318 research outputs found

    The NASA SBIR product catalog

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    The purpose of this catalog is to assist small business firms in making the community aware of products emerging from their efforts in the Small Business Innovation Research (SBIR) program. It contains descriptions of some products that have advanced into Phase 3 and others that are identified as prospective products. Both lists of products in this catalog are based on information supplied by NASA SBIR contractors in responding to an invitation to be represented in this document. Generally, all products suggested by the small firms were included in order to meet the goals of information exchange for SBIR results. Of the 444 SBIR contractors NASA queried, 137 provided information on 219 products. The catalog presents the product information in the technology areas listed in the table of contents. Within each area, the products are listed in alphabetical order by product name and are given identifying numbers. Also included is an alphabetical listing of the companies that have products described. This listing cross-references the product list and provides information on the business activity of each firm. In addition, there are three indexes: one a list of firms by states, one that lists the products according to NASA Centers that managed the SBIR projects, and one that lists the products by the relevant Technical Topics utilized in NASA's annual program solicitation under which each SBIR project was selected

    Design and fabrication of novel microfluidic systems for microsphere generation

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    In this thesis, a study of the rational design and fabrication of microfluidic systems for microsphere generation is presented. The required function of microfluidic systems is to produce microspheres with the following attributes: (i) the microsphere size being around one micron or less, (ii) the size uniformity (in particular coefficient of variation (CV)) being less than 5%, and (iii) the size range being adjustable as widely as possible. Micro-electro-mechanical system (MEMS) technology, largely referring to various micro-fabrication techniques in the context of this thesis, has been applied for decades to develop microfluidic systems that can fulfill the foregoing required function of microsphere generation; however, this goal has yet to be achieved. To change this situation was a motivation of the study presented in this thesis. The philosophy behind this study stands on combining an effective design theory and methodology called Axiomatic Design Theory (ADT) with advanced micro-fabrication techniques for the microfluidic systems development. Both theoretical developments and experimental validations were carried out in this study. Consequently, the study has led to the following conclusions: (i) Existing micro-fluidic systems are coupled designs according to ADT, which is responsible for a limited achievement of the required function; (ii) Existing micro-fabrication techniques, especially for pattern transfer, have difficulty in producing a typical feature of micro-fluidic systems - that is, a large overall size (~ mm) of the device but a small channel size (~nm); and (iii) Contemporary micro-fabrication techniques to the silicon-based microfluidic system may have reached a size limit for microspheres, i.e., ~1 micron. Through this study, the following contributions to the field of the microfluidic system technology have been made: (i) Producing three rational designs of microfluidic systems, device 1 (perforated silicon membrane), device 2 (integration of hydrodynamic flow focusing and crossflow principles), and device 3 (liquid chopper using a piezoelectric actuator), with each having a distinct advantage over the others and together having achieved the requirements, size uniformity (CV ≤ 5%) and size controllability (1-186 µm); (ii) Proposing a new pattern transfer technique which combines a photolithography process with a direct writing lithography process (e.g., focused ion beam process); (iii) Proposing a decoupled design principle for micro-fluidic systems, which is effective in improving microfluidic systems for microsphere generation and is likely applicable to microfluidic systems for other applications; and (iv) Developing the mathematical models for the foregoing three devices, which can be used to further optimize the design and the microsphere generation process

    NASA Tech Briefs, April 1990

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    Topics: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences

    MME2010 21st Micromechanics and Micro systems Europe Workshop : Abstracts

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    Air Force Institute of Technology Research Report 2000

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    This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems and Engineering Management, Operational Sciences, and Engineering Physics

    Fiscal year 1973 scientific and technical reports, articles, papers, and presentations

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    Formal NASA technical reports, papers published in technical journals, and presentations by MSFC personnel in FY73 are presented. Papers of MSFC contractors are also included

    Micro-Resonators: The Quest for Superior Performance

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    Microelectromechanical resonators are no longer solely a subject of research in university and government labs; they have found a variety of applications at industrial scale, where their market is predicted to grow steadily. Nevertheless, many barriers to enhance their performance and further spread their application remain to be overcome. In this Special Issue, we will focus our attention to some of the persistent challenges of micro-/nano-resonators such as nonlinearity, temperature stability, acceleration sensitivity, limits of quality factor, and failure modes that require a more in-depth understanding of the physics of vibration at small scale. The goal is to seek innovative solutions that take advantage of unique material properties and original designs to push the performance of micro-resonators beyond what is conventionally achievable. Contributions from academia discussing less-known characteristics of micro-resonators and from industry depicting the challenges of large-scale implementation of resonators are encouraged with the hopes of further stimulating the growth of this field, which is rich with fascinating physics and challenging problems

    Fiscal year 1977 scientific and technical reports, articles, papers, and presentations

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    This bibliography lists 78 NASA technical memoranda, notes, papers, and reports presented by Marshall Space Flight Center personnel in FY 1977. In addition, 525 papers by contractors to that facility are cited along with 129 papers cleared for presentation

    Simulation and Modeling of Microfluidic Systems

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    In the present dissertation, fluid flow and heat transfer in microfluidic systems is investigated numerically. Fluid flow in most applications of microfluidic systems is in the slip flow regime, which is characterized by the slip flow and the jump temperature at the wall. Flow in microfluidic devices shows significant slip since the characteristic length is in the order of the mean free path of the fluid or gas molecules. The slip velocity and the jump temperature at the wall is the most important feature in the micro- or nano scale that differs from conventional internal flow. The slip flow and heat transfer in microchannels are simulated. Microfluidic systems are separated into straight and curved microchannels. A good understanding of fluid flow in microfluidic systems can be obtained when the results of straight and curved channels are considered together. Effects of rarefaction on forced convection heat transfer of laminar, steady and incompressible slip flow in straight and curved microchannels with uniform heat flux are investigated. The slip velocity and the jump temperature boundary conditions at the wall are employed. Effects of centrifugal force in the curved microchannels on the hydraulic and thermal behaviors of fluid flow are studied. The Navier-Stokes and energy equations are discretized using the Finite Volume technique. The calculated results show good agreement with previous numerical data and analytical solutions. The calculated results show that the entrance length and the curvature effects can be neglected, when the Reynolds number is less than 100. As a result, microfluidic systems are simulated with considering a very long straight microchannel, which can be modeled as totally fully developed region. The fully developed equations are obtained with considering the Navier-Stokes equations at the fully developed conditions. The analytical solution, which is an eigenvalue problem, is presented. The calculated results for two- and three-dimensional straight microchannels are presented. Flow velocity and temperature fields are calculated with very low computational time. Employing nanofluids is one of the best and practical methods for increasing heat transfer in microchannels. Thermal and hydraulic behaviors of nanofluid flow in microchannels with consideration of the slip velocity and the jump temperature conditions are investigated. Forced convection nanofluid flow in microchannels is simulated to study effects of rarefaction and Al2O3 nanoparticles concentration on the slip flow regimes. The Brownian motions of nanoparticles are considered to determine the thermal conductivity of nanofluid
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