efficient forces engineers and scientists to look for lighter, cheaper, more reliable technologies. Light weight, immunity to EMI, fire safety, high bandwidth, and high signal fidelity have already made photonics in general and fiber optics in particular an extremely attractive medium for communication purposes. With the fiber optics serving as a central nervous system of the vehicle, generation, detection, and processing of the signal occurs at the peripherals that include smart structures and devices. Due to their interdisciplinary nature, photonic technologies cover such diverse areas as optical sensors and actuators, embedded and distributed sensors, sensing schemes and architectures, harnesses and connectors, signal processing and algorithms. The paper includes a brief description of work in the photonic area that is going on at NASA, especially at the Glenn Research Center (GRC).

Java: A New Brew for Educators, Administrators and Students.

ERIC Educational Resources Information Center

Gordon, Barbara

1996-01-01

Java is an object-oriented programming language developed by Sun Microsystems; its benefits include platform independence, security, and interactivity. Within the college community, Java is being used in programming courses, collaborative technology research projects, computer graphics instruction, and distance education. (AEF)

Family Wellness: An Ecological Perspective.

ERIC Educational Resources Information Center

Fannin, Ronald A.

Bronfenbrenner's (1979) concept of human ecology emphasizes the effect of the environment, both physical and psychological, on individual development. Bronfenbrenner's contexts which affect the development of the individual (microsystem, mesosystem, exosystem, macrosystem) can also be defined for the family in an ecological model of family…

NETS - A NEURAL NETWORK DEVELOPMENT TOOL, VERSION 3.0 (MACINTOSH VERSION)

NASA Technical Reports Server (NTRS)

Phillips, T. A.

1994-01-01

NETS, A Tool for the Development and Evaluation of Neural Networks, provides a simulation of Neural Network algorithms plus an environment for developing such algorithms. Neural Networks are a class of systems modeled after the human brain. Artificial Neural Networks are formed from hundreds or thousands of simulated neurons, connected to each other in a manner similar to brain neurons. Problems which involve pattern matching readily fit the class of problems which NETS is designed to solve. NETS uses the back propagation learning method for all of the networks which it creates. The nodes of a network are usually grouped together into clumps called layers. Generally, a network will have an input layer through which the various environment stimuli are presented to the network, and an output layer for determining the network's response. The number of nodes in these two layers is usually tied to some features of the problem being solved. Other layers, which form intermediate stops between the input and output layers, are called hidden layers. NETS allows the user to customize the patterns of connections between layers of a network. NETS also provides features for saving the weight values of a network during the learning process, which allows for more precise control over the learning process. NETS is an interpreter. Its method of execution is the familiar "read-evaluate-print" loop found in interpreted languages such as BASIC and LISP. The user is presented with a prompt which is the simulator's way of asking for input. After a command is issued, NETS will attempt to evaluate the command, which may produce more prompts requesting specific information or an error if the command is not understood. The typical process involved when using NETS consists of translating the problem into a format which uses input/output pairs, designing a network configuration for the problem, and finally training the network with input/output pairs until an acceptable error is reached. NETS allows the user to generate C code to implement the network loaded into the system. This permits the placement of networks as components, or subroutines, in other systems. In short, once a network performs satisfactorily, the Generate C Code option provides the means for creating a program separate from NETS to run the network. Other features: files may be stored in binary or ASCII format; multiple input propagation is permitted; bias values may be included; capability to scale data without writing scaling code; quick interactive testing of network from the main menu; and several options that allow the user to manipulate learning efficiency. NETS is written in ANSI standard C language to be machine independent. The Macintosh version (MSC-22108) includes code for both a graphical user interface version and a command line interface version. The machine independent version (MSC-21588) only includes code for the command line interface version of NETS 3.0. The Macintosh version requires a Macintosh II series computer and has been successfully implemented under System 7. Four executables are included on these diskettes, two for floating point operations and two for integer arithmetic. It requires Think C 5.0 to compile. A minimum of 1Mb of RAM is required for execution. Sample input files and executables for both the command line version and the Macintosh user interface version are provided on the distribution medium. The Macintosh version is available on a set of three 3.5 inch 800K Macintosh format diskettes. The machine independent version has been successfully implemented on an IBM PC series compatible running MS-DOS, a DEC VAX running VMS, a SunIPC running SunOS, and a CRAY Y-MP running UNICOS. Two executables for the IBM PC version are included on the MS-DOS distribution media, one compiled for floating point operations and one for integer arithmetic. The machine independent version is available on a set of three 5.25 inch 360K MS-DOS format diskettes (standard distribution medium) or a .25 inch streaming magnetic tape cartridge in UNIX tar format. NETS was developed in 1989 and updated in 1992. IBM PC is a registered trademark of International Business Machines. MS-DOS is a registered trademark of Microsoft Corporation. DEC, VAX, and VMS are trademarks of Digital Equipment Corporation. SunIPC and SunOS are trademarks of Sun Microsystems, Inc. CRAY Y-MP and UNICOS are trademarks of Cray Research, Inc.

NETS - A NEURAL NETWORK DEVELOPMENT TOOL, VERSION 3.0 (MACHINE INDEPENDENT VERSION)

NASA Technical Reports Server (NTRS)

Baffes, P. T.

1994-01-01

NETS, A Tool for the Development and Evaluation of Neural Networks, provides a simulation of Neural Network algorithms plus an environment for developing such algorithms. Neural Networks are a class of systems modeled after the human brain. Artificial Neural Networks are formed from hundreds or thousands of simulated neurons, connected to each other in a manner similar to brain neurons. Problems which involve pattern matching readily fit the class of problems which NETS is designed to solve. NETS uses the back propagation learning method for all of the networks which it creates. The nodes of a network are usually grouped together into clumps called layers. Generally, a network will have an input layer through which the various environment stimuli are presented to the network, and an output layer for determining the network's response. The number of nodes in these two layers is usually tied to some features of the problem being solved. Other layers, which form intermediate stops between the input and output layers, are called hidden layers. NETS allows the user to customize the patterns of connections between layers of a network. NETS also provides features for saving the weight values of a network during the learning process, which allows for more precise control over the learning process. NETS is an interpreter. Its method of execution is the familiar "read-evaluate-print" loop found in interpreted languages such as BASIC and LISP. The user is presented with a prompt which is the simulator's way of asking for input. After a command is issued, NETS will attempt to evaluate the command, which may produce more prompts requesting specific information or an error if the command is not understood. The typical process involved when using NETS consists of translating the problem into a format which uses input/output pairs, designing a network configuration for the problem, and finally training the network with input/output pairs until an acceptable error is reached. NETS allows the user to generate C code to implement the network loaded into the system. This permits the placement of networks as components, or subroutines, in other systems. In short, once a network performs satisfactorily, the Generate C Code option provides the means for creating a program separate from NETS to run the network. Other features: files may be stored in binary or ASCII format; multiple input propagation is permitted; bias values may be included; capability to scale data without writing scaling code; quick interactive testing of network from the main menu; and several options that allow the user to manipulate learning efficiency. NETS is written in ANSI standard C language to be machine independent. The Macintosh version (MSC-22108) includes code for both a graphical user interface version and a command line interface version. The machine independent version (MSC-21588) only includes code for the command line interface version of NETS 3.0. The Macintosh version requires a Macintosh II series computer and has been successfully implemented under System 7. Four executables are included on these diskettes, two for floating point operations and two for integer arithmetic. It requires Think C 5.0 to compile. A minimum of 1Mb of RAM is required for execution. Sample input files and executables for both the command line version and the Macintosh user interface version are provided on the distribution medium. The Macintosh version is available on a set of three 3.5 inch 800K Macintosh format diskettes. The machine independent version has been successfully implemented on an IBM PC series compatible running MS-DOS, a DEC VAX running VMS, a SunIPC running SunOS, and a CRAY Y-MP running UNICOS. Two executables for the IBM PC version are included on the MS-DOS distribution media, one compiled for floating point operations and one for integer arithmetic. The machine independent version is available on a set of three 5.25 inch 360K MS-DOS format diskettes (standard distribution medium) or a .25 inch streaming magnetic tape cartridge in UNIX tar format. NETS was developed in 1989 and updated in 1992. IBM PC is a registered trademark of International Business Machines. MS-DOS is a registered trademark of Microsoft Corporation. DEC, VAX, and VMS are trademarks of Digital Equipment Corporation. SunIPC and SunOS are trademarks of Sun Microsystems, Inc. CRAY Y-MP and UNICOS are trademarks of Cray Research, Inc.

Aerospace applications of mass market MEMS products

NASA Astrophysics Data System (ADS)

Bauer, Karin; Kroetz, Gerhard; Schalk, Josef; Mueller, Gerhard

2002-07-01

Aerospace applications of MEMS products, originally developed for automotive mass markets, are discussed. Various sensor examples with a high dual use potential are presented: inertial sensing, flow and gas sensing, robust micro sensors including SiC- and GaN-based devices, as well as first approaches towards flexible and distributed microsystems. In Europe the automotive industry is one of the main MEMS market drivers, simply because of the sheer size of this market and Europe's strong position in this industrial field. Main MEMS activities are development and integration of vehicle dynamics sensing systems, passenger safety and navigation systems, air and fuel intake systems, as well as sensor systems for exhaust gas after treatment and climate control. Benefits on the customer side are increased safety, passenger comfort and reduced fuel consumption. Benefits on the manufacturer's side are increased sub-system integration, modularity and reduced production cost. In the future the aerospace industry is likely to benefit from the introduction of micro-systems for the same reasons as the automotive industry. Interests of the aerospace industry are increasing safety and reliability of airplane operation, health and state monitoring of fuselage and airplane subsystems as well as improving service and maintenance procedures. In comparison to automotive applications, the numbers of devices needed is likely to be much smaller, however, new challenges arise in so far as distributed sensing and actuating microsystems will be needed. The idea is to identify and to exploit synergies between automotive mass market MEMS applications and lower-volume aerospace ones. The effort necessary to meet aerospace requirements and the extent of necessary trade-offs in customizing automotive MEMS is addressed considering the above-mentioned examples.

TOPICAL REVIEW: Ultra-thin film encapsulation processes for micro-electro-mechanical devices and systems

NASA Astrophysics Data System (ADS)

Stoldt, Conrad R.; Bright, Victor M.

2006-05-01

A range of physical properties can be achieved in micro-electro-mechanical systems (MEMS) through their encapsulation with solid-state, ultra-thin coatings. This paper reviews the application of single source chemical vapour deposition and atomic layer deposition (ALD) in the growth of submicron films on polycrystalline silicon microstructures for the improvement of microscale reliability and performance. In particular, microstructure encapsulation with silicon carbide, tungsten, alumina and alumina-zinc oxide alloy ultra-thin films is highlighted, and the mechanical, electrical, tribological and chemical impact of these overlayers is detailed. The potential use of solid-state, ultra-thin coatings in commercial microsystems is explored using radio frequency MEMS as a case study for the ALD alloy alumina-zinc oxide thin film.

New Tools and New Biology: Recent Miniaturized Systems for Molecular and Cellular Biology

PubMed Central

Hamon, Morgan; Hong, Jong Wook

2013-01-01

Recent advances in applied physics and chemistry have led to the development of novel microfluidic systems. Microfluidic systems allow minute amounts of reagents to be processed using μm-scale channels and offer several advantages over conventional analytical devices for use in biological sciences: faster, more accurate and more reproducible analytical performance, reduced cell and reagent consumption, portability, and integration of functional components in a single chip. In this review, we introduce how microfluidics has been applied to biological sciences. We first present an overview of the fabrication of microfluidic systems and describe the distinct technologies available for biological research. We then present examples of microsystems used in biological sciences, focusing on applications in molecular and cellular biology. PMID:24305843

The Beginner's Guide to Wind Tunnels with TunnelSim and TunnelSys

NASA Technical Reports Server (NTRS)

Benson, Thomas J.; Galica, Carol A.; Vila, Anthony J.

2010-01-01

The Beginner's Guide to Wind Tunnels is a Web-based, on-line textbook that explains and demonstrates the history, physics, and mathematics involved with wind tunnels and wind tunnel testing. The Web site contains several interactive computer programs to demonstrate scientific principles. TunnelSim is an interactive, educational computer program that demonstrates basic wind tunnel design and operation. TunnelSim is a Java (Sun Microsystems Inc.) applet that solves the continuity and Bernoulli equations to determine the velocity and pressure throughout a tunnel design. TunnelSys is a group of Java applications that mimic wind tunnel testing techniques. Using TunnelSys, a team of students designs, tests, and post-processes the data for a virtual, low speed, and aircraft wing.

Ecological Theory: Preventing Youth Bullying, Aggression, and Victimization

ERIC Educational Resources Information Center

Espelage, Dorothy L.

2014-01-01

Bronfenbrenner's (1977) classic ecological theory is used as a framework to review the documented risk and protective factors associated with involvement in school-related bullying during childhood and adolescence. Microsystems such as peers (socialization during adolescence), family (violence, lack of parental monitoring), community…

Three dimensional multilayer solenoid microcoils inside silica glass

NASA Astrophysics Data System (ADS)

Meng, Xiangwei; Yang, Qing; Chen, Feng; Shan, Chao; Liu, Keyin; Li, Yanyang; Bian, Hao; Si, Jinhai; Hou, Xun

2016-01-01

Three dimensional (3D) solenoid microcoils could generate uniform magnetic field. Multilayer solenoid microcoils are highly pursued for strong magnetic field and high inductance in advanced magnetic microsystems. However, the fabrication of the 3D multilayer solenoid microcoils is still a challenging task. In this paper, 3D multilayer solenoid microcoils with uniform diameters and high aspect ratio were fabricated in silica glass. An alloy (Bi/In/Sn/Pb) with high melting point was chosen as the conductive metal to overcome the limitation of working temperature and improve the electrical property. The inductance of the three layers microcoils was measured, and the value is 77.71 nH at 100 kHz and 17.39 nH at 120 MHz. The quality factor was calculated, and it has a value of 5.02 at 120 MHz. This approach shows an improvement method to achieve complex 3D metal microstructures and electronic components, which could be widely integrated in advanced magnetic microsystems.

Study on the photocatalytic reaction kinetics in a TiO2 nanoparticles coated microreactor integrated microfluidics device.

PubMed

Liu, Ai-Lin; Li, Zhong-Qiu; Wu, Zeng-Qiang; Xia, Xing-Hua

2018-05-15

For study of the photocatalytic reaction kinetics in a confined microsystem, a photocatalysis microreactor integrated on a microfluidic device has been fabricated using an on-line UV/vis detector. The performance of the photocatalysis microreactor is evaluated by the photocatalytic degradation of Rhodamine B chosen as model target by using commercial titanium dioxide (Degussa P25, TiO 2 ) nanoparticles as a photocatalyst. Results show that the photocatalytic reaction occurs via the Langmuir-Hinshelwood mechanism and the photocatalysis kinetics in the confined microsystem (r = 0.359 min -1 ) is about 10 times larger than that in macrosystem (r = 0.033 min -1 ). In addition, the photocatalysis activity of the immobilized TiO 2 nanoparticles in the microreactor exhibits good stability under flowing conditions. The present microchip device offers an interesting platform for screening of photocatalysts and exploration of photocatalysis mechanisms and kinetics. Copyright © 2018 Elsevier B.V. All rights reserved.

Electronic Sleep Stage Classifiers: A Survey and VLSI Design Methodology.

PubMed

Kassiri, Hossein; Chemparathy, Aditi; Salam, M Tariqus; Boyce, Richard; Adamantidis, Antoine; Genov, Roman

2017-02-01

First, existing sleep stage classifier sensors and algorithms are reviewed and compared in terms of classification accuracy, level of automation, implementation complexity, invasiveness, and targeted application. Next, the implementation of a miniature microsystem for low-latency automatic sleep stage classification in rodents is presented. The classification algorithm uses one EMG (electromyogram) and two EEG (electroencephalogram) signals as inputs in order to detect REM (rapid eye movement) sleep, and is optimized for low complexity and low power consumption. It is implemented in an on-board low-power FPGA connected to a multi-channel neural recording IC, to achieve low-latency (order of 1 ms or less) classification. Off-line experimental results using pre-recorded signals from nine mice show REM detection sensitivity and specificity of 81.69% and 93.86%, respectively, with the maximum latency of 39 [Formula: see text]. The device is designed to be used in a non-disruptive closed-loop REM sleep suppression microsystem, for future studies of the effects of REM sleep deprivation on memory consolidation.

The Application of Metal Oxide Nanomaterials for Chemical Sensor Development

NASA Technical Reports Server (NTRS)

Xu, Jennifer C.; Hunter, Gary W.; Evans, Laura J.; VanderWal, Randy L.; Berger, Gordon M.

2007-01-01

NASA Glenn Research Center (GRC) has been developing miniature chemical sensors for a variety of applications including fire detection, emissions monitoring, fuel leak detection, and environmental monitoring. Smart Lick and Stick sensor technology which integrates a sensor array, electronics, telemetry, and power into one microsystem are being developed. These microsystems require low power consumption for long-term aerospace applications. One approach to decreasing power consumption is the use of nanotechnology. Nanocrystalline tin oxide (SnO2) carbon monoxide (CO) sensors developed previously by this group have been successfully used for fire detection and emissions monitoring. This presentation will briefly review the overall NASA GRC chemical sensor program and discuss our further effort in nanotechnology applications. New carbon dioxide (CO2) sensing material using doped nanocrystalline SnO2 will be discussed. Nanocrystalline SnO2 coated solid electrolyte CO2 sensors and SnO2 nanorod and nanofiber hydrogen (H2) sensors operated at reduced or room temperatures will also be discussed.

Rural neighborhoods and child aggression.

PubMed

Bowen, Natasha K; Wretman, Christopher J

2014-12-01

Structural equation modeling with latent variables was used to evaluate the direct and mediated effects of a neighborhood risk factor (negative teen behaviors) on the parent-report aggressive behavior of 213 students in grades 3 through 5 attending a school in a low-income, rural community. Contagion and social control hypotheses were examined as well as hypotheses about whether the neighborhood served as a microsystem or exosystem for rural pre-adolescents. Analyses took into account the clustering of students and ordinal nature of the data. Findings suggest that rural neighborhoods may operate as both a microsystem and exosystem for children, with direct contagion effects on their aggressive behaviors as well as indirect social control effects through parenting practices. Direct effects on aggression were also found for parenting practices and child reports of friends' negative behaviors. Pre-adolescence may be a transitional stage, when influences of the neighborhood on child behavior begin to compete with influences of caregivers. Findings can inform the timing and targets of violence prevention in rural communities.

Raman spectroscopic differentiation of beef and horse meat using a 671 nm microsystem diode laser

NASA Astrophysics Data System (ADS)

Ebrahim, Halah Al; Sowoidnich, Kay; Kronfeldt, Heinz-Detlef

2013-11-01

A non-invasive Raman spectroscopic approach for meat species identification and quality detection was successfully demonstrated for the two closely related species beef and horse. Fresh beef and horse muscles were cut and ice-stored at 5 °C, and time-dependent Raman measurements were performed daily up to 12 days postmortem. Applying a 671 nm microsystem diode laser and a laser power of 50 mW, spectra were recorded with integration times of 1-4 s. A pronounced offset of the Raman spectra was observed between horse and beef, with high fluorescence background for horse compared to beef for all days of storage. Principal components analysis was applied for data evaluation revealing a clear distinction between beef and horse meat which can be attributed to differences in the myoglobin content of both species. Furthermore, separations according to aging and spoilage for the two species could be identified simultaneously. Therefore, Raman spectroscopy might be an efficient test method for meat species identification in combination with spoilage detection.

The Influence of Organizational Systems on Information Exchange in Long-Term Care Facilities: An Institutional Ethnography.

PubMed

Caspar, Sienna; Ratner, Pamela A; Phinney, Alison; MacKinnon, Karen

2016-06-01

Person-centered care is heavily dependent on effective information exchange among health care team members. We explored the organizational systems that influence resident care attendants' (RCAs) access to care information in long-term care (LTC) settings. We conducted an institutional ethnography in three LTC facilities. Investigative methods included naturalistic observations, in-depth interviews, and textual analysis. Practical access to texts containing individualized care-related information (e.g., care plans) was dependent on job classification. Regulated health care professionals accessed these texts daily. RCAs lacked practical access to these texts and primarily received and shared information orally. Microsystems of care, based on information exchange formats, emerged. Organizational systems mandated written exchange of information and did not formally support an oral exchange. Thus, oral information exchanges were largely dependent on the quality of workplace relationships. Formal systems are needed to support structured oral information exchange within and between the microsystems of care found in LTC. © The Author(s) 2016.

New Web Server - the Java Version of Tempest - Produced

NASA Technical Reports Server (NTRS)

York, David W.; Ponyik, Joseph G.

2000-01-01

A new software design and development effort has produced a Java (Sun Microsystems, Inc.) version of the award-winning Tempest software (refs. 1 and 2). In 1999, the Embedded Web Technology (EWT) team received a prestigious R&D 100 Award for Tempest, Java Version. In this article, "Tempest" will refer to the Java version of Tempest, a World Wide Web server for desktop or embedded systems. Tempest was designed at the NASA Glenn Research Center at Lewis Field to run on any platform for which a Java Virtual Machine (JVM, Sun Microsystems, Inc.) exists. The JVM acts as a translator between the native code of the platform and the byte code of Tempest, which is compiled in Java. These byte code files are Java executables with a ".class" extension. Multiple byte code files can be zipped together as a "*.jar" file for more efficient transmission over the Internet. Today's popular browsers, such as Netscape (Netscape Communications Corporation) and Internet Explorer (Microsoft Corporation) have built-in Virtual Machines to display Java applets.

Hybrid integration of III-V and silicon materials and devices

NASA Astrophysics Data System (ADS)

Luo, Zhongsheng

Laser liftoff (LLO) based hybrid integration techniques including the double-transfer process and the pixel-to-point transfer process have been developed to integrate III-V photonics with silicon materials and circuitry. No degradation in the device performance has been observed using the LLO based transfer techniques. On the contrary, performance improvements in both electrical characteristics and electroluminescence (EL) output have been found for the (In,Ga)N light emitting diodes (LEDs) transferred onto Si substrate. Based on computer simulation, it is found that as much as 70% enhancement in EL output could be expected by optimizing the metal layering on the backside of the transferred LEDs. In order to understand the existing experimental data and improve controllability and damage-free transfer yield of the LLO process, a novel, comprehensive LLO model based on thermal-mechanical analysis has been proposed and developed. The LLO model has been validated in the well-studied GaN/sapphire system. By employing the LLO based transfer technique, two optoelectronic systems have been designed and demonstrated. The first one is an integrated fluorescence microsystem, which involved the integration of Cd(S,Se) bandgap filters, (In,Ga)N LEDs, Poly(dimethylsiloxane) (PDMS) microfluidic channels with a pre-fabricated Si PIN photodiode chip. Prototypes with both one color (blue LED) excitation and two-color (blue and green LED) excitation have consistently demonstrated a detection capability of as low as 1 nM fluosphere beads using Molecular Probes FluoSpheresRTM dye. Furthermore, the feasibility of multi-wavelength design has been verified using the bi-wavelength prototype. To optimize signal-to-noise ratio and detection sensitivity of the microsystem via system design, an in-depth mathematic analysis has also been performed. The second application is a zero-footprint optical metrology wafer, which relies on the reflection at the optical detection window, through which important parameters such as thickness, refractive index and density of the film on top of the detecting window can be probed in a real-time and location-specific manner. A novel methodology has been developed to ensure accurate and precise measurement across the wafer. A prototype wafer with 3x3 metrology cells has been prototyped and calibrated using a SF6 plasma etching process of silicon oxide.

Exploring the experiences of female students in introductory project-based engineering courses at two- and four-year institutions

NASA Astrophysics Data System (ADS)

Swan, Amy K.

2011-12-01

This qualitative study explored the experiential and contextual factors that shaped female students' pathways into introductory project-based engineering classes at two community colleges and one four-year institution, as well as female students' experiences within and outside of these classes. The study was framed by Social Cognitive Career Theory (SCCT) (Lent, Brown & Hackett, 1996) and Bronfenbrenner's (1979) ecological systems theory. Findings were based on analyses of data gathered through multiple methods: observations; individual interviews with female students; focus group interviews with project teams; and document collection. The findings of this study revealed that while positive experiences with math or science were a likely pre-cursor to engineering interest, experiential learning appeared to be a more powerful force in fostering students' engineering interest. Specifically, participants developed an interest in engineering through academic, professional, and extracurricular engineering- and design-related activities that familiarized them with the tasks and skills involved in engineering work and helped them develop a sense of selfefficacy with regard to this work. Interest and self-efficacy, in turn, played a role in students' postsecondary educational decision-making processes, as did contextual factors including families and finances. This study's findings also showed that participants' project teams were a critically important microsystem within participants' ecological environments. Within this sometimes "chilly" microsystem, female students negotiated intrateam processes, which were in some cases affected by gender norms. Intrateam processes that influenced female students' project-based learning experiences included: interpersonal dynamics; leadership; and division of labor. This study also identified several ways in which the lived experiences of participants at the community colleges were different from, or similar to, those of participants at the four-year institution. In the classroom, similarities and differences were related to projects, learning outcomes, language and time, while outside of the classroom they were primarily linked to time and peer support. This study's findings suggest a need for expanded access to experiential learning opportunities and ongoing attention to the role of community colleges in engineering education. Study findings also point toward ways that engineering educators might attend to the intrateam processes identified, and better accommodate the needs of all students in project-based introductory courses.

Ultra Low Power, Radiation Tolerant UHF Radio Technologies for In Situ Communication Applications

NASA Technical Reports Server (NTRS)

Lay, N. E.

2001-01-01

For future deep space missions, significant reductions in the mass and power requirements for short-range telecommunication systems will be critical in enabling a wide variety of new mission concepts. These possibilities include penetrators, gliders, miniature rovers, and sensor networks. Under joint funding from NASA's Cross Enterprise and JPL's Telecommunications and Mission technology programs, recent development activity has focused on the design of ultralow mass and power transceiver systems and subsystems suitable for operation in a flight environment. For these efforts, the functionality of the transceiver has been targeted towards a specific Mars communications scenario. However, the overall architecture is well suited to any short or medium range application where a remote probe will aperiodically communicate with a base station, possibly an orbiter, for the eventual purpose of relaying science information back to Earth. In 2001, these sponsors have been augmented with collaborative expertise and funding from JPL's Center for Integrated Space Microsystems in order to migrate existing concepts and designs to a System on a Chip (SOAC) solution. Additional information is contained in the original extended abstract.

Regular Topologies for Gigabit Wide-Area Networks: Congestion Avoidance Testbed Experiments. Volume 3

NASA Technical Reports Server (NTRS)

Denny, Barbara A.; McKenney, Paul E., Sr.; Lee, Danny

1994-01-01

This document is Volume 3 of the final technical report on the work performed by SRI International (SRI) on SRI Project 8600. The document includes source listings for all software developed by SRI under this effort. Since some of our work involved the use of ST-II and the Sun Microsystems, Inc. (Sun) High-Speed Serial Interface (HSI/S) driver, we have included some of the source developed by LBL and BBN as well. In most cases, our decision to include source developed by other contractors depended on whether it was necessary to modify the original code. If we have modified the software in any way, it is included in this document. In the case of the Traffic Generator (TG), however, we have included all the ST-II software, even though BBN performed the integration, because the ST-II software is part of the standard TG release. It is important to note that all the code developed by other contractors is in the public domain, so that all software developed under this effort can be re-created from the source included here.

Digital Communications Terminal High Order Programming Language Study (DCT HOL Study). Volume I.

DTIC Science & Technology

1980-11-26

3-3 PASCAL/M Digital Marketing ......... 3-3 PASCAL/MT MT MicroSystems .................... 3-3 PASCAL/Z Ithaca IntersysteMs...II Avocet Systems, Inc. 3.6 PASCAL - ISO PASCAL Whitesmith, Ltd. - PASCAL 64000 lbwlett-Packard - PASCAL/H Digital Marketing - PASCAL/MT MT

Method of producing an electronic unit having a polydimethylsiloxane substrate and circuit lines

DOEpatents

Davidson, James Courtney [Livermore, CA; Krulevitch, Peter A [Pleasanton, CA; Maghribi, Mariam N [Livermore, CA; Benett, William J [Livermore, CA; Hamilton, Julie K [Tracy, CA; Tovar, Armando R [San Antonio, TX

2012-06-19

A system of metalization in an integrated polymer microsystem. A flexible polymer substrate is provided and conductive ink is applied to the substrate. In one embodiment the flexible polymer substrate is silicone. In another embodiment the flexible polymer substrate comprises poly(dimethylsiloxane).

Children in Contemporary Society: Child Ecology.

ERIC Educational Resources Information Center

Frank, Mary, Ed.

This collection of short articles focuses on various dimensions of childhood ecology. Section I introduces a conceptual framework for the study of childhood ecology and poses 4 methodological principles for human development specialists. Four ecological subsystems are identified and discussed briefly. Section II discusses the family microsystem in…

Mechanics of Multifunctional Materials & Microsystems

DTIC Science & Technology

2012-03-09

Mechanics of Materials; Life Prediction (Materials & Micro-devices); Sensing, Precognition & Diagnosis; Multifunctional Design of Autonomic...Life Prediction (Materials & Micro-devices); Sensing, Precognition & Diagnosis; Multifunctional Design of Autonomic Systems; Multifunctional...release; distribution is unlimited. 7 VISION: EXPANDED • site specific • autonomic AUTONOMIC AEROSPACE STRUCTURES • Sensing & Precognition • Self

Pin-deposition of conductive inks for microelectrodes and contact via filling

DOEpatents

Davidson, J. Courtney; Krulevitch, Peter A.; Maghribi, Mariam N.; Hamilton, Julie K.; Benett, William J.; Tovar, Armando R.

2006-05-02

A method of metalization of an integrated microsystem. The method comprises providing a substrate and applying a conductive material to the substrate by taking up small aliquots of conductive material and releasing the conductive material onto the substrate to produce a circuit component.

Becoming a leader in patient satisfaction: changing the culture of care in an academic community hospital.

PubMed

Deitrick, Lynn M; Capuano, Terry A; Paxton, Stuart S; Stern, Glenn; Dunleavy, Jack; Miller, William L

2006-01-01

In the context of the current health care payer system, quality of care standards, financial incentives and consumer choice are not well aligned, yet competition for increased admissions has become a matter of survival. Satisfaction and loyalty are two constructs that are the most meaningful measures in the context of sustaining and increasing admissions. Lehigh Valley Hospital and Health Network (LVHHN) launched an ambitious patient satisfaction improvement initiative in 2001. LVHHN augmented existing patient service excellence programs with an ethnographic study of a representative unit. Interview and observational data were analyzed using NVivo software. These results (four distilled domains of patient experience) can then be used to identify key components of the care environment that made meaningful differences in the perceptions of patients and their satisfaction. A designated interdepartmental task force can then develop interventions from those learnings, track outcomes through the Press Ganey scores, and ultimately yield increased admissions through unit-specific process change across the hospital. Admissions for fiscal year 2001 to fiscal year 2003 increased from 5,817 to 7,795 patients. The clear value and return on this initiative for our organization included a 34% increase in patient admissions over a four-year period. Improvements in both patient satisfaction and loyalty were demonstrated by a 24% increase for the question, "Likelihood of your recommending this hospital to others" as measured by the Press Ganey Inpatient survey. This initiative demonstrates the successful application of qualitative methods in a clinical microsystem to better understand patient perceptions that determine their satisfaction with medical care.

Total integrated slidable and valveless solid phase extraction-polymerase chain reaction-capillary electrophoresis microdevice for mini Y chromosome short tandem repeat genotyping.

PubMed

Kim, Yong Tae; Lee, Dohwan; Heo, Hyun Young; Sim, Jeong Eun; Woo, Kwang Man; Kim, Do Hyun; Im, Sung Gap; Seo, Tae Seok

2016-04-15

A fully integrated slidable and valveless microsystem, which performs solid phase DNA extraction (SPE), micro-polymerase chain reaction (μPCR) and micro-capillary electrophoresis (μCE) coupled with a portable genetic analyser, has been developed for forensic genotyping. The use of a slidable chip, in which a 1 μL-volume of the PCR chamber was patterned at the center, does not necessitate any microvalves and tubing systems for fluidic control. The functional micro-units of SPE, μPCR, and μCE were fabricated on a single glass wafer by conventional photolithography, and the integrated microdevice consists of three layers: from top to bottom, a slidable chip, a channel wafer in which a SPE chamber, a mixing microchannel, and a CE microchannel were fabricated, and a Ti/Pt resistance temperature detector (RTD) wafer. The channel glass wafer and the RTD glass wafer were thermally bonded, and the slidable chip was placed on the designated functional unit. The entire process from the DNA extraction using whole human blood sample to identification of target Y chromosomal short tandem repeat (STR) loci was serially carried out with simply sliding the slidable chamber from one to another functional unit. Monoplex and multiplex detection of amelogenin and mini Y STR loci were successfully analysed on the integrated slidable SPE-μPCR-μCE microdevice by using 1 μL whole human blood within 60 min. The proposed advanced genetic analysis microsystem is capable of point-of-care DNA testing with sample-in-answer-out capability, more importantly, without use of complicated microvalves and microtubing systems for liquid transfer. Copyright © 2015 Elsevier B.V. All rights reserved.

Intelligent biomedical clothing for personal health and disease management: state of the art and future vision.

PubMed

Lymberis, Andreas; Olsson, Silas

2003-01-01

Telemedicine has been introduced to overcome distance in order to get prompt access to medical knowledge and appropriate health care. More recently, work in telemedicine has aimed at developing solutions to support the management of chronic diseases such as diabetes, and lung and heart diseases, as well as to provide support for home care services. Telemedicine is also entering the fields of health promotion/prevention disease, life style management, and well-being. The evolution and broadening of telemedicine gives birth to a nomenclature that includes "e-health," "telehealth," and "telecare." The latest developments in microsystems and nanotechnologies as well as in information processing and communication technologies allow miniaturization and non-invasive smart monitoring of physiological and physical data. Ongoing cutting-edge multidisciplinary research in textile fibers, biomedical sensors, and wireless and mobile telecommunications integrated with telemedicine, aims at developing intelligent biomedical clothing (IBC) that could pave the way to support personalized management of health and diseases at the point of need and at any time. In this study, we aim to describe the current status of multidisciplinary research and development of IBC, based on bibliographic research and reports from seminars, workshops, conferences, and working groups. A further aim is to inform the developers, the decision makers, and users in the health and healthcare sector regarding future solutions to support personalized health care and disease management. Both the textile sector and healthcare sector are looking with great interest at the innovative products and applications that could result from the integration of microsystems, nanotechnologies, biomedical sensors, textiles, and mobile telecommunications. For health monitoring, disease prevention and management, rehabilitation, and sport medicine, IBC may offer, in the mid-term future, a unique, wearable non-obtrusive telemedicine platform for individualized services that is readily accessible and of good quality.

Multi-wafer bonding technology for the integration of a micromachined Mirau interferometer

NASA Astrophysics Data System (ADS)

Wang, Wei-Shan; Lullin, Justine; Froemel, Joerg; Wiemer, Maik; Bargiel, Sylwester; Passilly, Nicolas; Gorecki, Christophe; Gessner, Thomas

2015-02-01

The paper presents the multi-wafer bonding technology as well as the integration of electrical connection to the zscanner wafer of the micromachined array-type Mirau interferometer. A Mirau interferometer, which is a key-component of optical coherence tomography (OCT) microsystem, consists of a microlens doublet, a MOEMS Z-scanner, a focusadjustment spacer and a beam splitter plate. For the integration of this MOEMS device heterogeneous bonding of Si, glass and SOI wafers is necessary. Previously, most of the existing methods for multilayer wafer bonding require annealing at high temperature, i.e., 1100°C. To be compatible with MEMS devices, bonding of different material stacks at temperatures lower than 400°C has also been investigated. However, if more components are involved, it becomes less effective due to the alignment accuracy or degradation of surface quality of the not-bonded side after each bonding operation. The proposed technology focuses on 3D integration of heterogeneous building blocks, where the assembly process is compatible with the materials of each wafer stack and with position accuracy which fits optical requirement. A demonstrator with up to 5 wafers bonded lower than 400°C is presented and bond interfaces are evaluated. To avoid the complexity of through wafer vias, a design which creates electrical connections along vertical direction by mounting a wafer stack on a flip chip PCB is proposed. The approach, which adopts vertically-stacked wafers along with electrical connection functionality, provides not only a space-effective integration of MOEMS device but also a design where the Mirau stack can be further integrated with other components of the OCT microsystem easily.

Real-time implementation of a multispectral mine target detection algorithm

NASA Astrophysics Data System (ADS)

Samson, Joseph W.; Witter, Lester J.; Kenton, Arthur C.; Holloway, John H., Jr.

2003-09-01

Spatial-spectral anomaly detection (the "RX Algorithm") has been exploited on the USMC's Coastal Battlefield Reconnaissance and Analysis (COBRA) Advanced Technology Demonstration (ATD) and several associated technology base studies, and has been found to be a useful method for the automated detection of surface-emplaced antitank land mines in airborne multispectral imagery. RX is a complex image processing algorithm that involves the direct spatial convolution of a target/background mask template over each multispectral image, coupled with a spatially variant background spectral covariance matrix estimation and inversion. The RX throughput on the ATD was about 38X real time using a single Sun UltraSparc system. A goal to demonstrate RX in real-time was begun in FY01. We now report the development and demonstration of a Field Programmable Gate Array (FPGA) solution that achieves a real-time implementation of the RX algorithm at video rates using COBRA ATD data. The approach uses an Annapolis Microsystems Firebird PMC card containing a Xilinx XCV2000E FPGA with over 2,500,000 logic gates and 18MBytes of memory. A prototype system was configured using a Tek Microsystems VME board with dual-PowerPC G4 processors and two PMC slots. The RX algorithm was translated from its C programming implementation into the VHDL language and synthesized into gates that were loaded into the FPGA. The VHDL/synthesizer approach allows key RX parameters to be quickly changed and a new implementation automatically generated. Reprogramming the FPGA is done rapidly and in-circuit. Implementation of the RX algorithm in a single FPGA is a major first step toward achieving real-time land mine detection.

The Fe-Rich Clay Microsystems in Basalt-Komatiite Lavas: Importance of Fe-Smectites for Pre-Biotic Molecule Catalysis During the Hadean Eon

NASA Astrophysics Data System (ADS)

Meunier, Alain; Petit, Sabine; Cockell, Charles S.; El Albani, Abderrazzak; Beaufort, Daniel

2010-06-01

During the Hadean to early Archean period (4.5-3.5 Ga), the surface of the Earth’s crust was predominantly composed of basalt and komatiite lavas. The conditions imposed by the chemical composition of these rocks favoured the crystallization of Fe-Mg clays rather than that of Al-rich ones (montmorillonite). Fe-Mg clays were formed inside chemical microsystems through sea weathering or hydrothermal alteration, and for the most part, through post-magmatic processes. Indeed, at the end of the cooling stage, Fe-Mg clays precipitated directly from the residual liquid which concentrated in the voids remaining in the crystal framework of the mafic-ultramafic lavas. Nontronite-celadonite and chlorite-saponite covered all the solid surfaces (crystals, glass) and are associated with tiny pyroxene and apatite crystals forming the so-called “mesostasis”. The mesostasis was scattered in the lava body as micro-settings tens of micrometres wide. Thus, every square metre of basalt or komatiite rocks was punctuated by myriads of clay-rich patches, each of them potentially behaving as a single chemical reactor which could concentrate the organics diluted in the ocean water. Considering the high catalytic potentiality of clays, and particularly those of the Fe-rich ones (electron exchangers), it is probable that large parts of the surface of the young Earth participated in the synthesis of prebiotic molecules during the Hadean to early Archean period through innumerable clay-rich micro-settings in the massive parts and the altered surfaces of komatiite and basaltic lavas. This leads us to suggest that Fe,Mg-clays should be preferred to Al-rich ones (montmorillonite) to conduct experiments for the synthesis and the polymerisation of prebiotic molecules.

Understanding Students' Precollege Experiences with Racial Diversity: The High School as Microsystem

ERIC Educational Resources Information Center

Park, Julie J.; Chang, Stephanie H.

2015-01-01

Few qualitative studies consider how high school experiences affect readiness for diversity engagement in college. Using data from an ethnographic case study, three central trends (student experiences within homogeneous high schools, racial divisions within diverse high schools, and students who attended diverse high schools but had little…

Harmonising the Microsystem of the Educational Concept "Competence"

ERIC Educational Resources Information Center

Pukelis, Kestutis; Smetona, Antanas

2012-01-01

Various texts related to education policy and education research have recently started using two conjugate concepts "competency" and "competence". These terms are sometimes treated as synonyms of a single concept; however, in other cases they are separated and used as two terms of different educational concepts. English also…

Micropackaging for the Next Generation of Optical and Electrical Components

DTIC Science & Technology

2007-01-01

Naperville, IL 60563 Phone: 630-946-5420 E-mail: John_Dallesasse@emcore.com Hongyu Deng Finisar 41762 Christy Street Freemont, CA 94538 Phone...kotura.com Dilip Modi Product Line Manager Sun Microsystems 7788 Gateway, Blvd., Bldg 19Mailstop UNWK19-202 Newark, CA 94560 Phone: 510-936-4916

Cognitive Socialization and Competence: The Academic Development of Chicanos. Chapter 7.

ERIC Educational Resources Information Center

Laosa, Luis M.; Henderson, Ronald W.

This chapter focuses on the innermost level of Bronfenbrenner's four-level conception of the human environmental ecology, namely the microsystem, and more specifically, the child's socialization in the family. Following discussion of concepts related to socialization, competence, and environmental ecology, selected research studies are reviewed to…

Messages about Sexuality: An Ecological Perspective

ERIC Educational Resources Information Center

Boone, Tanya L.

2015-01-01

The goal of this two-part study was to identify the perceived influence of sexuality messages from parents, peers, school and the media--four microsystems within the Ecological Model--on emerging adult US college women's sexual attitudes. Findings suggest that parents were the most likely source of the message to "remain abstinent until…

Microcomputer Security Issues in an Office Environment.

DTIC Science & Technology

1986-11-01

Holmes Inc. A. 4605 Post Oak Place Drive, Suite 209 Houston, Texas 77027 r -w (713) 840-7771 Lockit I/Lockit II Security Microsystems Consultants 16...9300 MultiSentry/ComputerSentry Tact Technology 100 North 20th Street Philadelphia, PA 19103 (215) 569-1300 . Sherlock PC/ISM/ISM-Federal Analytics

A Bio-Ecological Interpretation of the Relationship Challenges in the Context of the Reconstituted Family

ERIC Educational Resources Information Center

Ebersohn, S.; Bouwer, A. C.

2015-01-01

From an educational psychology perspective, family life--as a child's primary educational situation--is changing drastically as divorces increase worldwide. Various challenges to relationships accompany the restructuring of family systems after divorce. When remarriage occurs, children's shared membership of two family microsystems and the…

The Scenario Analysis Tool Suite: A User’s Guide

DTIC Science & Technology

2009-01-01

be exported at any stage and continued manually. The free, open-source integrated development environment (IDE) NetBeans [14] was used in the creation...and Technology Organisation, Australia. 14. Sun Microsystems & CollabNet (2008) NetBeans IDE 6.0, http://wwwnetbeans.org. 15. Tri, N., Boswell, S

Preschool Inclusion in the United States: A Review of Research from an Ecological Systems Perspective

ERIC Educational Resources Information Center

Odom, Samuel L.; Vitztum, Joann; Wolery, Ruth; Lieber, Joan; Sandall, Susan; Hanson, Marci J.; Beckman, Paula; Schwartz, Ilene; Horn, Eva

2004-01-01

Using an ecological systems conceptual framework proposed by Bronfenbrenner, research on the inclusion of preschool children with disabilities in programs with typically developing children was reviewed. Drawing mainly from studies conducted in the United States, research on child characteristics (biosystem), classroom practices (microsystem),…

MEMS Device Being Developed for Active Cooling and Temperature Control

NASA Technical Reports Server (NTRS)

Moran, Matthew E.

2001-01-01

High-capacity cooling options remain limited for many small-scale applications such as microelectronic components, miniature sensors, and microsystems. A microelectromechanical system (MEMS) is currently under development at the NASA Glenn Research Center to meet this need. It uses a thermodynamic cycle to provide cooling or heating directly to a thermally loaded surface. The device can be used strictly in the cooling mode, or it can be switched between cooling and heating modes in milliseconds for precise temperature control. Fabrication and assembly are accomplished by wet etching and wafer bonding techniques routinely used in the semiconductor processing industry. Benefits of the MEMS cooler include scalability to fractions of a millimeter, modularity for increased capacity and staging to low temperatures, simple interfaces and limited failure modes, and minimal induced vibration.

Structured Coaching Programs to Develop Staff.

PubMed

Dyess, Susan MacLeod; Sherman, Rose; Opalinski, Andra; Eggenberger, Terry

2017-08-01

Health care environments are complex and chaotic, therein challenging patients and professionals to attain satisfaction, well-being, and exceptional outcomes. These chaotic environments increase the stress and burnout of professionals and reduce the likelihood of optimizing success in many dimensions. Coaching is evolving as a professional skill that may influence the optimization of the health care environment. This article reflects on three coaching programs: Gallup Strengths-Based Coaching, Dartmouth Microsystem Coaching, and Health and Wellness Nurse Coaching. Each approach is presented, processes and outcomes are considered, and implications for educators are offered. Continuing education departments may recognize various coaching approaches as opportunities to support staff professionals achieve not only the triple aim, but also the quadruple aim. J Contin Educ Nurs. 2017;48(8):373-378. Copyright 2017, SLACK Incorporated.

Importance of the concept of inner organs-dental relations in dentistry.

PubMed

Abasova, I; Rustamova, P; Seidbekov, O

2009-12-01

The current article is presenting an effective treatment scheme, providing reliable positive result of therapy and prophylaxis of dental diseases and its complications on the patients through the study of pathology of meridian - inner organs - dental system, bound by system of traces - meridians, using Doppler ultrasonography, rheovasography, photoplethysmography, Electroacupuncture, ultrasound investigations of the inner organs, X-Ray, laboratory investigations, electrocardiography methods. We had studied the efficiency of the odontic Microsystem, developed by R. Voll and R. Dale in dental practice by oral examination of 100 patients, average aged 25,5+/-0,74, which were divided into three groups. The necessity of complex treatment of the patients with pathology of inner organs and related with that demineralization process of the hard tissues of the teeth and the periodontitis had been demonstrated.

Kinetic mechanism for modeling of electrochemical reactions.

PubMed

Cervenka, Petr; Hrdlička, Jiří; Přibyl, Michal; Snita, Dalimil

2012-04-01

We propose a kinetic mechanism of electrochemical interactions. We assume fast formation and recombination of electron donors D- and acceptors A+ on electrode surfaces. These mediators are continuously formed in the electrode matter by thermal fluctuations. The mediators D- and A+, chemically equivalent to the electrode metal, enter electrochemical interactions on the electrode surfaces. Electrochemical dynamics and current-voltage characteristics of a selected electrochemical system are studied. Our results are in good qualitative agreement with those given by the classical Butler-Volmer kinetics. The proposed model can be used to study fast electrochemical processes in microsystems and nanosystems that are often out of the thermal equilibrium. Moreover, the kinetic mechanism operates only with the surface concentrations of chemical reactants and local electric potentials, which facilitates the study of electrochemical systems with indefinable bulk.

EDITORIAL: Selected papers from the 22nd MicroMechanics and Microsystems Europe Workshop (MME 2011) Selected papers from the 22nd MicroMechanics and Microsystems Europe Workshop (MME 2011)

NASA Astrophysics Data System (ADS)

Ohlckers, Per

2012-07-01

This special section of Journal of Micromechanics and Microengineering is a selection of 13 of the best papers presented at the 22nd Micromechanics and Microsystems Europe Workshop, which was arranged in Toensberg, Norway, 19-22 June, 2011. 110 participants attended the 3 day workshop that had 5 invited keynote speakers and 80 submitted poster presentations. The MME Workshop is organized every year to gather mostly European scientists and people from industry to discuss topics related to research in micromechanics and microsystems in an informal manner. A distinct feature of this specialized workshop is to be an excellent venue for young scientists in the field, such as PhD students, to present their latest work. This workshop series was inaugurated in Enschede, the Netherlands in 1989, followed by: Berlin, Germany (1990), Leuven, Belgium (1992), Neuchatel, Switzerland (1993), Pisa, Italy (1994), Copenhagen, Denmark (1995), Barcelona, Spain (1996) [1], Southampton, UK (1997) [2], Ulvik, Norway (1998) [3], Gif-sur-Yvette, France (1999) [4], Uppsala, Sweden (2000), Cork, Ireland (2001) [5], Sinaia, Romania (2002) [6], Delft, The Netherlands (2003) [7], Leuven, Belgium (2004) [8], Goteborg, Sweden (2005) [9], Southampton, UK (2006) [10], Guimaraes, Portugal (2007) [11], Aachen, Germany (2008) [12], Toulouse, France (2009) [13] and Enschede, the Netherlands (2010) [14]. The workshop series has remained remarkably true to its original concept such as still having micromechanics as a priority topic while, at the same time, adapting to recent research topics such as microsystems integration. It is nice to observe that an earlier fragmented and mostly academic research field now has matured into a very strong industrial field being one of the fastest growing industries in the world, with successful applications on all levels from high end to low end, from space to consumer applications, with the inclusion of microsystems in smartphones such as three-axis accelerometers and three-axis gyroscopes as the most recent 'killer' application. Regardless of application, low cost, high performance and high reliability seem to give us the winning hand leaving competing technology platforms in the dust, for instance in automotive applications. First, I would like to thank the authors of the selected papers for each of their individual excellent contributions. My gratitude also goes to my fellow members in the programme committee (Leon Abelmann, Marin Hill and Martin Hoffmann) for their devotion in the selection of invited speakers and submitted papers, as well as the anonymous JMM reviewers for their careful selection of the final 13 papers included here. Last, but not least, it has been an honour and pleasure for me to collaborate with the editorial staff of Journal of Micromechanics and Microengineering, with the selected best papers presented at MME 2011 included in this special section. This collaboration will continue also for MME 2012, and hopefully also for many future MME workshops. References [1] Morante J R 1997 Preface J. Micromech. Microeng. 7 [2] Evans A G R 1998 Preface J. Micromech. Microeng. 8 [3] Ohlckers P 1999 Introduction J. Micromech. Microeng. 9 [4] Bosseboeuf A 2000 Editorial J. Micromech. Microeng. 10 [5] Hill M 2002 Preface J. Micromech. Microeng. 12 [6] Dascalu D and Muller A 2003 Preface J. Micromech. Microeng. 13 [7] Wolffenbuttel R F 2004 14th Micromechanics Europe Workshop (MME 2003) J. Micromech. Microeng. 14 [8] Puers R 2005 15th European Workshop on Micromechanics (MME 2004) J. Micromech. Microeng. 15 [9] Enoksson P 2006 16th European Workshop on Micromechanics (MME 2005) J. Micromech. Microeng. 16 [10] Morgan H 2007 The 17th European Workshop on Micromechanics (MME 2006) J. Micromech. Microeng. 17 [11] Correia J H 2008 The 18th European Workshop on Micromechanics (MME 2007) J. Micromech. Microeng. 18 060201 [12] Schnakenberg U 2009 The 19th MicroMechanics Europe Workshop (MME 2008) J. Micromech. Microeng. 19 070201 [13] Pons P 2010 Selected papers from the 20th Micromechanics Europe Workshop (MME 2009) (Toulouse, France, 20-22 September, 2009) J. Micromech. Microeng. 20 060201 [14] Abelmann L 2011 Selected papers from the 21th Micromechanics Europe Workshop (MME 2010) (Enschede, the Netherlands, 26-29 September, 2010) J. Micromech. Microeng. 21 070201

Large Oligomers Stabilized by Whb Networks: Pentamers of Difluoromethane and its Water Clusters

NASA Astrophysics Data System (ADS)

Cocinero, Emilio J.; Uriarte, Iciar; Evangelisti, Luca; Calabrese, Camilla; Prampolini, Giacomo; Cacelli, Ivo; Pate, Brooks

2017-06-01

Microwave spectroscopy has been restricted to the investigation of small molecules in the last years. However, with the advent of FTMW and CP-FTMW spectroscopies coupled with laser vaporization techniques it has turned into a very competitive methodology in the studies of moderate-size molecules. In particular, the studies of relatively large molecular aggregates are very interesting, being a bridge between microsystems and molecular bulk. Here, we present the study of two pentarmers of difluoromethane (CH_2F_2)_5 and the water clusters (CH_2F_2)_1...(H_2O)_2, (CH_2F_2)_2...(H_2O)_1 and (CH_2F_2)_2...(H_2O)_2 stabilized by weak hydrogen bonds networks (O-H...F, C-H...F and C-H...O interactions). The experiments were carried out in the CP-FTMW spectrometers of Bilbao (Spain) and Virginia (USA). In addition, the experimental work was supported by theoretical calculations. The force fields were specifically parameterized for reproduce others oligomers where WHB interactions play a crucial role. T. Tang, Y. Xu, A. R. W. McKellar and W. Jäger, Science 29, 297, 2002. C. Pérez, M. T. Muckle, D. P. Zaleski, N. A. Seifert, B. Temelso, G. H. Shields, Z. Kisiel and B. H. Pate, Science 336, 897, 2012. I. Uriarte, C. Pérez, E. Caballero-Mancebo, F. J. Basterretxea, A. Lesarri, J. A. Fernández and E. J. Cocinero Chem. Eur. J. in press, 2017.

Sandia National Laboratories: Research: R&D 100 Awards

Science.gov Websites

high radiation environments such as space. Watch the video. control system for active damping of inter first commercially available, high-voltage, high-frequency, high-current, high-temperature, single-chip Materials Science Nanodevices & Microsystems Radiation Effects & High Energy Density Science

Exploring Primary Teacher Emotions in Hong Kong and Mainland China: A Qualitative Perspective

ERIC Educational Resources Information Center

Chen, Junjun

2017-01-01

This study aims to understand teacher emotions through interviewing 53 primary teachers in Hong Kong and Mainland China. Content analysis was employed to analyze the data. Teachers reported 68 different types of emotions which decreases as distance from the teachers increases at the five nested ecological system--microsystem, mesosystem,…

Split and flow: reconfigurable capillary connection for digital microfluidic devices.

PubMed

Lapierre, Florian; Harnois, Maxime; Coffinier, Yannick; Boukherroub, Rabah; Thomy, Vincent

2014-09-21

Supplying liquid to droplet-based microfluidic microsystems remains a delicate task facing the problems of coupling continuous to digital or macro- to microfluidic systems. Here, we take advantage of superhydrophobic microgrids to address this problem. Insertion of a capillary tube inside a microgrid aperture leads to a simple and reconfigurable droplet generation setup.

Electronic Mail: Defining a Role for the U.S. Postal Service.

ERIC Educational Resources Information Center

McLaughlin, John F.

Threatened by competitive diversification and by increasing costs, the United States Postal Service has investigated two potential cost reducing systems: (1) a microsystem which would provide electronic facsimile transmission between major markets and (2) a macrosystem which could take digital input such as utility bills and deliver a hardcopy to…

Ion Beam Diagnostics Planar Epitaxial Structures Nanophotonics, Nanoelectronics and Microsystems Technology

ERIC Educational Resources Information Center

Afanasiev, Sergey A.; Afanasiev, Mikhail S.; Zhukov, Alexander O.; Egorov, Vladimir K.; Egorov, Evgeniy V.

2016-01-01

The background of the study is that the planar film heterostructures are nowadays the most common objects nanophotonic and nanoelectronic technologies. The authors noted that, among such objects found so-called quantum wells, which are formed by a complex series of nanoscale layers are deposited with differing elemental composition, and simple…

Goal Oriented and Risk Taking Behavior: The Roles of Multiple Systems for Caucasian and Arab-American Adolescents

ERIC Educational Resources Information Center

Tynan, Joshua J.; Somers, Cheryl L.; Gleason, Jamie H.; Markman, Barry S.; Yoon, Jina

2015-01-01

With Bronfenbrenner's (1977) ecological theory and other multifactor models (e.g. Pianta, 1999; Prinstein, Boergers, & Spirito, 2001) underlying this study design, the purpose was to examine, simultaneously, key variables in multiple life contexts (microsystem, mesosystem, exosystem levels) for their individual and combined roles in predicting…

Large-Scale Economic Change and Youth Development: The Case of Urban China

ERIC Educational Resources Information Center

Yoshikawa, Hirokazu; Way, Niobe; Chen, Xinyin

2012-01-01

Social ecological and dynamic systems theories propose that human development is shaped by the cumulative impact of social interactions in proximal and distal settings, which are themselves influenced by social and economic forces. The understanding of the links between microsystem-level factors (such as parenting styles and parent-child…

Software Graphical User Interface For Analysis Of Images

NASA Technical Reports Server (NTRS)

Leonard, Desiree M.; Nolf, Scott R.; Avis, Elizabeth L.; Stacy, Kathryn

1992-01-01

CAMTOOL software provides graphical interface between Sun Microsystems workstation and Eikonix Model 1412 digitizing camera system. Camera scans and digitizes images, halftones, reflectives, transmissives, rigid or flexible flat material, or three-dimensional objects. Users digitize images and select from three destinations: work-station display screen, magnetic-tape drive, or hard disk. Written in C.

Psychological, Family, and Social Factors Linked with Juvenile Theft in Korea

ERIC Educational Resources Information Center

Lee, DongHun; Han, Yoonsun; Park, ManSik; Roh, SeakZoon

2015-01-01

The absence of an approach which encompasses several micro-systems in Korea may leave important factors of youth risk behaviors undetected. Thus, an examination of a broad set of ecological factors within the micro-system--including individual characteristics as well as immediate family, peer, and school environments surrounding the youth--that is…

Implantable Microsystems for Anatomical Rewiring of Cortical Circuitry: A New Approach for Brain Repair

DTIC Science & Technology

2009-03-01

dopamine or serotonin, provide outputs to large regions of the brain that affect mood, learning, and cognition [4]. Hence, understanding brain function on a...Sutton, B. T. Higashikubo, C. A. Chestek, H. J. Chiel, and H. B. Martin, “Diamond electrodes for neurodynamic studies in Aplysia californica,” Diam

TOPICAL REVIEW: Integrated genetic analysis microsystems

NASA Astrophysics Data System (ADS)

Lagally, Eric T.; Mathies, Richard A.

2004-12-01

With the completion of the Human Genome Project and the ongoing DNA sequencing of the genomes of other animals, bacteria, plants and others, a wealth of new information about the genetic composition of organisms has become available. However, as the demand for sequence information grows, so does the workload required both to generate this sequence and to use it for targeted genetic analysis. Microfabricated genetic analysis systems are well poised to assist in the collection and use of these data through increased analysis speed, lower analysis cost and higher parallelism leading to increased assay throughput. In addition, such integrated microsystems may point the way to targeted genetic experiments on single cells and in other areas that are otherwise very difficult. Concomitant with these advantages, such systems, when fully integrated, should be capable of forming portable systems for high-speed in situ analyses, enabling a new standard in disciplines such as clinical chemistry, forensics, biowarfare detection and epidemiology. This review will discuss the various technologies available for genetic analysis on the microscale, and efforts to integrate them to form fully functional robust analysis devices.

Bio-hybrid cell-based actuators for microsystems.

PubMed

Carlsen, Rika Wright; Sitti, Metin

2014-10-15

As we move towards the miniaturization of devices to perform tasks at the nano and microscale, it has become increasingly important to develop new methods for actuation, sensing, and control. Over the past decade, bio-hybrid methods have been investigated as a promising new approach to overcome the challenges of scaling down robotic and other functional devices. These methods integrate biological cells with artificial components and therefore, can take advantage of the intrinsic actuation and sensing functionalities of biological cells. Here, the recent advancements in bio-hybrid actuation are reviewed, and the challenges associated with the design, fabrication, and control of bio-hybrid microsystems are discussed. As a case study, focus is put on the development of bacteria-driven microswimmers, which has been investigated as a targeted drug delivery carrier. Finally, a future outlook for the development of these systems is provided. The continued integration of biological and artificial components is envisioned to enable the performance of tasks at a smaller and smaller scale in the future, leading to the parallel and distributed operation of functional systems at the microscale. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Neural prostheses in clinical applications--trends from precision mechanics towards biomedical microsystems in neurological rehabilitation.

PubMed

Stieglitz, T; Schuettler, M; Koch, K P

2004-04-01

Neural prostheses partially restore body functions by technical nerve excitation after trauma or neurological diseases. External devices and implants have been developed since the early 1960s for many applications. Several systems have reached nowadays clinical practice: Cochlea implants help the deaf to hear, micturition is induced by bladder stimulators in paralyzed persons and deep brain stimulation helps patients with Parkinson's disease to participate in daily life again. So far, clinical neural prostheses are fabricated with means of precision mechanics. Since microsystem technology opens the opportunity to design and develop complex systems with a high number of electrodes to interface with the nervous systems, the opportunity for selective stimulation and complex implant scenarios seems to be feasible in the near future. The potentials and limitations with regard to biomedical microdevices are introduced and discussed in this paper. Target specifications are derived from existing implants and are discussed on selected applications that has been investigated in experimental research: a micromachined implant to interface a nerve stump with a sieve electrode, cuff electrodes with integrated electronics, and an epiretinal vision prosthesis.

Monolithic integration of elliptic-symmetry diffractive optical element on silicon-based 45 degrees micro-reflector.

PubMed

Lan, Hsiao-Chin; Hsiao, Hsu-Liang; Chang, Chia-Chi; Hsu, Chih-Hung; Wang, Chih-Ming; Wu, Mount-Learn

2009-11-09

A monolithically integrated micro-optical element consisting of a diffractive optical element (DOE) and a silicon-based 45 degrees micro-reflector is experimentally demonstrated to facilitate the optical alignment of non-coplanar fiber-to-fiber coupling. The slanted 45 degrees reflector with a depth of 216 microm is fabricated on a (100) silicon wafer by anisotropic wet etching. The DOE with a diameter of 174.2 microm and a focal length of 150 microm is formed by means of dry etching. Such a compact device is suitable for the optical micro-system to deflect the incident light by 90 degrees and to focus it on the image plane simultaneously. The measured light pattern with a spot size of 15 microm has a good agreement with the simulated result of the elliptic-symmetry DOE with an off-axis design for eliminating the strongly astigmatic aberration. The coupling efficiency is enhanced over 10-folds of the case without a DOE on the 45 degrees micro-reflector. This device would facilitate the optical alignment of non-coplanar light coupling and further miniaturize the volume of microsystem.

Fast and simultaneous detection of prominent natural antioxidants using analytical microsystems for capillary electrophoresis with a glassy carbon electrode: a new gateway to food environments.

PubMed

Blasco, Antonio Javier; Barrigas, Inés; González, María Cristina; Escarpa, Alberto

2005-12-01

This paper examines for the first time the analytical possibilities of fast and simultaneous detection of prominent natural antioxidants including examples of flavonoids and vitamins using a CE microchip with electrochemical detection (ED). Unpinched injection conditions, zone electrophoretic separation and amperometric detection were carefully assayed and optimised. Analysis involved the zone electrophoretic separation of arbutin, (+)-catechin and ascorbic acid in less than 4 min using a borate buffer (pH 9.0, 50 mM), employing 2 kV as the separation voltage and +1.0 V as the detection potential. In addition, the separation of different 'couples' of natural antioxidants of food significance including (+)-catechin and ascorbic acid, (+)-catechin and rutin, as well as arbutin and phlorizdin is proposed. To demonstrate the potential and future role of CE microsystems, analytical possibilities and a new route in the raw sample analysis are presented. The preliminary results obtained allow the proposal of CE-ED microchips as a real gateway to microanalysis in foods.

Magnetophoretic manipulation in microsystem using carbonyl iron-polydimethylsiloxane microstructures

PubMed Central

Faivre, Magalie; Gelszinnis, Renaud; Degouttes, Jérôme; Terrier, Nicolas; Rivière, Charlotte; Ferrigno, Rosaria; Deman, Anne-Laure

2014-01-01

This paper reports the use of a recent composite material, noted hereafter i-PDMS, made of carbonyl iron microparticles mixed in a PolyDiMethylSiloxane (PDMS) matrix, for magnetophoretic functions such as capture and separation of magnetic species. We demonstrated that this composite which combine the advantages of both components, can locally generate high gradients of magnetic field when placed between two permanent magnets. After evaluating the magnetic susceptibility of the material as a function of the doping ratio, we investigated the molding resolution offered by i-PDMS to obtain microstructures of various sizes and shapes. Then, we implemented 500 μm i-PDMS microstructures in a microfluidic channel and studied the influence of flow rate on the deviation and trapping of superparamagnetic beads flowing at the neighborhood of the composite material. We characterized the attraction of the magnetic composite by measuring the distance from the i-PDMS microstructure, at which the beads are either deviated or captured. Finally, we demonstrated the interest of i-PDMS to perform magnetophoretic functions in microsystems for biological applications by performing capture of magnetically labeled cells. PMID:25332740

GaAs MOEMS Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

SPAHN, OLGA B.; GROSSETETE, GRANT D.; CICH, MICHAEL J.

2003-03-01

Many MEMS-based components require optical monitoring techniques using optoelectronic devices for converting mechanical position information into useful electronic signals. While the constituent piece-parts of such hybrid opto-MEMS components can be separately optimized, the resulting component performance, size, ruggedness and cost are substantially compromised due to assembly and packaging limitations. GaAs MOEMS offers the possibility of monolithically integrating high-performance optoelectronics with simple mechanical structures built in very low-stress epitaxial layers with a resulting component performance determined only by GaAs microfabrication technology limitations. GaAs MOEMS implicitly integrates the capability for radiation-hardened optical communications into the MEMS sensor or actuator component, a vitalmore » step towards rugged integrated autonomous microsystems that sense, act, and communicate. This project establishes a new foundational technology that monolithically combines GaAs optoelectronics with simple mechanics. Critical process issues addressed include selectivity, electrochemical characteristics, and anisotropy of the release chemistry, and post-release drying and coating processes. Several types of devices incorporating this novel technology are demonstrated.« less

Media processors using a new microsystem architecture designed for the Internet era

NASA Astrophysics Data System (ADS)

Wyland, David C.

1999-12-01

The demands of digital image processing, communications and multimedia applications are growing more rapidly than traditional design methods can fulfill them. Previously, only custom hardware designs could provide the performance required to meet the demands of these applications. However, hardware design has reached a crisis point. Hardware design can no longer deliver a product with the required performance and cost in a reasonable time for a reasonable risk. Software based designs running on conventional processors can deliver working designs in a reasonable time and with low risk but cannot meet the performance requirements. What is needed is a media processing approach that combines very high performance, a simple programming model, complete programmability, short time to market and scalability. The Universal Micro System (UMS) is a solution to these problems. The UMS is a completely programmable (including I/O) system on a chip that combines hardware performance with the fast time to market, low cost and low risk of software designs.

Consequences of detritus type in an aquatic microsystem: effects on water quality, micro-organisms and performance of the dominant consumer

PubMed Central

YEE, DONALD A.; JULIANO, STEVEN A.

2007-01-01

SUMMARY 1. Variation in detritus quality and quantity can have significant effects on aquatic invertebrate food webs. Allochthonous inputs of detritus are the principal energy source for organisms in aquatic tree hole microsystems. We compared the effects of two major detritus types found in tree holes, senescent leaves (Sugar Maple and White Oak) and invertebrate carcasses (dead adult fruit flies and crickets), on several water quality characteristics of laboratory microcosms as well as on mass, survival and population performance of the dominant tree hole consumer, Ochlerotatus triseriatus (Diptera: Culicidae). To date, no study has documented the effects of animal detritus in tree hole microsystems or on resident consumers. 2. Aquatic environments receiving invertebrate carcasses had significantly greater total nitrogen, total reactive phosphorus and higher pH, than leaf-based environments. Decay rate of invertebrate carcasses was greater compared to leaf material. Consumption of O2 by micro-organisms increased with increasing detritus amounts, but we detected no difference between detritus types. 3. Ochlerotatus triseriatus larvae grew faster in animal-based treatments, and mean mass of larvae was significantly greater when more animal detritus was used. The effect of animal-based treatments on larvae translated into higher performance for adults, which were three times heavier than counterparts from plant-based containers. Survivorship and estimated population growth rates were significantly greater for O. triseriatus reared on animal-based versus plant-based detritus. 4. We hypothesise two mechanisms for the pronounced effect of invertebrate carcasses on mosquito performance relative to that associated with leaf detritus: (i) invertebrate carcasses decompose more quickly and release nutrients more effectively into the aquatic environment; or (ii) O. triseriatus larvae may directly ingest nutrient-rich components of invertebrate carcasses. Because even relatively small animal detritus additions can have strong effects on O. triseriatus populations, studies need to be conducted to explore the overall role of animal detritus in tree holes in nature. PMID:17476312

Shrinking the apparatus size for DNA analysis

NASA Astrophysics Data System (ADS)

Zimmer, Klaus-Peter; Braun, Alexander; Kostrzewa, M.

2001-03-01

Miniaturization of chemical and/or biological analytical systems requires an innovative design and new manufacturing methods. This includes the fabrication of components or structures, the assembly of these parts, and a testing strategy. The separation of an entire device into a disposable microfluidic system and a multi-use supply unit and housing allows an easy fabrication as well as low cost of operation. A simple, replicated, micro-sized, and disposable unit guarantees the same initial conditions for every analytic cycle, whereas, on the other hand all microfluidic actuators and other key elements can remain outside of the microsystem. In order to drive the implemented passive elements of the microfluidic system by external forces of the base unit, elasticity is a crucial material property. Thus silicone was used as material for the microsystem. A microfluidic system intended for use in DNA analysis employing the principles of the polymerase chain reaction (PCR) is presented. All functional units have been integrated into a complex module using a CAD-program. The 3D-drawing was converted into several machining layers for a direct laser writing CNC-code. A focussed excimer laser beam was used in order to micromachine the negative channel and reservoir system in a polycarbonate slab employing ablative photo-decomposition. Excimer laser micromachining proofed to be an ideal prototyping technique for this purpose with sufficient lateral and depth control. Its rather low throughput was bypassed with an additional hot embossed intermediate positive polyethylene master which, in turn, replicated produces the negative fluidic system in the target material PDMS (polydimethylsiloxane) as an elastomeric material. The components of the fluidic systems have been sealed with flat slabs or other microsystem parts of either PDMS or glass. In either case both parts were exposed to a plasma discharge for some seconds in order to clean, oxidize and activate the surface. This enabled an irreversible seal when two oxidized

EDITORIAL: The 6th International Workshop on Micro and Nanotechnologies for Power Generation and Energy Conversion Applications (PowerMEMS 2006)

NASA Astrophysics Data System (ADS)

Fréchette, Luc G.

2007-09-01

Energy is a sector of paramount importance over the coming decades if we are to ensure sustainable development that respects our environment. The research and development of novel approaches to convert available energy into usable forms using micro and nanotechnologies can contribute towards this goal and meet the growing need for power in small scale portable applications. The dominant power sources for handheld and other portable electronics are currently primary and rechargeable batteries. Their limited energy density and adverse effects on the environment upon disposal suggest that alternative approaches need to be explored. This special issue will showcase some of the leading work in this area, initially presented at PowerMEMS 2006, the 6th International Workshop on Micro and Nanotechnologies for Power Generation and Energy Conversion Applications. Power MEMS are defined as microsystems for electrical power generation and other energy conversion applications, including propulsion and cooling. The range of power MEMS technologies includes micro thermodynamic machines, such as microturbines, miniature internal combustion engines and micro-coolers; solid-state direct energy conversion, such as thermoelectric and photovoltaic microstructures; micro electrochemical devices, such as micro fuel cells and nanostructure batteries; vibration energy harvesting devices, such as piezoelectric, magnetic or electrostatic micro generators, as well as micro thrusters and rocket engines for propulsion. These can either be driven by scavenging thermal, mechanical or solar energy from the environment, or from a stored energy source, such as chemical fuel or radioactive material. The unique scope leads to unique challenges in the development of power MEMS, ranging from the integration of novel materials to the efficient small scale implementation of energy conversion principles. In this special issue, Mitcheson et al provide a comparative assessment of three inertial vibration energy harvesting approaches. Technologies and approaches for micro heat engines are shared, ranging from a complete microsystem for thermal energy harvesting (Cho et al) to core bearing and microturbomachinery technologies for rotating micro heat engines (Waits et al, Nakajima et al). Electrochemical microsystems are also presented, based on methanol as fuel (Morse et al), as well as novel micro and nanofabrication approaches (Chu et al). Fuel cell microsystems with integrated hydrogen generation approaches are also investigated by Peterson et al and Varady et al, illustrating the benefits and challenges of miniaturizing complete power sources. Finally, biological micro fuel cells that leverage the principles found in nature are presented, in contrast to chemical fuel cells (Chen et al, Morishima et al). We hope that this work will inspire others to pursue innovative research and development activities in the area of power MEMS, and consequently contribute to addressing our energy challenges for the 21st century.

Magnetic susceptibility characterisation of superparamagnetic microspheres

NASA Astrophysics Data System (ADS)

Grob, David Tim; Wise, Naomi; Oduwole, Olayinka; Sheard, Steve

2018-04-01

The separation of magnetic materials in microsystems using magnetophoresis has increased in popularity. The wide variety and availability of magnetic beads has fuelled this drive. It is important to know the magnetic characteristics of the microspheres in order to accurately use them in separation processes integrated on a lab-on-a-chip device. To investigate the magnetic susceptibility of magnetic microspheres, the magnetic responsiveness of three types of Dynabeads microspheres were tested using two different approaches. The magnetophoretic mobility of individual microspheres is studied using a particle tracking system and the magnetization of each type of Dynabeads microsphere is measured using SQUID relaxometry. The magnetic beads' susceptibility is obtained at four different applied magnetic fields in the range of 38-70 mT for both the mobility and SQUID measurements. The susceptibility values in both approaches show a consistent magnetic field dependence.

Relations Between Neighborhood Factors, Parenting Behaviors, Peer Deviance, and Delinquency Among Serious Juvenile Offenders

PubMed Central

Chung, He Len; Steinberg, Laurence

2009-01-01

The present study examined relations among neighborhood structural and social characteristics, parenting practices, peer group affiliations, and delinquency among a group of serious adolescent offenders. The sample of 14–18-year-old boys (N = 488) was composed primarily of economically disadvantaged, ethnic-minority youth living in urban communities. The results indicate that weak neighborhood social organization is indirectly related to delinquency through its associations with parenting behavior and peer deviance and that a focus on just 1 of these microsystems can lead to oversimplified models of risk for juvenile offending. The authors also find that community social ties may confer both pro- and antisocial influences to youth, and they advocate for a broad conceptualization of neighborhood social processes as these relate to developmental risk for youth living in disadvantaged communities. PMID:16569170

Surface tension determination using liquid sample micromirror property

NASA Astrophysics Data System (ADS)

Hošek, Jan

2007-05-01

This paper presents an application of adaptive optics principle onto small sample of liquid surface tension measurement. The principle of experimental method devised by Ferguson (1924) is based on measurement of pressure difference across a liquid sample placed into small diameter capillary on condition of one flat meniscus of the liquid sample. Planarity or curvature radius of the capillary tip meniscus has to be measured and controlled, in order to fulfill this condition during measurement. Two different optical set-ups using liquid meniscus micromirror property are presented and its suitability for meniscus profile determination is compared. Meniscus radius optical measurement, data processing and control algorithm of the adaptive micromirror profile set are presented too. The presented adaptive optics system can be used for focal length control of microsystems based on liquid micromirrors or microlenses with long focal distances especially.

Engineering a biospecific communication pathway between cells and electrodes

NASA Astrophysics Data System (ADS)

Collier, Joel H.; Mrksich, Milan

2006-02-01

Methods for transducing the cellular activities of mammalian cells into measurable electronic signals are important in many biotechnical applications, including biosensors, cell arrays, and other cell-based devices. This manuscript describes an approach for functionally integrating cellular activities and electrical processes in an underlying substrate. The cells are engineered with a cell-surface chimeric receptor that presents the nonmammalian enzyme cutinase. Action of this cell-surface cutinase on enzyme substrate self-assembled monolayers switches a nonelectroactive hydroxyphenyl ester to an electroactive hydroquinone, providing an electrical activity that can be identified with cyclic voltammetry. In this way, cell-surface enzymatic activity is transduced into electronic signals. The development of strategies to directly interface the activities of cells with materials will be important to enabling a broad class of hybrid microsystems that combine living and nonliving components. biomaterial | extracellular matrix | signal transduction

Multi-Scale Low-Entropy Method for Optimizing the Processing Parameters during Automated Fiber Placement

PubMed Central

Han, Zhenyu; Sun, Shouzheng; Fu, Hongya; Fu, Yunzhong

2017-01-01

Automated fiber placement (AFP) process includes a variety of energy forms and multi-scale effects. This contribution proposes a novel multi-scale low-entropy method aiming at optimizing processing parameters in an AFP process, where multi-scale effect, energy consumption, energy utilization efficiency and mechanical properties of micro-system could be taken into account synthetically. Taking a carbon fiber/epoxy prepreg as an example, mechanical properties of macro–meso–scale are obtained by Finite Element Method (FEM). A multi-scale energy transfer model is then established to input the macroscopic results into the microscopic system as its boundary condition, which can communicate with different scales. Furthermore, microscopic characteristics, mainly micro-scale adsorption energy, diffusion coefficient entropy–enthalpy values, are calculated under different processing parameters based on molecular dynamics method. Low-entropy region is then obtained in terms of the interrelation among entropy–enthalpy values, microscopic mechanical properties (interface adsorbability and matrix fluidity) and processing parameters to guarantee better fluidity, stronger adsorption, lower energy consumption and higher energy quality collaboratively. Finally, nine groups of experiments are carried out to verify the validity of the simulation results. The results show that the low-entropy optimization method can reduce void content effectively, and further improve the mechanical properties of laminates. PMID:28869520

Multi-Scale Low-Entropy Method for Optimizing the Processing Parameters during Automated Fiber Placement.

PubMed

Han, Zhenyu; Sun, Shouzheng; Fu, Hongya; Fu, Yunzhong

2017-09-03

Automated fiber placement (AFP) process includes a variety of energy forms and multi-scale effects. This contribution proposes a novel multi-scale low-entropy method aiming at optimizing processing parameters in an AFP process, where multi-scale effect, energy consumption, energy utilization efficiency and mechanical properties of micro-system could be taken into account synthetically. Taking a carbon fiber/epoxy prepreg as an example, mechanical properties of macro-meso-scale are obtained by Finite Element Method (FEM). A multi-scale energy transfer model is then established to input the macroscopic results into the microscopic system as its boundary condition, which can communicate with different scales. Furthermore, microscopic characteristics, mainly micro-scale adsorption energy, diffusion coefficient entropy-enthalpy values, are calculated under different processing parameters based on molecular dynamics method. Low-entropy region is then obtained in terms of the interrelation among entropy-enthalpy values, microscopic mechanical properties (interface adsorbability and matrix fluidity) and processing parameters to guarantee better fluidity, stronger adsorption, lower energy consumption and higher energy quality collaboratively. Finally, nine groups of experiments are carried out to verify the validity of the simulation results. The results show that the low-entropy optimization method can reduce void content effectively, and further improve the mechanical properties of laminates.

An Ecological Systems Approach to Bullying Behaviors among Middle School Students in the United States

ERIC Educational Resources Information Center

Lee, Chang-Hun

2011-01-01

The aim of this study is to identify an ecological prediction model of bullying behaviors. Based on an ecological systems theory, this study identifies significant factors influencing bullying behaviors at different levels of middle and high school. These levels include the microsystem, mesosystem, exosystem, and macrosystem. More specifically,…

A Hands-On Freshman Survey Course to Steer Undergraduates into Microsystems Coursework and Research

ERIC Educational Resources Information Center

Eddings, M. A.; Stephenson, J. C.; Harvey, I. R.

2009-01-01

Full class loads and inflexible schedules can be a significant obstacle in the implementation of freshman survey courses designed to guide engineering students into emerging research areas such as micro- and nanosystems. A hands-on, interactive course was developed to excite freshmen early in their engineering program to pursue research and…

A Testbed for Advancing the Role of Digital Technologies for Library Preservation and Access. Final Report.

ERIC Educational Resources Information Center

Kenney, Anne R.; Personius, Lynne K.

In cooperation with the Commission on Preservation and Access, Xerox Corporation, Sun Microsystems, Inc., and the New York State Program for the Conservation and Preservation of Library Research Materials, Cornell University (New York) studied and established the effectiveness of digital technology to preserve and make available research library…

In situ MEMS testing: correlation of high-resolution X-ray diffraction with mechanical experiments and finite element analysis

NASA Astrophysics Data System (ADS)

Schifferle, Andreas; Dommann, Alex; Neels, Antonia

2017-12-01

New methods are needed in microsystems technology for evaluating microelectromechanical systems (MEMS) because of their reduced size. The assessment and characterization of mechanical and structural relations of MEMS are essential to assure the long-term functioning of devices, and have a significant impact on design and fabrication.

The Start of a Tech Revolution

ERIC Educational Resources Information Center

Dyrli, Kurt O.

2009-01-01

We are at the start of a revolution in the use of computers, one that analysts predict will rival the development of the PC in its significance. Companies such as Google, HP, Amazon, Sun Microsystems, Sony, IBM, and Apple are orienting their entire business models toward this change, and software maker SAS has announced plans for a $70 million…

Apparatus and method for fabricating a microbattery

DOEpatents

Shul, Randy J.; Kravitz, Stanley H.; Christenson, Todd R.; Zipperian, Thomas E.; Ingersoll, David

2002-01-01

An apparatus and method for fabricating a microbattery that uses silicon as the structural component, packaging component, and semiconductor to reduce the weight, size, and cost of thin film battery technology is described. When combined with advanced semiconductor packaging techniques, such a silicon-based microbattery enables the fabrication of autonomous, highly functional, integrated microsystems having broad applicability.

Telelearning standards and their application in medical education.

PubMed

Duplaga, Mariusz; Juszkiewicz, Krzysztof; Leszczuk, Mikolaj

2004-01-01

Medial education, both on the graduate and postgraduate levels, has become a real challenge nowadays. The volume of information in medical sciences grows so rapidly that many health professionals experience essential problems in keeping track of the state of the art in this domain. e-learning offers important advantages to medical education continuation due to its universal availability and opportunity for implementation of flexible patterns of training. An important trace of medical education is developing practical skills. Some examples of standardization efforts include: the CEN/ISSS Workshop on Learning Technology (WSLT), the Advanced Learning Infrastructure Consortium (ALIC), Education Network Australia (EdNA) and PROmoting Multimedia access to Education and Training in European Society (PROMETEUS). Sun Microsystems' support (Sun ONE, iPlanetTM ) for many of the above-mentioned standards is described as well. Development of a medical digital video library with recordings of invasive procedures incorporating additional information and commentary may improve the efficiency of the training process in interventional medicine. A digital video library enabling access to videos of interventional procedures performed in the area of thoracic medicine may be a valuable element for developing practical skills. The library has been filled with video resources recorded at the Department of Interventional Pulmonology; it enhances training options for pulmonologists and thoracic surgeons. The main focus was put on demonstration of bronchofiberoscopic and videothoracoscopic procedures. The opportunity to browse video recordings of procedures performed in the specific field also considerably enhances the options for training in other medical specialties. In the era of growing health consumer awareness, patients are also perceived as the target audience for medical digital libraries. As a case study of Computer-Based Training systems, the Medical Digital Video Library is presented.

New Effective Material Couple--Oxide Ceramic and Carbon Nanotube-- Developed for Aerospace Microsystem and Micromachine Technologies

NASA Technical Reports Server (NTRS)

Miyoshi, Kazuhisa; VanderWal, Randall L.; Tomasek, Aaron J.; Sayir, Ali; Farmer, Serene C.

2004-01-01

The prime driving force for using microsystem and micromachine technologies in transport vehicles, such as spacecraft, aircraft, and automobiles, is to reduce the weight, power consumption, and volume of components and systems to lower costs and increase affordability and reliability. However, a number of specific issues need to be addressed with respect to using microsystems and micromachines in aerospace applications--such as the lack of understanding of material characteristics; methods for producing and testing the materials in small batches; the limited proven durability and lifetime of current microcomponents, packaging, and interconnections; a cultural change with respect to system designs; and the use of embedded software, which will require new product assurance guidelines. In regards to material characteristics, there are significant adhesion, friction, and wear issues in using microdevices. Because these issues are directly related to surface phenomena, they cannot be scaled down linearly and they become increasingly important as the devices become smaller. When microsystems have contacting surfaces in relative motion, the adhesion and friction affect performance, energy consumption, wear damage, maintenance, lifetime and catastrophic failure, and reliability. Ceramics, for the most part, do not have inherently good friction and wear properties. For example, coefficients of friction in excess of 0.7 have been reported for ceramics and ceramic composite materials. Under Alternate Fuels Foundation Technologies funding, two-phase oxide ceramics developed for superior high-temperature wear resistance in NASA's High Operating Temperature Propulsion Components (HOTPC) project and new two-layered carbon nanotube (CNT) coatings (CNT topcoat/iron bondcoat/quartz substrate) developed in NASA's Revolutionary Aeropropulsion Concepts (RAC) project have been chosen as a materials couple for aerospace applications, including micromachines, in the nanotechnology lubrication task because of their potential for superior friction and wearf properties in air and in an ultrahigh vacuum, spacelike environment. At the NASA Glenn Research Center, two-phase oxide ceramic eutectics, Al2O3/ZrO2(Y2O3), were directionally solidified using the laser-float-zone process, and carbon nanotubes were synthesized within a high-temperature tube furnace at 800 C. Physical vapor deposition was used to coat all quartz substrates with 5-nm-thick iron as catalyst and bondcoat, which formed iron islands resembling droplets and serving as catalyst particles on the quartz. A series of scanning electron micrographs showing multiwalled carbon nanotubes directionally grown as aligned "nanograss" on quartz is presented. Unidirectional sliding friction eperiments were conducted at Glenn with the two-layered CNT coatings in contact with the two-phase Al2O3/ZrO2(Y2O3) eutectics in air and in ultrachigh vacuum. The main criteria for judging the performance of the materials couple for solid lubrication and antistick applications in a space environment were the coefficient of friction and the wear resistance (reciprocal of wear rate), which had to be less than 0.2 and greater than 10(exp 5) N(raised dot)/cubic millimetes, respectively, in ultrahigh vacuum. In air, the coefficient of friction for the CNT coatings in contact with Al2O3/ZrO2 (Y2O3) eutectics was 0.04, one-fourth of that for quartz. In an ultrahigh vacuum, the coefficient of friction for CNT coatings in contact with Al2O3/ZrO2 (Y2O3) was one-third of that for quartz. The two-phase Al2O3/ZrO2 (Y2O3) eutectic coupled with the two-layered CNT coating met the coefficient of friction and wear resistance criteria both in air and in an ultrahigh vacuum, spacelike environment. This material's couple can dramatically improve the stiction (or adhesion), friction, and wear resistance of the contacting surfaces, which are major issues for microdevices and micromachines.

New computer and communications environments for light armored vehicles

NASA Astrophysics Data System (ADS)

Rapanotti, John L.; Palmarini, Marc; Dumont, Marc

2002-08-01

Light Armoured Vehicles (LAVs) are being developed to meet the modern requirements of rapid deployment and operations other than war. To achieve these requirements, passive armour is minimized and survivability depends more on sensors, computers and countermeasures to detect and avoid threats. The performance, reliability, and ultimately the cost of these components, will be determined by the trends in computing and communications. These trends and the potential impact on DAS (Defensive Aids Suite) development were investigated and are reported in this paper. Vehicle performance is affected by communication with other vehicles and other ISTAR (Intelligence, Surveillance, Target Acquisition and Reconnaissance) battlefield assets. This investigation includes the networking technology Jini developed by SUN Microsystems, which can be used to interface the vehicle to the ISTAR network. VxWorks by Wind River Systems, is a real time operating system designed for military systems and compatible with Jini. Other technologies affecting computer hardware development include, dynamic reconfiguration, hot swap, alternate pathing, CompactPCI, and Fiber Channel serial communication. To achieve the necessary performance at reasonable cost, and over the long service life of the vehicle, a DAS should have two essential features. A fitted for, but not fitted with approach will provide the necessary rapid deployment without a need to equip the entire fleet. With an expected vehicle service life of 50 years, 5-year technology upgrades can be used to maintain vehicle performance over the entire service life. A federation of modules instead of integrated fused sensors will provide the capability for incremental upgrades and mission configurability. A plug and play capability can be used for both hardware and expendables.

Willingness to Communicate in English: A Microsystem Model in the Iranian EFL Classroom Context

ERIC Educational Resources Information Center

Khajavy, Gholam Hassan; Ghonsooly, Behzad; Fatemi, Azar Hosseini; Choi, Charles W.

2016-01-01

This study examined willingness to communicate (WTC) in English among Iranian EFL learners in the classroom context. For this purpose, a second language willingness to communicate (L2WTC) model based on WTC theory (MacIntyre, Clément, Dörnyei, and Noels, 1998) and empirical studies was proposed and tested using structural equation modeling (SEM).…

The Impact of Emerging MEMS-Based Microsystems on US Defense Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

STAPLE,BEVAN D.; JAKUBCZAK II,JEROME F.

2000-01-20

This paper examines the impact of inserting Micro-Electro-Mechanical Systems (MEMS) into US defense applications. As specific examples, the impacts of micro Inertial Measurement Units (IMUs), radio frequency MEMS (RF MEMS), and Micro-Opto-Electro-Mechanical Systems (MOEMS) to provide integrated intelligence, communication, and control to the defense infrastructure with increased affordability, functionality, and performance are highlighted.

75 FR 36442 - In the Matter of Certain Inkjet Ink Cartridges With Printheads and Components Thereof; Notice of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-25

... Co., Ltd., 1F, No. 28, R&D 2nd Rd., Science-Based Industrial Park, Hsinchu City, Taiwan 30076, Asia Pacific Microsystems, Inc., No. 2, R&D Rd. 6, Science-Based Industrial Park, Hsinchu City, Taiwan 30076... Science & Technology Co., Ltd., Guangzhou, Rm. 3310-3313, Xin Yuan Building, No. 898 North Tianhe Road...

Probabilistic commodity-flow-based focusing of monitoring activities to facilitate early detection of Phytophthora ramorum outbreaks

Treesearch

Steven C. McKelvey; William D. Smith; Frank Koch

2012-01-01

This project summary describes a probabilistic model developed with funding support from the Forest Health Monitoring Program of the Forest Service, U.S. Department of Agriculture (BaseEM Project SO-R-08-01). The model has been implemented in SODBuster, a standalone software package developed using the Java software development kit from Sun Microsystems.

VLSI Microsystem for Rapid Bioinformatic Pattern Recognition

NASA Technical Reports Server (NTRS)

Fang, Wai-Chi; Lue, Jaw-Chyng

2009-01-01

A system comprising very-large-scale integrated (VLSI) circuits is being developed as a means of bioinformatics-oriented analysis and recognition of patterns of fluorescence generated in a microarray in an advanced, highly miniaturized, portable genetic-expression-assay instrument. Such an instrument implements an on-chip combination of polymerase chain reactions and electrochemical transduction for amplification and detection of deoxyribonucleic acid (DNA).

Some metal oxides and their applications for creation of Microsystems (MEMS) and Energy Harvesting Devices (EHD)

NASA Astrophysics Data System (ADS)

Denishev, K.

2016-10-01

This is a review of a part of the work of the Technological Design Group at Technical University of Sofia, Faculty of Electronic Engineering and Technologies, Department of Microelectronics. It is dealing with piezoelectric polymer materials and their application in different microsystems (MEMS) and Energy Harvesting Devices (EHD), some organic materials and their applications in organic (OLED) displays, some transparent conductive materials etc. The metal oxides Lead Zirconium Titanate (PZT) and Zinc Oxide (ZnO) are used as piezoelectric layers - driving part of different sensors, actuators and EHD. These materials are studied in term of their performance in dependence on the deposition conditions and parameters. They were deposited as thin films by using RF Sputtering System. As technological substrates, glass plates and Polyethylenetherephtalate (PET) foils were used. For characterization of the materials, a test structure, based on Surface Acoustic Waves (SAW), was designed and prepared. The layers were characterized by Fourier Transform Infrared spectroscopy (FTIR). The piezoelectric response was tested at variety of mechanical loads (tensile strain, stress) in static and dynamic (multiple bending) mode. The single-layered and double-layered structures were prepared for piezoelectric efficiency increase. A structure of piezoelectric energy transformer is proposed and investigated.

One lens missing? Clarifying the clinical microsystem framework with learning theories.

PubMed

Norman, Ann-Charlott; Fritzen, Lena; Fridh, Marianne Lindblad

2013-01-01

The clinical microsystem (CMS) approach is widely used and is perceived as helpful in practice but, we ask the question: "Is its learning potential sufficiently utilized?" To scrutinize aspects of learning within the CMS framework and to clarify the learning aspects the framework includes and thereby support the framework with the enhanced learning perspective that becomes visible. Literature on the CMS framework was systematically searched and selected using inclusion criteria. An analytical tool was constructed in the form of a theoretical lens that was used to clarify learning aspects that are associated with the framework. The analysis revealed 3 learning aspects: (1) The CMS framework describes individual and social learning but not how to adapt learning strategies for purposes of change. (2) The metaphorical language of how to reach a holistic health care system for each patient has developed over time but can still be improved by naming social interactions to transcend organizational boundaries. (3) Power structures are recognized but not as a characteristic that restricts learning due to asymmetric communication. The "lens" perspective reveals new meanings to learning that enhance our understanding of health care as a social system and provides new practical learning strategies.

Remotely adjustable check-valves with an electrochemical release mechanism for implantable biomedical microsystems.

PubMed

Pan, Tingrui; Baldi, Antonio; Ziaie, Babak

2007-06-01

In this paper, we present two remotely adjustable check-valves with an electrochemical release mechanism for implantable biomedical microsystems. These valves allow one to vary the opening pressure set-point and flow resistance over a period of time. The first design consists of a micromachined check-valve array using a SU-8 polymer structural layer deposited on the top of a gold sacrificial layer. The second design is based on a variable length cantilever beam structure with a gold sacrificial layer. The adjustable cantilever-beam structure is fabricated by gold thermo-compression bond of a thin silicon wafer over a glass substrate. In both designs, the evaporated gold can be electrochemically dissolved using a constant DC current via a telemetry link. In the first design the dissolution simply opens up individual outlets, while in the second design, gold anchors are sequentially dissolved hence increasing the effective length of the cantilever beam (reducing the opening pressure). A current density of 35 mA/cm(2) is used to dissolve the gold sacrificial layers. Both gravity and syringe-pump driven flow are used to characterize the valve performance. A multi-stage fluidic performance (e.g. flow resistance and opening pressure) is clearly demonstrated.

Restoring visual perception using microsystem technologies: engineering and manufacturing perspectives.

PubMed

Krisch, I; Hosticka, B J

2007-01-01

Microsystem technologies offer significant advantages in the development of neural prostheses. In the last two decades, it has become feasible to develop intelligent prostheses that are fully implantable into the human body with respect to functionality, complexity, size, weight, and compactness. Design and development enforce collaboration of various disciplines including physicians, engineers, and scientists. The retina implant system can be taken as one sophisticated example of a prosthesis which bypasses neural defects and enables direct electrical stimulation of nerve cells. This micro implantable visual prosthesis assists blind patients to return to the normal course of life. The retina implant is intended for patients suffering from retinitis pigmentosa or macular degeneration. In this contribution, we focus on the epiretinal prosthesis and discuss topics like system design, data and power transfer, fabrication, packaging and testing. In detail, the system is based upon an implantable micro electro stimulator which is powered and controlled via a wireless inductive link. Microelectronic circuits for data encoding and stimulation are assembled on flexible substrates with an integrated electrode array. The implant system is encapsulated using parylene C and silicone rubber. Results extracted from experiments in vivo demonstrate the retinotopic activation of the visual cortex.

Hydrodynamic cavitation in microsystems. II. Simulations and optical observations

NASA Astrophysics Data System (ADS)

Medrano, M.; Pellone, C.; Zermatten, P. J.; Ayela, F.

2012-04-01

Numerical calculations in the single liquid phase and optical observations in the two-phase cavitating flow regime have been performed on microdiaphragms and microventuris fed with deionized water. Simulations have confirmed the influence of the shape of the shrinkage upon the contraction of the jet, and so on the localisation of possible cavitating area downstream. Observations of cavitating flow patterns through hybrid silicon-pyrex microdevices have been performed either via a laser excitation with a pulse duration of 6 ns, or with the help of a high-speed camera. Recorded snapshots and movies are presented. Concerning microdiaphragms, it is confirmed that very high shear rates downstream the diaphragms are the cause of bubbly flows. Concerning microventuris, a gaseous cavity forms on a boundary downstream the throat. As a consequence of a microsystem instability, the cavity displays a high frequency pulsation. Low values Strouhal numbers are associated to such a sheet cavitation. Moreover, when the intensity of the cavitating flow is reduced, there is a mismatch between the frequency of the pulsation of the cavity and the frequency of shedded clouds downstream the channel. That may be the consequence of viscous effects limiting the impingement of a re-entrant liquid jet on the attached cavity.

Optical Scattering Characterization for the Glennan Microsystems Microscale Particulate Classifier

NASA Technical Reports Server (NTRS)

Lock, James A.

2002-01-01

Small sensors that are tolerant to mechanically and thermally harsh environments present the possibility for in-situ particle characterization in propulsion, industrial, and planetary science applications. Under a continuing grant from the Glennan Microsystems Initiative to the Microgravity Fluids Physics Branch of the NASA-Glenn Research Center, a Microscale Particle Classifier (MiPAC) instrument is being developed. The MiPAC instrument will be capable of determining the size distribution of airborne particles from about 1 nm to 30 micrometers, and will provide partial information as to the concentration, charge state, shape, and structure of the particles, while being an order of magnitude smaller in size and lighter in weight than presently commercially available instruments. The portion of the instrument that will characterize the nm-range particles will employ electrical mobility techniques and is being developed under a separate grant to Prof. David Pui of the University of Minnesota. The portion of the instrument that will characterize the micrometer-size particles such as dirt, pollens, spores, molds, soot, and combustion aerosols will use light scattering techniques. The development of data analysis techniques to be employed in the light scattering portion of the instrument is covered by this grant.

Magnetic particles for in vitro molecular diagnosis: From sample preparation to integration into microsystems.

PubMed

Tangchaikeeree, Tienrat; Polpanich, Duangporn; Elaissari, Abdelhamid; Jangpatarapongsa, Kulachart

2017-10-01

Colloidal magnetic particles (MPs) have been developed in association with molecular diagnosis for several decades. MPs have the great advantage of easy manipulation using a magnet. In nucleic acid detection, these particles can act as a capture support for rapid and simple biomolecule separation. The surfaces of MPs can be modified by coating with various polymer materials to provide functionalization for different applications. The use of MPs enhances the sensitivity and specificity of detection due to the specific activity on the surface of the particles. Practical applications of MPs demonstrate greater efficiency than conventional methods. Beyond traditional detection, MPs have been successfully adopted as a smart carrier in microfluidic and lab-on-a-chip biosensors. The versatility of MPs has enabled their integration into small single detection units. MPs-based biosensors can facilitate rapid and highly sensitive detection of very small amounts of a sample. In this review, the application of MPs to the detection of nucleic acids, from sample preparation to analytical readout systems, is described. State-of-the-art integrated microsystems containing microfluidic and lab-on-a-chip biosensors for the nucleic acid detection are also addressed. Copyright © 2017 Elsevier B.V. All rights reserved.

A Ubiquitous Optical Microsystem Platform with Application to Optical Metrology and Chemical Sensing

NASA Astrophysics Data System (ADS)

Gerling, John David

This dissertation is concerned with the development of a novel, versatile optical sensor platform for optical metrology and chemical sensing. We demonstrate the feasibility of embedding optical components between bonded silicon wafers with receptor cavities and optical windows to create a self-contained sensor microsystem that can be used for in-situ measurement of hostile environments. Arrays of these sensors internal to a silicon wafer can enable optical sensing for in-situ, real-time mapping and process development for the semiconductor industry in the form of an instrumented substrate. Single-die versions of these optical sensor platforms can also enable point-of-care diagnostics, high throughput disease screening, bio-warfare agent detection, and environmental monitoring. Our first discussion will focus on a single-wavelength interferometry-based prototype sensor. Several applications are demonstrated using this single wavelength prototype: refractive index monitoring, SiO2 plasma etching, chemical mechanical polishing, photoresist cure and dissolution, copper etch end-point detection, and also nanopore wetting phenomena. Subsequent sections of this dissertation will describe efforts to improve the optical sensor platform to achieve multi-wavelength sensing function. We explore the use of an off-the-shelf commercial RGB sensor for colorimetric monitoring of copper and aluminum thin-film etchings. We then expand upon our prior work and concepts to realize a fully integrated, chip-sized microspectrometer with a photon engine based on a diffraction grating. The design, fabrication, and demonstration of a working prototype with dimensions < 1 mm thick using standard planar microfabrication techniques is described. Proof-of-concept demonstrations indicate the working principle of dispersion, although with a low spectral resolution of 120 nm. With working knowledge of the issues of the first prototype, we present an improved 5-channel microspectrometer with a spectral range 400-900 nm and demonstrate its ability for spectral identification with 3 different phosphor powder samples. Finally, we conclude with suggestions for future areas of research.

System Model for MEMS based Laser Ultrasonic Receiver

NASA Technical Reports Server (NTRS)

Wilson, William C.

2002-01-01

A need has been identified for more advanced nondestructive Evaluation technologies for assuring the integrity of airframe structures, wiring, etc. Laser ultrasonic inspection instruments have been shown to detect flaws in structures. However, these instruments are generally too bulky to be used in the confined spaces that are typical of aerospace vehicles. Microsystems technology is one key to reducing the size of current instruments and enabling increased inspection coverage in areas that were previously inaccessible due to instrument size and weight. This paper investigates the system modeling of a Micro OptoElectroMechanical System (MOEMS) based laser ultrasonic receiver. The system model is constructed in software using MATLAB s dynamical simulator, Simulink. The optical components are modeled using geometrical matrix methods and include some image processing. The system model includes a test bench which simulates input stimuli and models the behavior of the material under test.

Organs-on-a-chip for drug discovery.

PubMed

Selimović, Seila; Dokmeci, Mehmet R; Khademhosseini, Ali

2013-10-01

The current drug discovery process is arduous and costly, and a majority of the drug candidates entering clinical trials fail to make it to the marketplace. The standard static well culture approaches, although useful, do not fully capture the intricate in vivo environment. By merging the advances in microfluidics with microfabrication technologies, novel platforms are being introduced that lead to the creation of organ functions on a single chip. Within these platforms, microengineering enables precise control over the cellular microenvironment, whereas microfluidics provides an ability to perfuse the constructs on a chip and to connect individual sections with each other. This approach results in microsystems that may better represent the in vivo environment. These organ-on-a-chip platforms can be utilized for developing disease models as well as for conducting drug testing studies. In this article, we highlight several key developments in these microscale platforms for drug discovery applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

Micromolding of polymer waveguides

NASA Astrophysics Data System (ADS)

Hanemann, Thomas; Ulrich, Hermann; Ruprecht, Robert; Hausselt, Juergen H.

1999-10-01

In microsystem technology the fabrication of either passive or active micro optical components made from polymers becomes more and more evident with respect to the intense expanding application possibilities e.g. in telecommunication. Actually, the LIGA process developed at the FZK, Germany allows the direct fabrication of microcomponents with lateral dimensions in the micrometer range, structural details in the submicrometer range, high aspect ratios of up to several hundreds and a final average surface roughness of less than 50 nm in small up to large scales. The molding of polymer components for microoptical applications, especially in the singlemode range, is determined by the achievable maximum accuracy of the molding technique itself and of the acceptable tolerances for low damping and coupling losses. Following the LIGA and related technique e.g. mechanical microengineering we want to present in this work the fabrication of polymer singlemode waveguides using a combination of micromolding and light- curing steps.

Thin Carbon Layers on Nanostructured Silicon-Properties and Applications

NASA Astrophysics Data System (ADS)

Angelescu, Anca; Kleps, Irina; Miu, Mihaela; Simion, Monica; Bragaru, Adina; Petrescu, Stefana; Paduraru, Crina; Raducanu, Aurelia

Thin carbon layers such as silicon carbide (SiC) and diamond like carbon (DLC) layers on silicon, or on nanostructured silicon substrats were obtained by different methods. This paper is a review of our results in the areas of carbon layer microfabrication technologies and their properties related to different microsystem apllications. So, silicon membranes using a-SiC or DLC layers as etching mask, as well as silicon carbide membranes using a combined porous silicon — DLC structure were fabricated for sensor applications. A detailed evaluation of the field emission (FE) properties of these films was done to demonstrate their capability to be used in field emission devices. Carbon thin layers on nanostructured silicon samples were also investigated with respect to the living cell adhesion on these structures. The experiments indicate that the cell attachment on the surface of carbon coatings can be controlled by deposition parameters during the technological process.

Effect of viscoelasticity on the flow pattern and the volumetric flow rate in electroosmotic flows through a microchannel.

PubMed

Park, H M; Lee, W M

2008-07-01

Many lab-on-a-chip based microsystems process biofluids such as blood and DNA solutions. These fluids are viscoelastic and show extraordinary flow behaviors, not existing in Newtonian fluids. Adopting appropriate constitutive equations these exotic flow behaviors can be modeled and predicted reasonably using various numerical methods. In the present paper, we investigate viscoelastic electroosmotic flows through a rectangular straight microchannel with and without pressure gradient. It is shown that the volumetric flow rates of viscoelastic fluids are significantly different from those of Newtonian fluids under the same external electric field and pressure gradient. Moreover, when pressure gradient is imposed on the microchannel there appear appreciable secondary flows in the viscoelastic fluids, which is never possible for Newtonian laminar flows through straight microchannels. The retarded or enhanced volumetric flow rates and secondary flows affect dispersion of solutes in the microchannel nontrivially.

Using evaporation to control capillary instabilities in micro-systems.

PubMed

Ledesma-Aguilar, Rodrigo; Laghezza, Gianluca; Yeomans, Julia M; Vella, Dominic

2017-12-06

The instabilities of fluid interfaces represent both a limitation and an opportunity for the fabrication of small-scale devices. Just as non-uniform capillary pressures can destroy micro-electrical mechanical systems (MEMS), so they can guide the assembly of novel solid and fluid structures. In many such applications the interface appears during an evaporation process and is therefore only present temporarily. It is commonly assumed that this evaporation simply guides the interface through a sequence of equilibrium configurations, and that the rate of evaporation only sets the timescale of this sequence. Here, we use Lattice-Boltzmann simulations and a theoretical analysis to show that, in fact, the rate of evaporation can be a factor in determining the onset and form of dynamical capillary instabilities. Our results shed light on the role of evaporation in previous experiments, and open the possibility of exploiting diffusive mass transfer to directly control capillary flows in MEMS applications.

Deformation analysis of MEMS structures by modified digital moiré methods

NASA Astrophysics Data System (ADS)

Liu, Zhanwei; Lou, Xinhao; Gao, Jianxin

2010-11-01

Quantitative deformation analysis of micro-fabricated electromechanical systems is of importance for the design and functional control of microsystems. In this paper, two modified digital moiré processing methods, Gaussian blurring algorithm combined with digital phase shifting and geometrical phase analysis (GPA) technique based on digital moiré method, are developed to quantitatively analyse the deformation behaviour of micro-electro-mechanical system (MEMS) structures. Measuring principles and experimental procedures of the two methods are described in detail. A digital moiré fringe pattern is generated by superimposing a specimen grating etched directly on a microstructure surface with a digital reference grating (DRG). Most of the grating noise is removed from the digital moiré fringes, which enables the phase distribution of the moiré fringes to be obtained directly. Strain measurement result of a MEMS structure demonstrates the feasibility of the two methods.

Creating innovative clinical nurse leader practicum experiences through academic and practice partnerships.

PubMed

Jukkala, Angela; Greenwood, Rebecca; Motes, Terry; Block, Velinda

2013-01-01

The new Clinical Nurse Leader (CNL) nursing role was developed to meet the complex health care needs of patients, families, and health care systems. This article describes the process used by nurse leaders at the University of Alabama at Birmingham School of Nursing and Hospital to develop Model C CNL practicum courses, recruit and prepare clinical preceptors, prepare clinical microsystems for CNL students, and develop additional practice partnerships throughout the region. MANAGEMENT AND OUTCOME: Critical to the success of the CNL role is a dynamic partnership between academic and practice leaders.The partnership allows faculty to develop curricula that are relevant and responsive to the rapidly changing health care system. Clinical leaders become more aware of trends and issues in nursing education. Continued growth and success of the CNL role is largely dependent on the ability of faculty and practice partners to collaborate on innovative educational programs and models of care delivery.

Nanotexturing of surfaces to reduce melting point.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia, Ernest J.; Zubia, David; Mireles, Jose

2011-11-01

This investigation examined the use of nano-patterned structures on Silicon-on-Insulator (SOI) material to reduce the bulk material melting point (1414 C). It has been found that sharp-tipped and other similar structures have a propensity to move to the lower energy states of spherical structures and as a result exhibit lower melting points than the bulk material. Such a reduction of the melting point would offer a number of interesting opportunities for bonding in microsystems packaging applications. Nano patterning process capabilities were developed to create the required structures for the investigation. One of the technical challenges of the project was understandingmore » and creating the specialized conditions required to observe the melting and reshaping phenomena. Through systematic experimentation and review of the literature these conditions were determined and used to conduct phase change experiments. Melting temperatures as low as 1030 C were observed.« less

Three-dimensional integrated circuits for lab-on-chip dielectrophoresis of nanometer scale particles

NASA Astrophysics Data System (ADS)

Dickerson, Samuel J.; Noyola, Arnaldo J.; Levitan, Steven P.; Chiarulli, Donald M.

2007-01-01

In this paper, we present a mixed-technology micro-system for electronically manipulating and optically detecting virusscale particles in fluids that is designed using 3D integrated circuit technology. During the 3D fabrication process, the top-most chip tier is assembled upside down and the substrate material is removed. This places the polysilicon layer, which is used to create geometries with the process' minimum feature size, in close proximity to a fluid channel etched into the top of the stack. By taking advantage of these processing features inherent to "3D chip-stacking" technology, we create electrode arrays that have a gap spacing of 270 nm. Using 3D CMOS technology also provides the ability to densely integrate analog and digital control circuitry for the electrodes by using the additional levels of the chip stack. We show simulations of the system with a physical model of a Kaposi's sarcoma-associated herpes virus, which has a radius of approximately 125 nm, being dielectrophoretically arranged into striped patterns. We also discuss how these striped patterns of trapped nanometer scale particles create an effective diffraction grating which can then be sensed with macro-scale optical techniques.

Social Interface Model: Theorizing Ecological Post-Delivery Processes for Intervention Effects.

PubMed

Pettigrew, Jonathan; Segrott, Jeremy; Ray, Colter D; Littlecott, Hannah

2018-01-03

Successful prevention programs depend on a complex interplay among aspects of the intervention, the participant, the specific intervention setting, and the broader set of contexts with which a participant interacts. There is a need to theorize what happens as participants bring intervention ideas and behaviors into other life-contexts, and theory has not yet specified how social interactions about interventions may influence outcomes. To address this gap, we use an ecological perspective to develop the social interface model. This paper presents the key components of the model and its potential to aid the design and implementation of prevention interventions. The model is predicated on the idea that intervention message effectiveness depends not only on message aspects but also on the participants' adoption and adaptation of the message vis-à-vis their social ecology. The model depicts processes by which intervention messages are received and enacted by participants through social processes occurring within and between relevant microsystems. Mesosystem interfaces (negligible interface, transference, co-dependence, and interdependence) can facilitate or detract from intervention effects. The social interface model advances prevention science by theorizing that practitioners can create better quality interventions by planning for what occurs after interventions are delivered.

STAR- A SIMPLE TOOL FOR AUTOMATED REASONING SUPPORTING HYBRID APPLICATIONS OF ARTIFICIAL INTELLIGENCE (DEC VAX VERSION)

NASA Technical Reports Server (NTRS)

Borchardt, G. C.

1994-01-01

The Simple Tool for Automated Reasoning program (STAR) is an interactive, interpreted programming language for the development and operation of artificial intelligence (AI) application systems. STAR provides an environment for integrating traditional AI symbolic processing with functions and data structures defined in compiled languages such as C, FORTRAN and PASCAL. This type of integration occurs in a number of AI applications including interpretation of numerical sensor data, construction of intelligent user interfaces to existing compiled software packages, and coupling AI techniques with numerical simulation techniques and control systems software. The STAR language was created as part of an AI project for the evaluation of imaging spectrometer data at NASA's Jet Propulsion Laboratory. Programming in STAR is similar to other symbolic processing languages such as LISP and CLIP. STAR includes seven primitive data types and associated operations for the manipulation of these structures. A semantic network is used to organize data in STAR, with capabilities for inheritance of values and generation of side effects. The AI knowledge base of STAR can be a simple repository of records or it can be a highly interdependent association of implicit and explicit components. The symbolic processing environment of STAR may be extended by linking the interpreter with functions defined in conventional compiled languages. These external routines interact with STAR through function calls in either direction, and through the exchange of references to data structures. The hybrid knowledge base may thus be accessed and processed in general by either side of the application. STAR is initially used to link externally compiled routines and data structures. It is then invoked to interpret the STAR rules and symbolic structures. In a typical interactive session, the user enters an expression to be evaluated, STAR parses the input, evaluates the expression, performs any file input/output required, and displays the results. The STAR interpreter is written in the C language for interactive execution. It has been implemented on a VAX 11/780 computer operating under VMS, and the UNIX version has been implemented on a Sun Microsystems 2/170 workstation. STAR has a memory requirement of approximately 200K of 8 bit bytes, excluding externally compiled functions and application-dependent symbolic definitions. This program was developed in 1985.

STAR- A SIMPLE TOOL FOR AUTOMATED REASONING SUPPORTING HYBRID APPLICATIONS OF ARTIFICIAL INTELLIGENCE (UNIX VERSION)

NASA Technical Reports Server (NTRS)

Borchardt, G. C.

1994-01-01

The Simple Tool for Automated Reasoning program (STAR) is an interactive, interpreted programming language for the development and operation of artificial intelligence (AI) application systems. STAR provides an environment for integrating traditional AI symbolic processing with functions and data structures defined in compiled languages such as C, FORTRAN and PASCAL. This type of integration occurs in a number of AI applications including interpretation of numerical sensor data, construction of intelligent user interfaces to existing compiled software packages, and coupling AI techniques with numerical simulation techniques and control systems software. The STAR language was created as part of an AI project for the evaluation of imaging spectrometer data at NASA's Jet Propulsion Laboratory. Programming in STAR is similar to other symbolic processing languages such as LISP and CLIP. STAR includes seven primitive data types and associated operations for the manipulation of these structures. A semantic network is used to organize data in STAR, with capabilities for inheritance of values and generation of side effects. The AI knowledge base of STAR can be a simple repository of records or it can be a highly interdependent association of implicit and explicit components. The symbolic processing environment of STAR may be extended by linking the interpreter with functions defined in conventional compiled languages. These external routines interact with STAR through function calls in either direction, and through the exchange of references to data structures. The hybrid knowledge base may thus be accessed and processed in general by either side of the application. STAR is initially used to link externally compiled routines and data structures. It is then invoked to interpret the STAR rules and symbolic structures. In a typical interactive session, the user enters an expression to be evaluated, STAR parses the input, evaluates the expression, performs any file input/output required, and displays the results. The STAR interpreter is written in the C language for interactive execution. It has been implemented on a VAX 11/780 computer operating under VMS, and the UNIX version has been implemented on a Sun Microsystems 2/170 workstation. STAR has a memory requirement of approximately 200K of 8 bit bytes, excluding externally compiled functions and application-dependent symbolic definitions. This program was developed in 1985.

Automated Design Tools for Integrated Mixed-Signal Microsystems (NeoCAD)

DTIC Science & Technology

2005-02-01

method, Model Order Reduction (MOR) tools, system-level, mixed-signal circuit synthesis and optimization tools, and parsitic extraction tools. A unique...Mission Area: Command and Control mixed signal circuit simulation parasitic extraction time-domain simulation IC design flow model order reduction... Extraction 1.2 Overall Program Milestones CHAPTER 2 FAST TIME DOMAIN MIXED-SIGNAL CIRCUIT SIMULATION 2.1 HAARSPICE Algorithms 2.1.1 Mathematical Background

TDC Array Tradeoffs in Current and Upcoming Digital SiPM Detectors for Time-of-Flight PET

NASA Astrophysics Data System (ADS)

Tétrault, Marc-André; Therrien, Audrey Corbeil; Lemaire, William; Fontaine, Réjean; Pratte, Jean-François

2017-03-01

Radiation detection used in positron emission tomography (PET) exploits the timing information to remove background noise and refine position measurement through time-of-flight information. Fine time resolution in the order of 10 ps full-width at half-maximum (FWHM) would not only improve contrast in the image, but would also enable direct image reconstruction without iterative or back-projected algorithms. Currently, PET experimental setups based on silicon photomultipliers (SiPMs) reach 73 ps FWHM, where the scintillation process plays the larger role in spreading the timing resolution. This will change with the optimization of faster light emission mechanisms (prompt photons), where readout optoelectronics will once more have a noticeable contribution to the timing resolution limit. In addition to reducing electronic jitter as much as possible, other aspects of the design space must also explored, especially for digital SiPMs. Unlike traditional SiPMs, digital SiPMs can integrate circuits like time-to-digital converters (TDCs) directly with individual or groups of light sensing cells. Designers should consider the number of TDCs to integrate, the area they occupy, their power consumption, their resolution, and the impact of signal processing algorithms and find a compromise with the figure of merit and the coincidence timing resolution (CTR). This paper presents a parametric simulation flow for digital SiPM microsystems that evaluates CTR based on these aspects and on the best linear unbiased estimator (BLUE) in order to guide their design for present and future PET systems. For a small 1.1 × 1.1 × 3.0 mm3 LYSO crystal, the simulations indicate that for a low jitter digital SiPM microsystem with 18.2% photon detection efficiency, fewer than four timestamps with any multi-TDC configuration scheme nearly obtain the optimal CTR with BLUE (just below 100 ps FWHM), but with limited 5% improvement over only using the first observed photon. On the other hand, if a similar crystal but with 2.5% prompt photon fraction is considered, BLUE provides an improvement between 80% and 200% (depending on electronic jitter) over using only the first observed photon. In this case, a few tens of timestamps are required, yielding very different design guidelines than for standard LYSO scintillators.

Using data to improve medical practice by measuring processes and outcomes of care.

PubMed

Nelson, E C; Splaine, M E; Godfrey, M M; Kahn, V; Hess, A; Batalden, P; Plume, S K

2000-12-01

The purpose of this article is to help clinicians expand their use of data to improve medical practice performance and to do improvement research. Clinical practices can be viewed as small, complex organizations (microsystems) that produce services for specific patient populations. These services can be greatly improved by embedding measurement into the flow of daily work in the practice. WHY DO IT?: Four good reasons to build measures into daily medical practice are to (1) diagnose strengths and weaknesses in practice performance; (2) improve and innovate in providing care and services using improvement research; (3) manage patients and the practice; and (4) evaluate changes in results over time. It is helpful to have a "physiological" model of a medical practice to analyze the practice, to manage it, and to improve it. One model views clinical practices as microsystems that are designed to generate desired health outcomes for specific subsets of patients and to use resources efficiently. This article provides case study examples to show what an office-based practice might look like if it were using front-line measurement to improve care and services most of the time and to conduct clinical improvement research some of the time. WHAT ARE THE PRINCIPLES FOR USING DATA TO IMPROVE PROCESSES AND OUTCOMES OF CARE?: Principles reflected in the case study examples--such as "Keep Measurement Simple. Think Big and Start Small" and "More Data Is Not Necessarily Better Data. Seek Usefulness, Not Perfection, in Your Measures"--may help guide the development of data to study and improve practice. HOW CAN A PRACTICE START TO USE DATA TO IMPROVE CARE AND CONDUCT IMPROVEMENT RESEARCH?: Practical challenges are involved in starting to use data for enhancing care and improvement research. To increase the odds for success, it would be wise to use a change management strategy to launch the startup plan. Other recommendations include "Establish a Sense of Urgency. (Survival Is Not Mandatory)" and "Create the Guiding Coalition. (A Small, Devoted Group of People Can Change the World)." Over the long term, we must transform thousands of local practice cultures so that useful data are used every day in countless ways to assist clinicians, support staff, patients, families, and communities.

A practical guide to microfluidic perfusion culture of adherent mammalian cells.

PubMed

Kim, Lily; Toh, Yi-Chin; Voldman, Joel; Yu, Hanry

2007-06-01

Culturing cells at microscales allows control over microenvironmental cues, such as cell-cell and cell-matrix interactions; the potential to scale experiments; the use of small culture volumes; and the ability to integrate with microsystem technologies for on-chip experimentation. Microfluidic perfusion culture in particular allows controlled delivery and removal of soluble biochemical molecules in the extracellular microenvironment, and controlled application of mechanical forces exerted via fluid flow. There are many challenges to designing and operating a robust microfluidic perfusion culture system for routine culture of adherent mammalian cells. The current literature on microfluidic perfusion culture treats microfluidic design, device fabrication, cell culture, and micro-assays independently. Here we systematically present and discuss important design considerations in the context of the entire microfluidic perfusion culture system. These design considerations include the choice of materials, culture configurations, microfluidic network fabrication and micro-assays. We also present technical issues such as sterilization; seeding cells in both 2D and 3D configurations; and operating the system under optimized mass transport and shear stress conditions, free of air-bubbles. The integrative and systematic treatment of the microfluidic system design and fabrication, cell culture, and micro-assays provides novices with an effective starting point to build and operate a robust microfludic perfusion culture system for various applications.

Energy Harvesting for Self-Powered, Ultra-Low Power Microsystems With a Focus on Vibration-Based Electromechanical Conversion

DTIC Science & Technology

2009-09-01

harmonic frequency of the system , ωn, given as ,n k m   (5) must equal the excitation frequency in order to achieve maximum power. Because of ...characteristic of persistence in mind, a management system is required to mediate the profiles of energy generation and consumption. 53 V. CONCLUSION...they do have a long-term negative environmental impact . An alternative to

Electrokinetic acceleration of DNA hybridization in microsystems.

PubMed

Lei, Kin Fong; Wang, Yun-Hsiang; Chen, Huai-Yi; Sun, Jia-Hong; Cheng, Ji-Yen

2015-06-01

In this work, electrokinetic acceleration of DNA hybridization was investigated by different combinations of frequencies and amplitudes of actuating electric signals. Because the frequencies from low to high can induce different kinds of electrokinetic forces, i.e., electroosmotic to electrothermal forces, this work provides an in-depth investigation of electrokinetic enhanced hybridization. Concentric circular Cr/Au microelectrodes of 350 µm in diameter were fabricated on a glass substrate and probe DNA was immobilized on the electrode surface. Target DNA labeled with fluorescent dyes suspending in solution was then applied to the electrode. Different electrokinetic forces were induced by the application of different electric signals to the circular microelectrodes. Local microfluidic vortexes were generated to increase the collision efficiency between the target DNA suspending in solution and probe DNA immobilized on the electrode surface. DNA hybridization on the electrode surface could be accelerated by the electrokinetic forces. The level of hybridization was represented by the fluorescent signal intensity ratio. Results revealed that such 5-min dynamic hybridization increased 4.5 fold of signal intensity ratio as compared to a 1-h static hybridization. Moreover, dynamic hybridization was found to have better differentiation ability between specific and non-specific target DNA. This study provides a strategy to accelerate DNA hybridization in microsystems. Copyright © 2015 Elsevier B.V. All rights reserved.

Electronic nose for detecting multiple targets

NASA Astrophysics Data System (ADS)

Chakraborty, Anirban; Parthasarathi, Ganga; Poddar, Rakesh; Zhao, Weiqiang; Luo, Cheng

2006-05-01

The discovery of high conductivity in doped polyacetylene in 1977 (garnering the 2000 Nobel Prize in Chemistry for the three discovering scientists) has attracted considerable interest in the application of polymers as the semiconducting and conducting materials due to their promising potential to replace silicon and metals in building devices. Previous and current efforts in developing conducting polymer microsystems mainly focus on generating a device of a single function. When multiple micropatterns made of different conducting polymers are produced on the same substrate, many microsystems of multiple functions can be envisioned. For example, analogous to the mammalian olfactory system which includes over 1,000 receptor genes in detecting various odors (e.g., beer, soda etc.), a sensor consisting of multiple distinct conducting polymer sensing elements will be capable of detecting a number of analytes simultaneously. However, existing techniques present significant technical challenges of degradation, low throughput, low resolution, depth of field, and/or residual layer in producing conducting polymer microstructures. To circumvent these challenges, an intermediate-layer lithography method developed in our group is used to generate multiple micropatterns made of different, commonly used conducting polymers, Polypyrrole (PPy), Poly(3,4-ethylenedioxy)thiophene (PEDOT) and Polyaniline (PANI). The generated multiple micropatterns are further used in an "electronic nose" to detect water vapor, glucose, toluene and acetone.

Impact of radiations on the electromechanical properties of materials and on the piezoresistive and capacitive transduction mechanisms used in microsystems

NASA Astrophysics Data System (ADS)

Francis, Laurent A.; Gkotsis, Petros; Kilchytska, Valeriya; Tang, Xiaohui; Druart, Sylvain; Raskin, Jean-Pierre; Flandre, Denis

2013-03-01

The impact of different types of radiation on the electromechanical properties of materials used in microfabrication and on the capacitive and piezoresistive transduction mechanisms of MEMS is investigated. MEMS technologies could revolutionize avionics, satellite and space applications provided that the stress conditions which can compromise the reliability of microsystems in these environments are well understood. Initial tests with MEMS revealed a vulnerability of some types of devices to radiation induced dielectric charging, a physical mechanism which also affects microelectronics, however integration of novel functional materials in microfabrication and the current trend to substitute SiO2 with high-k dielectrics in ICs pose new questions regarding reliability in radiation environments. The performance of MEMS devices with moving parts could also degrade due to radiation induced changes in the mechanical properties of the materials. It is thus necessary to investigate the effects of radiation on the properties of thin films used in microfabrication and here we report on tests with γ, high energy protons and fast neutrons radiation. Prototype SOI based MEMS magnetometers which were developed in UCL are also used as test vehicles to investigate radiation effects on the reliability of magnetically actuated and capacitively coupled MEMS.

Low temperature wafer-level bonding for hermetic packaging of 3D microsystems

NASA Astrophysics Data System (ADS)

Tan, C. S.; Fan, J.; Lim, D. F.; Chong, G. Y.; Li, K. H.

2011-07-01

Metallic copper-copper (Cu-Cu) thermo-compression bonding, oxide-oxide (SiO2-SiO2) fusion bonding and silicon-silicon (Si-Si) direct bonding are investigated for potential application as hermetic seal in 3D microsystem packaging. Cavities are etched to a volume of 1.4 × 10-3 cm3 in accordance with the MIL-STD-883E standard prescribed for microelectronics packaging. In the case of metal bonding, a clean Cu layer with a thickness of 300 nm and a Ti barrier layer with an underlying thickness of 50 nm are used. The wafer pair is bonded at 300 °C under the application of a bonding force of 5500 N for 1 h. On the other hand, Si-Si bonding and SiO2-SiO2 bonding are initiated at room ambient after surface activation, followed by annealing in inert ambient at 300 °C for 1 h. The bonded cavities are stored in a helium bomb chamber and the leak rate is measured with a mass spectrometer. An excellent helium leak rate below 5 × 10-9 atm cm3 s-1 is detected for all cases and this is at least ten times better than the reject limit.

ACTS 118x Final Report High-Speed TCP Interoperability Testing

NASA Technical Reports Server (NTRS)

Ivancic, William D.; Zernic, Mike; Hoder, Douglas J.; Brooks, David E.; Beering, Dave R.; Welch, Arun

1999-01-01

With the recent explosion of the Internet and the enormous business opportunities available to communication system providers, great interest has developed in improving the efficiency of data transfer using the Transmission Control Protocol (TCP) of the Internet Protocol (IP) suite. The satellite system providers are interested in solving TCP efficiency problems associated with long delays and error-prone links. Similarly, the terrestrial community is interested in solving TCP problems over high-bandwidth links. Whereas the wireless community is interested in improving TCP performance over bandwidth constrained, error-prone links. NASA realized that solutions had already been proposed for most of the problems associated with efficient data transfer over large bandwidth-delay links (which include satellite links). The solutions are detailed in various Internet Engineering Task Force (IETF) Request for Comments (RFCs). Unfortunately, most of these solutions had not been tested at high-speed (155+ Mbps). Therefore, the NASA's ACTS experiments program initiated a series of TCP experiments to demonstrate scalability of TCP/IP and determine how far the protocol can be optimized over a 622 Mbps satellite link. These experiments were known as the 118i and 118j experiments. During the 118i and 118j experiments, NASA worked closely with SUN Microsystems and FORE Systems to improve the operating system, TCP stacks. and network interface cards and drivers. We were able to obtain instantaneous data throughput rates of greater than 520 Mbps and average throughput rates of 470 Mbps using TCP over Asynchronous Transfer Mode (ATM) over a 622 Mbps Synchronous Optical Network (SONET) OC12 link. Following the success of these experiments and the successful government/industry collaboration, a new series of experiments. the 118x experiments. were developed.

Team dynamics within quality improvement teams: a scoping review.

PubMed

Rowland, Paula; Lising, Dean; Sinclair, Lynne; Baker, G Ross

2018-03-31

This scoping review examines what is known about the processes of quality improvement (QI) teams, particularly related to how teams impact outcomes. The aim is to provide research-informed guidance for QI leaders and to inform future research questions. Databases searched included: MedLINE, EMBASE, CINAHL, Web of Science and SCOPUS. Eligible publications were written in English, published between 1999 and 2016. Articles were included in the review if they examined processes of the QI team, were related to healthcare QI and were primary research studies. Studies were excluded if they had insufficient detail regarding QI team processes. Descriptive detail extracted included: authors, geographical region and health sector. The Integrated (Health Care) Team Effectiveness Model was used to synthesize findings of studies along domains of team effectiveness: task design, team process, psychosocial traits and organizational context. Over two stages of searching, 4813 citations were reviewed. Of those, 48 full-text articles are included in the synthesis. This review demonstrates that QI teams are not immune from dysfunction. Further, a dysfunctional QI team is not likely to influence practice. However, a functional QI team alone is unlikely to create change. A positive QI team dynamic may be a necessary but insufficient condition for implementing QI strategies. Areas for further research include: interactions between QI teams and clinical microsystems, understanding the role of interprofessional representation on QI teams and exploring interactions between QI team task, composition and process.

The giant cold-water coral mound as a nested microbial/metazoan system: physical, chemical, biological and geological picture (ESF EuroDiversity MiCROSYSTEMS)

NASA Astrophysics Data System (ADS)

Henriet, J. P.; Microsystems Team

2009-04-01

The MiCROSYSTEMS project under the ESF EUROCORES EuroDiversity scheme is a holistic and multi-scale approach in studying microbial diversity and functionality in a nested microbial/metazoan system, which thrives in deep waters: the giant cold-water coral mound. Studies on prolific cold-water coral sites have been carried out from the canyons of the Bay of Biscay to the fjords of the Norwegian margin, while the Pen Duick carbonate mound province off Morocco developed into a joint natural lab for studying in particular the impact of biogeochemical and microbial processes on modern sedimentary diagenesis within the reef sediments, in complement to the studies on I0DP Exp. 307 cores (Challenger Mound, off Ireland). Major outcomes of this research can be summarized as follows. • IODP Exp. 307 on Challenger Mound had revealed a significant prokaryotic community both within and beneath the carbonate mound. MiCROSYSTEMS unveils a remarkable degree of compartmentalization in such community from the seawater, the coral skeleton surface and mucus to the reef sediments. The occurrence of such multiple and distinct microbial compartments associated with cold-water coral ecosystems promotes opportunities for microbial diversity in the deep ocean. • New cases of co-habitation of cold-water corals and giant deep-water oysters were discovered in the Bay of Biscay, which add a new facet of macrofaunal diversity to cold-water coral reef systems. • The discovery of giant, ancient coral graveyards on the Moroccan mounds not only fuels the debate about natural versus anthropogenic mass extinction, but these open frameworks simultaneously invite for the study of bio-erosion and early diagenesis, in particular organo-mineralization, and of the possible role and significance of these thick, solid rubble patches in 3D mound-building and consolidation. • The assessment of the carbonate budget of a modern cold-water coral mound (Challenger Mound) reveals that only 33 to 40 wt % of carbonate is derived from corals and suggests a selective enrichment of the hemipelagic carbonate fraction, compared to adjacent sediment drift deposits. • The detection of allochthonous fluids, in particular brines, in the pore space of the surficial mound sediments on the Pen Duick Escarpment hints towards the presence of salt deposits deep underneath, and simultaneously provides the first direct evidence of advective fluid transfer from the deep, throughout the mound substrate and the full mound height. Potential stratigraphic pathways leading from the deeper basinal realms directly to the mound setting have been imaged in a spectacular way through high-resolution pseudo-3D seismic imaging. Geophysical signatures of free gas accumulations have been detected a few hundreds of meters below the mound base, but low concentrations of methane and the absence of lipid biomarkers from methane-dependent prokaryotes suggest low fluxes of methane-derived carbon and thus very small rates of anaerobic oxidation of methane (AOM) in the immediate mound subsurface. Local changes in the sediment biogeochemistry are most likely dictated by slow diffusive fluid transfer, operating in a heterogeneous way in the subsurface. • Cultivation experiments with sediments from microbially active mound zones have allowed to study microbially induced carbonate precipitation and provide a tool for the interpretation of carbonate mineralogy. The development and operation of a continuous high-pressure bioreactor (100 bars) allows to simulate in an ex situ mode the impact of environmental parameter changes onto the functioning of relevant microbial communities. • The detected influx of sulfate in mound sediments implies that bacterial sulfate reduction can be the dominant anaerobic carbon mineralization process. Groundwater flow modeling suggests that currents impinging on the escarpment and the flanks of an exposed mound can account for a significant influx and transport of sulfate through convective fluid transfer within the mound sediments. Oceanic currents consequently provide not only a major control on the external flux of nutrients to the mound-building communities, but they also potentially drive internal flow in the mound. The extant hydrodynamic climate of the mound setting is documented through long-term lander deployments and CTD stations: the current records reveal a significant tidal and seasonal variability. The past environmental record over the last 400 ka is documented in a most comprehensive sedimentary archive, sampled with long cores at the foot of the Pen Duick Escarpment during the MD169 ‘MiCROSYSTEMS' cruise in July 2008. • MiCROSYSTEMS has significantly contributed to the successful submission of IODP proposal 673-Full, which should (i) document the whole-mound architecture and the mound setting on Pen Duick Escarpment as well as a most comprehensive stratigraphic record on a reference site at the foot of the escarpment, (ii) reveal the full spatial pattern in microbial diversity, activity and functionality throughout the mound and underneath, and (iii) unravel the plumbing system of a mound and the dynamic interaction between advective, convective and diffusive transfers of organic and inorganic compounds, which impact on biogeochemical equilibria, microbial activity and early diagenetic processes.

HONTIOR - HIGHER-ORDER NEURAL NETWORK FOR TRANSFORMATION INVARIANT OBJECT RECOGNITION

NASA Technical Reports Server (NTRS)

Spirkovska, L.

1994-01-01

Neural networks have been applied in numerous fields, including transformation invariant object recognition, wherein an object is recognized despite changes in the object's position in the input field, size, or rotation. One of the more successful neural network methods used in invariant object recognition is the higher-order neural network (HONN) method. With a HONN, known relationships are exploited and the desired invariances are built directly into the architecture of the network, eliminating the need for the network to learn invariance to transformations. This results in a significant reduction in the training time required, since the network needs to be trained on only one view of each object, not on numerous transformed views. Moreover, one hundred percent accuracy is guaranteed for images characterized by the built-in distortions, providing noise is not introduced through pixelation. The program HONTIOR implements a third-order neural network having invariance to translation, scale, and in-plane rotation built directly into the architecture, Thus, for 2-D transformation invariance, the network needs only to be trained on just one view of each object. HONTIOR can also be used for 3-D transformation invariant object recognition by training the network only on a set of out-of-plane rotated views. Historically, the major drawback of HONNs has been that the size of the input field was limited to the memory required for the large number of interconnections in a fully connected network. HONTIOR solves this problem by coarse coding the input images (coding an image as a set of overlapping but offset coarser images). Using this scheme, large input fields (4096 x 4096 pixels) can easily be represented using very little virtual memory (30Mb). The HONTIOR distribution consists of three main programs. The first program contains the training and testing routines for a third-order neural network. The second program contains the same training and testing procedures as the first, but it also contains a number of functions to display and edit training and test images. Finally, the third program is an auxiliary program which calculates the included angles for a given input field size. HONTIOR is written in C language, and was originally developed for Sun3 and Sun4 series computers. Both graphic and command line versions of the program are provided. The command line version has been successfully compiled and executed both on computers running the UNIX operating system and on DEC VAX series computer running VMS. The graphic version requires the SunTools windowing environment, and therefore runs only on Sun series computers. The executable for the graphics version of HONTIOR requires 1Mb of RAM. The standard distribution medium for HONTIOR is a .25 inch streaming magnetic tape cartridge in UNIX tar format. It is also available on a 3.5 inch diskette in UNIX tar format. The package includes sample input and output data. HONTIOR was developed in 1991. Sun, Sun3 and Sun4 are trademarks of Sun Microsystems, Inc. UNIX is a registered trademark of AT&T Bell Laboratories. DEC, VAX, and VMS are trademarks of Digital Equipment Corporation.

Evaluation of Multimodal Imaging Biomarkers of Prostate Cancer

DTIC Science & Technology

2014-09-01

scan duration ~ 21 min). PET imaging was performed on a Concorde Microsystems microPET Focus 220. Approximately 120 uCi of tracer was administered... PET tracer targeting translocator protein expression (TSPO), using 18F-VUIIS1008 (a probe developed in-house), and hypoxia, using 18F...manuscripts describing these efforts. First, we plan to submit a manuscript validating the use of the TSPO PET tracer developed in house in the Pten/p53

Applying a Service-Oriented Architecture to Operational Flight Program Development

DTIC Science & Technology

2007-09-01

using two Java 2 Enterprise Edition (J2EE) Web servers. The weapon models were accessed using a SUN Microsystems Java Web Services Development Pack...Oriented Architectures 22 CROSSTALK The Journal of Defense Software Engineering September 2007 tion, and Spring/ Hibernate to provide the data access...tion since a major coding effort was avoided. The majority of the effort was tweaking pre-existing Java source code and editing of eXtensible Markup

3D sensors and micro-fabricated detector systems

NASA Astrophysics Data System (ADS)

Da Vià, Cinzia

2014-11-01

Micro-systems based on the Micro Electro Mechanical Systems (MEMS) technology have been used in miniaturized low power and low mass smart structures in medicine, biology and space applications. Recently similar features found their way inside high energy physics with applications in vertex detectors for high-luminosity LHC Upgrades, with 3D sensors, 3D integration and efficient power management using silicon micro-channel cooling. This paper reports on the state of this development.

ActiveX vs. Java. What roles will these technologies play?

PubMed

McCormack, J

1997-09-01

ActiveX and Java capitalize on distributed object computing and have great potential for making information systems truly interoperable. But a battle for market dominance between their developers--Microsoft Corp. and Sun Microsystems Inc., respectively--could cause confusion. And it's unclear what role these two important new technologies will play in health care. For now, a number of pioneering organizations are experimenting with using the technology to improve data flow and access.

Biologically-Inspired Microrobots. Volume 3. Micro-Robot Based on Abstracted Biological Principles

DTIC Science & Technology

2006-04-01

Roy E. Ritzmann, Jeremy Morrey and Andrew Horchler Se. TASK NUMBER Sf. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) 8...SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM( S ) Sponsor: Defense Advanced Research Projects Agency (DARPA...Microsystems Technology Office (Elana Ethridge) 3701 North Fairfax Drive Arlington, VA 22203-1714 11. SPONSOR/MONITOR’S REPORT NUMBER( S ) NATICK/TR-05

The Intersection of CMOS Microsystems and Upconversion Nanoparticles for Luminescence Bioimaging and Bioassays

PubMed Central

Wei, Liping.; Doughan, Samer.; Han, Yi.; DaCosta, Matthew V.; Krull, Ulrich J.; Ho, Derek.

2014-01-01

Organic fluorophores and quantum dots are ubiquitous as contrast agents for bio-imaging and as labels in bioassays to enable the detection of biological targets and processes. Upconversion nanoparticles (UCNPs) offer a different set of opportunities as labels in bioassays and for bioimaging. UCNPs are excited at near-infrared (NIR) wavelengths where biological molecules are optically transparent, and their luminesce in the visible and ultraviolet (UV) wavelength range is suitable for detection using complementary metal-oxide-semiconductor (CMOS) technology. These nanoparticles provide multiple sharp emission bands, long lifetimes, tunable emission, high photostability, and low cytotoxicity, which render them particularly useful for bio-imaging applications and multiplexed bioassays. This paper surveys several key concepts surrounding upconversion nanoparticles and the systems that detect and process the corresponding luminescence signals. The principle of photon upconversion, tuning of emission wavelengths, UCNP bioassays, and UCNP time-resolved techniques are described. Electronic readout systems for signal detection and processing suitable for UCNP luminescence using CMOS technology are discussed. This includes recent progress in miniaturized detectors, integrated spectral sensing, and high-precision time-domain circuits. Emphasis is placed on the physical attributes of UCNPs that map strongly to the technical features that CMOS devices excel in delivering, exploring the interoperability between the two technologies. PMID:25211198

TOPICAL REVIEW: Self-assembly from milli- to nanoscales: methods and applications

NASA Astrophysics Data System (ADS)

Mastrangeli, M.; Abbasi, S.; Varel, C.; Van Hoof, C.; Celis, J.-P.; Böhringer, K. F.

2009-08-01

The design and fabrication techniques for microelectromechanical systems (MEMS) and nanodevices are progressing rapidly. However, due to material and process flow incompatibilities in the fabrication of sensors, actuators and electronic circuitry, a final packaging step is often necessary to integrate all components of a heterogeneous microsystem on a common substrate. Robotic pick-and-place, although accurate and reliable at larger scales, is a serial process that downscales unfavorably due to stiction problems, fragility and sheer number of components. Self-assembly, on the other hand, is parallel and can be used for device sizes ranging from millimeters to nanometers. In this review, the state-of-the-art in methods and applications for self-assembly is reviewed. Methods for assembling three-dimensional (3D) MEMS structures out of two-dimensional (2D) ones are described. The use of capillary forces for folding 2D plates into 3D structures, as well as assembling parts onto a common substrate or aggregating parts to each other into 2D or 3D structures, is discussed. Shape matching and guided assembly by magnetic forces and electric fields are also reviewed. Finally, colloidal self-assembly and DNA-based self-assembly, mainly used at the nanoscale, are surveyed, and aspects of theoretical modeling of stochastic assembly processes are discussed.

Self-assembly from milli- to nanoscales: methods and applications

PubMed Central

Mastrangeli, M; Abbasi, S; Varel, C; Van Hoof, C; Celis, J-P; Böhringer, K F

2009-01-01

The design and fabrication techniques for microelectromechanical systems (MEMS) and nanodevices are progressing rapidly. However, due to material and process flow incompatibilities in the fabrication of sensors, actuators and electronic circuitry, a final packaging step is often necessary to integrate all components of a heterogeneous microsystem on a common substrate. Robotic pick-and-place, although accurate and reliable at larger scales, is a serial process that downscales unfavorably due to stiction problems, fragility and sheer number of components. Self-assembly, on the other hand, is parallel and can be used for device sizes ranging from millimeters to nanometers. In this review, the state-of-the-art in methods and applications for self-assembly is reviewed. Methods for assembling three-dimensional (3D) MEMS structures out of two-dimensional (2D) ones are described. The use of capillary forces for folding 2D plates into 3D structures, as well as assembling parts onto a common substrate or aggregating parts to each other into 2D or 3D structures, is discussed. Shape matching and guided assembly by magnetic forces and electric fields are also reviewed. Finally, colloidal self-assembly and DNA-based self-assembly, mainly used at the nanoscale, are surveyed, and aspects of theoretical modeling of stochastic assembly processes are discussed. PMID:20209016

Drosophila as an unconventional substrate for microfabrication

NASA Astrophysics Data System (ADS)

Shum, Angela J.; Parviz, Babak A.

2007-02-01

We present the application of Drosophila fruit flies as an unconventional substrate for microfabrication. Drosophila by itself represents a complex system capable of many functions not attainable with current microfabrication technology. By using Drosophila as a substrate, we are able to capitalize on these natural functions while incorporating additional functionality into a superior hybrid system. In the following, development of microfabrication processes for Drosophila substrates is discussed. In particular, results of a study on Drosophila tolerance to vacuum pressure during multiple stages of development are given. A remarkable finding that adult Drosophila may withstand up to 3 hours of exposure to vacuum with measurable survival is noted. This finding opens a number of new opportunities for performing fabrication processes, similar to the ones performed on a silicon wafer, on a fruit fly as a live substrate. As a model microfabrication process, it is shown how a collection of Drosophila can be made to self-assemble into an array of microfabricated recesses on a silicon wafer and how a shadow mask can be used to thermally evaporate 100 nm of indium on flies. The procedure resulted in the production of a number of live flies with a pre-designed metal micropattern on their wings. This demonstration of vacuum microfabrication on a live organism provides the first step towards the development of a hybrid biological/solid-state manufacturing process for complex microsystems.

Highly energetic phenomena in water electrolysis

NASA Astrophysics Data System (ADS)

Postnikov, A. V.; Uvarov, I. V.; Lokhanin, M. V.; Svetovoy, V. B.

2016-12-01

Water electrolysis performed in microsystems with a fast change of voltage polarity produces optically invisible nanobubbles containing H2 and O2 gases. In this form the gases are able to the reverse reaction of water formation. Here we report extreme phenomena observed in a millimeter-sized open system. Under a frequency of driving pulses above 100 kHz the process is accompanied by clicking sounds repeated every 50 ms or so. Fast video reveals that synchronously with the click a bubble is growing between the electrodes which reaches a size of 300 μm in 50 μs. Detailed dynamics of the system is monitored by means of a vibrometer by observing a piece of silicon floating above the electrodes. The energy of a single event is estimated as 0.3 μJ and a significant part of this energy is transformed into mechanical work moving the piece. The observations are explained by the combustion of hydrogen and oxygen mixture in the initial bubble with a diameter of about 40 μm. Unusual combustion mechanism supporting spontaneous ignition at room temperature is responsible for the process. The observed effect demonstrates a principal possibility to build a microscopic internal combustion engine.

Meissner-levitated micro-systems

NASA Astrophysics Data System (ADS)

Coombs, T. A.; Samad, I.; Hong, Z.; Eves, D.; Rastogi, A.

2006-06-01

Advanced silicon processing techniques developed for the Very Large Scale Integration (VLSI) industry have been exploited in recent years to enable the production of micro-fabricated moving mechanical systems known as Micro Electro Mechanical Systems (MEMS). These devices offer advantages in terms of cost, scalability and robustness over their preceding equivalents. Cambridge University have worked for many years on the investigation of high temperature superconductors (HTS) in flywheel energy storage applications. This experience is now being used to research into superconducting Micro-Bearings for MEMS, whereby circular permanent magnet arrays are levitated and spun above a superconductor to produce bearings suitable for motors and other micron scale devices. The novelty in the device lies in the fact that the rotor is levitated into position by Meissner flux exclusion, whilst stability is provided by flux pinned within the body of the superconductor. This work includes: the investigation of the properties of various magnetic materials, their fabrication processes and their suitability for MEMS; finite element analysis to analyse the interaction between the magnetic materials and YBCO to determine the stiffness and height of levitation. Finally a micro-motor with the above principles is currently being fabricated within the group.

Engineering functionality gradients by dip coating process in acceleration mode.

PubMed

Faustini, Marco; Ceratti, Davide R; Louis, Benjamin; Boudot, Mickael; Albouy, Pierre-Antoine; Boissière, Cédric; Grosso, David

2014-10-08

In this work, unique functional devices exhibiting controlled gradients of properties are fabricated by dip-coating process in acceleration mode. Through this new approach, thin films with "on-demand" thickness graded profiles at the submillimeter scale are prepared in an easy and versatile way, compatible for large-scale production. The technique is adapted to several relevant materials, including sol-gel dense and mesoporous metal oxides, block copolymers, metal-organic framework colloids, and commercial photoresists. In the first part of the Article, an investigation on the effect of the dip coating speed variation on the thickness profiles is reported together with the critical roles played by the evaporation rate and by the viscosity on the fluid draining-induced film formation. In the second part, dip-coating in acceleration mode is used to induce controlled variation of functionalities by playing on structural, chemical, or dimensional variations in nano- and microsystems. In order to demonstrate the full potentiality and versatility of the technique, original graded functional devices are made including optical interferometry mirrors with bidirectional gradients, one-dimensional photonic crystals with a stop-band gradient, graded microfluidic channels, and wetting gradient to induce droplet motion.

A distributed computing system for magnetic resonance imaging: Java-based processing and binding of XML.

PubMed

de Beer, R; Graveron-Demilly, D; Nastase, S; van Ormondt, D

2004-03-01

Recently we have developed a Java-based heterogeneous distributed computing system for the field of magnetic resonance imaging (MRI). It is a software system for embedding the various image reconstruction algorithms that we have created for handling MRI data sets with sparse sampling distributions. Since these data sets may result from multi-dimensional MRI measurements our system has to control the storage and manipulation of large amounts of data. In this paper we describe how we have employed the extensible markup language (XML) to realize this data handling in a highly structured way. To that end we have used Java packages, recently released by Sun Microsystems, to process XML documents and to compile pieces of XML code into Java classes. We have effectuated a flexible storage and manipulation approach for all kinds of data within the MRI system, such as data describing and containing multi-dimensional MRI measurements, data configuring image reconstruction methods and data representing and visualizing the various services of the system. We have found that the object-oriented approach, possible with the Java programming environment, combined with the XML technology is a convenient way of describing and handling various data streams in heterogeneous distributed computing systems.

Strong-Field Emission From High Aspect Ratio Si Emitter Arrays

NASA Astrophysics Data System (ADS)

Keathley, Phillip; Swanwick, Michael; Sell, Alexander; Putnam, William; Guerrera, Stephen; Velásquez-García, Luis; Kärtner, Franz

2013-03-01

We discuss photoelectron emission from an arrays of high aspect ratio, sharp Si emitters both experimentally and theoretically. The structures are prepared from highly doped single-crystal silicon having a pencil-like shape with end radii of curvature of around 10 nm. The tips were illuminated at a grazing incidence of roughly 84deg.with a laser pulse having a center wavelength of 800 nm, and a pulse duration of 35 fs from a regenerative amplifier system. Native oxide coated Si tips were characterized using a time of flight (TOF) electron energy spectrometer. An annealing process was observed, resulting in a red shift of the energy spectra along with an increased electron yield. Total current yield from samples having the oxide stripped were also studied. Apeak total emission of 0.68 pC/bunch, corresponding to around 1.5x103 electrons/tip/pulse was observed at a DC bias of 70 V. Both spectral and current characterization results are consistent with a stong-field photoemission process at the surface of the tip apex. This work was funded by Defense Advanced Research Projects Agency (DARPA)/Microsystems Technology Office and the Space and Naval Warfare Systems Center (SPAWAR) under contract N66001-11-1-4192.

Development of microtitre plates for electrokinetic assays

NASA Astrophysics Data System (ADS)

Burt, J. P. H.; Goater, A. D.; Menachery, A.; Pethig, R.; Rizvi, N. H.

2007-02-01

Electrokinetic processes have wide ranging applications in microsystems technology. Their optimum performance at micro and nano dimensions allows their use both as characterization and diagnostic tools and as a means of general particle manipulation. Within analytical studies, measurement of the electrokinesis of biological cells has the sensitivity and selectivity to distinguish subtle differences between cell types and cells undergoing changes and is gaining acceptance as a diagnostic tool in high throughput screening for drug discovery applications. In this work the development and manufacture of an electrokinetic-based microtitre plate is described. The plate is intended to be compatible with automated sample loading and handling systems. Manufacturing of the microtitre plate, which employs indium tin oxide microelectrodes, has been entirely undertaken using excimer and ultra-fast pulsed laser micromachining due to its flexibility in materials processing and accuracy in microstructuring. Laser micromachining has the ability to rapidly realize iterations in device prototype design while also having the capability to be scaled up for large scale manufacture. Device verification is achieved by the measurement of the electrorotation and dielectrophoretic properties of yeast cells while the flexibility of the developed microtitre plate is demonstrated by the selective separation of live yeast from polystyrene microbeads.

Excimer laser annealing of NiTi shape memory alloy thin film

NASA Astrophysics Data System (ADS)

Xie, Qiong; Huang, Weimin; Hong, Ming Hui; Song, Wendong; Chong, Tow Chong

2003-02-01

NiTi Shape Memory Alloy (SMA) is with great potential for actuation in microsystems. It is particularly suitable for medical applications due to its excellent biocompatibility. In MEMS, local annealing of SMA is required in the process of fabrication. In this paper, local annealing of Ni52Ti48 SMA with excimer laser is proposed for the first time. The Ni52Ti48 thin film in a thickness of 5 μm was deposited on Si (100) wafer by sputtering at room temperature. After that, the thin film was annealed by excimer laser (248nm KrF laser) for the first time. Field-Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM) were used to characterize the surface profile of the deposited film after laser annealing. The phase transformation was measured by Differential Scanning Calorimeter (DSC) test. It is concluded that NiTi film sputtering on Si(100) substrate at room temperature possesses phase transformation after local laser annealing but with cracks.

Preparation and Analysis of Platinum Thin Films for High Temperature Sensor Applications

NASA Technical Reports Server (NTRS)

Wrbanek, John D.; Laster, Kimala L. H.

2005-01-01

A study has been made of platinum thin films for application as high temperature resistive sensors. To support NASA Glenn Research Center s high temperature thin film sensor effort, a magnetron sputtering system was installed recently in the GRC Microsystems Fabrication Clean Room Facility. Several samples of platinum films were prepared using various system parameters to establish run conditions. These films were characterized with the intended application of being used as resistive sensing elements, either for temperature or strain measurement. The resistances of several patterned sensors were monitored to document the effect of changes in parameters of deposition and annealing. The parameters were optimized for uniformity and intrinsic strain. The evaporation of platinum via oxidation during annealing over 900 C was documented, and a model for the process developed. The film adhesion was explored on films annealed to 1000 C with various bondcoats on fused quartz and alumina. From this compiled data, a list of optimal parameters and characteristics determined for patterned platinum thin films is given.

Dielectrophoresis-Based Sample Handling in General-Purpose Programmable Diagnostic Instruments

PubMed Central

Gascoyne, Peter R. C.; Vykoukal, Jody V.

2009-01-01

As the molecular origins of disease are better understood, the need for affordable, rapid, and automated technologies that enable microscale molecular diagnostics has become apparent. Widespread use of microsystems that perform sample preparation and molecular analysis could ensure that the benefits of new biomedical discoveries are realized by a maximum number of people, even those in environments lacking any infrastructure. While progress has been made in developing miniaturized diagnostic systems, samples are generally processed off-device using labor-intensive and time-consuming traditional sample preparation methods. We present the concept of an integrated programmable general-purpose sample analysis processor (GSAP) architecture where raw samples are routed to separation and analysis functional blocks contained within a single device. Several dielectrophoresis-based methods that could serve as the foundation for building GSAP functional blocks are reviewed including methods for cell and particle sorting, cell focusing, cell ac impedance analysis, cell lysis, and the manipulation of molecules and reagent droplets. PMID:19684877

Lab-on-CMOS Integration of Microfluidics and Electrochemical Sensors

PubMed Central

Huang, Yue; Mason, Andrew J.

2013-01-01

This paper introduces a CMOS-microfluidics integration scheme for electrochemical microsystems. A CMOS chip was embedded into a micro-machined silicon carrier. By leveling the CMOS chip and carrier surface to within 100 nm, an expanded obstacle-free surface suitable for photolithography was achieved. Thin film metal planar interconnects were microfabricated to bridge CMOS pads to the perimeter of the carrier, leaving a flat and smooth surface for integrating microfluidic structures. A model device containing SU-8 microfluidic mixers and detection channels crossing over microelectrodes on a CMOS integrated circuit was constructed using the chip-carrier assembly scheme. Functional integrity of microfluidic structures and on-CMOS electrodes was verified by a simultaneous sample dilution and electrochemical detection experiment within multi-channel microfluidics. This lab-on-CMOS integration process is capable of high packing density, is suitable for wafer-level batch production, and opens new opportunities to combine the performance benefits of on-CMOS sensors with lab-on-chip platforms. PMID:23939616

Lab-on-CMOS integration of microfluidics and electrochemical sensors.

PubMed

Huang, Yue; Mason, Andrew J

2013-10-07

This paper introduces a CMOS-microfluidics integration scheme for electrochemical microsystems. A CMOS chip was embedded into a micro-machined silicon carrier. By leveling the CMOS chip and carrier surface to within 100 nm, an expanded obstacle-free surface suitable for photolithography was achieved. Thin film metal planar interconnects were microfabricated to bridge CMOS pads to the perimeter of the carrier, leaving a flat and smooth surface for integrating microfluidic structures. A model device containing SU-8 microfluidic mixers and detection channels crossing over microelectrodes on a CMOS integrated circuit was constructed using the chip-carrier assembly scheme. Functional integrity of microfluidic structures and on-CMOS electrodes was verified by a simultaneous sample dilution and electrochemical detection experiment within multi-channel microfluidics. This lab-on-CMOS integration process is capable of high packing density, is suitable for wafer-level batch production, and opens new opportunities to combine the performance benefits of on-CMOS sensors with lab-on-chip platforms.

Microfluidic devices for cell cultivation and proliferation

PubMed Central

Tehranirokh, Masoomeh; Kouzani, Abbas Z.; Francis, Paul S.; Kanwar, Jagat R.

2013-01-01

Microfluidic technology provides precise, controlled-environment, cost-effective, compact, integrated, and high-throughput microsystems that are promising substitutes for conventional biological laboratory methods. In recent years, microfluidic cell culture devices have been used for applications such as tissue engineering, diagnostics, drug screening, immunology, cancer studies, stem cell proliferation and differentiation, and neurite guidance. Microfluidic technology allows dynamic cell culture in microperfusion systems to deliver continuous nutrient supplies for long term cell culture. It offers many opportunities to mimic the cell-cell and cell-extracellular matrix interactions of tissues by creating gradient concentrations of biochemical signals such as growth factors, chemokines, and hormones. Other applications of cell cultivation in microfluidic systems include high resolution cell patterning on a modified substrate with adhesive patterns and the reconstruction of complicated tissue architectures. In this review, recent advances in microfluidic platforms for cell culturing and proliferation, for both simple monolayer (2D) cell seeding processes and 3D configurations as accurate models of in vivo conditions, are examined. PMID:24273628

Modular Polymer Biosensors by Solvent Immersion Imprint Lithography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, Jayven S.; Xantheas, Sotiris S.; Grate, Jay W.

2016-01-01

We recently demonstrated Solvent Immersion Imprint Lithography (SIIL), a rapid benchtop microsystem prototyping technique, including polymer functionalization, imprinting and bonding. Here, we focus on the realization of planar polymer sensors using SIIL through simple solvent immersion without imprinting. We describe SIIL’s impregnation characteristics, including an inherent mechanism that not only achieves practical doping concentrations, but their unexpected 4-fold enhancement compared to the immersion solution. Subsequently, we developed and characterized optical sensors for detecting molecular O2. To this end, a high dynamic range is reported, including its control through the immersion duration, a manifestation of SIIL’s modularity. Overall, SIIL exhibits themore » potential of improving the operating characteristics of polymer sensors, while significantly accelerating their prototyping, as it requires a few seconds of processing and no need for substrates or dedicated instrumentation. These are critical for O2 sensing as probed by way of example here, as well as any polymer permeable reactant.« less

Solid supports for extraction and preconcentration of proteins and peptides in microfluidic devices: A review.

PubMed

Dziomba, Szymon; Araya-Farias, Monica; Smadja, Claire; Taverna, Myriam; Carbonnier, Benjamin; Tran, N Thuy

2017-02-22

Determination of proteins and peptides is among the main challenges of today's bioanalytical chemistry. The application of microchip technology in this field is an exhaustively developed concept that aims to create integrated and fully automated analytical devices able to quantify or detect one or several proteins from a complex matrix. Selective extraction and preconcentration of targeted proteins and peptides especially from biological fluids is of the highest importance for a successful realization of these microsystems. Incorporation of solid structures or supports is a convenient solution employed to face these demands. This review presents a critical view on the latest achievements in sample processing techniques for protein determination using solid supports in microfluidics. The study covers the period from 2006 to 2015 and focuses mainly on the strategies based on microbeads, monolithic materials and membranes. Less common approaches are also briefly discussed. The reviewed literature suggests future trends which are discussed in the concluding remarks. Copyright © 2016 Elsevier B.V. All rights reserved.

Multiplexed detection of DNA sequences using a competitive displacement assay in a microfluidic SERRS-based device.

PubMed

Yazdi, Soroush H; Giles, Kristen L; White, Ian M

2013-11-05

We demonstrate sensitive and multiplexed detection of DNA sequences through a surface enhanced resonance Raman spectroscopy (SERRS)-based competitive displacement assay in an integrated microsystem. The use of the competitive displacement scheme, in which the target DNA sequence displaces a Raman-labeled reporter sequence that has lower affinity for the immobilized probe, enables detection of unlabeled target DNA sequences with a simple single-step procedure. In our implementation, the displacement reaction occurs in a microporous packed column of silica beads prefunctionalized with probe-reporter pairs. The use of a functionalized packed-bead column in a microfluidic channel provides two major advantages: (i) immobilization surface chemistry can be performed as a batch process instead of on a chip-by-chip basis, and (ii) the microporous network eliminates the diffusion limitations of a typical biological assay, which increases the sensitivity. Packed silica beads are also leveraged to improve the SERRS detection of the Raman-labeled reporter. Following displacement, the reporter adsorbs onto aggregated silver nanoparticles in a microfluidic mixer; the nanoparticle-reporter conjugates are then trapped and concentrated in the silica bead matrix, which leads to a significant increase in plasmonic nanoparticles and adsorbed Raman reporters within the detection volume as compared to an open microfluidic channel. The experimental results reported here demonstrate detection down to 100 pM of the target DNA sequence, and the experiments are shown to be specific, repeatable, and quantitative. Furthermore, we illustrate the advantage of using SERRS by demonstrating multiplexed detection. The sensitivity of the assay, combined with the advantages of multiplexed detection and single-step operation with unlabeled target sequences makes this method attractive for practical applications. Importantly, while we illustrate DNA sequence detection, the SERRS-based competitive displacement assay is applicable to detection of a variety of biological macromolecules, including proteins and proteolytic enzymes.

LTCC interconnects in microsystems

NASA Astrophysics Data System (ADS)

Rusu, Cristina; Persson, Katrin; Ottosson, Britta; Billger, Dag

2006-06-01

Different microelectromechanical system (MEMS) packaging strategies towards high packaging density of MEMS devices and lower expenditure exist both in the market and in research. For example, electrical interconnections and low stress wafer level packaging are essential for improving device performance. Hybrid integration of low temperature co-fired ceramics (LTCC) with Si can be a way for an easier packaging system with integrated electrical interconnection, and as well towards lower costs. Our research on LTCC-Si integration is reported in this paper.

Scalable Electrospray Components for Portable Power Applications Using MEMS Fabrication Techniques

DTIC Science & Technology

2006-11-01

electric field induced between the electrode and the conducting liquid initially causes a Taylor cone to form at the tip of the tube where the field...voltage source, creating a strong electrical potential difference between the two. A Taylor -cone forms at the tip of each nozzle from the electro...Combustion Institute, 20, pp. 965-972. Muler, N. and Fréchette, L.G., 2002: Performance Analysis of Brayton and Rankine Cycle Microsystems for

Hand-held Raman sensor head for in-situ characterization of meat quality applying a microsystem 671 nm diode laser

NASA Astrophysics Data System (ADS)

Schmidt, Heinar; Sowoidnich, Kay; Maiwald, Martin; Sumpf, Bernd; Kronfeldt, Heinz-Detlef

2009-05-01

A hand-held Raman sensor head was developed for the in-situ characterization of meat quality. As light source, a microsystem based external cavity diode laser module (ECDL) emitting at 671 nm was integrated in the sensor head and attached to a miniaturized optical bench which contains lens optics for excitation and signal collection as well as a Raman filter stage for Rayleigh rejection. The signal is transported with an optical fiber to the detection unit which was in the initial phase a laboratory spectrometer with CCD detector. All elements of the ECDL are aligned on a micro optical bench with 13 x 4 mm2 footprint. The wavelength stability is provided by a reflection Bragg grating and the laser has an optical power of up to 200 mW. However, for the Raman measurements of meat only 35 mW are needed to obtain Raman spectra within 1 - 5 seconds. Short measuring times are essential for the hand-held device. The laser and the sensor head are characterized in terms of stability and performance for in-situ Raman investigations. The function is demonstrated in a series of measurements with raw and packaged pork meat as samples. The suitability of the Raman sensor head for the quality control of meat and other products will be discussed.

Low-Temperature Variation of Acoustic Velocity in PDMS for High-Frequency Applications.

PubMed

Streque, Jeremy; Rouxel, Didier; Talbi, Abdelkrim; Thomassey, Matthieu; Vincent, Brice

2018-05-01

Polydimethylsiloxane (PDMS) and other related silicon-based polymers are among the most widely employed elastomeric materials in microsystems, owing to their physical and chemical properties. Meanwhile, surface acoustic wave (SAW) and bulk acoustic wave (BAW) sensors and filters have been vastly explored for sensing and wireless applications. Many fields could benefit from the combined use of acoustic wave devices, and polydimethylsiloxane-based soft-substrates, microsystems, or packaging elements. The mechanical constants of PDMS strongly depend on frequency, similar to rubber materials. This brings to the exploration of the specific mechanical properties of PDMS encountered at high frequency, required for its exploitation in SAW or BAW devices. First, low-frequency mechanical behavior is confirmed from stress strain measurements, remaining useful for the exploitation of PDMS as a soft substrate or packaging material. The study, then, proposes a temperature-dependent, high-frequency mechanical study of PDMS based on Brillouin spectroscopy to determine the evolution of the longitudinal acoustic velocity in this material, which constitutes the main mechanical parameter for the design of acoustic wave devices. The PDMS glass transition is then retrieved by differential scanning calorimetry in order to confirm the observations made by Brillouin spectroscopy. This paper validates Brillouin spectroscopy as a very suitable characterization technique for the retrieval of longitudinal mechanical properties at low temperature, as a preliminary investigation for the design of acoustic wave devices coupled with soft materials.

A low temperature drift coefficient crystal-less frequency reference clock compensated by temperature sensor for microsystem

NASA Astrophysics Data System (ADS)

Gao, Zhiqiang; Wu, Ruixuan; Wang, Yuteng; Gao, Yuan; Liu, Xiaowei; Zhu, Jiaqi

2018-05-01

Quartz oscillator has been widely used as reference clock source in the microsystems due to its good performance. But a good crystal oscillator costs too much and its bulky size is not desired. This paper aims at designing an alternative integrated oscillator to replace the external quartz oscillator. The proposed circuit used maneatis delay cell to construct a ring oscillator for its superior linear I-V characteristic. As for a frequency reference clock, its frequency stability over temperature is required at first. After detailed mathematical deducing and careful analysis, a formula is proposed to describe the relationship between desired control voltage and temperature by assuming the frequency as constant. This paper utilized bipolar transistor as the temperature sensor, combining it with CTAT current source and resistor to create a first-order temperature compensation control voltage. The chip with typical frequency of 10 MHz was fabricated in a 0.35 μm CMOS technology and occupied 0.45 mm2. The measured results show that the frequency variation is ±0.2% for supply changes from 4.8 V to 5 V, and frequency variation is 48 ppm when the temperature change is from ‑40∘C to 85∘C, while the average current of the tested chip consumes 50 μA from 5 V.

What attributions do Australian high-performing general practices make for their success? Applying the clinical microsystems framework: a qualitative study

PubMed Central

Dunham, Annette H; Dunbar, James A; Johnson, Julie K; Fuller, Jeff; Morgan, Mark; Ford, Dale

2018-01-01

Objectives To identify the success attributions of high-performing Australian general practices and the enablers and barriers they envisage for practices wishing to emulate them. Design Qualitative study using semi-structured interviews and content analysis of the data. Responses were recorded, transcribed verbatim and coded according to success characteristics of high-performing clinical microsystems. Setting Primary healthcare with the participating general practices representing all Australian states and territories, and representing metropolitan and rural locations. Participants Twenty-two general practices identified as high performing via a number of success criteria. The 52 participants were 19 general practitioners, 18 practice managers and 15 practice nurses. Results Participants most frequently attributed success to the interdependence of the team members, patient-focused care and leadership of the practice. They most often signalled practice leadership, team interdependence and staff focus as enablers that other organisations would need to emulate their success. They most frequently identified barriers that might be encountered in the form of potential deficits or limitations in practice leadership, staff focus and mesosystem support. Conclusions Practice leaders need to empower their teams to take action through providing inclusive leadership that facilitates team interdependence. Mesosystem support for quality improvement in general practice should focus on enabling this leadership and team building, thereby ensuring improvement efforts are converted into effective healthcare provision. PMID:29643162

Microfluidic platform integrated with worm-counting setup for assessing manganese toxicity

PubMed Central

Zhang, Beibei; Li, Yinbao; He, Qidi; Qin, Jun; Yu, Yanyan; Li, Xinchun; Zhang, Lin; Yao, Meicun; Liu, Junshan; Chen, Zuanguang

2014-01-01

We reported a new microfluidic system integrated with worm responders for evaluating the environmental manganese toxicity. The micro device consists of worm loading units, worm observing chambers, and a radial concentration gradient generator (CGG). Eight T-shape worm loading units of the micro device were used to load the exact number of worms into the corresponding eight chambers with the assistance of worm responders and doorsills. The worm responder, as a key component, was employed for performing automated worm-counting assay through electric impedance sensing. This label-free and non-invasive worm-counting technique was applied to the microsystem for the first time. In addition, the disk-shaped CGG can generate a range of stepwise concentrations of the appointed chemical automatically and simultaneously. Due to the scalable architecture of radial CGG, it has the potential to increase the throughput of the assay. Dopaminergic (DAergic) neurotoxicity of manganese on C. elegans was quantitatively assessed via the observation of green fluorescence protein-tagged DAergic neurons of the strain BZ555 on-chip. In addition, oxidative stress triggered by manganese was evaluated by the quantitative fluorescence intensity of the strain CL2166. By scoring the survival ratio and stroke frequency of worms, we characterized the dose- and time-dependent mobility defects of the manganese-exposed worms. Furthermore, we applied the microsystem to investigate the effect of natural antioxidants to protect manganese-induced toxicity. PMID:25538805

Biocompatible circuit-breaker chip for thermal management of biomedical microsystems

NASA Astrophysics Data System (ADS)

Luo, Yi; Dahmardeh, Masoud; Takahata, Kenichi

2015-05-01

This paper presents a thermoresponsive micro circuit breaker for biomedical applications specifically targeted at electronic intelligent implants. The circuit breaker is micromachined to have a shape-memory-alloy cantilever actuator as a normally closed temperature-sensitive switch to protect the device of interest from overheating, a critical safety feature for smart implants including those that are electrothermally driven with wireless micro heaters. The device is fabricated in a size of 1.5  ×  2.0  ×  0.46 mm3 using biocompatible materials and a chip-based titanium package, exhibiting a nominal cold-state resistance of 14 Ω. The breaker rapidly enters the full open condition when the chip temperature exceeds 63 °C, temporarily breaking the circuit of interest to lower its temperature until chip temperature drops to 51 °C, at which the breaker closes the circuit to allow current to flow through it again, physically limiting the maximum temperature of the circuit. This functionality is tested in combination with a wireless resonant heater powered by radio-frequency electromagnetic radiation, demonstrating self-regulation of heater temperature. The developed circuit-breaker chip operates in a fully passive manner that removes the need for active sensor and circuitry to achieve temperature regulation in a target device, contributing to the miniaturization of biomedical microsystems including electronic smart implants where thermal management is essential.

A micro-flow-batch analyzer with solenoid micro-pumps for the photometric determination of iodate in table salt.

PubMed

Lima, Marcelo B; Barreto, Inakã S; Andrade, Stéfani Iury E; Almeida, Luciano F; Araújo, Mário C U

2012-10-15

In this study, a micro-flow-batch analyzer (μFBA) with solenoid micro-pumps for the photometric determination of iodate in table salt is described. The method is based on the reaction of iodate with iodide to form molecular iodine followed by the reaction with N,N-diethyl-p-phenylenediamine (DPD). The analytical signal was measured at 520 nm using a green LED integrated into the μFBA built in the urethane-acrylate resin. The analytical curve for iodate was linear in the range of 0.01-10.0 mg L(-1) with a correlation coefficient of 0.997. The limit of detection and relative standard deviation were estimated at 0.004 mg L(-1) and<1.5% (n=3), respectively. The accuracy was assessed through recovery test (97.6-103.5%) and independent analysis by a conventional titrimetric method. Comparing this technique with the conventional method, no statistically significant differences were observed when applying the paired t-test at a 95% confidence level. The proposed microsystem using solenoid micro-pumps presented satisfactory robustness and high sampling rate (170 h(-1)), with a low reagents consumption and a low cost to build the device. The proposed microsystem is a new alternative for automatic determination of iodate in table salt, comparing satisfactory to the recently flow system. Copyright © 2012 Elsevier B.V. All rights reserved.

Development and Application of Microfabricated Chemical Gas Sensors For Aerospace Applications

NASA Technical Reports Server (NTRS)

Hunter, G. W.; Neudeck, P. G.; Fralick, G.; Thomas, V.; Liu, C. C.; Wu, Q. H.; Sawayda, M. S.; Jin, A.; Hammond, J.; Makel, D.;

PREFACE: 1st European Conference on Gas Micro Flows (GasMems 2012)

NASA Astrophysics Data System (ADS)

Frijns, Arjan; Valougeorgis, Dimitris; Colin, Stéphane; Baldas, Lucien

2012-05-01

The aim of the 1st European Conference on Gas Micro Flows is to advance research in Europe and worldwide in the field of gas micro flows as well as to improve global fundamental knowledge and to enable technological applications. Gas flows in microsystems are of great importance and touch almost every industrial field (e.g. fluidic microactuators for active control of aerodynamic flows, vacuum generators for extracting biological samples, mass flow and temperature micro-sensors, pressure gauges, micro heat-exchangers for the cooling of electronic components or for chemical applications, and micro gas analyzers or separators). The main characteristic of gas microflows is their rarefaction, which for device design often requires modelling and simulation both by continuous and molecular approaches. In such flows various non-equilibrium transport phenomena appear, while the role played by the interaction between the gas and the solid device surfaces becomes essential. The proposed models of boundary conditions often need an empirical adjustment strongly dependent on the micro manufacturing technique. The 1st European Conference on Gas Micro Flows is organized under the umbrella of the recently established GASMEMS network (www.gasmems.eu/) consisting of 13 participants and six associate members. The main objectives of the network are to structure research and train researchers in the fields of micro gas dynamics, measurement techniques for gaseous flows in micro experimental setups, microstructure design and micro manufacturing with applications in lab and industry. The conference takes place on June 6-8 2012, at the Skiathos Palace Hotel, on the beautiful island of Skiathos, Greece. The conference has received funding from the European Community's Seventh Framework Programme FP7/2007-2013 under grant agreement ITN GASMEMS no. 215504. It owes its success to many people. We would like to acknowledge the support of all members of the Scientific Committee and of all referees for their thorough reviews and evaluation of the full papers. Above all, we would like to sincerely thank all authors for their valuable contributions to these proceedings as well as all the participants for creating a stimulating atmosphere through their presentations and discussions and making this conference a great success. Dr Arjan Frijns Editor and Event Coordinator Prof. Dimitris Valougeorgis Local Organizer Prof. Stéphane Colin Network Coordinator Dr Lucien Baldas Assistant Network Coordinator The PDF also contains details of the Conference Organizers.

Measurement of Microscale Bio-Thermal Responses by Means of a Micro-Thermocouple Probe

DTIC Science & Technology

2001-10-25

3) A silane coupler (VM-652, HD MicroSystems) was applied as a primer for good adhesion of the polyimide coating (Pyralin® PI2556, HD...MicroSystems), which was used as an insulating layer. We also used SiO2 instead of polyimide . (4) A gold (Au) thin film was deposited by means of the ion...sputtering technique. (5) A coating of polyimide /SiO2 was applied. (6) Finally, a coating of MPC (2-methacryloyloxyethyl phosphorylcholine) copolymers

Exploring microdischarges for portable sensing applications.

PubMed

Gianchandani, Y B; Wright, S A; Eun, C K; Wilson, C G; Mitra, B

2009-10-01

This paper describes the use of microdischarges as transducing elements in sensors and detectors. Chemical and physical sensing of gases, chemical sensing of liquids, and radiation detection are described. These applications are explored from the perspective of their use in portable microsystems, with emphasis on compactness, power consumption, the ability to operate at or near atmospheric pressure (to reduce pumping challenges), and the ability to operate in an air ambient (to reduce the need for reservoirs of carrier gases). Manufacturing methods and performance results are described for selected examples.

Microsystem enabled photovoltaic modules and systems

DOEpatents

Nielson, Gregory N.; Sweatt, William C.; Okandan, Murat

2017-09-12

A photovoltaic (PV) module includes an absorber layer coupled to an optic layer. The absorber layer includes an array of PV elements. The optic layer includes a close-packed array of Keplerian telescope elements, each corresponding to one of an array of pupil elements. The Keplerian telescope substantially couple radiation that is incident on their objective surfaces into the corresponding pupil elements. Each pupil element relays radiation that is coupled into it from the corresponding Keplerian telescope element into the corresponding PV element.

Fourier-transform optical microsystems

NASA Technical Reports Server (NTRS)

Collins, S. D.; Smith, R. L.; Gonzalez, C.; Stewart, K. P.; Hagopian, J. G.; Sirota, J. M.

1999-01-01

The design, fabrication, and initial characterization of a miniature single-pass Fourier-transform spectrometer (FTS) that has an optical bench that measures 1 cm x 5 cm x 10 cm is presented. The FTS is predicated on the classic Michelson interferometer design with a moving mirror. Precision translation of the mirror is accomplished by microfabrication of dovetailed bearing surfaces along single-crystal planes in silicon. Although it is miniaturized, the FTS maintains a relatively high spectral resolution, 0.1 cm-1, with adequate optical throughput.

Photo-control of nanointeractions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomes, William Joseph, Jr.; Potter, Barrett George, Jr.; Jiang, Liu

2005-02-01

The manipulation of physical interactions between structural moieties on the molecular scale is a fundamental hurdle in the realization and operation of nanostructured materials and high surface area microsystem architectures. These include such nano-interaction-based phenomena as self-assembly, fluid flow, and interfacial tribology. The proposed research utilizes photosensitive molecular structures to tune such interactions reversibly. This new material strategy provides optical actuation of nano-interactions impacting behavior on both the nano- and macroscales and with potential to impact directed nanostructure formation, microfluidic rheology, and tribological control.

Integrated Microsensors for Autonomous Microrobots

DOE Office of Scientific and Technical Information (OSTI.GOV)

ADKINS, DOUGLAS R.; BYRNE, RAYMOND H.; HELLER, EDWIN J.

2003-02-01

This report describes the development of a miniature mobile microrobot device and several microsystems needed to create a miniature microsensor delivery platform. This work was funded under LDRD No.10785, entitled, ''Integrated Microsensors for Autonomous Microrobots''. The approach adopted in this project was to develop a mobile platform, to which would be attached wireless RF remote control and data acquisition in addition to various microsensors. A modular approach was used to produce a versatile microrobot platform and reduce power consumption and physical size.

The shape memory alloy actuator controlled by the Sun’s radiation

NASA Astrophysics Data System (ADS)

Riad, Amine; Alhamany, Abdelilah; Benzohra, Mouna

2017-07-01

Shape memory alloys (SMAs) have many thermo-mechanical characteristics which can return to their original value once exposed to a specific temperature. These materials are able to change their mechanical features such as shape, displacement or frequency in response to stress or heating; this may be useful for actuators in many fields such as aircraft, robotics and microsystems. In order to know the effect of the Sun’s radiation on SMAs we have conducted a numerical study that simulates a SMA actuator.

Innovative Microsystems: Novel Nanostructures to Capture Circulating Breast Cancer Cells

DTIC Science & Technology

2009-05-01

temperature to promote a Schiff-base reaction. Recombinant protein G from E . coli (Zymed Lab Inc.) 50 μg/ml in Ca- and Mg-free phosphate-buffered...recombinant protein G from E . coli (Zymed Lab Inc.), at a concentration of 50 mg ml1 in 1 PBS, is incubated on the activated surface overnight at 4 C...reaction. Recombinant protein G from E . coli (Zymed Lab Inc.) 50 μg/ml in Ca- and Mg-free phosphate-buffered saline (CMF-PBS), is incubated on the

Platform-independent software for medical image processing on the Internet

NASA Astrophysics Data System (ADS)

Mancuso, Michael E.; Pathak, Sayan D.; Kim, Yongmin

1997-05-01

We have developed a software tool for image processing over the Internet. The tool is a general purpose, easy to use, flexible, platform independent image processing software package with functions most commonly used in medical image processing.It provides for processing of medical images located wither remotely on the Internet or locally. The software was written in Java - the new programming language developed by Sun Microsystems. It was compiled and tested using Microsoft's Visual Java 1.0 and Microsoft's Just in Time Compiler 1.00.6211. The software is simple and easy to use. In order to use the tool, the user needs to download the software from our site before he/she runs it using any Java interpreter, such as those supplied by Sun, Symantec, Borland or Microsoft. Future versions of the operating systems supplied by Sun, Microsoft, Apple, IBM, and others will include Java interpreters. The software is then able to access and process any image on the iNternet or on the local computer. Using a 512 X 512 X 8-bit image, a 3 X 3 convolution took 0.88 seconds on an Intel Pentium Pro PC running at 200 MHz with 64 Mbytes of memory. A window/level operation took 0.38 seconds while a 3 X 3 median filter took 0.71 seconds. These performance numbers demonstrate the feasibility of using this software interactively on desktop computes. Our software tool supports various image processing techniques commonly used in medical image processing and can run without the need of any specialized hardware. It can become an easily accessible resource over the Internet to promote the learning and of understanding image processing algorithms. Also, it could facilitate sharing of medical image databases and collaboration amongst researchers and clinicians, regardless of location.

A deep etching mechanism for trench-bridging silicon nanowires

NASA Astrophysics Data System (ADS)

Tasdemir, Zuhal; Wollschläger, Nicole; Österle, Werner; Leblebici, Yusuf; Erdem Alaca, B.

2016-03-01

Introducing a single silicon nanowire with a known orientation and dimensions to a specific layout location constitutes a major challenge. The challenge becomes even more formidable, if one chooses to realize the task in a monolithic fashion with an extreme topography, a characteristic of microsystems. The need for such a monolithic integration is fueled by the recent surge in the use of silicon nanowires as functional building blocks in various electromechanical and optoelectronic applications. This challenge is addressed in this work by introducing a top-down, silicon-on-insulator technology. The technology provides a pathway for obtaining well-controlled silicon nanowires along with the surrounding microscale features up to a three-order-of-magnitude scale difference. A two-step etching process is developed, where the first shallow etch defines a nanoscale protrusion on the wafer surface. After applying a conformal protection on the protrusion, a deep etch step is carried out forming the surrounding microscale features. A minimum nanowire cross-section of 35 nm by 168 nm is demonstrated in the presence of an etch depth of 10 μm. Nanowire cross-sectional features are characterized via transmission electron microscopy and linked to specific process steps. The technology allows control on all dimensional aspects along with the exact location and orientation of the silicon nanowire. The adoption of the technology in the fabrication of micro and nanosystems can potentially lead to a significant reduction in process complexity by facilitating direct access to the nanowire during surface processes such as contact formation and doping.

A deep etching mechanism for trench-bridging silicon nanowires.

PubMed

Tasdemir, Zuhal; Wollschläger, Nicole; Österle, Werner; Leblebici, Yusuf; Alaca, B Erdem

2016-03-04

Introducing a single silicon nanowire with a known orientation and dimensions to a specific layout location constitutes a major challenge. The challenge becomes even more formidable, if one chooses to realize the task in a monolithic fashion with an extreme topography, a characteristic of microsystems. The need for such a monolithic integration is fueled by the recent surge in the use of silicon nanowires as functional building blocks in various electromechanical and optoelectronic applications. This challenge is addressed in this work by introducing a top-down, silicon-on-insulator technology. The technology provides a pathway for obtaining well-controlled silicon nanowires along with the surrounding microscale features up to a three-order-of-magnitude scale difference. A two-step etching process is developed, where the first shallow etch defines a nanoscale protrusion on the wafer surface. After applying a conformal protection on the protrusion, a deep etch step is carried out forming the surrounding microscale features. A minimum nanowire cross-section of 35 nm by 168 nm is demonstrated in the presence of an etch depth of 10 μm. Nanowire cross-sectional features are characterized via transmission electron microscopy and linked to specific process steps. The technology allows control on all dimensional aspects along with the exact location and orientation of the silicon nanowire. The adoption of the technology in the fabrication of micro and nanosystems can potentially lead to a significant reduction in process complexity by facilitating direct access to the nanowire during surface processes such as contact formation and doping.

PICSiP: new system-in-package technology using a high bandwidth photonic interconnection layer for converged microsystems

NASA Astrophysics Data System (ADS)

Tekin, Tolga; Töpper, Michael; Reichl, Herbert

2009-05-01

Technological frontiers between semiconductor technology, packaging, and system design are disappearing. Scaling down geometries [1] alone does not provide improvement of performance, less power, smaller size, and lower cost. It will require "More than Moore" [2] through the tighter integration of system level components at the package level. System-in-Package (SiP) will deliver the efficient use of three dimensions (3D) through innovation in packaging and interconnect technology. A key bottleneck to the implementation of high-performance microelectronic systems, including SiP, is the lack of lowlatency, high-bandwidth, and high density off-chip interconnects. Some of the challenges in achieving high-bandwidth chip-to-chip communication using electrical interconnects include the high losses in the substrate dielectric, reflections and impedance discontinuities, and susceptibility to crosstalk [3]. Obviously, the incentive for the use of photonics to overcome the challenges and leverage low-latency and highbandwidth communication will enable the vision of optical computing within next generation architectures. Supercomputers of today offer sustained performance of more than petaflops, which can be increased by utilizing optical interconnects. Next generation computing architectures are needed with ultra low power consumption; ultra high performance with novel interconnection technologies. In this paper we will discuss a CMOS compatible underlying technology to enable next generation optical computing architectures. By introducing a new optical layer within the 3D SiP, the development of converged microsystems, deployment for next generation optical computing architecture will be leveraged.

The next step in health behavior research: the need for ecological moderation analyses - an application to diet and physical activity at childcare.

PubMed

Gubbels, Jessica S; Van Kann, Dave Hh; de Vries, Nanne K; Thijs, Carel; Kremers, Stef Pj

2014-04-17

The ecological perspective holds that human behavior depends on the interaction of different environmental factors and personal characteristics, but it lacks validation and operationalization. In the current paper, an ecological view was adopted to examine the interactive impact of several ecological systems on children's dietary intake and physical activity at childcare or similar facilities. The ecological view was operationalized into three types of interaction: 1) interaction between types of childcare environment (physical, social, political, economic); 2) interaction between micro-systems (the childcare and home environment) in meso-systems; and 3) interaction between childcare environment and child characteristics. The predictive value of each of these interactions was tested based on a systematic review of the literature. Several studies support the hypothesis that the influence of the childcare environment on children's physical activity and diet is moderated by child characteristics (age, gender), but interaction between environmental types as well as between micro-systems is hardly examined in the field of behavioral nutrition and physical activity. Qualitative studies and general child development research provide some valuable insights, but we advocate quantitative research adopting an ecological perspective on environmental influences. Empirical studies operationalizing a true ecological view on diet and physical activity are scarce. Theorizing and assessment of interaction is advocated to become common practice rather than an exception in behavioral nutrition and physical activity research, in order to move the field forward.

Influencing factors on high-risk sexual behaviors in young people: an ecological perspective.

PubMed

Arabi-Mianrood, Hoda; Hamzehgardeshi, Zeinab; Khoori, Elham; Moosazadeh, Mahmood; Shahhosseini, Zohreh

2017-04-19

Background In recent years, high-risk sexual behaviors due to their negative consequences both for the individual and society have received more attention than other high-risk behaviors. Objective The aim of this study was to review the influencing factors of high-risk sexual behaviors among young people from an ecological point of view. Methods This review was conducted through searching databases including PubMed, Web of Science, Scopus, Google Scholar and the Cochrane Library with keywords such as sexual risk-taking behavior, high-risk sex, unprotected sex and unsafe sex. The relevant papers published between 1995 and 2016 were extracted. After reviewing the abstract and full text of the articles, 45 papers were used to write this article. Results From an ecological theory approach, factors which influence high-risk sexual behaviors are divided into three categories - the microsystem, the mesosystem and the macrosystem. The microsystem includes factors such as age, gender, race, marital status, place of residence, religion, level of education, personality traits, psychological problems, childhood experiences, body image and coincidence of high-risk behaviors; the mesosystem includes factors such as family structure, peers and sex education; in the macrosystem, the impact of culture and traditions of the society, economic status and the media are presented. Conclusion Given that high-risk sexual behaviors often have multiple causes, it seems that health policymakers must consider multi-dimensional interventions to influence high-risk sexual behaviors based on the ecological approach.

What attributions do Australian high-performing general practices make for their success? Applying the clinical microsystems framework: a qualitative study.

PubMed

Dunham, Annette H; Dunbar, James A; Johnson, Julie K; Fuller, Jeff; Morgan, Mark; Ford, Dale

2018-04-10

To identify the success attributions of high-performing Australian general practices and the enablers and barriers they envisage for practices wishing to emulate them. Qualitative study using semi-structured interviews and content analysis of the data. Responses were recorded, transcribed verbatim and coded according to success characteristics of high-performing clinical microsystems. Primary healthcare with the participating general practices representing all Australian states and territories, and representing metropolitan and rural locations. Twenty-two general practices identified as high performing via a number of success criteria. The 52 participants were 19 general practitioners, 18 practice managers and 15 practice nurses. Participants most frequently attributed success to the interdependence of the team members, patient-focused care and leadership of the practice. They most often signalled practice leadership, team interdependence and staff focus as enablers that other organisations would need to emulate their success. They most frequently identified barriers that might be encountered in the form of potential deficits or limitations in practice leadership, staff focus and mesosystem support. Practice leaders need to empower their teams to take action through providing inclusive leadership that facilitates team interdependence. Mesosystem support for quality improvement in general practice should focus on enabling this leadership and team building, thereby ensuring improvement efforts are converted into effective healthcare provision. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The next step in health behavior research: the need for ecological moderation analyses - an application to diet and physical activity at childcare

PubMed Central

2014-01-01

Background The ecological perspective holds that human behavior depends on the interaction of different environmental factors and personal characteristics, but it lacks validation and operationalization. In the current paper, an ecological view was adopted to examine the interactive impact of several ecological systems on children’s dietary intake and physical activity at childcare or similar facilities. The ecological view was operationalized into three types of interaction: 1) interaction between types of childcare environment (physical, social, political, economic); 2) interaction between micro-systems (the childcare and home environment) in meso-systems; and 3) interaction between childcare environment and child characteristics. The predictive value of each of these interactions was tested based on a systematic review of the literature. Discussion Several studies support the hypothesis that the influence of the childcare environment on children’s physical activity and diet is moderated by child characteristics (age, gender), but interaction between environmental types as well as between micro-systems is hardly examined in the field of behavioral nutrition and physical activity. Qualitative studies and general child development research provide some valuable insights, but we advocate quantitative research adopting an ecological perspective on environmental influences. Summary Empirical studies operationalizing a true ecological view on diet and physical activity are scarce. Theorizing and assessment of interaction is advocated to become common practice rather than an exception in behavioral nutrition and physical activity research, in order to move the field forward. PMID:24742167

Characterization of the magnetic properties of NdFeB thick films exposed to elevated temperatures

NASA Astrophysics Data System (ADS)

Fujiwara, Ryogen; Devillers, Thibaut; Givord, Dominique; Dempsey, Nora M.

2018-05-01

Hard magnetic films used in magnetic micro-systems may be exposed to elevated temperatures during film and system fabrication and also during use of the micro-system. In this work, we studied the influence of temperature on the magnetic properties of 10 μm thick out-of-plane textured NdFeB films fabricated by high rate triode sputtering. Out-of-plane hysteresis loops were measured in the range 300K - 650K to establish the temperature dependence of coercivity, magnetization at 7 T and remanent magnetization. Thermal demagnetization was measured and magnetization losses were recorded from 350K in films heated under zero or low (-0.1 T) external field and from 325 K for films heated under an external field of -0.5 T. The effect of thermal cycling under zero field on the remanent magnetization was also studied and it was found that cycling between room temperature and 323 K did not lead to any significant loss in remanence at room temperature, while a 4% drop is recorded when the sample is cycled between RT and 343K. Measurement of hysteresis loops at room temperature following exposure to elevated temperatures reveals that while remanent magnetisation is practically recovered in all cases, irreversible losses in coercivity occur (6.7 % following heating to 650K, and 1.3 % following heating to 343K). The relevance of these results is discussed in terms of system fabrication and use.

Micro-patterning and characterization of PHEMA-co-PAM-based optical chemical sensors for lab-on-a-chip applications.

PubMed

Zhu, Haixin; Zhou, Xianfeng; Su, Fengyu; Tian, Yanqing; Ashili, Shashanka; Holl, Mark R; Meldrum, Deirdre R

2012-10-01

We report a novel method for wafer level, high throughput optical chemical sensor patterning, with precise control of the sensor volume and capability of producing arbitrary microscale patterns. Monomeric oxygen (O(2)) and pH optical probes were polymerized with 2-hydroxyethyl methacrylate (HEMA) and acrylamide (AM) to form spin-coatable and further crosslinkable polymers. A micro-patterning method based on micro-fabrication techniques (photolithography, wet chemical process and reactive ion etch) was developed to miniaturize the sensor film onto glass substrates in arbitrary sizes and shapes. The sensitivity of fabricated micro-patterns was characterized under various oxygen concentrations and pH values. The process for spatially integration of two sensors (Oxygen and pH) on the same substrate surface was also developed, and preliminary fabrication and characterization results were presented. To the best of our knowledge, it is the first time that poly (2-hydroxylethyl methacrylate)-co-poly (acrylamide) (PHEMA-co-PAM)-based sensors had been patterned and integrated at the wafer level with micron scale precision control using microfabrication techniques. The developed methods can provide a feasible way to miniaturize and integrate the optical chemical sensor system and can be applied to any lab-on-a-chip system, especially the biological micro-systems requiring optical sensing of single or multiple analytes.

Maintaining equilibrium in professional role identity: a grounded theory study of health visitors' perceptions of their changing professional practice context.

PubMed

Machin, Alison I; Machin, Tony; Pearson, Pauline

2012-07-01

This article reports the study of a group of United Kingdom health visitors' interactions with their changing practice context, focusing on role identity and influences on its stability. United Kingdom policies have urged health visitors to refocus their role as key public health nurses. Reduced role identity clarity precipitated the emergence of different models of health visiting public health work. An inconsistent role standard can lead to role identity fragmentation and conflict across a group. It may precipitate individual role crisis, affecting optimum role performance. Seventeen health visitors in two United Kingdom community healthcare organizations participated in a grounded theory study, incorporating constant comparative analysis. Direct observations and individual interviews were undertaken between 2002 and 2008. Four interlinked categories emerged: professional role identity (core category); professional role in action; interprofessional working; and local micro-systems for practice; each influencing participants' sense of identity and self-worth. The Role Identity Equilibrium Process explains interactive processes occurring at different levels of participants' practice. Re-establishing equilibrium and consistency in health visiting identity is a priority. This study's findings have significance for other nurses and health professionals working in complex systems, affected by role change and challenges to role identity. © 2011 Blackwell Publishing Ltd.

Near Infrared Dyes as Lifetime Solvatochromic Probes for Micropolarity Measurements of Biological Systems

PubMed Central

Berezin, Mikhail Y.; Lee, Hyeran; Akers, Walter; Achilefu, Samuel

2007-01-01

The polarity of biological mediums controls a host of physiological processes such as digestion, signaling, transportation, metabolism, and excretion. With the recent widespread use of near-infrared (NIR) fluorescent dyes for biological imaging of cells and living organisms, reporting medium polarity with these dyes would provide invaluable functional information in addition to conventional optical imaging parameters. Here, we report a new approach to determine polarities of macro- and microsystems for in vitro and potential in vivo applications using NIR polymethine molecular probes. Unlike the poor solvatochromic response of NIR dyes in solvents with diverse polarity, their fluorescence lifetimes are highly sensitive, increasing by a factor of up to 8 on moving from polar to nonpolar mediums. We also established a correlation between fluorescence lifetime and solvent orientation polarizability and developed a lifetime polarity index for determining the polarity of complex systems, including micelles and albumin binding sites. Because of the importance of medium polarity in molecular, cellular, and biochemical processes and the significance of reduced autofluorescence and deep tissue penetration of light in the NIR region, the findings reported herein represent an important advance toward using NIR molecular probes to measure the polarity of complex biological systems in vitro and in vivo. PMID:17573433

Characteristics of health care organizations associated with learning and development: lessons from a pilot study.

PubMed

Nyström, Monica

2009-01-01

Characteristics of health care organizations associated with an ability to learn from experiences and to develop and manage change were explored in this study. Understanding of these characteristics is necessary to identify factors influencing success in learning from the past and achieving future health care quality objectives. A literature review of the quality improvement, strategic organizational development and change management, organizational learning, and microsystems fields identified 20 organizational characteristics, grouped under (a) organizational systems, (b) key actors, and (c) change management processes. Qualitative methods, using interviews, focus group reports, and archival records, were applied to find associations between identified characteristics and 6 Swedish health care units externally evaluated as delivering high-quality care. Strong support for a characteristic was defined as units having more than 4 sources describing the characteristic as an important success factor. Eighteen characteristics had strong support from at least 2 units. The strongest evidence was found for the following: (i) key actors have long-term commitment, provide support, and make sense of ambiguous situations; (ii) organizational systems encourage employee commitment, participation, and involvement; and (iii) change management processes are employed systematically. Based on the results, a new model of "characteristics associated with learning and development in health care organizations" is proposed.

MEMS Technology for Space Applications

NASA Technical Reports Server (NTRS)

vandenBerg, A.; Spiering, V. L.; Lammerink, T. S. J.; Elwenspoek, M.; Bergveld, P.

1995-01-01

Micro-technology enables the manufacturing of all kinds of components for miniature systems or micro-systems, such as sensors, pumps, valves, and channels. The integration of these components into a micro-electro-mechanical system (MEMS) drastically decreases the total system volume and mass. These properties, combined with the increasing need for monitoring and control of small flows in (bio)chemical experiments, makes MEMS attractive for space applications. The level of integration and applied technology depends on the product demands and the market. The ultimate integration is process integration, which results in a one-chip system. An example of process integration is a dosing system of pump, flow sensor, micromixer, and hybrid feedback electronics to regulate the flow. However, for many applications, a hybrid integration of components is sufficient and offers the advantages of design flexibility and even the exchange of components in the case of a modular set up. Currently, we are working on hybrid integration of all kinds of sensors (physical and chemical) and flow system modules towards a modular system; the micro total analysis system (micro TAS). The substrate contains electrical connections as in a printed circuit board (PCB) as well as fluid channels for a circuit channel board (CCB) which, when integrated, form a mixed circuit board (MCB).

The Burden of Disaster: Part I. Challenges and Opportunities Within a Child’s Social Ecology

PubMed Central

Noffsinger, Mary A.; Pfefferbaum, Betty; Pfefferbaum, Rose L.; Sherrieb, Kathleen; Norris, Fran H.

2013-01-01

Child development and adaptation are best understood as biological and psychological individual processes occurring within the context of interconnecting groups, systems, and communities which, along with family, constitute the child’s social ecology. This first of two articles describes the challenges and opportunities within a child’s social ecology, consisting of Micro-, Meso-, Exo-, and Macrosystems. The parent-child relationship, the most salient Microsystem influence in children’s lives, plays an influential role in children’s reactions to and recovery from disasters. Children, parents, and other adults participate in Mesosystem activities at schools and faith-based organizations. The Exosystem—including workplaces, spcial agencies, neighborhood, and mass media—directly affects important adults in children’s lives. The Macrosystem affects disaster response and recovery indirectly through intangible cultural, social, economic, and political structures and processes. Children’s responses to adversity occur in the context of these dynamically interconnected and interdependent nested environments, all of which endure the burden of disaster. Increased understanding of the influences of and the relationships between key components contributes to recovery and rebuilding efforts, limiting disruption to the child and his or her social ecology. A companion article (R. L. Pfefferbaum et al., in press) describes interventions across the child’s social ecology. PMID:23156957

Deep-brain stimulator and control of Parkinson's disease

NASA Astrophysics Data System (ADS)

Varadan, Vijay K.; Harbaugh, Robert; Abraham, Jose K.

2004-07-01

The design of a novel feedback sensor system with wireless implantable polymer MEMS sensors for detecting and wirelessly transmitting physiological data that can be used for the diagnosis and treatment of various neurological disorders, such as Parkinson's disease, epilepsy, head injury, stroke, hydrocephalus, changes in pressure, patient movements, and tremors is presented in this paper. The sensor system includes MEMS gyroscopes, accelerometers, and pressure sensors. This feedback sensor system focuses on the development and integration of implantable systems with various wireless sensors for medical applications, particularly for the Parkinson's disease. It is easy to integrate and modify the sensor network feed back system for other neurological disorders mentioned above. The monitoring and control of tremor in Parkinson's disease can be simulated on a skeleton via wireless telemetry system communicating with electroactive polymer actuator, and microsensors attached to the skeleton hand and legs. Upon sensing any abnormal motor activity which represent the characteristic rhythmic motion of a typical Parkinson's (PD) patient, these sensors will generate necessary control pulses which will be transmitted to a hat sensor system on the skeleton head. Tiny inductively coupled antennas attached to the hat sensor system can receive these control pulses, demodulate and deliver it to actuate the parts of the skeleton to control the abnormal motor activity. This feedback sensor system can further monitor and control depending on the amplitude of the abnormal motor activity. This microsystem offers cost effective means of monitoring and controlling of neurological disorders in real PD patients. Also, this network system offers a remote monitoring of the patients conditions without visiting doctors office or hospitals. The data can be monitored using PDA and can be accessed using internet (or cell phone). Cellular phone technology will allow a health care worker to be automatically notified if monitoring indicates an emergency situation. The main advantage of such system is that it can effectively monitor large number of patients at the same time, which helps to compensate the present shortage of health care workers.

Skin-interfaced systems for sweat collection and analytics

PubMed Central

Choi, Jungil; Ghaffari, Roozbeh; Baker, Lindsay B.; Rogers, John A.

2018-01-01

Recent interdisciplinary advances in materials, mechanics, and microsystem designs for biocompatible electronics, soft microfluidics, and electrochemical biosensors establish the foundations for emerging classes of thin, skin-interfaced platforms capable of capturing, storing, and performing quantitative, spatiotemporal measurements of sweat chemistry, instantaneous local sweat rate, and total sweat loss. This review summarizes scientific and technical progress in this area and highlights the implications in real time and ambulatory modes of deployment during physical activities across a broad range of contexts in clinical health, physiology research, fitness/wellness, and athletic performance. PMID:29487915

Apparatus and method for electroforming high aspect ratio micro-parts

DOEpatents

Hachman, John T [Stockton, CA; Losey, Matthew W [Rancho Cucamonga, CA; McLean, Dorrance E [Manteca, CA

2009-11-27

A fixture is disclosed to more easily affix a workpiece in the proper orientation and spacing with sealed electrical interconnection within an electrochemical plating bath. The workpiece can be any planar metallic or non-metallic substrate such as a silicon wafer commonly used in LIGA or microsystem fabrication. The fixture described allows the workpiece to be submerged deep within an electrolytic cell, facing upwards, and allows easy transfer from one cell to another. The edges, backside, and electrical connections are sealed and protected from the electrolyte.

K-band single-chip electron spin resonance detector.

PubMed

Anders, Jens; Angerhofer, Alexander; Boero, Giovanni

2012-04-01

We report on the design, fabrication, and characterization of an integrated detector for electron spin resonance spectroscopy operating at 27 GHz. The microsystem, consisting of an LC-oscillator and a frequency division module, is integrated onto a single silicon chip using a conventional complementary metal-oxide-semiconductor technology. The achieved room temperature spin sensitivity is about 10(8)spins/G Hz(1/2), with a sensitive volume of about (100 μm)(3). Operation at 77K is also demonstrated. Copyright © 2012 Elsevier Inc. All rights reserved.

HAREM: high aspect ratio etching and metallization for microsystems fabrication

NASA Astrophysics Data System (ADS)

Sarajlic, Edin; Yamahata, Christophe; Cordero, Mauricio; Collard, Dominique; Fujita, Hiroyuki

2008-07-01

We report a simple bulk micromachining method for the fabrication of high aspect ratio monocrystalline silicon MEMS (microelectromechanical systems) in a standard silicon wafer. We call this two-mask microfabrication process high aspect ratio etching and metallization or HAREM: it combines double-side etching and metallization to create suspended micromechanical structures with electrically 'insulating walls' on their backside. The insulating walls ensure a proper electrical insulation between the different actuation and sensing elements situated on either fixed or movable parts of the device. To demonstrate the high potential of this simple microfabrication method, we have designed and characterized electrostatically actuated microtweezers that integrate a differential capacitive sensor. The prototype showed an electrical insulation better than 1 GΩ between the different elements of the device. Furthermore, using a lock-in amplifier circuit, we could measure the position of the moving probe with few nanometers resolution for a displacement range of about 3 µm. This work was presented in part at the 21st IEEE MEMS Conference (Tucson, AZ, USA, 13-17 January, 2008) (doi:10.1109/MEMSYS.2008.4443656).

UNIX-based operating systems robustness evaluation

NASA Technical Reports Server (NTRS)

Chang, Yu-Ming

1996-01-01

Robust operating systems are required for reliable computing. Techniques for robustness evaluation of operating systems not only enhance the understanding of the reliability of computer systems, but also provide valuable feed- back to system designers. This thesis presents results from robustness evaluation experiments on five UNIX-based operating systems, which include Digital Equipment's OSF/l, Hewlett Packard's HP-UX, Sun Microsystems' Solaris and SunOS, and Silicon Graphics' IRIX. Three sets of experiments were performed. The methodology for evaluation tested (1) the exception handling mechanism, (2) system resource management, and (3) system capacity under high workload stress. An exception generator was used to evaluate the exception handling mechanism of the operating systems. Results included exit status of the exception generator and the system state. Resource management techniques used by individual operating systems were tested using programs designed to usurp system resources such as physical memory and process slots. Finally, the workload stress testing evaluated the effect of the workload on system performance by running a synthetic workload and recording the response time of local and remote user requests. Moderate to severe performance degradations were observed on the systems under stress.

A Library of Rad Hard Mixed-Voltage/Mixed-Signal Building Blocks for Integration of Avionics Systems for Deep Space

NASA Technical Reports Server (NTRS)

Mojarradi, M. M.; Blaes, B.; Kolawa, E. A.; Blalock, B. J.; Li, H. W.; Buck, K.; Houge, D.

2001-01-01

To build the sensor intensive system-on-a-chip for the next generation spacecrafts for deep space, Center for Integration of Space Microsystems at JPL (CISM) takes advantage of the lower power rating and inherent radiation resistance of Silicon on Insulator technology (SOI). We are developing a suite of mixed-voltage and mixed-signal building blocks in Honeywell's SOI process that can enable the rapid integration of the next generation avionics systems with lower power rating, higher reliability, longer life, and enhanced radiation tolerance for spacecrafts such as the Europa Orbiter and Europa Lander. The mixed-voltage building blocks are predominantly for design of adaptive power management systems. Their design centers around an LDMOS structure that is being developed by Honeywell, Boeing Corp, and the University of Idaho. The mixed-signal building blocks are designed to meet the low power, extreme radiation requirement of deep space applications. These building blocks are predominantly used to interface analog sensors to the digital CPU of the next generation avionics system on a chip. Additional information is contained in the original extended abstract.

Microfluidic routing of aqueous and organic flows at high pressures: fabrication and characterization of integrated polymer microvalve elements.

PubMed

Kirby, Brian J; Reichmuth, David S; Renzi, Ronald F; Shepodd, Timothy J; Wiedenman, Boyd J

2005-02-01

This paper presents the first systematic engineering study of the impact of chemical formulation and surface functionalization on the performace of free-standing microfluidic polymer elements used for high-pressure fluid control in glass microsystems. System design, chemical wet-etch processes, and laser-induced polymerization techniques are described, and parametric studies illustrate the effects of polymer formulation, glass surface modification, and geometric constraints on system performance parameters. In particular, this study shows that highly crosslinked and fluorinated polymers can overcome deficiencies in previously-reported microvalve architectures, particularly limited solvent compatibility. Substrate surface modification is shown effective in reducing the friction of the polymer-glass interface and thereby facilitating valve actuation. A microchip one-way valve constructed using this architecture shows a 2 x 10(8) ratio of forward and backward flow rates at 7 MPa. This valve architecture is integrated on chip with minimal dead volumes (70 pl), and should be applicable to systems (including chromatography and chemical synthesis devices) requiring high pressures and solvents of varying polarity.

Professional equipoise: Getting beyond dominant discourses in an interprofessional team.

PubMed

Smith, C Scott; Gerrish, Winslow G; Nash, Melanie; Fisher, Amber; Brotman, Adam; Smith, Deborah; Student, Ami; Green, Melissa; Donovan, Jodie; Dreffin, Melissa

2015-01-01

In 2011, the US Department of Veterans Affairs established five Centers of Excellence to study training in the patient-centered medical home clinical microsystem. Early on, our center began a discourse analysis in order to better understand each profession's assumptions about roles, responsibilities, and the basis for "truth" in clinical care. We discovered that these different discourses were pervasive and led to unhelpful stereotypes of each other. This article describes the evidence we identified that led us to hypothesize these conflicting discourses and stereotypes. Specifically, we report on our attempts to identify the traditional discourses of four post-graduate professions--medicine, nurse practitioner, psychology, and pharmacy. We also share lessons from our efforts to defuse participants from their identified discursive assumptions, and develop appreciation and value for the discursive contributions of other professions--a process we call professional equipoise. We conclude that we can change these discourses and the professional identity formation of novices if we provide sustained, integrated interprofessional education curriculum. This implies that we need: embedded, longitudinal training; faculty role modeling of inquisitiveness, respectful relationships, and risk taking; and safe and honest discussion about our differences.

Development and analysis of new type microresonator with electro-optic feedback

NASA Astrophysics Data System (ADS)

Janusas, Giedrius; Palevicius, Arvydas; Cekas, Elingas; Brunius, Alfredas; Bauce, Jokubas

2016-04-01

Micro-resonators are fundamental components integrated in a hosts of MEMS applications: safety and stability systems, biometric sensors, switches, mechanical filters, micro-mirror devices, material characterization, gyroscopes, etc. A constituent part of the micro-resonator is a diffractive optical element (DOE). Different methods and materials are used to produce diffraction gratings for DOEs. Two-dimensional or three-dimensional periodic structures of micrometer-scale period are widely used in microsystems or their components. They can be used as elements for micro-scale synthesis, processing, and analysis of chemical and biological samples. On the other hand micro-resonator was designed using composite piezoelectric material. In case when microscopes, vibrometers or other direct measurement methods are destructive and hardly can be employed for in-situ analysis, indirect measurement of electrical signal generated by composite piezoelectric layer allows to measure natural frequency changes. Also piezoelectric layer allows to create a novel micro-resonator with controllable parameters, which could assure much higher functionality of micro-electromechanical systems. The novel micro-resonator for pollution detection is proposed. Mathematical model of the micro-resonator and its dynamical, electrical and optical characteristics are presented.

Carbon material based microelectromechanical system (MEMS): Fabrication and devices

NASA Astrophysics Data System (ADS)

Xu, Wenjun

This PhD dissertation presents the exploration and development of two carbon materials, carbon nanotubes (CNTs) and carbon fiber (CF), as either key functional components or unconventional substrates for a variety of MEMS applications. Their performance in three different types of MEMS devices, namely, strain/stress sensors, vibration-powered generators and fiber solar cells, were evaluated and the working mechanisms of these two non-traditional materials in these systems were discussed. The work may potentially enable the development of new types of carbon-MEMS devices. Carbon nanotubes were selected from the carbon family due to several advantageous characteristics that this nanomaterial offers. They carry extremely high mechanical strength (Ey=1TPa), superior electrical properties (current density of 4x109 A/cm2), exceptional piezoresistivity (G=2900), and unique spatial format (high aspect ratio hollow nanocylinder), among other properties. If properly utilized, all these merits can give rise to a variety of new types of carbon nanotube based micro- and nanoelectronics that can greatly fulfill the need for the next generation of faster, smaller and better devices. However, before these functions can be fully realized, one substantial issue to cope with is how to implement CNTs into these systems in an effective and controllable fashion. Challenges associated with CNTs integration include very poor dispersibility in solvents, lack of melting/sublimation point, and unfavorable rheology with regard to mixing and processing highly viscous, CNT-loaded polymer solutions. These issues hinder the practical progress of CNTs both in a lab scale and in the industrial level. To this end, a MEMS-assisted electrophoretic deposition technique was developed, aiming to achieve controlled integration of CNT into both conventional and flexible microsystems at room temperature with a relatively high throughput. MEMS technology has demonstrated strong capability in developing silicon and metal based microsystems. In this thesis, this mature technique was exploited to generate a variety of microelectrode structures to facilitate the micropatterning and manipulation of the CNTs. Selective deposition of electrically charged CNTs onto desired locations was realized in an EPD process through patterning of electric field lines created by the microelectrodes fabricated through MEMS techniques. A variety of 2-D and 3-D micropatterns of CNTs with waferscale areas have been successfully achieved in both rigid and elastic systems. The thickness and morphology of the generated CNT patterns was found to be readily controllable through the parameters of the fabrication process. Studies also showed that for this technique, high surface hydrophobicity of the non-conductive regions in microstructures was critical to accomplish well-defined selective micropatterning of CNTs. Upon clearing the hurdles of the CNT manipulation, a patterned PDMS/CNT nanocomposite was fabricated through the aforementioned approach and was incorporated, investigated and validated in elastic force/strain microsensors. The gauge factor of the sensor exhibited a strong dependence on both the initial resistance of the device and the applied strain. Detailed analysis of the data suggests that the piezoresistive effect of this specially constructed bi-layer composite could be due to three mechanisms, and the sensing mechanism may vary when physical properties of the CNT network embedded in the polymer matrix alter. The feasibility of the PDSM/CNT composite being utilized as an elastic electret was further explored. The nanocomposite composed of these two non-traditional electret materials exhibited electret characteristics with reasonable charge storage stability when charged using a corona discharge. The power generation capacity of the corona-charged composite has been characterized and successfully demonstrated in both a ball drop experiment and cyclic mechanical load experiments. Lastly, in an effort to develop carbon-material-based substrates for MEMS applications, a carbon fiber-based poly-Si solar cell was designed, fabricated and investigated. This fiber-type photovoltaics (PV) takes advantage of the excellent thermal stability, electrical conductivity and spatial format of the CF, which allows CF to serve as both the building block and the electrode in the PV configuration. The photovoltaic effects of the fiber PV were demonstrated with an open-circuit voltage of 0.14 V, a short-circuit current density of 1.7 mA/cm2, and output power density of 0.059mW/cm2 . The issues of this system were discussed as well.

NQS - NETWORK QUEUING SYSTEM, VERSION 2.0 (UNIX VERSION)

NASA Technical Reports Server (NTRS)

Walter, H.

1994-01-01

The Network Queuing System, NQS, is a versatile batch and device queuing facility for a single Unix computer or a group of networked computers. With the Unix operating system as a common interface, the user can invoke the NQS collection of user-space programs to move batch and device jobs freely around the different computer hardware tied into the network. NQS provides facilities for remote queuing, request routing, remote status, queue status controls, batch request resource quota limits, and remote output return. This program was developed as part of an effort aimed at tying together diverse UNIX based machines into NASA's Numerical Aerodynamic Simulator Processing System Network. This revision of NQS allows for creating, deleting, adding and setting of complexes that aid in limiting the number of requests to be handled at one time. It also has improved device-oriented queues along with some revision of the displays. NQS was designed to meet the following goals: 1) Provide for the full support of both batch and device requests. 2) Support all of the resource quotas enforceable by the underlying UNIX kernel implementation that are relevant to any particular batch request and its corresponding batch queue. 3) Support remote queuing and routing of batch and device requests throughout the NQS network. 4) Support queue access restrictions through user and group access lists for all queues. 5) Enable networked output return of both output and error files to possibly remote machines. 6) Allow mapping of accounts across machine boundaries. 7) Provide friendly configuration and modification mechanisms for each installation. 8) Support status operations across the network, without requiring a user to log in on remote target machines. 9) Provide for file staging or copying of files for movement to the actual execution machine. To support batch and device requests, NQS v.2 implements three queue types--batch, device and pipe. Batch queues hold and prioritize batch requests; device queues hold and prioritize device requests; pipe queues transport both batch and device requests to other batch, device, or pipe queues at local or remote machines. Unique to batch queues are resource quota limits that restrict the amounts of different resources that a batch request can consume during execution. Unique to each device queue is a set of one or more devices, such as a line printer, to which requests can be sent for execution. Pipe queues have associated destinations to which they route and deliver requests. If the proper destination machine is down or unreachable, pipe queues are able to requeue the request and deliver it later when the destination is available. All NQS network conversations are performed using the Berkeley socket mechanism as ported into the respective vendor kernels. NQS is written in C language. The generic UNIX version (ARC-13179) has been successfully implemented on a variety of UNIX platforms, including Sun3 and Sun4 series computers, SGI IRIS computers running IRIX 3.3, DEC computers running ULTRIX 4.1, AMDAHL computers running UTS 1.3 and 2.1, platforms running BSD 4.3 UNIX. The IBM RS/6000 AIX version (COS-10042) is a vendor port. NQS 2.0 will also communicate with the Cray Research, Inc. and Convex, Inc. versions of NQS. The standard distribution medium for either machine version of NQS 2.0 is a 60Mb, QIC-24, .25 inch streaming magnetic tape cartridge in UNIX tar format. Upon request the generic UNIX version (ARC-13179) can be provided in UNIX tar format on alternate media. Please contact COSMIC to discuss the availability and cost of media to meet your specific needs. An electronic copy of the NQS 2.0 documentation is included on the program media. NQS 2.0 was released in 1991. The IBM RS/6000 port of NQS was developed in 1992. IRIX is a trademark of Silicon Graphics Inc. IRIS is a registered trademark of Silicon Graphics Inc. UNIX is a registered trademark of UNIX System Laboratories Inc. Sun3 and Sun4 are trademarks of Sun Microsystems Inc. DEC and ULTRIX are trademarks of Digital Equipment Corporation.

Mechanisms of microregulation of private hospitals by health plan operators.

PubMed

Ugá, Maria Alicia Domínguez; Vasconcellos, Miguel Murat; Lima, Sheyla Maria Lemos; Portela, Margareth Crisóstomo; Gerschman, Silvia

2009-10-01

To analyze the mechanisms employed by health plan operators for microregulation of clinical management and health care qualification within care-providing hospitals. A nation-wide cross-sectional study was carried out. The universe consisted of hospitals which provided care to health plan operators in 2006. A sample of 83 units was selected, stratified by Brazilian macroregion and type of hospital. Data were obtained by means of a questionnaire administered to hospital managers. Microregulation of hospitals by health plan operators was minimal or almost absent in terms of health care qualification. Operator activity focused predominantly on intense control of the amount of services used by patients. Hospitals providing services to health plan operators did not constitute health micro-systems parallel or supplementary to the Sistema Unico de Saúde (SUS - Brazilian National Health System). The private care-providing hospitals were predominantly associated with SUS. However, these did not belong to a private care-provider network, even though their service usage was subject to strong regulation by health plan operators. Operator intervention in the form of system management was incipient or virtually absent. Roughly one-half of investigated hospitals reported adopting clinical directives, whereas only 25.4% reported managing pathology and 30.5% reported managing cases. Contractual relationships between hospitals and health plan operators are merely commercial contracts with little if any incorporation of aspects related to the quality of care, being generally limited to aspects such as establishment of prices, timeframes, and payment procedures.

Process-in-Network: A Comprehensive Network Processing Approach

PubMed Central

Urzaiz, Gabriel; Villa, David; Villanueva, Felix; Lopez, Juan Carlos

2012-01-01

A solid and versatile communications platform is very important in modern Ambient Intelligence (AmI) applications, which usually require the transmission of large amounts of multimedia information over a highly heterogeneous network. This article focuses on the concept of Process-in-Network (PIN), which is defined as the possibility that the network processes information as it is being transmitted, and introduces a more comprehensive approach than current network processing technologies. PIN can take advantage of waiting times in queues of routers, idle processing capacity in intermediate nodes, and the information that passes through the network. PMID:22969390

77 FR 7214 - Notice of Availability: Programmatic Environmental Assessment for Mail Processing Network...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-10

... Network Rationalization Initiative (Formerly Known as the ``Network Optimization'' Initiative), Nationwide... Processing Network Rationalization Initiative (the ``Proposed Action''), which is national in scope. This PEA... Network Rationalization Initiative to create a more streamlined processing and distribution network using...

671-nm microsystem diode laser based on portable Raman sensor device for in-situ identification of meat spoilage

NASA Astrophysics Data System (ADS)

Sowoidnich, Kay; Schmidt, Heinar; Schwägele, Fredi; Kronfeldt, Heinz-Detlef

2011-05-01

Based on a miniaturized optical bench with attached 671 nm microsystem diode laser we present a portable Raman system for the rapid in-situ characterization of meat spoilage. It consists of a handheld sensor head (dimensions: 210 x 240 x 60 mm3) for Raman signal excitation and collection including the Raman optical bench, a laser driver, and a battery pack. The backscattered Raman radiation from the sample is analyzed by means of a custom-designed miniature spectrometer (dimensions: 200 x 190 x 70 mm3) with a resolution of 8 cm-1 which is fiber-optically coupled to the sensor head. A netbook is used to control the detector and for data recording. Selected cuts from pork (musculus longissimus dorsi and ham) stored refrigerated at 5 °C were investigated in timedependent measurement series up to three weeks to assess the suitability of the system for the rapid detection of meat spoilage. Using a laser power of 100 mW at the sample meat spectra can be obtained with typical integration times of 5 - 10 seconds. The complex spectra were analyzed by the multivariate statistical tool PCA (principal components analysis) to determine the spectral changes occurring during the storage period. Additionally, the Raman data were correlated with reference analyses performed in parallel. In that way, a distinction between fresh and spoiled meat can be found in the time slot of 7 - 8 days after slaughter. The applicability of the system for the rapid spoilage detection of meat and other food products will be discussed.

In vivo RF powering for advanced biological research.

PubMed

Zimmerman, Mark D; Chaimanonart, Nattapon; Young, Darrin J

2006-01-01

An optimized remote powering architecture with a miniature and implantable RF power converter for an untethered small laboratory animal inside a cage is proposed. The proposed implantable device exhibits dimensions less than 6 mmx6 mmx1 mm, and a mass of 100 mg including a medical-grade silicon coating. The external system consists of a Class-E power amplifier driving a tuned 15 cmx25 cm external coil placed underneath the cage. The implant device is located in the animal's abdomen in a plane parallel to the external coil and utilizes inductive coupling to receive power from the external system. A half-wave rectifier rectifies the received AC voltage and passes the resulting DC current to a 2.5 kOmega resistor, which represents the loading of an implantable microsystem. An optimal operating point with respect to operating frequency and number of turns in each coil inductor was determined by analyzing the system efficiency. The determined optimal operating condition is based on a 4-turn external coil and a 20-turn internal coil operating at 4 MHz. With the Class-E amplifier consuming a constant power of 25 W, this operating condition is sufficient to supply a desired 3.2 V with 1.3 mA to the load over a cage size of 10 cmx20 cm with an animal tilting angle of up to 60 degrees, which is the worst case considered for the prototype design. A voltage regulator can be designed to regulate the received DC power to a stable supply for the bio-implant microsystem.

Beyond CMOS: heterogeneous integration of III–V devices, RF MEMS and other dissimilar materials/devices with Si CMOS to create intelligent microsystems

PubMed Central

Kazior, Thomas E.

2014-01-01

Advances in silicon technology continue to revolutionize micro-/nano-electronics. However, Si cannot do everything, and devices/components based on other materials systems are required. What is the best way to integrate these dissimilar materials and to enhance the capabilities of Si, thereby continuing the micro-/nano-electronics revolution? In this paper, I review different approaches to heterogeneously integrate dissimilar materials with Si complementary metal oxide semiconductor (CMOS) technology. In particular, I summarize results on the successful integration of III–V electronic devices (InP heterojunction bipolar transistors (HBTs) and GaN high-electron-mobility transistors (HEMTs)) with Si CMOS on a common silicon-based wafer using an integration/fabrication process similar to a SiGe BiCMOS process (BiCMOS integrates bipolar junction and CMOS transistors). Our III–V BiCMOS process has been scaled to 200 mm diameter wafers for integration with scaled CMOS and used to fabricate radio-frequency (RF) and mixed signals circuits with on-chip digital control/calibration. I also show that RF microelectromechanical systems (MEMS) can be integrated onto this platform to create tunable or reconfigurable circuits. Thus, heterogeneous integration of III–V devices, MEMS and other dissimilar materials with Si CMOS enables a new class of high-performance integrated circuits that enhance the capabilities of existing systems, enable new circuit architectures and facilitate the continued proliferation of low-cost micro-/nano-electronics for a wide range of applications. PMID:24567473

Structured light optical microscopy for three-dimensional reconstruction of technical surfaces

NASA Astrophysics Data System (ADS)

Kettel, Johannes; Reinecke, Holger; Müller, Claas

2016-04-01

In microsystems technology quality control of micro structured surfaces with different surface properties is playing an ever more important role. The process of quality control incorporates three-dimensional (3D) reconstruction of specularand diffusive reflecting technical surfaces. Due to the demand on high measurement accuracy and data acquisition rates, structured light optical microscopy has become a valuable solution to solve this problem providing high vertical and lateral resolution. However, 3D reconstruction of specular reflecting technical surfaces still remains a challenge to optical measurement principles. In this paper we present a measurement principle based on structured light optical microscopy which enables 3D reconstruction of specular- and diffusive reflecting technical surfaces. It is realized using two light paths of a stereo microscope equipped with different magnification levels. The right optical path of the stereo microscope is used to project structured light onto the object surface. The left optical path is used to capture the structured illuminated object surface with a camera. Structured light patterns are generated by a Digital Light Processing (DLP) device in combination with a high power Light Emitting Diode (LED). Structured light patterns are realized as a matrix of discrete light spots to illuminate defined areas on the object surface. The introduced measurement principle is based on multiple and parallel processed point measurements. Analysis of the measured Point Spread Function (PSF) by pattern recognition and model fitting algorithms enables the precise calculation of 3D coordinates. Using exemplary technical surfaces we demonstrate the successful application of our measurement principle.

Beyond CMOS: heterogeneous integration of III-V devices, RF MEMS and other dissimilar materials/devices with Si CMOS to create intelligent microsystems.

PubMed

Kazior, Thomas E

2014-03-28

Advances in silicon technology continue to revolutionize micro-/nano-electronics. However, Si cannot do everything, and devices/components based on other materials systems are required. What is the best way to integrate these dissimilar materials and to enhance the capabilities of Si, thereby continuing the micro-/nano-electronics revolution? In this paper, I review different approaches to heterogeneously integrate dissimilar materials with Si complementary metal oxide semiconductor (CMOS) technology. In particular, I summarize results on the successful integration of III-V electronic devices (InP heterojunction bipolar transistors (HBTs) and GaN high-electron-mobility transistors (HEMTs)) with Si CMOS on a common silicon-based wafer using an integration/fabrication process similar to a SiGe BiCMOS process (BiCMOS integrates bipolar junction and CMOS transistors). Our III-V BiCMOS process has been scaled to 200 mm diameter wafers for integration with scaled CMOS and used to fabricate radio-frequency (RF) and mixed signals circuits with on-chip digital control/calibration. I also show that RF microelectromechanical systems (MEMS) can be integrated onto this platform to create tunable or reconfigurable circuits. Thus, heterogeneous integration of III-V devices, MEMS and other dissimilar materials with Si CMOS enables a new class of high-performance integrated circuits that enhance the capabilities of existing systems, enable new circuit architectures and facilitate the continued proliferation of low-cost micro-/nano-electronics for a wide range of applications.

An Expanded Conceptual Framework of Medical Students' Primary Care Career Choice.

PubMed

Pfarrwaller, Eva; Audétat, Marie-Claude; Sommer, Johanna; Maisonneuve, Hubert; Bischoff, Thomas; Nendaz, Mathieu; Baroffio, Anne; Junod Perron, Noëlle; Haller, Dagmar M

2017-11-01

In many countries, the number of graduating medical students pursuing a primary care career does not meet demand. These countries face primary care physician shortages. Students' career choices have been widely studied, yet many aspects of this process remain unclear. Conceptual models are useful to plan research and educational interventions in such complex systems.The authors developed a framework of primary care career choice in undergraduate medical education, which expands on previously published models. They used a group-based, iterative approach to find the best way to represent the vast array of influences identified in previous studies, including in a recent systematic review of the literature on interventions to increase the proportion of students choosing a primary care career. In their framework, students enter medical school with their personal characteristics and initial interest in primary care. They complete a process of career decision making, which is subject to multiple interacting influences, both within and outside medical school, throughout their medical education. These influences are stratified into four systems-microsystem, mesosystem, exosystem, and macrosystem-which represent different levels of interaction with students' career choices.This expanded framework provides an updated model to help understand the multiple factors that influence medical students' career choices. It offers a guide for the development of new interventions to increase the proportion of students choosing primary care careers and for further research to better understand the variety of processes involved in this decision.

Laser microjoining of dissimilar and biocompatible materials

NASA Astrophysics Data System (ADS)

Bauer, Ingo; Russek, Ulrich A.; Herfurth, Hans J.; Witte, Reiner; Heinemann, Stefan; Newaz, Golam; Mian, A.; Georgiev, D.; Auner, Gregory W.

2004-07-01

Micro-joining and hermetic sealing of dissimilar and biocompatible materials is a critical issue for a broad spectrum of products such as micro-electronics, micro-optical and biomedical products and devices. Today, biocompatible titanium is widely applied as a material for orthopedic implants as well as for the encapsulation of implantable devices such as pacemakers, defibrillators, and neural stimulator devices. Laser joining is the process of choice to hermetically seal such devices. Laser joining is a contact-free process, therefore minimizing mechanical load on the parts to be joined and the controlled heat input decreases the potential for thermal damage to the highly sensitive components. Laser joining also offers flexibility, shorter processing time and higher quality. However, novel biomedical products, in particular implantable microsystems currently under development, pose new challenges to the assembly and packaging process based on the higher level of integration, the small size of the device's features, and the type of materials and material combinations. In addition to metals, devices will also include glass, ceramic and polymers as biocompatible building materials that must be reliably joined in similar and dissimilar combinations. Since adhesives often lack long-term stability or do not meet biocompatibility requirements, new joining techniques are needed to address these joining challenges. Localized laser joining provides promising developments in this area. This paper describes the latest achievements in micro-joining of metallic and non-metallic materials with laser radiation. The focus is on material combinations of metal-polymer, polymer-glass, metal-glass and metal-ceramic using CO2, Nd:YAG and diode laser radiation. The potential for applications in the biomedical sector will be demonstrated.

Performing a local reduction operation on a parallel computer

DOEpatents

Blocksome, Michael A; Faraj, Daniel A

2013-06-04

A parallel computer including compute nodes, each including two reduction processing cores, a network write processing core, and a network read processing core, each processing core assigned an input buffer. Copying, in interleaved chunks by the reduction processing cores, contents of the reduction processing cores' input buffers to an interleaved buffer in shared memory; copying, by one of the reduction processing cores, contents of the network write processing core's input buffer to shared memory; copying, by another of the reduction processing cores, contents of the network read processing core's input buffer to shared memory; and locally reducing in parallel by the reduction processing cores: the contents of the reduction processing core's input buffer; every other interleaved chunk of the interleaved buffer; the copied contents of the network write processing core's input buffer; and the copied contents of the network read processing core's input buffer.

Performing a local reduction operation on a parallel computer

DOEpatents

Blocksome, Michael A.; Faraj, Daniel A.

2012-12-11

A parallel computer including compute nodes, each including two reduction processing cores, a network write processing core, and a network read processing core, each processing core assigned an input buffer. Copying, in interleaved chunks by the reduction processing cores, contents of the reduction processing cores' input buffers to an interleaved buffer in shared memory; copying, by one of the reduction processing cores, contents of the network write processing core's input buffer to shared memory; copying, by another of the reduction processing cores, contents of the network read processing core's input buffer to shared memory; and locally reducing in parallel by the reduction processing cores: the contents of the reduction processing core's input buffer; every other interleaved chunk of the interleaved buffer; the copied contents of the network write processing core's input buffer; and the copied contents of the network read processing core's input buffer.

Design, fabrication and characterisation of a microfluidic time-temperature indicator

NASA Astrophysics Data System (ADS)

Schmitt, P.; Wedrich, K.; Müller, L.; Mehner, H.; Hoffmann, M.

2017-11-01

This paper describes a concept for a passive microfluidic time-temperature indicator (TTI) intended for intelligent food packaging. A microfluidic system is presented that makes use of the temperature-dependent flow of suitable food ingredients in a microcapillary. Based on the creeping distance inside the capillary, the time-temperature integral can be determined. A demonstrator of the microsystem has been designed, fabricated and characterised using liquid sugar alcohols as indicator fluids. To enable a first wireless read-out of the passive TTI, the sensor was read out using a commercial RFID equipment, and capacitive measurements have been carried out.

Coherent Frequency Shifter, Optical Isolator, Lasers on an Integrated Platform for Cold Atom Microsystems

DTIC Science & Technology

2017-10-11

power operation of optical frequency shifter; (7) a new design and theoretical analysis of frequency shifter with larger electro-optical coefficients...integrated laser. 15. SUBJECT TERMS coherent frequency shifter, optical isolation, integrated photonics, 780nm laser design and fabrication 16...coefficient (r33 and r42) ………………………………………………………………… 20 II.3. 780 nm Laser design , fabrication, and testing based on AlGaAs/GaAs Multiple Quantum Wells

Trapping of a microsphere pendulum resonator in an optical potential

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, J. M.; Photonics Centre, Tyndall National Institute, Prospect Row, Cork; Wu, Y.

We propose a method to spatially confine or corral the movements of a micropendulum via the optical forces produced by two simultaneously excited optical modes of a photonic molecule comprising two microspherical cavities. We discuss how the cavity-enhanced optical force generated in the photonic molecule can create an optomechanical potential of about 10 eV deep and 30 pm wide, which can be used to trap the pendulum at any given equilibrium position by a simple choice of laser frequencies. This result presents opportunities for very precise all-optical self-alignment of microsystems.

Comparative study of electrical characteristics for n-type 4H-SiC planar and trench MOS capacitors annealed in ambient NO

NASA Astrophysics Data System (ADS)

Shen, Zhan-Wei; Zhang, Feng; Dimitrijev, Sima; Han, Ji-Sheng; Yan, Guo-Guo; Wen, Zheng-Xin; Zhao, Wan-Shun; Wang, Lei; Liu, Xing-Fang; Sun, Guo-Sheng; Zeng, Yi-Ping

2017-09-01

Not Available Project supported by the National Basic Research Program of China (Grant No. 2015CB759600), the National Natural Science Foundation of China (Grant Nos. 61474113 and 61574140), the Beijing NOVA Program, China (Grant No. Z1611000049161132016071), China Academy of Engineering Physics (CAEP) Microsystem and THz Science and Technology Foundation, China (Grant No. CAEPMT201502), the Beijing Municipal Science and Technology Commission Project, China (Grant Nos. Z161100002116018 and D16110300430000), and the Youth Innovation Promotion Association of Chinese Academy of Sciences (Grant No. 2012098)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clancey, P.; Logg, C.

DEPOT has been developed to provide tracking for the Stanford Linear Collider (SLC) control system equipment. For each piece of equipment entered into the database, complete location, service, maintenance, modification, certification, and radiation exposure histories can be maintained. To facilitate data entry accuracy, efficiency, and consistency, barcoding technology has been used extensively. DEPOT has been an important tool in improving the reliability of the microsystems controlling SLC. This document describes the components of the DEPOT database, the elements in the database records, and the use of the supporting programs for entering data, searching the database, and producing reports from themore » information.« less

Detection of Brownian Torque in a Magnetically-Driven Rotating Microsystem

PubMed Central

Romodina, Maria N.; Lyubin, Evgeny V.; Fedyanin, Andrey A.

2016-01-01

Thermal fluctuations significantly affect the behavior of microscale systems rotating in shear flow, such as microvortexes, microbubbles, rotating micromotors, microactuators and other elements of lab-on-a-chip devices. The influence of Brownian torque on the motion of individual magnetic microparticles in a rotating magnetic field is experimentally determined using optical tweezers. Rotational Brownian motion induces the flattening of the breakdown transition between the synchronous and asynchronous modes of microparticle rotation. The experimental findings regarding microparticle rotation in the presence of Brownian torque are compared with the results of numerical Brownian dynamics simulations. PMID:26876334

Micro optical sensor systems for sunsensing applications

NASA Astrophysics Data System (ADS)

Leijtens, Johan; de Boom, Kees

2017-11-01

Optimum application of micro system technologies allows building small sensor systems that will alter procurement strategies for spacecraft manufacturers. One example is the decreased size and cost for state of the art sunsensors. Integrated sensor systems are being designed which, through use of microsystem technology, are an order of magnitutde smaller than most current sunsensors and which hold due to the large reproducibility through batch manufacturing the promise of drastic price reduction. If the Commercial Of The Shelf (COTS) approach is adopted by satellite manufacturers, this will drastically decrease mass and cost budgets associated with sunsensing applications.

MST development for medical applications: results of the German Research Programme on MST over ten years.

PubMed

Weiss, Christine

2007-01-01

Today microsystems are important for the prevention, diagnosis and therapy of diseases. Physicians use small endoscopes for minimally invasive surgery. Patients regain their mobility by high-tech prostheses equipped with several sensors and actuators. Intelligent implants such as pacemakers support existential functions. Cochlea-implants enable deaf persons to hear. Safe convalescence at home is possible by tele-monitoring devices. Point-of-care such as biochips supply quick diagnostic results. A number of these remarkable developments have been successfully supported by the German Federal Ministry of Education and Research (BMBF) since 1990.

Modeling Endoplasmic Reticulum Network Maintenance in a Plant Cell.

PubMed

Lin, Congping; White, Rhiannon R; Sparkes, Imogen; Ashwin, Peter

2017-07-11

The endoplasmic reticulum (ER) in plant cells forms a highly dynamic network of complex geometry. ER network morphology and dynamics are influenced by a number of biophysical processes, including filament/tubule tension, viscous forces, Brownian diffusion, and interactions with many other organelles and cytoskeletal elements. Previous studies have indicated that ER networks can be thought of as constrained minimal-length networks acted on by a variety of forces that perturb and/or remodel the network. Here, we study two specific biophysical processes involved in remodeling. One is the dynamic relaxation process involving a combination of tubule tension and viscous forces. The other is the rapid creation of cross-connection tubules by direct or indirect interactions with cytoskeletal elements. These processes are able to remodel the ER network: the first reduces network length and complexity whereas the second increases both. Using live cell imaging of ER network dynamics in tobacco leaf epidermal cells, we examine these processes on ER network dynamics. Away from regions of cytoplasmic streaming, we suggest that the dynamic network structure is a balance between the two processes, and we build an integrative model of the two processes for network remodeling. This model produces quantitatively similar ER networks to those observed in experiments. We use the model to explore the effect of parameter variation on statistical properties of the ER network. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Ku-band signal design study. [space shuttle orbiter data processing network

NASA Technical Reports Server (NTRS)

Rubin, I.

1978-01-01

Analytical tools, methods and techniques for assessing the design and performance of the space shuttle orbiter data processing system (DPS) are provided. The computer data processing network is evaluated in the key areas of queueing behavior synchronization and network reliability. The structure of the data processing network is described as well as the system operation principles and the network configuration. The characteristics of the computer systems are indicated. System reliability measures are defined and studied. System and network invulnerability measures are computed. Communication path and network failure analysis techniques are included.

Towards fast, reliable, and manufacturable DEAs: miniaturized motor and Rupert the rolling robot

NASA Astrophysics Data System (ADS)

Rosset, Samuel; Shea, Herbert

2015-04-01

Dielectric elastomer transducers (DETs) are known for their large strains, low mass and high compliance, making them very attractive for a broad range of applications, from soft robotics to tuneable optics, or energy harvesting. However, 15 years after the first major paper in the field, commercial applications of the technology are still scarce, owing to high driving voltages, short lifetimes, slow response speed, viscoelastic drift, and no optimal solution for the compliant electrodes. At the EPFL's Microsystems for Space Technologies laboratory, we have been working on the miniaturization and manufacturability of DETs for the past 10 years. In the frame of this talk, we present our fabrication processes for high quality thin-_lm silicone membranes, and for patterning compliant electrodes on the sub mm-scale. We use either implantation of gold nano-clusters through a mask, or pad-printing of conductive rubber to precisely shape the electrodes on the dielectric membrane. Our electrodes are compliant, time stable and present strong adhesion to the membrane. The combination of low mechanical- loss elastomers with robust and precisely-defined electrodes allows for the fabrication of very fast actuators that exhibit a long lifetime. We present different applications of our DET fabrication process, such as a soft tuneable lens with a settling time smaller than 175 microseconds, a motor spinning at 1500 rpm, and a self-commutating rolling robot.

The process of implementing a rural VA wound care program for diabetic foot ulcer patients.

PubMed

Reiber, Gayle E; Raugi, Gregory J; Rowberg, Donald

2007-10-01

Delivering and documenting evidence-based treatment to all Department of Veterans Affairs (VA) foot ulcer patients has wide appeal. However, primary and secondary care medical centers where 52% of these patients receive care are at a disadvantage given the frequent absence of trained specialists to manage diabetic foot ulcers. A retrospective review of diabetic foot ulcer patient records and a provider survey were conducted to document the foot ulcer problem and to assess practitioner needs. Results showed of the 125 persons with foot ulcers identified through administrative data, only, 21% of diabetic foot patients were correctly coded. Chronic Care and Microsystem models were used to prepare a tailored intervention in a VA primary care medical center. The site Principal Investigators, a multidisciplinary site wound care team, and study investigators jointly implemented a diabetic foot ulcer program. Intervention components include wound care team education and training, standardized good wound care practices based on strong scientific evidence, and a wound care template embedded in the electronic medical record to facilitate data collection, clinical decision making, patient ordering, and coding. A strategy for delivering offloading pressure devices, regular case management support, and 24/7 emergency assistance also was developed. It took 9 months to implement the model. Patients were enrolled and followed for 1 year. Process and outcome evaluations are on-going.

Manufacturing concepts and development trends in the industrial production of microelectromechanical systems

NASA Astrophysics Data System (ADS)

Schuenemann, Matthias; Grimme, Ralf; Kaufmann, Thomas; Schwaab, Gerhard; Baeder, Uwe; Schaefer, Wolfgang; Dorner, Johann

1998-01-01

During the past few years, remarkable affords have been made for the realization of microscale sensors, actuators and microelectromechanical system. Due to advances in solid state and micromachining technologies, significant advances in designing, fabricating and testing of microminiaturized devices have been achieved at laboratory level. However, the technical and economical realization of microelectromechanical systems is considerably impeded by the lack of satisfying device technology for their industrial production. A production concept for the industrial production of hybrid microelectromechanical systems was developed and investigated. The concept is based on the resources and requirements of medium-sized enterprises and is characterized by its flexibility. Microsystem fabrication is separated into microfabrication steps performed in-house and technological steps performed by external technology providers. The modularity of the concept allows for a gradual increase in the degree of automation and the in-house production depth, depending on market capacity and financial resources. To demonstrate the feasibility of this approach, the design and realization of a microfabrication process center, which includes tasks like transport and handling, processing, cleaning, testing and storing are discussed. Special attention is given to the supply and feeding of microparts, to the necessary magazines, trays and transport systems, to the implementation of homogeneous mechanical, environmental and information interfaces, to the employment of advanced control, scheduling, and lot tracking concepts, and to the application of highly modular and cost-efficient clean production concepts.

Micro-patterning and characterization of PHEMA-co-PAM-based optical chemical sensors for lab-on-a-chip applications

PubMed Central

Zhu, Haixin; Zhou, Xianfeng; Su, Fengyu; Tian, Yanqing; Ashili, Shashanka; Holl, Mark R.; Meldrum, Deirdre R.

2012-01-01

We report a novel method for wafer level, high throughput optical chemical sensor patterning, with precise control of the sensor volume and capability of producing arbitrary microscale patterns. Monomeric oxygen (O2) and pH optical probes were polymerized with 2-hydroxyethyl methacrylate (HEMA) and acrylamide (AM) to form spin-coatable and further crosslinkable polymers. A micro-patterning method based on micro-fabrication techniques (photolithography, wet chemical process and reactive ion etch) was developed to miniaturize the sensor film onto glass substrates in arbitrary sizes and shapes. The sensitivity of fabricated micro-patterns was characterized under various oxygen concentrations and pH values. The process for spatially integration of two sensors (Oxygen and pH) on the same substrate surface was also developed, and preliminary fabrication and characterization results were presented. To the best of our knowledge, it is the first time that poly (2-hydroxylethyl methacrylate)-co-poly (acrylamide) (PHEMA-co-PAM)-based sensors had been patterned and integrated at the wafer level with micron scale precision control using microfabrication techniques. The developed methods can provide a feasible way to miniaturize and integrate the optical chemical sensor system and can be applied to any lab-on-a-chip system, especially the biological micro-systems requiring optical sensing of single or multiple analytes. PMID:23175599