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Sample records for manufacture micro light

  1. Design and optimization of a light-emitting diode projection micro-stereolithography three-dimensional manufacturing system.

    PubMed

    Zheng, Xiaoyu; Deotte, Joshua; Alonso, Matthew P; Farquar, George R; Weisgraber, Todd H; Gemberling, Steven; Lee, Howon; Fang, Nicholas; Spadaccini, Christopher M

    2012-12-01

    The rapid manufacture of complex three-dimensional micro-scale components has eluded researchers for decades. Several additive manufacturing options have been limited by either speed or the ability to fabricate true three-dimensional structures. Projection micro-stereolithography (PμSL) is a low cost, high throughput additive fabrication technique capable of generating three-dimensional microstructures in a bottom-up, layer by layer fashion. The PμSL system is reliable and capable of manufacturing a variety of highly complex, three-dimensional structures from micro- to meso-scales with micro-scale architecture and submicron precision. Our PμSL system utilizes a reconfigurable digital mask and a 395 nm light-emitting diode (LED) array to polymerize a liquid monomer in a layer-by-layer manufacturing process. This paper discusses the critical process parameters that influence polymerization depth and structure quality. Experimental characterization and performance of the LED-based PμSL system for fabricating highly complex three-dimensional structures for a large range of applications is presented. PMID:23278017

  2. Laser 3D micro-manufacturing

    NASA Astrophysics Data System (ADS)

    Piqué, Alberto; Auyeung, Raymond C. Y.; Kim, Heungsoo; Charipar, Nicholas A.; Mathews, Scott A.

    2016-06-01

    Laser-based materials processing techniques are gaining widespread use in micro-manufacturing applications. The use of laser microfabrication techniques enables the processing of micro- and nanostructures from a wide range of materials and geometries without the need for masking and etching steps commonly associated with photolithography. This review aims to describe the broad applications space covered by laser-based micro- and nanoprocessing techniques and the benefits offered by the use of lasers in micro-manufacturing processes. Given their non-lithographic nature, these processes are also referred to as laser direct-write and constitute some of the earliest demonstrations of 3D printing or additive manufacturing at the microscale. As this review will show, the use of lasers enables precise control of the various types of processing steps—from subtractive to additive—over a wide range of scales with an extensive materials palette. Overall, laser-based direct-write techniques offer multiple modes of operation including the removal (via ablative processes) and addition (via photopolymerization or printing) of most classes of materials using the same equipment in many cases. The versatility provided by these multi-function, multi-material and multi-scale laser micro-manufacturing processes cannot be matched by photolithography nor with other direct-write microfabrication techniques and offer unique opportunities for current and future 3D micro-manufacturing applications.

  3. Laser-assisted manufacturing of micro-optical volume elements for enhancing the amount of light absorbed by solar cells in photovoltaic modules

    NASA Astrophysics Data System (ADS)

    Peharz, Gerhard; Kuna, Ladislav; Leiner, Claude

    2015-03-01

    The laser-generation of micro-optical volume elements is a promising approach to decrease the optical shadowing of front side metal contacts of solar cells. Focusing a femtosecond laser beam into the volume of the encapsulation material causes a local modification its optical constants. Suchlike fabricated micro-optical elements can be used to decrease the optical shadowing of the front side metallization of c-Si solar cells. Test samples comprising of a sandwich structure of a glass sheet with metallic grid-lines, an Ethylene-vinyl acetate (EVA) encapsulant and another glass sheet were manufactured in order to investigate the optical performance of the volume optics. Transmission measurements show that the shadowing of the metalling grid-lines is substantially decreased by the micro-optical volume elements created in the EVA bulk right above the grid-fingers. A detailed investigation of the optical properties of these volume elements was performed: (i) experimentally on the basis of goniometric measurements, as well as (ii) theoretically by applying optical modelling and optimization procedures. This resulted in a better understanding of the effectiveness of the optical volume elements in decreasing the optical shadowing of metal grid lines on the active cell surfaces. Moreover, results of photovoltaic mini-modules with incorporated micro-optical volume elements are presented. Results of optical simulation and Laser Beam Induced Current (LBIC) experiments show that the losses due to the grid fingers can be reduced by about 50%, when using this fs-laser structuring approach for the fabrication of micro-optical volume elements in the EVA material.

  4. Manufacture of an optical effector using silicon micro-machining

    NASA Astrophysics Data System (ADS)

    Berrill, M. G.; McKenzie, J. S.; Clark, C.

    2000-03-01

    Using a complex micro-machined structure a novel optical-to-fluid pressure converter has been developed. The device offers immunity from electromagnetic interference and the potential for intrinsic safety. The effector, an improved version of a previous device, has been further miniaturized and fully micro-machined from silicon and glass. The device operates when light enters a sealed air-filled cell, formed within a silicon wafer, and is converted to heat by an absorber. The associated rise in temperature increases the pressure inside the cell and forces a diaphragm to move. The diaphragm movement is detected by a change in the back pressure of an impinging jet of fluid; which can be either pneumatic or hydraulic. The response time of the device, of the order of tens of milliseconds, has been further reduced as a result of miniaturization. This paper outlines the manufacturing technique and presents selected experimental test results.

  5. Wafer-level micro-optics: trends in manufacturing, testing, packaging, and applications

    NASA Astrophysics Data System (ADS)

    Voelkel, Reinhard; Gong, Li; Rieck, Juergen; Zheng, Alan

    2012-11-01

    Micro-optics is an indispensable key enabling technology (KET) for many products and applications today. Probably the most prestigious examples are the diffractive light shaping elements used in high-end DUV lithography steppers. Highly efficient refractive and diffractive micro-optical elements are used for precise beam and pupil shaping. Micro-optics had a major impact on the reduction of aberrations and diffraction effects in projection lithography, allowing a resolution enhancement from 250 nm to 45 nm within the last decade. Micro-optics also plays a decisive role in medical devices (endoscopes, ophthalmology), in all laser-based devices and fiber communication networks (supercomputer, ROADM), bringing high-speed internet to our homes (FTTH). Even our modern smart phones contain a variety of micro-optical elements. For example, LED flashlight shaping elements, the secondary camera, and ambient light and proximity sensors. Wherever light is involved, micro-optics offers the chance to further miniaturize a device, to improve its performance, or to reduce manufacturing and packaging costs. Wafer-scale micro-optics fabrication is based on technology established by semiconductor industry. Thousands of components are fabricated in parallel on a wafer. We report on the state of the art in wafer-based manufacturing, testing, packaging and present examples and applications for micro-optical components and systems.

  6. Micro-optics in lighting applications

    NASA Astrophysics Data System (ADS)

    Mönch, Wolfgang

    2015-02-01

    The intention of this article is to give a concise overview on current applications of micro-optical components in lighting, including general lighting, automotive lighting, projection, and display backlighting. Regarding the light sources, the focus of this paper is on inorganic light-emitting diodes (LEDs) and the characteristic problems encountered with them. Lasers, laser diodes, and organic light-emitting diodes (OLEDs) are out of scope of this paper. Micro-optical components for current applications of inorganic LEDs may be categorized essentially into three classes: First, components for light shaping, i.e., adjusting the intensity distribution to a desired target; second, components for light homogenization with respect to space and color, and third, large-area micro-optical elements. These large-area elements comprise micro-optical slabs and sheets for guiding, reflection, and refraction of light and are designed without regard to particular details of type, design, arrangement, and layout of the individual light emitters. References are given to textbooks and review articles to guide the interested reader to further and more detailed studies on the problems discussed here.

  7. Manufacturing: 3D printed micro-optics

    NASA Astrophysics Data System (ADS)

    Juodkazis, Saulius

    2016-08-01

    Uncompromised performance of micro-optical compound lenses has been achieved by high-fidelity shape definition during two-photon absorption microfabrication. The lenses have been made directly onto image sensors and even onto the tip of an optic fibre.

  8. Micro-lens array design on a flexible light-emitting diode package for indoor lighting.

    PubMed

    Lee, Hsiao-Wen; Lin, Bor-Shyh

    2015-10-01

    An advanced, ultra-thin, flexible LED (FLED) package technique is first proposed in this study, where a polyimide substrate was used as the lead frame package material due to its physical stability in thermal processing. The experimental results showed that the thickness of the mockup sample measured by a vernier caliper was 260 μm and 35% thinner than the Panasonic organic LED lighting panel announced on 4 March 2014 in Tokyo. Moreover, the flexible angle of the ultra-thin LED package was 200.54° when it surrounded a disk with a 1 cm radius. A design of a micro-lens array manufactured by silicone molding on the FLED is also proposed in this study. Finally, different types of micro-lenses were applied to different lighting regions to investigate their lighting effects. PMID:26479655

  9. Solid State Lighting LED Manufacturing Roundtable Summary

    SciTech Connect

    none,

    2010-03-31

    Summary of a meeting of LED experts to develop proposed priority tasks for the Manufacturing R&D initiative, including task descriptions, discussion points, recommendations, and presentation highlights.

  10. Solid State Lighting OLED Manufacturing Roundtable Summary

    SciTech Connect

    none,

    2010-03-31

    Summary of a meeting of OLED experts to develop proposed priority tasks for the Manufacturing R&D initiative, including task descriptions, discussion points, recommendations, and presentation highlights.

  11. Capabilities Of Micro Powder Injection Molding For Microparts Manufacturing

    NASA Astrophysics Data System (ADS)

    Kong, X.; Barriere, T.; Gelin, J. C.

    2011-01-01

    The Micro-PIM processing technology satisfies the increasing demand in terms of smaller parts and miniaturization. Research works in this area have been carried out at FEMTO-ST Institute by performing the injection molding with 316L stainless steel fine powders and polymer binders. Several formulations with different proportion of powders and binders as well various polymers have been tested, and then a well adapted one has been selected. The process to select the well adapted formulation and the rheological characteristics of the feedstock realized according with the selected formulation are also detailed. Several test specimens have been successfully manufactured.

  12. Micro optical fiber light source and sensor and method of fabrication thereof

    DOEpatents

    Kopelman, R.; Tan, W.; Shi, Z.Y.

    1997-05-06

    This invention relates generally to the development of and a method of fabricating a fiber optic micro-light source and sensor. An optical fiber micro-light source is presented whose aperture is extremely small yet able to act as an intense light source. Light sources of this type have wide ranging applications, including use as micro-sensors in NSOM. Micro-sensor light sources have excellent detection limits as well as photo stability, reversibility, and millisecond response times. Furthermore, a method for manufacturing a micro optical fiber light source is provided. It involves the photo-chemical attachment of an optically active material onto the end surface of an optical fiber cable which has been pulled to form an end with an extremely narrow aperture. More specifically, photopolymerization has been applied as a means to photo-chemically attach an optically active material. This process allows significant control of the size of the micro light source. Furthermore, photo-chemically attaching an optically active material enables the implementation of the micro-light source in a variety of sensor applications. 10 figs.

  13. Micro optical fiber light source and sensor and method of fabrication thereof

    DOEpatents

    Kopelman, R.; Tan, W.; Shi, Z.Y.

    1994-11-01

    This invention relates generally to the development of and a method of fabricating a micro optical fiber light source. An optical fiber micro-light source is presented whose aperture is extremely small yet able to act as an intense light source. Light sources of this type have wide ranging applications, including use as micro-sensors in NSOM. Micro-sensor light sources have excellent detection limits as well as photo stability, reversibility, and millisecond response times. Furthermore, a method for manufacturing a micro optical fiber light source is provided. It involves the photo-chemical attachment of an optically active material onto the end surface of an optical fiber cable which has been pulled to form an end with an extremely narrow aperture. More specifically, photopolymerization has been applied as a means to photo-chemically attach an optically active material. This process allows significant control of the size of the micro light source. Furthermore, photo-chemically attaching an optically active material enables the implementation of the micro-light source in a variety of sensor applications. 4 figs.

  14. Micro optical fiber light source and sensor and method of fabrication thereof

    DOEpatents

    Kopelman, Raoul; Tan, Weihong; Shi, Zhong-You

    1997-01-01

    This invention relates generally to the development of and a method of fabricating a fiber optic micro-light source and sensor (50). An optical fiber micro-light source (50) is presented whose aperture is extremely small yet able to act as an intense light source. Light sources of this type have wide ranging applications, including use as micro-sensors (22) in NSOM. Micro-sensor light sources have excellent detection limits as well as photo stability, reversibility, and millisecond response times. Furthermore, a method for manufacturing a micro optical fiber light source is provided. It involves the photo-chemical attachment of an optically active material onto the end surface of an optical fiber cable which has been pulled to form an end with an extremely narrow aperture. More specifically, photopolymerization has been applied as a means to photo-chemically attach an optically active material (60). This process allows significant control of the size of the micro light source (50). Furthermore, photo-chemically attaching an optically active material (60) enables the implementation of the micro-light source in a variety of sensor applications.

  15. Micro optical fiber light source and sensor and method of fabrication thereof

    DOEpatents

    Kopelman, Raoul; Tan, Weihong; Shi, Zhong-You

    1994-01-01

    This invention relates generally to the development of and a method of fabricating a micro optical fiber light source. An optical fiber micro-light source is presented whose aperture is extremely small yet able to act as an intense light source. Light sources of this type have wide ranging applications, including use as micro-sensors in NSOM. Micro-sensor light sources have excellent detection limits as well as photo stability, reversibility, and millisecond response times. Furthermore, a method for manufacturing a micro optical fiber light source is provided. It involves the photo-chemical attachment of an optically active material onto the end surface of an optical fiber cable which has been pulled to form an end with an extremely narrow aperture. More specifically, photopolymerization has been applied as a means to photo-chemically attach an optically active material. This process allows significant control of the size of the micro light source. Furthermore, photo-chemically attaching an optically active material enables the implementation of the micro-light source in a variety of sensor applications.

  16. Micro-valve pump light valve display

    DOEpatents

    Yeechun Lee.

    1993-01-19

    A flat panel display incorporates a plurality of micro-pump light valves (MLV's) to form pixels for recreating an image. Each MLV consists of a dielectric drop sandwiched between substrates, at least one of which is transparent, a holding electrode for maintaining the drop outside a viewing area, and a switching electrode from accelerating the drop from a location within the holding electrode to a location within the viewing area. The sustrates may further define non-wetting surface areas to create potential energy barriers to assist in controlling movement of the drop. The forces acting on the drop are quadratic in nature to provide a nonlinear response for increased image contrast. A crossed electrode structure can be used to activate the pixels whereby a large flat panel display is formed without active driver components at each pixel.

  17. Micro-valve pump light valve display

    DOEpatents

    Lee, Yee-Chun

    1993-01-01

    A flat panel display incorporates a plurality of micro-pump light valves (MLV's) to form pixels for recreating an image. Each MLV consists of a dielectric drop sandwiched between substrates, at least one of which is transparent, a holding electrode for maintaining the drop outside a viewing area, and a switching electrode from accelerating the drop from a location within the holding electrode to a location within the viewing area. The sustrates may further define non-wetting surface areas to create potential energy barriers to assist in controlling movement of the drop. The forces acting on the drop are quadratic in nature to provide a nonlinear response for increased image contrast. A crossed electrode structure can be used to activate the pixels whereby a large flat panel display is formed without active driver components at each pixel.

  18. Clean Energy Manufacturing Initiative Solid-State Lighting Video

    SciTech Connect

    Thomas, Sunil; Edmond, John; Krames, Michael; Raman, Sudhakar

    2014-09-23

    The importance of U.S. manufacturing for clean energy technologies, such as solid-state lighting (SSL), is paramount to increasing competitiveness in a global marketplace. SSLs are poised to drive the lighting market, worldwide. In order to continue that competitiveness and support further innovation, the time to invest in U.S. manufacturing of clean energy technologies is now. Across the country, companies developing innovative clean energy technologies find competitive advantages to manufacturing in the U.S. The Department of Energy's Building Technology Office SSL Manufacturing Roadmap is just one example of how we support manufacturing through convening industry perspectives on opportunities to significantly reduce risk, improve quality, increase yields, and lower costs.

  19. Clean Energy Manufacturing Initiative Solid-State Lighting

    SciTech Connect

    Thomas, Sunil; Edmond, John; Krames, Michael; Raman, Sudhakar

    2014-09-23

    The importance of U.S. manufacturing for clean energy technologies, such as solid-state lighting (SSL), is paramount to increasing competitiveness in a global marketplace. SSLs are poised to drive the lighting market, worldwide. In order to continue that competitiveness and support further innovation, the time to invest in U.S. manufacturing of clean energy technologies is now. Across the country, companies developing innovative clean energy technologies find competitive advantages to manufacturing in the U.S. The Department of Energy's Building Technology Office SSL Manufacturing Roadmap is just one example of how we support manufacturing through convening industry perspectives on opportunities to significantly reduce risk, improve quality, increase yields, and lower costs.

  20. Clean Energy Manufacturing Initiative Solid-State Lighting

    ScienceCinema

    Thomas, Sunil; Edmond, John; Krames, Michael; Raman, Sudhakar

    2014-12-03

    The importance of U.S. manufacturing for clean energy technologies, such as solid-state lighting (SSL), is paramount to increasing competitiveness in a global marketplace. SSLs are poised to drive the lighting market, worldwide. In order to continue that competitiveness and support further innovation, the time to invest in U.S. manufacturing of clean energy technologies is now. Across the country, companies developing innovative clean energy technologies find competitive advantages to manufacturing in the U.S. The Department of Energy's Building Technology Office SSL Manufacturing Roadmap is just one example of how we support manufacturing through convening industry perspectives on opportunities to significantly reduce risk, improve quality, increase yields, and lower costs.

  1. The proposed Institute for Micro-manufacturing, Louisiana Tech University

    SciTech Connect

    Not Available

    1994-07-01

    The Department of Energy (DOE) has prepared an Environmental Assessment (EA) DOE/EA-0958, evaluating the construction and equipping of two components of the proposed Institute for Micro-manufacturing at Louisiana Tech University (LTU), a proposed R and D facility to be located in Ruston, LA. and, the proposed installation of a beamline for micro-machining applications at the Center for Advanced Microstructures and Devices (CAMD) facility at Louisiana State University in Baton Rouge, LA. The objective of the proposed project is to focus on the applied, rather than basic research emphasizing the design and development, metrology, inspection and testing, and the assembly and production of micron and submicron structures and devices. Also, the objective of the beamline at CAMD would be the fundamental study of processing and analysis technologies, including x-ray lithography, which are important to microstructures fabrication and electronic device development. Based on the analysis in the EA, the DOE has determined that the proposed action does not constitute a major federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an Environmental Impact Statement is not required.

  2. Manufacturing of an aluminum alloy mold for micro-hot embossing of polymeric micro-devices

    NASA Astrophysics Data System (ADS)

    Tran, N. K.; Lam, Y. C.; Yue, C. Y.; Tan, M. J.

    2010-05-01

    In micro-hot embossing of polymeric micro-devices, e.g. microfluidic devices, the quality of the mold plays an important role in determining not only the product quality but also the overall production cost. Often the mold is made of silicon, which is brittle and fails after producing a limited number of parts. Metallic molds produced by micro-machining have a much longer life; however, the surface finish of the mold is not ideal for producing polymeric devices that require good surface finish. The metallic glass mold produced by micro-hot embossing with a silicon master is a recent development, which could produce high quality and high strength molds with long life span. However, metallic glasses are rather costly. In an attempt to reduce the production cost of the mold with acceptable quality, strength and life span, we explore here the manufacture of an aluminum alloy (AA6061-T6) mold by hot embossing using a silicon master. Using a set of channels to be produced on the aluminum alloy as the benchmark, we examine the orientation effect of the channels on the AA6061-T6 mold produced by hot embossing. Finally, to examine the effectiveness of the AA6061-T6 mold, it is employed for the hot embossing of polymeric (TOPAS 8007) substrates.

  3. Light diffusing effects of nano and micro-structures on OLED with microcavity.

    PubMed

    Cho, Doo-Hee; Shin, Jin-Wook; Joo, Chul Woong; Lee, Jonghee; Park, Seung Koo; Moon, Jaehyun; Cho, Nam Sung; Chu, Hye Yong; Lee, Jeong-Ik

    2014-10-20

    We examined the light diffusing effects of nano and micro-structures on microcavity designed OLEDs. The results of FDTD simulations and experiments showed that the pillar shaped nano-structure was more effective than the concave micro-structure for light diffusing of microcavity OLEDs. The sharp luminance distribution of the microcavity OLED was changed to near Lambertian luminance distribution by the nano-structure, and light diffusing effects increased with the height of the nano-structure. Furthermore, the nano-structure has advantages including light extraction of the substrate mode, reproducibility of manufacturing process, and minimizing pixel blur problems in an OLED display panel. The nano-structure is a promising candidate for a light diffuser, resolving the viewing angle problems in microcavity OLEDs. PMID:25607307

  4. Micro Dot Patterning on the Light Guide Panel Using Powder Blasting

    PubMed Central

    Jang, Ho Su; Cho, Myeong Woo; Park, Dong Sam

    2008-01-01

    This study is to develop a micromachining technology for a light guide panel(LGP) mold, whereby micro dot patterns are formed on a LGP surface by a single injection process instead of existing screen printing processes. The micro powder blasting technique is applied to form micro dot patterns on the LGP mold surface. The optimal conditions for masking, laminating, exposure, and developing processes to form the micro dot patterns are first experimentally investigated. A LGP mold with masked micro patterns is then machined using the micro powder blasting method and the machinability of the micro dot patterns is verified. A prototype LGP is test- injected using the developed LGP mold and a shape analysis of the patterns and performance testing of the injected LGP are carried out. As an additional approach, matte finishing, a special surface treatment method, is applied to the mold surface to improve the light diffusion characteristics, uniformity and brightness of the LGP. The results of this study show that the applied powder blasting method can be successfully used to manufacture LGPs with micro patterns by just single injection using the developed mold and thereby replace existing screen printing methods.

  5. Advancing three-dimensional MEMS by complimentary laser micro manufacturing

    NASA Astrophysics Data System (ADS)

    Palmer, Jeremy A.; Williams, John D.; Lemp, Tom; Lehecka, Tom M.; Medina, Francisco; Wicker, Ryan B.

    2006-01-01

    This paper describes improvements that enable engineers to create three-dimensional MEMS in a variety of materials. It also provides a means for selectively adding three-dimensional, high aspect ratio features to pre-existing PMMA micro molds for subsequent LIGA processing. This complimentary method involves in situ construction of three-dimensional micro molds in a stand-alone configuration or directly adjacent to features formed by x-ray lithography. Three-dimensional micro molds are created by micro stereolithography (MSL), an additive rapid prototyping technology. Alternatively, three-dimensional features may be added by direct femtosecond laser micro machining. Parameters for optimal femtosecond laser micro machining of PMMA at 800 nanometers are presented. The technical discussion also includes strategies for enhancements in the context of material selection and post-process surface finish. This approach may lead to practical, cost-effective 3-D MEMS with the surface finish and throughput advantages of x-ray lithography. Accurate three-dimensional metal microstructures are demonstrated. Challenges remain in process planning for micro stereolithography and development of buried features following femtosecond laser micro machining.

  6. Micro spectrometer for parallel light and method of use

    NASA Technical Reports Server (NTRS)

    Park, Yeonjoon (Inventor); Choi, Sang H. (Inventor); King, Glen C. (Inventor); Elliott, James R. (Inventor)

    2011-01-01

    A spectrometer system includes an optical assembly for collimating light, a micro-ring grating assembly having a plurality of coaxially-aligned ring gratings, an aperture device defining an aperture circumscribing a target focal point, and a photon detector. An electro-optical layer of the grating assembly may be electrically connected to an energy supply to change the refractive index of the electro-optical layer. Alternately, the gratings may be electrically connected to the energy supply and energized, e.g., with alternating voltages, to change the refractive index. A data recorder may record the predetermined spectral characteristic. A method of detecting a spectral characteristic of a predetermined wavelength of source light includes generating collimated light using an optical assembly, directing the collimated light onto the micro-ring grating assembly, and selectively energizing the micro-ring grating assembly to diffract the predetermined wavelength onto the target focal point, and detecting the spectral characteristic using a photon detector.

  7. Method of Manufacturing Micro-Disperse Particles of Sodium Borohydride

    DOEpatents

    Kravitz, Stanley H.; Hecht, Andrew M.; Sylwester. Alan P.; Bell, Nelson S.

    2008-09-23

    A compact solid source of hydrogen gas, where the gas is generated by contacting water with micro-disperse particles of sodium borohydride in the presence of a catalyst, such as cobalt or ruthenium. The micro-disperse particles can have a substantially uniform diameter of 1-10 microns, and preferably about 3-5 microns. Ruthenium or cobalt catalytic nanoparticles can be incorporated in the micro-disperse particles of sodium borohydride, which allows a rapid and complete reaction to occur without the problems associated with caking and scaling of the surface by the reactant product sodium metaborate. A closed loop water management system can be used to recycle wastewater from a PEM fuel cell to supply water for reacting with the micro-disperse particles of sodium borohydride in a compact hydrogen gas generator. Capillary forces can wick water from a water reservoir into a packed bed of micro-disperse fuel particles, eliminating the need for using an active pump.

  8. Light driven micro-robotics with holographic 3D tracking

    NASA Astrophysics Data System (ADS)

    Glückstad, Jesper

    2016-04-01

    We recently pioneered the concept of light-driven micro-robotics including the new and disruptive 3D-printed micro-tools coined Wave-guided Optical Waveguides that can be real-time optically trapped and "remote-controlled" in a volume with six-degrees-of-freedom. To be exploring the full potential of this new drone-like 3D light robotics approach in challenging microscopic geometries requires a versatile and real-time reconfigurable light coupling that can dynamically track a plurality of "light robots" in 3D to ensure continuous optimal light coupling on the fly. Our latest developments in this new and exciting area will be reviewed in this invited paper.

  9. Review of Polyimides Used in the Manufacturing of Micro Systems

    NASA Technical Reports Server (NTRS)

    Wilson, William C.; Atkinson, Gary M.

    2007-01-01

    Since their invention, polyimides have found numerous uses in MicroElectroMechanical Systems (MEMS) technology. Polyimides can act as photoresist, sacrificial layers, structural layers, and even as a replacement for silicon as the substrate during MEMS fabrication. They enable fabrication of both low and high aspect ratio devices. Polyimides have been used to fabricate expendable molds and reusable flexible molds. Development of a variety of devices that employ polyimides for sensor applications has occurred. Micro-robotic actuator applications include hinges, thermal actuators and residual stress actuators. Currently, polyimides are being used to create new sensors and devices for aerospace applications. This paper presents a review of some of the many uses of polyimides in the development of MEMS devices, including a new polyimide based MEMS fabrication process.

  10. 3D manufacturing of micro and nano-architected materials

    NASA Astrophysics Data System (ADS)

    Valdevit, Lorenzo

    2016-04-01

    Reducing mass without sacrificing mechanical integrity and performance is a critical goal in a vast range of applications. Introducing a controlled amount of porosity in a strong and dense material (hence fabricating a cellular solid) is an obvious avenue to weight reduction. The mechanical effectiveness of this strategy, though, depends strongly on the architecture of the resulting cellular material (i.e., the topology of the introduced porosity). Recent progress in additive manufacturing enables fabrication of macro-scale cellular materials (both single-phase and hybrid) with unprecedented dimensional control on the unit-cell and sub-unit-cell features, potentially producing architectures with structural hierarchy from the nano to the macro-scale. As mechanical properties of materials often exhibit beneficial size effects at the nano-scale (e.g., strengthening of metals and toughening of ceramics), these novel manufacturing approaches provide a unique opportunity to translate these beneficial effects to the macro-scale, further improving the mechanical performance of architected materials. The enormous design space for architected materials, and the strong relationship between the topological features of the architecture and the effective physical and mechanical properties of the material at the macro-scale, present both a huge opportunity and an urgent need for the development of suitable optimal design strategies. Here we present a number of strategies for the advanced manufacturing, characterization and optimal design of a variety of lightweight architected materials with unique combinations of mechanical properties (stiffness, strength, damping coefficient…). The urgent need to form strong synergies among the fields of additive manufacturing, topology optimization and architectureproperties relations is emphasized throughout.

  11. Design of a micro lapping system based on double-feedback control algorithm for manufacturing optical micro components

    NASA Astrophysics Data System (ADS)

    Che, Lin; Li, Guo; Wang, Bo; Ding, Fei; Mao, Xing; Dong, Wenxia

    2014-08-01

    This paper presents a micro lapping machine tool, which is dedicated for manufacturing the high-precision optical micro components with 3-D micro structures. And it can remove the damaged surface layer efficiently.In order to control machining process precisely, a double-feedback control system strategy is proposed and implemented. Lapping force signal from the clamp feeds back at the same time with position signal from grating scale close-looped devices. With the function of position keeping , a dual-stage drive micro-displacement servo system is used to provide the desired performance in the vertical feeding direction. Random lapping trace is formed with combinations of two mutually-perpendicular horizontal liner motion. A clamp with the function of micro force detection is designed to monitor the machining process and control the lapping force. Based on force feedback, a tool auto-checking strategy is conducted to realize the tool checking in limited tiny space. Corresponding experiments are undertaken to test the properties of the machine tool.And, the optical micro components are manufactured successfully. The optical components are measured and analysised before and after processing. The experimental results show that the position-keeping accuracy of the dual-stage feed drive system can reach to ±0.02μm, the resolution of motion control can reach to 20nm.The Sa value of the processed component can reach 0.0882um. Surface quality can be improved obviously and the damaged surface layer is removed efficiently.The theoretical and experimental results show the validity of the machine tool and the control algorithm.

  12. 76 FR 77585 - Notice to Manufacturers of Airport Lighting and Navigation Aid Equipment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-13

    ...Projects funded under the Airport Improvement Program (AIP) must meet the requirements of 49 U.S.C. 50101, Buy American Preferences. The Federal Aviation Administration (FAA) is considering issuing waivers to foreign manufacturers of certain airport lighting and navigation aid equipment that is lit with Light Emitting Diode (LED) lighting. This notice requests information from manufacturers of......

  13. Plasmonic micro lens for extraordinary transmission of broadband light.

    PubMed

    Saxena, Sumit; Chaudhary, Raghvendra Pratap; Singh, Abhay; Awasthi, Saurabh; Shukla, Shobha

    2014-01-01

    Extraordinary transmittance and focusing of light in quasi far field region using miniaturized optical devices is a daunting task. A polarization independent, broadband, planar metallic transmissive micro aperture capable of achromatically focusing visible light in quasi far field region is proposed. The calculated enhancement factor of transmission efficiency was about ~2.2. The total transmission after the aperture is about 60%. This high throughput focusing device will open new avenues for focusing electromagnetic energy in the wide area of sensors and energy concentration. PMID:25014061

  14. Plasmonic Micro Lens for Extraordinary Transmission of Broadband Light

    NASA Astrophysics Data System (ADS)

    Saxena, Sumit; Chaudhary, Raghvendra Pratap; Singh, Abhay; Awasthi, Saurabh; Shukla, Shobha

    2014-07-01

    Extraordinary transmittance and focusing of light in quasi far field region using miniaturized optical devices is a daunting task. A polarization independent, broadband, planar metallic transmissive micro aperture capable of achromatically focusing visible light in quasi far field region is proposed. The calculated enhancement factor of transmission efficiency was about ~2.2. The total transmission after the aperture is about 60%. This high throughput focusing device will open new avenues for focusing electromagnetic energy in the wide area of sensors and energy concentration.

  15. Rapid manufacture of monolithic micro-actuated forceps inspired by echinoderm pedicellariae.

    PubMed

    Leigh, S J; Bowen, J; Purssell, C P; Covington, J A; Billson, D R; Hutchins, D A

    2012-12-01

    The concept of biomimetics and bioinspiration has been used to enhance the function of materials and devices in fields ranging from healthcare to renewable energy. By developing advanced design and manufacturing processes, researchers are rapidly accelerating their ability to mimic natural systems. In this paper we show how micro-actuated forceps inspired by echinoderm pedicellarie have been produced using the rapid manufacturing technology of micro-stereolithography. The manufactured monolithic devices are composed of sets of jaws on the surface of thin polymer resin membranes, which serve as musculature for the jaws. The membranes are suspended above a pneumatic chamber with the jaws opened and closed through pneumatic pressure changes exerted by a simple syringe. The forceps can be used for tasks such as grasping of microparticles. Furthermore, when an object is placed in the centre of the membrane, the membrane flexes and the jaws of the device close and grasp the object in a responsive manner. When uncured liquid photopolymer is used to actuate the devices hydraulically instead of pneumatically, the devices exhibit self-healing behaviour, sealing the damaged regions and maintaining hydraulic integrity. The manufactured devices present exciting possibilities in fields such as micromanipulation and micro-robotics for healthcare. PMID:22791684

  16. Using artificial neural networks to model extrusion processes for the manufacturing of polymeric micro-tubes

    NASA Astrophysics Data System (ADS)

    Mekras, N.; Artemakis, I.

    2012-09-01

    In this paper a methodology and an application example are presented aiming to show how Artificial Neural Networks (ANNs) can be used to model manufacturing processes when mathematical models are missing or are not applicable e.g. due to the micro- & nano-scaling, due to non-conventional processes, etc. Besides the ANNs methodology, the results of a Software System developed will be presented, which was used to create ANNs models for micro & nano manufacturing processes. More specifically results of a specific application example will be presented, concerning the modeling of extrusion processes for polymeric micro-tubes. ANNs models are capable for modeling manufacturing processes as far as adequate experimental and/or historical data of processes' inputs & outputs are available for their training. The POLYTUBES ANNs models have been trained and tested with experimental data records of process' inputs and outputs concerning a micro-extrusion process of polymeric micro-tubes for several materials such as: COC, PC, PET, PETG, PP and PVDF. The main ANN model of the extrusion application example has 3 inputs and 9 outputs. The inputs are: tube's inner & outer diameters, and the material density. The model outputs are 9 process parameters, which correspond to the specific inputs e.g. process temperature, die inner & outer diameters, extrusion pressure, draw speed etc. The training of the ANN model was completed, when the errors for the model's outputs, which expressed the difference between the training target values and the ANNs outputs, were minimized to acceptable levels. After the training, the micro-extrusion ANN is capable to simulate the process and can be used to calculate model's outputs, which are the process parameters for any new set of inputs. By this way a satisfactory functional approximation of the whole process is achieved. This research work has been supported by the EU FP7 NMP project POLYTUBES.

  17. MATERIALS, FABRICATION, AND MANUFACTURING OF MICRO/NANOSTRUCTURED SURFACES FOR PHASE-CHANGE HEAT TRANSFER ENHANCEMENT

    SciTech Connect

    McCarthy, M; Gerasopoulos, K; Maroo, SC; Hart, AJ

    2014-07-23

    This article describes the most prominent materials, fabrication methods, and manufacturing schemes for micro- and nanostructured surfaces that can be employed to enhance phase-change heat transfer phenomena. The numerous processes include traditional microfabrication techniques such as thin-film deposition, lithography, and etching, as well as template-assisted and template-free nanofabrication techniques. The creation of complex, hierarchical, and heterogeneous surface structures using advanced techniques is also reviewed. Additionally, research needs in the field and future directions necessary to translate these approaches from the laboratory to high-performance applications are identified. Particular focus is placed on the extension of these techniques to the design of micro/nanostructures for increased performance, manufacturability, and reliability. The current research needs and goals are detailed, and potential pathways forward are suggested.

  18. Net shape manufacturing of ceramic micro parts with tailored graded layers

    NASA Astrophysics Data System (ADS)

    Hassanin, H.; Jiang, K.

    2014-01-01

    Presented in this paper is a novel net shape manufacturing technology for making three-dimensional micro parts with functionally graded layers. Alumina/zirconia micro parts with either core-shell or top-bottom functionally graded material (FGM) profiles have been successfully fabricated by altering both the surface characteristics of polydimethylsiloxane (PDMS) micro moulds and ceramic suspensions composition. PDMS surface modifications were performed to achieve moulds with hydrophilic surfaces, which were used to form core/shell FGM green layers. On the other hand, moulds with hydrophobic surfaces were used to form top-bottom green layers. Cracks have been found between consecutive layers in both the green and sintered micro parts. It was found that, at dispersant concentration of about 9.0 mg g-1, the differences in the drying shrinkage between layers is less than 0.5%. In addition, layers of composition of 100% Al2O3-0% YSZ, 20% Al2O3-80% YSZ and 40% Al2O3-60% YSZ were found to produce less shrinkage difference during sintering. After optimization of both green and sintering layers, crack free core/shell and top-bottom alumina/zirconia FGM micro parts were successfully obtained. The proposed process enables the production of micro patterns tailored with functionally graded microstructures to locally enhance properties and performance.

  19. An experimental analysis of process parameters to manufacture micro-channels in AISI H13 tempered steel by laser micro-milling

    NASA Astrophysics Data System (ADS)

    Teixidor, D.; Ferrer, I.; Ciurana, J.

    2012-04-01

    This paper reports the characterization of laser machining (milling) process to manufacture micro-channels in order to understand the incidence of process parameters on the final features. Selection of process operational parameters is highly critical for successful laser micromachining. A set of designed experiments is carried out in a pulsed Nd:YAG laser system using AISI H13 hardened tool steel as work material. Several micro-channels have been manufactured as micro-mold cavities varying parameters such as scanning speed (SS), pulse intensity (PI) and pulse frequency (PF). Results are obtained by evaluating the dimensions and the surface finish of the micro-channel. The dimensions and shape of the micro-channels produced with laser-micro-milling process exhibit variations. In general the use of low scanning speeds increases the quality of the feature in both surface finishing and dimensional.

  20. Demonstration of Light-Matter Micro-Macro Quantum Correlations.

    PubMed

    Tiranov, Alexey; Lavoie, Jonathan; Strassmann, Peter C; Sangouard, Nicolas; Afzelius, Mikael; Bussières, Félix; Gisin, Nicolas

    2016-05-13

    Quantum mechanics predicts microscopic phenomena with undeniable success. Nevertheless, current theoretical and experimental efforts still do not yield conclusive evidence that there is or is not a fundamental limitation on the possibility to observe quantum phenomena at the macroscopic scale. This question prompted several experimental efforts producing quantum superpositions of large quantum states in light or matter. We report on the observation of quantum correlations, revealed using an entanglement witness, between a single photon and an atomic ensemble of billions of ions frozen in a crystal. The matter part of the state involves the superposition of two macroscopically distinguishable solid-state components composed of several tens of atomic excitations. Assuming the insignificance of the time ordering our experiment indirectly shows light-matter micro-macro entanglement. Our approach leverages from quantum memory techniques and could be used in other systems to expand the size of quantum superpositions in matter. PMID:27232010

  1. Demonstration of Light-Matter Micro-Macro Quantum Correlations

    NASA Astrophysics Data System (ADS)

    Tiranov, Alexey; Lavoie, Jonathan; Strassmann, Peter C.; Sangouard, Nicolas; Afzelius, Mikael; Bussières, Félix; Gisin, Nicolas

    2016-05-01

    Quantum mechanics predicts microscopic phenomena with undeniable success. Nevertheless, current theoretical and experimental efforts still do not yield conclusive evidence that there is or is not a fundamental limitation on the possibility to observe quantum phenomena at the macroscopic scale. This question prompted several experimental efforts producing quantum superpositions of large quantum states in light or matter. We report on the observation of quantum correlations, revealed using an entanglement witness, between a single photon and an atomic ensemble of billions of ions frozen in a crystal. The matter part of the state involves the superposition of two macroscopically distinguishable solid-state components composed of several tens of atomic excitations. Assuming the insignificance of the time ordering our experiment indirectly shows light-matter micro-macro entanglement. Our approach leverages from quantum memory techniques and could be used in other systems to expand the size of quantum superpositions in matter.

  2. Plasmofluidics: Merging Light and Fluids at the Micro-/Nanoscale.

    PubMed

    Wang, Mingsong; Zhao, Chenglong; Miao, Xiaoyu; Zhao, Yanhui; Rufo, Joseph; Liu, Yan Jun; Huang, Tony Jun; Zheng, Yuebing

    2015-09-16

    Plasmofluidics is the synergistic integration of plasmonics and micro/nanofluidics in devices and applications in order to enhance performance. There has been significant progress in the emerging field of plasmofluidics in recent years. By utilizing the capability of plasmonics to manipulate light at the nanoscale, combined with the unique optical properties of fluids and precise manipulation via micro/nanofluidics, plasmofluidic technologies enable innovations in lab-on-a-chip systems, reconfigurable photonic devices, optical sensing, imaging, and spectroscopy. In this review article, the most recent advances in plasmofluidics are examined and categorized into plasmon-enhanced functionalities in microfluidics and microfluidics-enhanced plasmonic devices. The former focuses on plasmonic manipulations of fluids, bubbles, particles, biological cells, and molecules at the micro/nanoscale. The latter includes technological advances that apply microfluidic principles to enable reconfigurable plasmonic devices and performance-enhanced plasmonic sensors. The article is concluded with perspectives on the upcoming challenges, opportunities, and possible future directions of the emerging field of plasmofluidics. PMID:26140612

  3. Manufacture of micro fluidic devices by laser welding using thermal transfer printing techniques

    NASA Astrophysics Data System (ADS)

    Klein, R.; Klein, K. F.; Tobisch, T.; Thoelken, D.; Belz, M.

    2016-03-01

    Micro-fluidic devices are widely used today in the areas of medical diagnostics and drug research, as well as for applications within the process, electronics and chemical industry. Microliters of fluids or single cell to cell interactions can be conveniently analyzed with such devices using fluorescence imaging, phase contrast microscopy or spectroscopic techniques. Typical micro-fluidic devices consist of a thermoplastic base component with chambers and channels covered by a hermetic fluid and gas tight sealed lid component. Both components are usually from the same or similar thermoplastic material. Different mechanical, adhesive or thermal joining processes can be used to assemble base component and lid. Today, laser beam welding shows the potential to become a novel manufacturing opportunity for midsize and large scale production of micro-fluidic devices resulting in excellent processing quality by localized heat input and low thermal stress to the device during processing. For laser welding, optical absorption of the resin and laser wavelength has to be matched for proper joining. This paper will focus on a new approach to prepare micro-fluidic channels in such devices using a thermal transfer printing process, where an optical absorbing layer absorbs the laser energy. Advantages of this process will be discussed in combination with laser welding of optical transparent micro-fluidic devices.

  4. Micro-Plasma Transferred Arc Additive Manufacturing for Die and Mold Surface Remanufacturing

    NASA Astrophysics Data System (ADS)

    Jhavar, Suyog; Paul, Christ Prakash; Jain, Neelesh Kumar

    2016-05-01

    Micro-plasma transferred arc (µPTA) additive manufacturing is one of the newest options for remanufacturing of dies and molds surfaces in the near-millimeter range leading to extended usage of the same. We deployed an automatic micro-plasma deposition setup to deposit a wire of 300 µm of AISI P20 tool steel on the substrate of same material for the potential application in remanufacturing of the die and mold surface. Our present research effort is to establish µPTA additive manufacturing as a viable economical and cleaner methodology for potential industrial applications. We undertook the optimization of single weld bead geometry as the first step in our present study. Bead-on-plate trials were conducted to deposit single bead geometry at various processing parameters. The bead geometry (shape and size) and dilution were measured and the parametric dependence was derived. A set of parameters leading to reproducible regular and smooth single bead geometry were identified and used to prepare a thin wall for mechanical testing. The deposits were subjected to material characterization such as microscopic studies, micro-hardness measurements and tensile testing. The process was compared qualitatively with other deposition processes involving high-energy density beams and was found to be advantageous in terms of low initial and running costs with comparable properties. The outcome of the study confirmed the process capability of µPTA deposition leading to deployment of cost-effective and environmentally friendlier technology for die and mold remanufacturing.

  5. Micro-Plasma Transferred Arc Additive Manufacturing for Die and Mold Surface Remanufacturing

    NASA Astrophysics Data System (ADS)

    Jhavar, Suyog; Paul, Christ Prakash; Jain, Neelesh Kumar

    2016-07-01

    Micro-plasma transferred arc ( µPTA) additive manufacturing is one of the newest options for remanufacturing of dies and molds surfaces in the near-millimeter range leading to extended usage of the same. We deployed an automatic micro-plasma deposition setup to deposit a wire of 300 µm of AISI P20 tool steel on the substrate of same material for the potential application in remanufacturing of the die and mold surface. Our present research effort is to establish µPTA additive manufacturing as a viable economical and cleaner methodology for potential industrial applications. We undertook the optimization of single weld bead geometry as the first step in our present study. Bead-on-plate trials were conducted to deposit single bead geometry at various processing parameters. The bead geometry (shape and size) and dilution were measured and the parametric dependence was derived. A set of parameters leading to reproducible regular and smooth single bead geometry were identified and used to prepare a thin wall for mechanical testing. The deposits were subjected to material characterization such as microscopic studies, micro-hardness measurements and tensile testing. The process was compared qualitatively with other deposition processes involving high-energy density beams and was found to be advantageous in terms of low initial and running costs with comparable properties. The outcome of the study confirmed the process capability of µPTA deposition leading to deployment of cost-effective and environmentally friendlier technology for die and mold remanufacturing.

  6. A remotely driven and controlled micro-gripper fabricated from light-induced deformation smart material

    NASA Astrophysics Data System (ADS)

    Huang, Chaolei; Lv, Jiu-an; Tian, Xiaojun; Wang, Yuechao; Liu, Jie; Yu, Yanlei

    2016-09-01

    Micro-gripper is an important tool to manipulate and assemble micro-scale objects. Generally, as micro-gripper is too small to be directly driven by general motors, it always needs special driving devices and suitable structure design. In this paper, two-finger micro-grippers are designed and fabricated, which utilize light-induced deformation smart material to make one of the two fingers. As the smart material is directly driven and controlled by remote lights instead of lines and motors, this light-driven mode simplifies the design of the two-finger micro-gripper and avoids special drivers and complex mechanical structure. In addition, a micro-manipulation experiment system is set up which is based on the light-driven micro-gripper. Experimental results show that this remotely light-driven micro-gripper has ability to manipulate and assemble micro-scale objects both in air and water. Furthermore, two micro-grippers can also work together for cooperation which can further enhance the assembly ability. On the other hand, this kind of remotely controllable micro-gripper that does not require on-board energy storage, can be used in mobile micro-robot as a manipulation hand.

  7. Manufacture of gradient micro-structures of magnesium alloys using two stage extrusion dies

    SciTech Connect

    Hwang, Yeong-Maw; Huang, Tze-Hui; Alexandrov, Sergei; Naimark, Oleg Borisovich; Jeng, Yeau-Ren

    2013-12-16

    This paper aims to manufacture magnesium alloy metals with gradient micro-structures using hot extrusion process. The extrusion die was designed to have a straight channel part combined with a conical part. Materials pushed through this specially-designed die generate a non-uniform velocity distribution at cross sections inside the die and result in different strain and strain rate distributions. Accordingly, a gradient microstructure product can be obtained. Using the finite element analysis, the forming temperature, effective strain, and effective strain rate distributions at the die exit were firstly discussed for various inclination angles in the conical die. Then, hot extrusion experiments with a two stage die were conducted to obtain magnesium alloy products with gradient micro-structures. The effects of the inclination angle on the grain size distribution at cross sections of the products were also discussed. Using a die of an inclination angle of 15°, gradient micro-structures of the grain size decreasing gradually from 17 μm at the center to 4 μm at the edge of product were achieved.

  8. US manufacturers of commercially available stand-alone photovoltaic lighting systems

    SciTech Connect

    McNutt, P

    1994-05-01

    This report introduces photovoltaic (PV) lighting systems, gives some specifications for ordering these systems, and provides a list of some of the manufacturers of these systems in the United States. These PV lighting systems are all commercially available. They are stand-alone systems because they are not tied to the electric utility power grid.

  9. Ultraminiature Broadband Light Source and Method of Manufacturing Same

    NASA Technical Reports Server (NTRS)

    Tuma, Margaret L. (Inventor); Collura, Joseph S. (Inventor); Helvajian, Henry (Inventor); Pocha, Michael D. (Inventor); Meyer, Glenn A. (Inventor); McConaghy, Charles F. (Inventor); Olsen, Barry L. (Inventor); Hansen, William W. (Inventor)

    2010-01-01

    An ultraminiature light source using a double-spiral shaped tungsten filament includes end contact portions which are separated to allow for radial and length-wise unwinding of the spiral. The double-spiral filament is spaced relatively far apart at the end portions thereof so that contact between portions of the filament upon expansion is avoided. The light ource is made by fabricating a double-spiral ultraminiature tungsten filament from tungsten foil and housing the filament in a ceramic package having a reflective bottom and a well wherein the filament is suspended. A vacuum furnace brazing process attaches the filament to contacts of the ceramic package. Finally, a cover with a transparent window is attached onto the top of the ceramic package by solder reflow in a second vacuum furnace process to form a complete hermetically sealed package.

  10. Nano/Micro-Manufacturing of Bioinspired Materials: a Review of Methods to Mimic Natural Structures.

    PubMed

    Zhang, Chaoqun; Mcadams, Daniel A; Grunlan, Jaime C

    2016-08-01

    Through billions of years of evolution and natural selection, biological systems have developed strategies to achieve advantageous unification between structure and bulk properties. The discovery of these fascinating properties and phenomena has triggered increasing interest in identifying characteristics of biological materials, through modern characterization and modeling techniques. In an effort to produce better engineered materials, scientists and engineers have developed new methods and approaches to construct artificial advanced materials that resemble natural architecture and function. A brief review of typical naturally occurring materials is presented here, with a focus on chemical composition, nano-structure, and architecture. The critical mechanisms underlying their properties are summarized, with a particular emphasis on the role of material architecture. A review of recent progress on the nano/micro-manufacturing of bio-inspired hybrid materials is then presented in detail. In this case, the focus is on nacre and bone-inspired structural materials, petals and gecko foot-inspired adhesive films, lotus and mosquito eye inspired superhydrophobic materials, brittlestar and Morpho butterfly-inspired photonic structured coatings. Finally, some applications, current challenges and future directions with regard to manufacturing bio-inspired hybrid materials are provided. PMID:27144950

  11. EDITORIAL: Extreme Ultraviolet Light Sources for Semiconductor Manufacturing

    NASA Astrophysics Data System (ADS)

    Attwood, David

    2004-12-01

    The International Technology Roadmap for Semiconductors (ITRS) [1] provides industry expectations for high volume computer chip fabrication a decade into the future. It provides expectations to anticipated performance and requisite specifications. While the roadmap provides a collective projection of what international industry expects to produce, it does not specify the technology that will be employed. Indeed, there are generally several competing technologies for each two or three year step forward—known as `nodes'. Recent successful technologies have been based on KrF (248 nm), and now ArF (193 nm) lasers, combined with ultraviolet transmissive refractive optics, in what are known as step and scan exposure tools. Less fortunate technologies in the recent past have included soft x-ray proximity printing and, it appears, 157 nm wavelength F2 lasers. In combination with higher numerical aperture liquid emersion optics, 193 nm is expected to be used for the manufacture of leading edge chip performance for the coming five years. Beyond that, starting in about 2009, the technology to be employed is less clear. The leading candidate for the 2009 node is extreme ultraviolet (EUV) lithography, however this requires that several remaining challenges, including sufficient EUV source power, be overcome in a timely manner. This technology is based on multilayer coated reflective optics [2] and an EUV emitting plasma. Following Moore's Law [3] it is expected, for example, that at the 2009 `32 nm node' (printable patterns of 32 nm half-pitch), isolated lines with 18 nm width will be formed in resist (using threshold effects), and that these will be further narrowed to 13 nm in transfer to metalized electronic gates. These narrow features are expected to provide computer chips of 19 GHz clock frequency, with of the order of 1.5 billion transistors per chip [1]. This issue of Journal of Physics D: Applied Physics contains a cluster of eight papers addressing the critical

  12. Experimental Study of Red-, Green-, and Blue-Based Light Emitting Diodes Visible Light Communications for Micro-Projector Application

    NASA Astrophysics Data System (ADS)

    Chou, H.-H.; Liaw, S.-K.; Jiang, J.-S.; Teng, C.

    2016-05-01

    In this research, an experimental short-range visible light communication link using red-, green-, and blue-based light-emitting diodes (LEDs) for portable micro-projector applications is presented. A Reconfigurable design of a post-equalizer aimed to improve the inherent narrow modulation bandwidth of red-, green-, and blue-based LEDs has been experimentally implemented, and its effectiveness with optical filters at the receiver is investigated. Reflective liquid-crystal-on-silicon-based micro-projection architecture, widely used in portable micro-projectors, was set up to evaluate the proposed visible light communication system. The measurement results demonstrated that a significant aggregative bandwidth improvement of 162 MHz as well as an aggregative data transmission rate of nearly 400 Mb/s can be achieved by using a non-return-to-zero-on-off keying (NRZ-OOK) modulation scheme based on only one polarization state of incident light without any offline signal processing.

  13. Waste generation and utilisation in micro-sized furniture-manufacturing enterprises in Turkey.

    PubMed

    Top, Y

    2015-01-01

    The number of small-scale businesses within most national economies is generally high, especially in developing countries. Often these businesses have a weak economic status and limited environmental awareness. The type and amount of waste produced, and the recycling methods adopted by these businesses during their operation can have negative effects on the environment. This study investigated the types of waste generated and the recycling methods adopted in micro-sized enterprises engaged in the manufacture of furniture. An assessment was also made of whether the characteristics of the enterprise had any effect on the waste recycling methods that were practised. A survey was conducted of 31 enterprises in the furniture industry in Gumushane province, Turkey, which is considered a developing economy. Surveys were undertaken via face-to-face interviews. It was found that medium-density fibreboard (MDF), and to a lesser extent, chipboard, were used in the manufacture of furniture, and two major types of waste in the form of fine dust and small fragments of board are generated during the cutting of these boards. Of the resulting composite board waste, 96.9% was used for heating homes and workplaces, where it was burnt under conditions of incomplete combustion. Enterprises were found to have adopted other methods to utilise their wastes in addition to using them as fuel. Such enterprises include those operating from a basement or first floor of a building in the cities, those continuing production throughout the year, those in need for capital and those enterprises not operating a dust-collection system. PMID:25453314

  14. Study of Selecting on Light Source Used for Micro-algae Cultivation in Space

    NASA Astrophysics Data System (ADS)

    Ai, Weidang; Ai, Weidang; Guo, Shuang-Sheng; Gao, Feng; Tang, Yong-Kang; Qin, Li-Feng

    To select suitable light source for micro-algae cultivation in future space station, the selected Spirulina plastensis(No.7) were cultured under different lightening qualities, including six light sources that were made up of different combinations of red and blue light-emitting diode(LED). The growth, photosynthetic efficiency and nutrition quality of the Spirulina, were analyzed. From the experiments, the red light may promote the cumulation of biomass of the Spirulina, and the cumulating rate was the highest under all red light source, but the syntheses of protein, phycobiliprotein, β-carotene, VE and other nutrients needs a certain portion of blue light; yet, the complete blue light condition is not favorable to the growth of Spirulina, and may bring pollution by chlorella and other kinds of micro-algae. It is concluded that the LEDs can be used as the light resource of micro-algae cultivation. The normal growth and development of microalgae need two light sources of both red and blue LEDs. The comprehensive analyses of the various factors that affect the growth of Spirulina, such as nutrition quality and photosynthetic activities, etc., showed that the combination of 80% red and 20% blue LED is the optimum one among those tested combinations. Key word: light-emitting diode; micro-algae; controlled ecological life support system (CELSS); space cultivation

  15. Creation of a U.S. Phosphorescent OLED Lighting Panel Manufacturing Facility

    SciTech Connect

    Hack, Michael

    2013-09-30

    Universal Display Corporation (UDC) has pioneered high efficacy phosphorescent OLED (PHOLED™) technology to enable the realization of an exciting new form of high quality, energy saving solid-date lighting. In laboratory test devices, we have demonstrated greater than 100 lm/W conversion efficacy. In this program, Universal Display will demonstrate the scalability of its proprietary UniversalPHOLED technology and materials for the manufacture of white OLED lighting panels that meet commercial lighting targets. Moser Baer Technologies will design and build a U.S.- based pilot facility. The objective of this project is to establish a pilot phosphorescent OLED (PHOLED) manufacturing line in the U.S. Our goal is that at the end of the project, prototype lighting panels could be provided to U.S. luminaire manufacturers for incorporation into products to facilitate the testing of design concepts and to gauge customer acceptance, so as to facilitate the growth of the embryonic U.S. OLED lighting industry. In addition, the team will provide a cost of ownership analysis to quantify production costs including OLED performance metrics which relate to OLED cost such as yield, materials usage, cycle time, substrate area, and capital depreciation. This project was part of a new DOE initiative designed to help establish and maintain U.S. leadership in this program will support key DOE objectives by showing a path to meet Department of Energy Solid-State Lighting Manufacturing Roadmap cost targets, as well as meeting its efficiency targets by demonstrating the energy saving potential of our technology through the realization of greater than 76 lm/W OLED lighting panels by 2012.

  16. PowerLight Corporation Lean Manufacturing, PV Manufacturing R&D Phase I Report: 6 December 2001--31 March 2003

    SciTech Connect

    Hargis, L; Botkin, J.

    2005-06-01

    PowerLight Corporation (PowerLight) has completed Phase I of its PV Manufacturing R&D subcontract, ''PowerGuard Lean Manufacturing,'' Subcontract No. NDO-1-30628-04. The overall technical goal of this project was to reduce the cost of PowerGuard manufacturing while simultaneously improving product quality. This will enable PowerLight to scale up production capacity as the market for PowerGuard continues to grow. Through the introduction of world-class lean manufacturing techniques, PowerLight was to cut out waste in the manufacturing process of PowerGuard. The manufacturing process was to be overhauled with an objective of removing as much as possible those steps that do not add value to the product. Quality of finished goods was also to be improved through the use of statistical process control and error-proofing in the manufacturing process. Factory operations were also to be addressed to streamline those factory activities that support the manufacturing process. This report de tails the progress made toward the above listed goals during the first phase of this subcontract.

  17. Shedding new light on historical metal samples using micro-focused synchrotron X-ray fluorescence and spectroscopy

    NASA Astrophysics Data System (ADS)

    Grolimund, D.; Senn, M.; Trottmann, M.; Janousch, M.; Bonhoure, I.; Scheidegger, A. M.; Marcus, M.

    2004-10-01

    insights concerning the nature and origin of used raw materials as well as regarding employed processing techniques during historic iron fabrication and weapon manufacturing.The study demonstrates the potential of oxidation state and mineral phase mapping based on energy selective micro-XRF maps and spectroscopic phase identification. Such a spatially resolved recording of the chemical speciation is based on X-ray absorption spectroscopy. This analytical technique is exclusive to synchrotron light sources. However, the steadily increasing number of available synchrotron-based X-ray microprobes allows nowadays for more routine utilization of such micro-XAS techniques.

  18. 49 CFR 579.21 - Reporting requirements for manufacturers of 5,000 or more light vehicles annually.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... each make, model, and model year of light vehicle manufactured during the reporting period and the nine... defect in the manufacturer's vehicle, together with each incident involving one or more deaths occurring... the manufacturer's vehicle, if that vehicle is identical or substantially similar to a vehicle...

  19. 49 CFR 579.21 - Reporting requirements for manufacturers of 5,000 or more light vehicles annually.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... each make, model, and model year of light vehicle manufactured during the reporting period and the nine... defect in the manufacturer's vehicle, together with each incident involving one or more deaths occurring... the manufacturer's vehicle, if that vehicle is identical or substantially similar to a vehicle...

  20. 49 CFR 579.21 - Reporting requirements for manufacturers of 5,000 or more light vehicles annually.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... each make, model, and model year of light vehicle manufactured during the reporting period and the nine... defect in the manufacturer's vehicle, together with each incident involving one or more deaths occurring... the manufacturer's vehicle, if that vehicle is identical or substantially similar to a vehicle...

  1. Customized homogenization and shaping of LED light by micro cells arrays

    NASA Astrophysics Data System (ADS)

    Asoubar, Daniel; Hellmann, Christian; Schweitzer, Hagen; Kuhn, Michael; Wyrowski, Frank

    2015-03-01

    The energy-efficient use of LED light requires the development of compact illumination systems for the customized homogenization and shaping of partially-coherent LED light. Therefore a design concept which is based on arrays of aperiodic micro structures, namely cells, for primary or secondary optics is introduced. Each cell of the array deflects locally the light into predefined directions and results in a light spot in the target plane. The light spots of all array cells together form the desired light pattern. The performance of three different cell geometries (linear gratings, micro prisms andmicromirrors) on the homogenization and shaping ofmonochromatic as well as white light LEDs is demonstrated. For the realistic evaluation of the illumination system an LED model including power spectrum, polarization, spatial and temporal coherence is chosen. Furthermore wave-optical effects like diffraction at the cell apertures are taken into account. For the grating cells arrays a rigorous analysis of the diffraction efficiencies is included.

  2. X-ray micro-Tomography at the Advanced Light Source

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The X-ray micro-Tomography Facility at the Advanced Light Source has been in operation since 2004. The source is a superconducting bend magnet of critical energy 10.5KeV; photon energy coverage is 8-45 KeV in monochromatic mode, and a filtered white light option yields useful photons up to 50 KeV. A...

  3. Nano-sized light mill drives micro-sized disk

    SciTech Connect

    2010-01-01

    Filmed through water, a silica microdisk embedded with a gold, gammadion-shaped light mill nanomotor rotates in one direction under illumination from laser light at 810 nanometers wavelength. When the wavelength is switched to 1,715 nanometers, the rotational direction is reversed. Torque is produced when the laser light frequencies resonate with the frequencie of the metal's plasmons. (Movie courtesy of Zhang group)

  4. Light controlled drug delivery containers based on spiropyran doped liquid crystal micro spheres

    PubMed Central

    Petriashvili, Gia; Devadze, Lali; Zurabishvili, Tsisana; Sepashvili, Nino; Chubinidze, Ketevan

    2016-01-01

    We have developed a novel, light activated drug delivery containers, based on spiropyran doped liquid crystal micro spheres. Upon exposure to UV/violet light, the spiropyran molecules entrapped inside the nematic liquid crystal micro spheres, interconvert from the hydrophobic, oil soluble form, to the hydrophilic, water soluble merocyanine one, which stimulates the translocation of the merocyanine molecules across the nematic liquid crystal-water barrier and results their homogeneous distribution throughout in an aqueous environment. Light controllable switching property and extremely high solubility of spiropyran in the nematic liquid crystal, promise to elaborate a novel and reliable vehicles for the drug delivery systems. PMID:26977353

  5. Trapping light with micro lenses in thin film organic photovoltaic cells.

    PubMed

    Tvingstedt, Kristofer; Dal Zilio, Simone; Inganäs, Olle; Tormen, Massimo

    2008-12-22

    We demonstrate a novel light trapping configuration based on an array of micro lenses in conjunction with a self aligned array of micro apertures located in a highly reflecting mirror. When locating the light trapping element, that displays strong directional asymmetric transmission, in front of thin film organic photovoltaic cells, an increase in cell absorption is obtained. By recycling reflected photons that otherwise would be lost, thinner films with more beneficial electrical properties can effectively be deployed. The light trapping element enhances the absorption rate of the solar cell and increases the photocurrent by as much as 25%. PMID:19104592

  6. Light controlled drug delivery containers based on spiropyran doped liquid crystal micro spheres.

    PubMed

    Petriashvili, Gia; Devadze, Lali; Zurabishvili, Tsisana; Sepashvili, Nino; Chubinidze, Ketevan

    2016-02-01

    We have developed a novel, light activated drug delivery containers, based on spiropyran doped liquid crystal micro spheres. Upon exposure to UV/violet light, the spiropyran molecules entrapped inside the nematic liquid crystal micro spheres, interconvert from the hydrophobic, oil soluble form, to the hydrophilic, water soluble merocyanine one, which stimulates the translocation of the merocyanine molecules across the nematic liquid crystal-water barrier and results their homogeneous distribution throughout in an aqueous environment. Light controllable switching property and extremely high solubility of spiropyran in the nematic liquid crystal, promise to elaborate a novel and reliable vehicles for the drug delivery systems. PMID:26977353

  7. Improvement of illumination uniformity for LED flat panel light by using micro-secondary lens array.

    PubMed

    Lee, Hsiao-Wen; Lin, Bor-Shyh

    2012-11-01

    LED flat panel light is an innovative lighting product in recent years. However, current flat panel light products still contain some drawbacks, such as narrow lighting areas and hot spots. In this study, a micro-secondary lens array technique was proposed and applied for the design of the light guide surface to improve the illumination uniformity. By using the micro-secondary lens array, the candela distribution of the LED flat panel light can be adjusted to similar to batwing distribution to improve the illumination uniformity. The experimental results show that the enhancement of the floor illumination uniformity is about 61%, and that of the wall illumination uniformity is about 20.5%. PMID:23187654

  8. Improvement of illumination uniformity for LED flat panel light by using micro-secondary lens array.

    PubMed

    Lee, Hsiao-Wen; Lin, Bor-Shyh

    2012-11-01

    LED flat panel light is an innovative lighting product in recent years. However, current flat panel light products still contain some drawbacks, such as narrow lighting areas and hot spots. In this study, a micro-secondary lens array technique was proposed and applied for the design of the light guide surface to improve the illumination uniformity. By using the micro-secondary lens array, the candela distribution of the LED flat panel light can be adjusted to similar to batwing distribution to improve the illumination uniformity. The experimental results show that the enhancement of the floor illumination uniformity is about 61%, and that of the wall illumination uniformity is about 20.5%. PMID:23326825

  9. Micro/nano-hybrid lens for enhancing light extraction using micro-milling and anodic aluminium oxide (AAO)

    NASA Astrophysics Data System (ADS)

    Kim, Shin Hyeong; Kim, Min Gu; Kang, Jeong Jin; Lee, Pyeong An; Kim, Bo Hyun; Cho, Young Hak

    2016-01-01

    In the recent past there has been much research towards increasing the transmission of light in optical systems by reducing the Fresnel reflection of radiation, as the reflection of light from surfaces seriously decreases the performance of an optical device. These drawbacks have been overcome by mainly two methods, which are anti-reflective coating and anti-reflective nanostructure formation. In this study, we developed a simple fabrication process for Al micro/nano hybrid lens (MNHL) moulds for efficient light extraction using micro-milling and anodic aluminum oxide (AAO). From these moulds, two different types of polymer MNHL were fabricated using hot-embossing; one was a polymer MNHL that was covered with nanostructures over the entire surface, and the other was one for which only the microlens surface was covered with nanostructures. Two different types of polymer MNHLs were evaluated and compared with each other concerning the light extraction performance. The MNHL with nanostructures only on the microlens surface exhibited a higher light extraction performance than the other by 20.7%. It is expected that the fabricated MNHL can be used for the amplification of small signals when observing the presence of bio-molecules dyed with a fluorescent material.

  10. Anisotropic micro-cloths fabricated from DNA-stabilized carbon nanotubes: one-stop manufacturing with electrode needles

    NASA Astrophysics Data System (ADS)

    Frusawa, Hiroshi; Yoshii, Gen

    2015-03-01

    Among a variety of solution-based approaches to fabricate anisotropic films of aligned carbon nanotubes (CNTs), we focus on the dielectrophoretic assembly method using AC electric fields in DNA-stabilized CNT suspensions. We demonstrate that a one-stop manufacturing system using electrode needles can draw anisotropic DNA-CNT hybrid films of 10 to 100 µm in size (i.e., free-standing DNA-CNT micro-cloths) from the remaining suspension into the atmosphere while maintaining structural order. It has been found that a maximal degree of polarization (ca. 40%) can be achieved by micro-cloths fabricated from a variety of DNA-CNT mixtures. Our results suggest that the one-stop method can impart biocompatibility to the downsized CNT films and that the DNA-stabilized CNT micro-cloths directly connected to an electrode could be useful for biofuel cells in terms of electron transfer and/or enzymatic activity.

  11. Study on micro-bend light transmission performance of novel liquid-core optical fiber

    NASA Astrophysics Data System (ADS)

    Ma, Junyan; Zhao, Zhimin; Wang, Kaisheng; Guo, Linfeng

    2007-01-01

    With the increasing development of material technology and electronic integration technology, optical fiber and its using in smart structure have become hot in the field of material research. And liquid-core optical fiber is a special kind of optical fiber, which is made using liquid material as core and polymer material as optical layer and protective covering, and it has the characteristics of large core diameter, high numerical aperture, large-scope and efficient spectrum transmission and long life for using. So the liquid-core optical fiber is very suitable for spectrum cure, ultraviolet solidification, fluorescence detection, criminal investigation and evidence obtainment, etc, and especially as light transfer element in some new structures for the measurement of some signals, such as concentration, voltage, temperature, light intensity and so on. In this paper, the novel liquid-core optical fiber is self-made, and then through the test of its light transmission performance in free state, the relation between axial micro-bend and light-intensity loss are presented. When the liquid-core optical fiber is micro-bent axially, along with the axial displacement's increase, output power of light is reducing increasingly, and approximately has linear relation to micro-displacement in a range. According to the results liquid-core fiber-optic micro-bend sensor can be designed to measure micro-displacement of the tested objects. Experimental data and analysis provide experimental basis for further application of liquid-core optical fiber.

  12. Cyanobacteria use micro-optics to sense light direction

    PubMed Central

    Schuergers, Nils; Lenn, Tchern; Kampmann, Ronald; Meissner, Markus V; Esteves, Tiago; Temerinac-Ott, Maja; Korvink, Jan G; Lowe, Alan R; Mullineaux, Conrad W; Wilde, Annegret

    2016-01-01

    Bacterial phototaxis was first recognized over a century ago, but the method by which such small cells can sense the direction of illumination has remained puzzling. The unicellular cyanobacterium Synechocystis sp. PCC 6803 moves with Type IV pili and measures light intensity and color with a range of photoreceptors. Here, we show that individual Synechocystis cells do not respond to a spatiotemporal gradient in light intensity, but rather they directly and accurately sense the position of a light source. We show that directional light sensing is possible because Synechocystis cells act as spherical microlenses, allowing the cell to see a light source and move towards it. A high-resolution image of the light source is focused on the edge of the cell opposite to the source, triggering movement away from the focused spot. Spherical cyanobacteria are probably the world’s smallest and oldest example of a camera eye. DOI: http://dx.doi.org/10.7554/eLife.12620.001 PMID:26858197

  13. Investigations on the micro-scale surface interactions at the tool and workpiece interface in micro-manufacturing of bipolar plates for proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Peker, Mevlut Fatih

    the surface topography changes during long-run micro-stamping of BPPs, and establish relationships between surface roughness--corrosion resistance and surface roughness-contact resistance characteristics of BPPs. Formability levels of formed BPPs and repeatability characteristics of the process were investigated. In addition, blank thickness changes, von-Mises stress, plastic strain levels and distributions of micro-stamping process were determined via finite element analysis (FEA). Test results revealed that the surface roughness change for the stamping dies and BPPs was unsteady (no trend) due to the continuous change of surface topography (i.e. asperity deformation). Sub-micron range local plastic deformations on stamping dies led to surface topography changes on BPP in long-run manufacturing case. As surface defects trigger corrosion, the correlation between surface roughness and corrosion resistance of BPPs was found to be direct. Increasing number of surface irregularities (asperities) lowered contact surface area that resulted in increased contact resistance. ZrN coated BPPs, on the other hand, did not change surface roughness, however; it improved the protection of BPPs against corrosion significantly. In addition, ZrN coating increased the conductivity of BPPs and reduced the contact resistance between BPP and gas diffusion layer (GDL), at certain extent. As dimensional stability and repeatability was confirmed in forming of both uncoated and coated BPPs during the long run manufacturing, different formability levels were achieved for coated and uncoated samples. Lower channel height values were obtained for coated plates because of the different surface hardness of uncoated and coated plates. In tribological size effect part of study, micro stamping experiments using three different dies with distinct channel height values at different stamping force levels were performed. It was concluded that decrease in forming die dimensions led to increase in

  14. Micro-electromechanical spatial light modulators with integrated electronics

    NASA Astrophysics Data System (ADS)

    Cornelissen, Steven; Bifano, Thomas G.; Bierden, Paul A.

    2002-02-01

    This paper describes design and development of a microelectromechanical, micromachined spatial light modulator ((mu) SLM) integrated with complementary metal- oxide semiconductor (CMOS) electronics, for control of optical phase in phase-only optical correlators. The (mu) SLM will consist of a large array of piston-motion MEMS mirror segments (pixels) each of which capable of altering the phase of reflected light by up to one wavelength for infrared (1.5 micrometers ) illumination. Results of a proof-of- concept study are presented along with an electromechanical model and details of the fabrication process for the (mu) SLM.

  15. Fabrication, characterization and applications of flexible vertical InGaN micro-light emitting diode arrays.

    PubMed

    Tian, Pengfei; McKendry, Jonathan J D; Gu, Erdan; Chen, Zhizhong; Sun, Yongjian; Zhang, Guoyi; Dawson, Martin D; Liu, Ran

    2016-01-11

    Flexible vertical InGaN micro-light emitting diode (micro-LED) arrays have been fabricated and characterized for potential applications in flexible micro-displays and visible light communication. The LED epitaxial layers were transferred from initial sapphire substrates to flexible AuSn substrates by metal bonding and laser lift off techniques. The current versus voltage characteristics of flexible micro-LEDs degraded after bending the devices, but the electroluminescence spectra show little shift even under a very small bending radius 3 mm. The high thermal conductivity of flexible metal substrates enables high thermal saturation current density and high light output power of the flexible micro-LEDs, benefiting the potential applications in flexible high-brightness micro-displays and high-speed visible light communication. We have achieved ~40 MHz modulation bandwidth and 120 Mbit/s data transmission speed for a typical flexible micro-LED. PMID:26832299

  16. Development of micro-incandescent light sources on silicon substrate

    NASA Astrophysics Data System (ADS)

    Gollub, A. H.; Carvalho, D. O.; Rehder, G.; Alayo, M. I.

    2010-02-01

    In this work we report one simple fabrication process to build incandescent microlamps over silicon microtips. By taking advantage of the underetch observed when the Si substrate is anisotropically etched in KOH solutions, specific silicon microtips are created which serve as mechanical supports for the incandescent light sources. A thin film of chrome is deposited by sputtering technique above the microtip and defined by photolitography in order to create an electrical resistance. Consequently, the electrical energy transformed in heat is concentrated in a small spot achieving temperatures high enough to produce incandescent light similar to a blackbody spectrum. To reduce the heat loss caused by the high thermal conductivity of silicon, a layer of silicon dioxide (SiO2) placed between substrate and metal was necessary to avoid the use of large electrical currents to generate the incandescence in the light source. A SiO2 film is also used as a protection layer against moisture and specially oxygen, since at high temperatures chrome can easily oxidize losing its electrical conductivity. As the microtips are very tall compared to photoresist thickness, the lift-off process was needed in order to guarantee that the top of the microtip would be covered by chrome. The results showed that it is possible to produce light in all visible spectrum by applying electrical power higher than 4 W.

  17. Multiscale Micro-Nano Nested Structures: Engineered Surface Morphology for Efficient Light Escaping in Organic Light-Emitting Diodes.

    PubMed

    Zhou, Lei; Dong, Xiaoxuan; Zhou, Yun; Su, Wenming; Chen, Xiaolian; Zhu, Yufu; Shen, Su

    2015-12-01

    Various micro-to-nanometer scale structures are extremely attractive for light escaping in organic light-emitting diodes. To develop and optimize such structures, an innovative approach was demonstrated for the first time to fabricate multiscale micro-nano nested structures by photolithography with a well-designed mask pattern followed by a controllable thermal reflow process. The experimental and theoretical characterizations verify that these unique nested structures hold the capability of light concentration, noticeable low haze, and efficient antireflection. As a proof-of-concept, the incorporation of this pattern onto the glass substrate efficiently facilitates light escaping from the device, resulting in current efficiency 1.60 times and external quantum efficiency 1.63 times that of a control flat device, respectively. Moreover, compared to a hexagonally arranged microlens array and quasi-random biomimetic moth eye nanostructures, the nested structures proposed here can magically tune the spatial emission profile to comply with the Lambertian radiation pattern. Hence, this novel structure is expected to be of great potential in related ubiquitous optoelectronic applications and provide scientific inspiration to other novel multiscale micro-nanostructure research. PMID:26575428

  18. Enhanced light collection in fluorescence microscopy using self-assembled micro-reflectors

    NASA Astrophysics Data System (ADS)

    Göröcs, Zoltán; McLeod, Euan; Ozcan, Aydogan

    2015-06-01

    In fluorescence microscopy, the signal-to-noise ratio (SNR) of the optical system is directly linked to the numerical aperture (NA) of the microscope objective, which creates detection challenges for low-NA, wide-field and high-throughput imaging systems. Here we demonstrate a method to increase the light collection efficiency from micron-scale fluorescent objects using self-assembled vapor-condensed polyethylene glycol droplets, which act as micro-reflectors for fluorescent light. Around each fluorescent particle, a liquid meniscus is formed that increases the excitation efficiency and redirects part of the laterally-emitted fluorescent light towards the detector due to internal reflections at the liquid-air interface of the meniscus. The three-dimensional shape of this micro-reflector can be tuned as a function of time, vapor temperature, and substrate contact angle, providing us optimized SNR performance for fluorescent detection. Based on these self-assembled micro-reflectors, we experimentally demonstrate ~2.5-3 fold enhancement of the fluorescent signal from 2-10 μm sized particles. A theoretical explanation of the formation rate and shapes of these micro-reflectors is presented, along with a ray tracing model of their optical performance. This method can be used as a sample preparation technique for consumer electronics-based microscopy and sensing tools, thus increasing the sensitivity of low-NA systems that image fluorescent micro-objects.

  19. Enhanced light collection in fluorescence microscopy using self-assembled micro-reflectors

    PubMed Central

    Göröcs, Zoltán; McLeod, Euan; Ozcan, Aydogan

    2015-01-01

    In fluorescence microscopy, the signal-to-noise ratio (SNR) of the optical system is directly linked to the numerical aperture (NA) of the microscope objective, which creates detection challenges for low-NA, wide-field and high-throughput imaging systems. Here we demonstrate a method to increase the light collection efficiency from micron-scale fluorescent objects using self-assembled vapor-condensed polyethylene glycol droplets, which act as micro-reflectors for fluorescent light. Around each fluorescent particle, a liquid meniscus is formed that increases the excitation efficiency and redirects part of the laterally-emitted fluorescent light towards the detector due to internal reflections at the liquid-air interface of the meniscus. The three-dimensional shape of this micro-reflector can be tuned as a function of time, vapor temperature, and substrate contact angle, providing us optimized SNR performance for fluorescent detection. Based on these self-assembled micro-reflectors, we experimentally demonstrate ~2.5-3 fold enhancement of the fluorescent signal from 2-10 μm sized particles. A theoretical explanation of the formation rate and shapes of these micro-reflectors is presented, along with a ray tracing model of their optical performance. This method can be used as a sample preparation technique for consumer electronics-based microscopy and sensing tools, thus increasing the sensitivity of low-NA systems that image fluorescent micro-objects. PMID:26083081

  20. Angularly-resolved elastic light scattering of micro-particles

    NASA Astrophysics Data System (ADS)

    Aptowicz, Kevin B.

    From microbiology to astrophysics, the scientific community has long embraced elastic light scattering from small particles as a diagnostic tool. Elastic light scattering has an extremely large scattering cross-section, allowing for single particle interrogation. This is critical in applications where trace amounts of suspect particles are to be detected in a diverse background of natural aerosols. By angularly-resolving the elastically scattered light, features can be detected in these patterns that are sensitive to a particle's morphology (shape, size, internal structure, and composition). An apparatus to collect LA TAOS (Large-Angle Two-dimensional Angular Optical Scattering) patterns from single particles in-situ and in real-time was designed and constructed. The setup utilizes a cross-beam trigger system to minimize the effects of the aberration coma stemming from the main collection optic, an ellipsoidal mirror. LA TAOS patterns of ambient aerosols were collected and analyzed. Approximately 15% of the ambient aerosol had a sphere-like shape. The refractive index of these spheres was estimated by curve-fitting to Lorenz-Mie theory. In addition, the island features prevalent in the LA TAOS pattern were analyzed. Metrics generated from these were used to get partial discrimination between clusters of Bacillus subtilis spores (a simulant for anthrax) and aerosol particles found in the ambient atmosphere. A novel experimental setup for collecting simultaneously LA TAOS patterns at two wavelengths in the mid-infrared was also implemented. With this setup, the relative strength of single-particle absorption could be discerned at the two illuminating wavelengths.

  1. Miniaturized optoelectronic tweezers controlled by GaN micro-pixel light emitting diode arrays.

    PubMed

    Zarowna-Dabrowska, Alicja; Neale, Steven L; Massoubre, David; McKendry, Jonathan; Rae, Bruce R; Henderson, Robert K; Rose, Mervyn J; Yin, Huabing; Cooper, Jonathan M; Gu, Erdan; Dawson, Martin D

    2011-01-31

    A novel, miniaturized optoelectronic tweezers (OET) system has been developed using a CMOS-controlled GaN micro-pixelated light emitting diode (LED) array as an integrated micro-light source. The micro-LED array offers spatio-temporal and intensity control of the emission pattern, enabling the creation of reconfigurable virtual electrodes to achieve OET. In order to analyse the mechanism responsible for particle manipulation in this OET system, the average particle velocity, electrical field and forces applied to the particles were characterized and simulated. The capability of this miniaturized OET system for manipulating and trapping multiple particles including polystyrene beads and live cells has been successfully demonstrated. PMID:21369093

  2. High angular accuracy manufacture method of micro v-grooves based on tool alignment by on-machine measurement.

    PubMed

    Zhang, Xiaodong; Jiang, Lili; Zeng, Zhen; Fang, Fengzhou; Liu, Xianlei

    2015-10-19

    Micro v-groove has found wide applications in optical areas as one of the most important structures. However, its performance is significantly affected by its angular geometry accuracy. The diamond cutting has been commonly used as the fabrication method of micro v-groove, but it is still difficult to guarantee the cutting tool angle, which is limited by the measurement accuracy in the manufacture and mounting of the diamond tool. A cutting tool alignment method based on the on-machine measurement is proposed to improve the fabricated quality of the v-groove angle. An on-machine probe is employed to scan the v-groove geometrical deviation precisely. The system errors model, data processing algorithm and tool alignment methods are analyzed in details. Experimental results show that the measurement standard deviation within 0.01° can be achieved. Retro-reflection mirrors are fabricated and measured finally by the proposed method for verification. PMID:26480443

  3. Investigations on the micro-scale surface interactions at the tool and workpiece interface in micro-manufacturing of bipolar plates for proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Peker, Mevlut Fatih

    the surface topography changes during long-run micro-stamping of BPPs, and establish relationships between surface roughness--corrosion resistance and surface roughness-contact resistance characteristics of BPPs. Formability levels of formed BPPs and repeatability characteristics of the process were investigated. In addition, blank thickness changes, von-Mises stress, plastic strain levels and distributions of micro-stamping process were determined via finite element analysis (FEA). Test results revealed that the surface roughness change for the stamping dies and BPPs was unsteady (no trend) due to the continuous change of surface topography (i.e. asperity deformation). Sub-micron range local plastic deformations on stamping dies led to surface topography changes on BPP in long-run manufacturing case. As surface defects trigger corrosion, the correlation between surface roughness and corrosion resistance of BPPs was found to be direct. Increasing number of surface irregularities (asperities) lowered contact surface area that resulted in increased contact resistance. ZrN coated BPPs, on the other hand, did not change surface roughness, however; it improved the protection of BPPs against corrosion significantly. In addition, ZrN coating increased the conductivity of BPPs and reduced the contact resistance between BPP and gas diffusion layer (GDL), at certain extent. As dimensional stability and repeatability was confirmed in forming of both uncoated and coated BPPs during the long run manufacturing, different formability levels were achieved for coated and uncoated samples. Lower channel height values were obtained for coated plates because of the different surface hardness of uncoated and coated plates. In tribological size effect part of study, micro stamping experiments using three different dies with distinct channel height values at different stamping force levels were performed. It was concluded that decrease in forming die dimensions led to increase in

  4. Laser machined macro and micro structures on glass for enhanced light trapping in solar cells

    NASA Astrophysics Data System (ADS)

    Moore, David; Rahman, Mahfujur; Dowling, Denis P.; McNally, Patrick J.; Brabazon, Dermot

    2013-03-01

    In order to increase the efficiency of solar cell modules it is necessary to make the optimum use of light incident upon them. Much research has been done on improving light absorption through front surface texturisation and light trapping schemes. Laser light is commonly used in industry for various applications including marking and texturisation. By controlling laser parameters, it is possible to tailor macro and micro structures in most materials. The CO2 laser used in this investigation emits radiation at 10.6 μm with the ability to pulse in the micro-second range. The laser was used to ablate grooved textures in the fused quartz material, used in this study as the light trapping medium, following which an analysis of the effects of the laser parameters on the texture geometry and surface morphology was performed through a combination of cross sectioning and scanning electron microscopy. Transmission through the textured glass was improved for most samples after acid etching. The light trapping effects of the best performing textures were analysed by investigating the effects on a silicon solar cell's performance at varying angles of incidence. Results indicated a significant increase in light trapping when light was incident at acute angles. For an angle of incidence of 10∘ a relative increase in efficiency of up to 51 % was observed.

  5. Method of Manufacturing a Light Emitting, Photovoltaic or Other Electronic Apparatus and System

    NASA Technical Reports Server (NTRS)

    Ray, William Johnstone (Inventor); Lowenthal, Mark David (Inventor); Shotton, Neil O. (Inventor); Blanchard, Richard A. (Inventor); Lewandowski, Mark Allan (Inventor); Fuller, Kirk A. (Inventor); Frazier, Donald Odell (Inventor)

    2014-01-01

    The present invention provides a method of manufacturing an electronic apparatus, such as a lighting device having light emitting diodes (LEDs) or a power generating device having photovoltaic diodes. The exemplary method includes depositing a first conductive medium within a plurality of channels of a base to form a plurality of first conductors; depositing within the plurality of channels a plurality of semiconductor substrate particles suspended in a carrier medium; forming an ohmic contact between each semiconductor substrate particle and a first conductor; converting the semiconductor substrate particles into a plurality of semiconductor diodes; depositing a second conductive medium to form a plurality of second conductors coupled to the plurality of semiconductor diodes; and depositing or attaching a plurality of lenses suspended in a first polymer over the plurality of diodes. In various embodiments, the depositing, forming, coupling and converting steps are performed by or through a printing process.

  6. Method of Manufacturing a Light Emitting, Photovoltaic or Other Electronic Apparatus and System

    NASA Technical Reports Server (NTRS)

    Ray, William Johnstone (Inventor); Lowenthal, Mark D. (Inventor); Shotton, Neil O. (Inventor); Blanchard, Richard A. (Inventor); Lewandowski, Mark Allan (Inventor); Fuller, Kirk A. (Inventor); Frazier, Donald Odell (Inventor)

    2013-01-01

    The present invention provides a method of manufacturing an electronic apparatus, such as a lighting device having light emitting diodes (LEDs) or a power generating device having photovoltaic diodes. The exemplary method includes forming at least one first conductor coupled to a base; coupling a plurality of substantially spherical substrate particles to the at least one first conductor; converting the substrate particles into a plurality of substantially spherical diodes; forming at least one second conductor coupled to the substantially spherical diodes; and depositing or attaching a plurality of substantially spherical lenses suspended in a first polymer. The lenses and the suspending polymer have different indices of refraction. In some embodiments, the lenses and diodes have a ratio of mean diameters or lengths between about 10:1 and 2:1. In various embodiments, the forming, coupling and converting steps are performed by or through a printing process.

  7. Method of Manufacturing a Light Emitting, Photovoltaic or Other Electronic Apparatus and System

    NASA Technical Reports Server (NTRS)

    Ray, William Johnstone (Inventor); Lowenthal, Mark D. (Inventor); Shotton, Neil O. (Inventor); Blanchard, Richard A. (Inventor); Lewandowski, Mark Allan (Inventor); Fuller, Kirk A. (Inventor); Frazier, Donald Odell (Inventor)

    2013-01-01

    The present invention provides a method of manufacturing an electronic apparatus, such as a lighting device having light emitting diodes (LEDs) or a power generating device having photovoltaic diodes. The exemplary method includes forming at least one first conductor coupled to a base; coupling a plurality of substrate particles to the at least one first conductor; converting the plurality of substrate particles into a plurality of diodes; forming at least one second conductor coupled to the plurality of spherical diodes; and depositing or attaching a plurality of substantially spherical lenses suspended in a first polymer, with the lenses and the suspending polymer having different indices of refraction. In some embodiments, the lenses and diodes have a ratio of mean diameters or lengths between about 10:1 and 2:1. In various embodiments, the forming, coupling and converting steps are performed by or through a printing process.

  8. Method of manufacturing a light emitting, photovoltaic or other electronic apparatus and system

    NASA Technical Reports Server (NTRS)

    Ray, William Johnstone (Inventor); Lowenthal, Mark D. (Inventor); Shotton, Neil O. (Inventor); Blanchard, Richard A. (Inventor); Lewandowski, Mark Allan (Inventor); Fuller, Kirk A. (Inventor); Frazier, Donald Odell (Inventor)

    2012-01-01

    The present invention provides a method of manufacturing an electronic apparatus, such as a lighting device having light emitting diodes (LEDs) or a power generating device having photovoltaic diodes. The exemplary method includes depositing a first conductive medium within a plurality of channels of a base to form a plurality of first conductors; depositing within the plurality of channels a plurality of semiconductor substrate particles suspended in a carrier medium; forming an ohmic contact between each semiconductor substrate particle and a first conductor; converting the semiconductor substrate particles into a plurality of semiconductor diodes; depositing a second conductive medium to form a plurality of second conductors coupled to the plurality of semiconductor diodes; and depositing or attaching a plurality of lenses suspended in a first polymer over the plurality of diodes. In various embodiments, the depositing, forming, coupling and converting steps are performed by or through a printing process.

  9. Grating micro-dot patterned light guide plates for LED backlights.

    PubMed

    Park, Seung Ryong; Kwon, Oh Jang; Shin, Dongho; Song, Seok-Ho; Lee, Hong-Seok; Choi, Hwan Young

    2007-03-19

    A novel LED backlight unit implementing a light guide plate (LGP) with a two-dimensional array of grating micro-dots is proposed. By optimizing grating-vector orientations of local gratings and applying suitable grating-depth modulation in the array, taking into consideration of the radiation pattern of the LED source, uniform out-coupled light distribution within a narrow luminance angle was achieved without recognizable hot spots. Such a light guide plate was fabricated using a dot-matrix holographic interferometer setup and a UV embossing replication. Fabricated polycarbonate LGP showed ~62% intensity uniformity within ~8 degrees and ~20 degrees luminance angles in two main directions. PMID:19532524

  10. Manipulation of Micro Scale Particles in Optical Traps Using Programmable Spatial Light Modulation

    NASA Technical Reports Server (NTRS)

    Seibel, Robin E.; Decker, Arthur J. (Technical Monitor)

    2003-01-01

    1064 nm light, from an Nd:YAG laser, was polarized and incident upon a programmable parallel aligned liquid crystal spatial light modulator (PAL-SLM), where it was phase modulated according to the program controlling the PAL-SLM. Light reflected from the PAL-SLM was injected into a microscope and focused. At the focus, multiple optical traps were formed in which 9.975 m spheres were captured. The traps and the spheres were moved by changing the program of the PAL-SLM. The motion of ordered groups of micro particles was clearly demonstrated.

  11. Research in manufacturing of micro-structured injection molded polymer parts

    NASA Astrophysics Data System (ADS)

    Lucyshyn, Thomas; Struklec, Tobias; Burgsteiner, Martin; Graninger, Georg; Holzer, Clemens

    2015-12-01

    An overview of current research results is given for the topic of injection molding of micro-structured polymer parts regarding filling behavior and demolding process of micro-structures as well as the production of micro-structures on curved surfaces. In order to better understand how micro-structures are formed during the filling stage of injection molding, a study was performed on a test part with micro-channels placed parallely and perpendicularly to flow direction. Short shots with a highly fluent Polypropylene grade were injection molded with the melt front stopping in the structure fields. The melt and mold temperature, the injection rate as well as the use of a variotherm heating system were varied in a systematic Design of Experiments. The shape of the flow front was investigated with the optical measurement system Alicona InfiniteFocus. The data gained was analyzed with Matlab scripts and provided the needed distance to completely fill the structures as a reference value. The next topic covers the demolding step, which is a crucial process step in injection molding of micro-structured parts as the successfully replicated structures often get destroyed in the following demolding step. In order to evaluate the influence of the four aspects polymer, mold surface (coatings), structure (geometry and placement) and process settings on the demolding behavior, an injection mold with integrated measurement system was built, which makes it possible to measure the demolding force respectively a demolding energy under process conditions. These values can be used to quantitatively compare the impact of the above mentioned influencing factors on demolding. Finally, a concept to produce micro-structures on curved surfaces with injection molding is shown: A flat metal premaster structure is used to produce an elastomeric polymer (dimethylsiloxane) master in a casting process. This master is fixed in a conventional injection mold and a thermoplastic polymer is replicated

  12. Light-Driven Reversible Shaping of Individual Azopolymeric Micro-Pillars

    PubMed Central

    Pirani, Federica; Angelini, Angelo; Frascella, Francesca; Rizzo, Riccardo; Ricciardi, Serena; Descrovi, Emiliano

    2016-01-01

    Azopolymers are known to exhibit a strong light responsivity known as athermal photofluidization. Although the underlying physics is still under debate, athermal photofluidization has been demonstrated to trigger mass-migration according to the polarization of a proper illumination light. Here, a polymer blend is proposed wherein a commercial azo-polyelectrolyte is mixed with a passive polymer. The blend is patterned as an array of micro-pillars that are individually exposed to visible laser illumination. Thanks to the interplay between the two blend components, a reversible and controlled deformation of the micro-pillars by periodically tuning the laser polarization in time is demonstrated. A reduced mobility of the azo-compound allows to repeatibly elongate and rotate micro-pillars along specific directions, with no significant material flow outisde the initial volume and no significant degradation of the structure morphology over several cycles. The proposed work suggests new degrees of freedom in controlling the mechanical features of micro-patterned light-responsive materials that can be usefully exploited in many application fields. PMID:27531219

  13. Ionogel-based light-actuated valves for controlling liquid flow in micro-fluidic manifolds.

    PubMed

    Benito-Lopez, Fernando; Byrne, Robert; Răduţă, Ana Maria; Vrana, Nihal Engin; McGuinness, Garrett; Diamond, Dermot

    2010-01-21

    We present the fabrication, characterisation and performance of four novel ionic liquid polymer gels (ionogels) as photo-actuated valves incorporated into micro-fluidic manifolds. The ionogels incorporate benzospiropyran units and phosphonium-based ionic liquids. Each ionogel is photo-polymerised in situ in the channels of a poly(methyl methacrylate) micro-fluidic device, generating a manifold incorporating four different micro-valves. The valves are actuated by simply applying localised white light irradiation, meaning that no physical contact between the actuation impulse (light) and the valve structure is required. Through variation of the composition of the ionogels, each of the micro-valves can be tuned to open at different times under similar illumination conditions. Therefore, flows through the manifold can be independently controlled by a single light source. At present, the contraction process to open the channel is relatively rapid (seconds) while the recovery (expansion) process to re-close the channel is relatively slow (minutes), meaning that the valve, in its current form, is better suited for single-actuation events. PMID:20066247

  14. Light-Driven Reversible Shaping of Individual Azopolymeric Micro-Pillars.

    PubMed

    Pirani, Federica; Angelini, Angelo; Frascella, Francesca; Rizzo, Riccardo; Ricciardi, Serena; Descrovi, Emiliano

    2016-01-01

    Azopolymers are known to exhibit a strong light responsivity known as athermal photofluidization. Although the underlying physics is still under debate, athermal photofluidization has been demonstrated to trigger mass-migration according to the polarization of a proper illumination light. Here, a polymer blend is proposed wherein a commercial azo-polyelectrolyte is mixed with a passive polymer. The blend is patterned as an array of micro-pillars that are individually exposed to visible laser illumination. Thanks to the interplay between the two blend components, a reversible and controlled deformation of the micro-pillars by periodically tuning the laser polarization in time is demonstrated. A reduced mobility of the azo-compound allows to repeatibly elongate and rotate micro-pillars along specific directions, with no significant material flow outisde the initial volume and no significant degradation of the structure morphology over several cycles. The proposed work suggests new degrees of freedom in controlling the mechanical features of micro-patterned light-responsive materials that can be usefully exploited in many application fields. PMID:27531219

  15. Optical sectioning microscopes with no moving parts using a micro-stripe array light emitting diode.

    PubMed

    Poher, V; Zhang, H X; Kennedy, G T; Griffin, C; Oddos, S; Gu, E; Elson, D S; Girkin, M; French, P M W; Dawson, M D; Neil, M A

    2007-09-01

    We describe an optical sectioning microscopy system with no moving parts based on a micro-structured stripe-array light emitting diode (LED). By projecting arbitrary line or grid patterns onto the object, we are able to implement a variety of optical sectioning microscopy techniques such as grid-projection structured illumination and line scanning confocal microscopy, switching from one imaging technique to another without modifying the microscope setup. The micro-structured LED and driver are detailed and depth discrimination capabilities are measured and calculated. PMID:19547474

  16. Sensing nanometric displacement of a micro-/nano-fiber induced by optical forces by use of white light interferometry

    NASA Astrophysics Data System (ADS)

    Qiu, Weiqia; Huang, Hankai; Yu, Jianhui; Dong, Huazhuo; Chen, Zhe; Lu, Huihui

    2015-07-01

    Sensing the nanometric displacement of a micro-/nano-fiber induced by optical forces is a key technology to study optical forces and optical momentum. When the gap between a micro-/nano-fiber and glass substrate becomes down to micrometer scale or less, a white light interference was observed. The gap changes when optical force arising from the propagating pump light along the micro-/nano-fiber causes a transversal nanometric displacement of a micro-/nanofiber, resulting in movement of the interferometric fringes. Therefore this movement of the interferometric fringes can be used to sense the nanometric displacement of the micro-/nano-fiber induced by optical forces. Experimental results show that the resolutions of this method can reach 7.27nm/pixel for tilted angle 0.8o between the micro-/nano-fiber and substrate. It is concluded that the white light interferometry method is suitable for measuring the weak optical force.

  17. High speed GaN micro-light-emitting diode arrays for data communications

    NASA Astrophysics Data System (ADS)

    Watson, Scott; McKendry, Jonathan J. D.; Zhang, Shuailong; Massoubre, David; Rae, Bruce R.; Green, Richard P.; Gu, Erdan; Henderson, Robert K.; Kelly, A. E.; Dawson, Martin D.

    2012-10-01

    Micro light-emitting diode (micro-LED) arrays based on an AlInGaN structure have attracted much interest recently as light sources for data communications. Visible light communication (VLC), over free space or plastic optical fibre (POF), has become a very important technique in the role of data transmission. The micro-LEDs which are reported here contain pixels ranging in diameter from 14 to 84μm and can be driven directly using a high speed probe or via complementary metal-oxide semiconductor (CMOS) technology. The CMOS arrays allow for easy, computer control of individual pixels within arrays containing up to 16×16 elements. The micro-LEDs best suited for data transmission have peak emissions of 450nm or 520nm, however various other wavelengths across the visible spectrum can also be used. Optical modulation bandwidths of over 400MHz have been achieved as well as error-free (defined as an error rate of <1x10-10) data transmission using on-off keying (OOK) non-return-to-zero (NRZ) modulation at data rates of over 500Mbit/s over free space. Also, as a step towards a more practical multi-emitter data transmitter, the frequency response of a micro-LED integrated with CMOS circuitry was measured and found to be up to 185MHz. Despite the reduction in bandwidth compared to the bare measurements using a high speed probe, a good compromise is achieved from the additional control available to select each pixel. It has been shown that modulating more than one pixel simultaneously can increase the data rate. As work continues in this area, the aim will be to further increase the data transmission rate by modulating more pixels on a single device to transmit multiple parallel data channels simultaneously.

  18. Mask-less ultraviolet photolithography based on CMOS-driven micro-pixel light emitting diodes.

    PubMed

    Elfström, D; Guilhabert, B; McKendry, J; Poland, S; Gong, Z; Massoubre, D; Richardson, E; Rae, B R; Valentine, G; Blanco-Gomez, G; Gu, E; Cooper, J M; Henderson, R K; Dawson, M D

    2009-12-21

    We report on an approach to ultraviolet (UV) photolithography and direct writing where both the exposure pattern and dose are determined by a complementary metal oxide semiconductor (CMOS) controlled micro-pixellated light emitting diode array. The 370 nm UV light from a demonstrator 8 x 8 gallium nitride micro-pixel LED is projected onto photoresist covered substrates using two back-to-back microscope objectives, allowing controlled demagnification. In the present setup, the system is capable of delivering up to 8.8 W/cm2 per imaged pixel in circular spots of diameter approximately 8 microm. We show example structures written in positive as well as in negative photoresist. PMID:20052059

  19. Monitoring deep twist drilling for a rapid manufacturing of light high-strength parts

    NASA Astrophysics Data System (ADS)

    López de Lacalle, L. N.; Fernández, A.; Olvera, D.; Lamikiz, A.; Olvera, D.; Rodríguez, C.; Elias, A.

    2011-10-01

    In this work the manufacturing of high strength and/or high functional components is presented, using a new technique based on considerably long twist drills, called Deep Twist Drilling (DTD). This technology opens a rapid and economical method to manufacture parts for structural applications. Components made with this technique can reach high mass reduction and better stress distribution in comparison with welding or bolted parts with the same weight. However the application of DTD must be optimized to improve the reliability of the process and to make it economically feasible. In order to reach it, previous optimization by process monitoring was performed in AISI 1045, stainless steels, Ti6Al4V and nodular cat iron GGG70(AISI A536, SAE-ASTM 100-70-03). These materials are commonly used for structural applications in several sectors. Monitoring opened the way to improve cutting conditions and allow the application of the DTD technique focusing on a new design concept. In the same way monitoring makes drilling process reliable enough to be systematically used in industrial applications by a controlled increase of the performance demanded from the tool. In this manner, not only the objective to produce high-strength and light pieces is achieved, but also a high repetitive process is reached. In this research work a case of study is presented. A monolithic satellite-type component, its mass were reduced from 25 to 4.5 kg. The structural behavior of the component was studied under FEM analysis and the results showed high strength to compression and shear forces. During the machining of this element there was a serious risk of drill breakage due to the depth of the holes and crossing points between them; however, the previous process optimization eliminated this drawback. As a matter of fact, this paper brings out a good example where manufacturing technology allows a better performance of mechanical components within the philosophy of "new processes drive to new

  20. Development of Advanced Manufacturing Methods for Warm White LEDs for General Lighting

    SciTech Connect

    Deshpande, Anirudha; Kolodin, Boris; Jacob, Cherian; Chowdhury, Ashfaqul; Kuenzler, Glenn; Sater, Karen; Aesram, Danny; Glaettli, Steven; Gallagher, Brian; Langer, Paul; Setlur, Anant; Beers, Bill

    2012-03-31

    GE Lighting Solutions will develop precise and efficient manufacturing techniques for the “remote phosphor” platform of warm-white LED products. In volume, this will be demonstrated to drive significant materials, labor and capital productivity to achieve a maximum possible 53% reduction in overall cost. In addition, the typical total color variation for these white LEDs in production will be well within the ANSI bins and as low as a 4-step MacAdam ellipse centered on the black body curve. Achievement of both of these objectives will be demonstrated while meeting a performance target of > 75 lm/W for a warm-white LED and a reliability target of <30% lumen drop / <2-step MacAdam ellipse shift, estimated over 50,000 hrs.

  1. Toxicity assessment of effluent from flash light manufacturing industry by bioassay tests in Trigonella foenumgracum.

    PubMed

    Kumari, Narendra; Kumar, Sanjeev; Bauddh, Kuldeep; Dwivedi, Neetu; Singh, D P; Barman, S C

    2014-11-01

    A rapid bioassay test was conducted to study heavy metal accumulation and biochemical changes in Trigonella foenumgracum (methi) irrigated with 25, 50, 75 and 100% of effluent from flash light manufacturing industry at 60 days after sowing. Total metal concentration in effluent samples was: Cr = 0.12 < Cd = 0.18 < Pb = 0.24 < Cu = 2.68 mg l(-1) whereas, metals were not detected in control. An increase in photosynthetic pigments of exposed plant was noticed up to 50% concentrations of the effluent followed by a decrease at higher concentration as compared to their respective control.An enhanced lipid peroxidation in the treated plants was observed, which was evident by increased level of antioxidants: proline, cysteine, malondialdehyde and ascorbic acid content. The treated plants accumulated metals in the following order: Cu > Pb > Cr > Cd in the roots and shoots. PMID:25522513

  2. Method of manufacturing a fully integrated and encapsulated micro-fabricated vacuum diode

    DOEpatents

    Resnick, Paul J.; Langlois, Eric

    2014-08-26

    Disclosed is an encapsulated micro-diode and a method for producing same. The method comprises forming a plurality columns in the substrate with a respective tip disposed at a first end of the column, the tip defining a cathode of the diode; disposing a sacrificial oxide layer on the substrate, plurality of columns and respective tips; forming respective trenches in the sacrificial oxide layer around the columns; forming an opening in the sacrificial oxide layer to expose a portion of the tips; depositing a conductive material in of the opening and on a surface of the substrate to form an anode of the diode; and removing the sacrificial oxide layer.

  3. Fully integrated and encapsulated micro-fabricated vacuum diode and method of manufacturing same

    SciTech Connect

    Resnick, Paul J.; Langlois, Eric

    2015-12-01

    Disclosed is an encapsulated micro-diode and a method for producing same. The method comprises forming a plurality columns in the substrate with a respective tip disposed at a first end of the column, the tip defining a cathode of the diode; disposing a sacrificial oxide layer on the substrate, plurality of columns and respective tips; forming respective trenches in the sacrificial oxide layer around the columns; forming an opening in the sacrificial oxide layer to expose a portion of the tips; depositing a conductive material in of the opening and on a surface of the substrate to form an anode of the diode; and removing the sacrificial oxide layer.

  4. Continuous Digital Light Processing (cDLP): Highly Accurate Additive Manufacturing of Tissue Engineered Bone Scaffolds.

    PubMed

    Dean, David; Jonathan, Wallace; Siblani, Ali; Wang, Martha O; Kim, Kyobum; Mikos, Antonios G; Fisher, John P

    2012-03-01

    Highly accurate rendering of the external and internal geometry of bone tissue engineering scaffolds effects fit at the defect site, loading of internal pore spaces with cells, bioreactor-delivered nutrient and growth factor circulation, and scaffold resorption. It may be necessary to render resorbable polymer scaffolds with 50 μm or less accuracy to achieve these goals. This level of accuracy is available using Continuous Digital Light processing (cDLP) which utilizes a DLP(®) (Texas Instruments, Dallas, TX) chip. One such additive manufacturing device is the envisionTEC (Ferndale, MI) Perfactory(®). To use cDLP we integrate a photo-crosslinkable polymer, a photo-initiator, and a biocompatible dye. The dye attenuates light, thereby limiting the depth of polymerization. In this study we fabricated scaffolds using the well-studied resorbable polymer, poly(propylene fumarate) (PPF), titanium dioxide (TiO(2)) as a dye, Irgacure(®) 819 (BASF [Ciba], Florham Park, NJ) as an initiator, and diethyl fumarate as a solvent to control viscosity. PMID:23066427

  5. Continuous Digital Light Processing (cDLP): Highly Accurate Additive Manufacturing of Tissue Engineered Bone Scaffolds

    PubMed Central

    Dean, David; Wallace, Jonathan; Siblani, Ali; Wang, Martha O.; Kim, Kyobum; Mikos, Antonios G.; Fisher, John P.

    2012-01-01

    Highly accurate rendering of the external and internal geometry of bone tissue engineering scaffolds effects fit at the defect site, loading of internal pore spaces with cells, bioreactor-delivered nutrient and growth factor circulation, and scaffold resorption. It may be necessary to render resorbable polymer scaffolds with 50 μm or less accuracy to achieve these goals. This level of accuracy is available using Continuous Digital Light processing (cDLP) which utilizes a DLP® (Texas Instruments, Dallas, TX) chip. One such additive manufacturing device is the envisionTEC (Ferndale, MI) Perfactory®. To use cDLP we integrate a photo-crosslinkable polymer, a photo-initiator, and a biocompatible dye. The dye attenuates light, thereby limiting the depth of polymerization. In this study we fabricated scaffolds using the well-studied resorbable polymer, poly(propylene fumarate) (PPF), titanium dioxide (TiO2) as a dye, Irgacure® 819 (BASF [Ciba], Florham Park, NJ) as an initiator, and diethyl fumarate as a solvent to control viscosity. PMID:23066427

  6. Light-induced mutagenicity in Salmonella TA102 and genotoxicity/cytotoxicity in human T-cells by 3,3'-dichlorobenzidine: a chemical used in the manufacture of dyes and pigments and in tattoo inks.

    PubMed

    Wang, Lei; Yan, Jian; Hardy, William; Mosley, Charity; Wang, Shuguang; Yu, Hongtao

    2005-02-28

    DCB, 3,3'-dichlorobenzidine, is used primarily as an intermediate in the manufacture of diarylide yellow or azo red pigments for printing ink, textile, paint, and plastics. It is also used in tattoo inks. In this article, we investigate light-induced toxicity of DCB in both bacteria and human Jurkat T-cells. DCB itself is not toxic or mutagenic to Salmonella typhimurium TA102, but is photomutagenic at concentrations as low as 2 microM and phototoxic at concentrations >100 microM when bacteria are exposed to DCB and light at the same time (1.2 J/cm2 of UVA and 2.1 J/cm2 of visible light). Furthermore, DCB is both photocytotoxic and photogenotoxic to human Jurkat T-cells. Under a light irradiation dose of 2.3 J/cm2 of UVA and 4.2 J/cm2 of visible light, it causes the Jurkat T-cells to become nonviable in a DCB dose-dependent manner and the nonviable cells reaches 60% at DCB concentrations higher than 50 microM. At the same time, DNA fragmentation is observed for cells exposed to both DCB and light, determined by single cell gel electrophoresis (alkaline comet assay). As much as 5% (average) DNA fragmentation was observed when exposed to 200 microM DCB and light irradiation. This suggests that DCB can penetrate the cell membrane and enter the cell. Upon light activation, DCB in the cells can cause various cellular damages, leading to nonviable Jurkat T-cells. It appears, the nonviable cells are not caused solely by fragmentation of cellular DNA, but by other damages such as to proteins and cell membranes, or DNA alkylation. Therefore, persons exposed to DCB through environmental contamination or through tattoo piercing using DCB-containing inks must not only concern about its toxicity without exposing to light, but also its phototoxicity. PMID:15664269

  7. Wafer-scale manufacturing and integration of micro-optical systems

    NASA Astrophysics Data System (ADS)

    Kathman, Alan D.; Boomgarden, Mark

    2001-11-01

    Demand for optical components and subsystems has exploded in the last decade. The question directed at component providers by customers is no longer when can you make it? The critical question is now become when can you make it in high volume? Wafer scale manufacturing, developed for the integrated circuit industry, has transitioned into the realm of optical fabrication and assembly. Photonic Chip optical subassemblies are products fabricated using these techniques. To create them, the optical elements are lithographically generated with integrated alignment and bonding features. Wafers of complimentary elements can be aligned and bonded at the wafer level, assembling hundreds of optical systems in parallel with a single operation. Electro-optical components, such as source and detector elements can be assembled into the system at the chip level, using flip-chip die bonding to complete the mechanical and electrical connection. The striking features of this manufacturing method are its parallel assembly techniques, broad use of automation, and very attractive intrinsic cost at high volume.

  8. Measurement of micro-V-groove dihedral using white light interferometry

    NASA Astrophysics Data System (ADS)

    Fang, Fengzhou; Zeng, Zhen; Zhang, Xiaodong; Jiang, Lili

    2016-01-01

    This study presents a micro-V-grooves dihedral measurement method using white light interferometry on multiple reflection phenomena. When an optical instrument is used to measure microstructures with steep large gradient faces with high reflection rate, considerable measurement errors caused by multiple scattering or multiple reflecting can be observed. These difficulties have limited the application of white light interferometry in the measurement of microstructures. However, the study has found that the multiple-reflection phenomena can be utilized to measure V-groove dihedral angle. The precision of dihedral measurement is a guarantee of ultra-precise machining of retro-reflection mirrors which requires a non-contact measurement to avoid scratches and surface defects caused by the contact probe. The proposed method is capable of obtaining more accurate surface profile data compared to common white light interferometry. Experimental results verify the method and the consistence between the proposed method and contact mode profilometer.

  9. Light micro-lensing effect in biosilica shells of diatoms microalgae

    NASA Astrophysics Data System (ADS)

    De Tommasi, E.; De Stefano, L.; Rea, I.; Moretti, L.; De Stefano, M.; Rendina, I.

    2008-04-01

    Diatoms are monocellular micro-algae provided with external valves, the frustules, made of amorphous hydrated silica. Frustules present patterns of regular arrays of holes, the areolae, characterized by sub-micrometric dimensions. In particular, frustules from centric diatoms are characterized by a radial disposition of areolae and exhibit several optical properties, such as photoluminescence variations in presence of organic vapors and photonic-crystal-like behaviour as long as propagation of electromagnetic field is concerned. We have studied the transmission of coherent light, at different wavelengths, through single frustules of Coscinodiscus Walesii diatoms, a centric species characterized by a diameter of about 150 μm. The frustules showed the ability to focalize the light in a spot of a few μm2, the focal length depending on the wavelength of the incident radiation. This focusing effect takes place at the centre of the frustule, where no areolae are present and, as it is confirmed by numerical simulations, it is probably due to coherent superposition of unfocused wave fronts coming from the surrounding areolae. Diatoms-based micro-lenses could be used in the production of lensed optical fibers without modifying the glass core and, in general, they could be exploited with success in most of the optical micro-arrays.

  10. Improved micro x-ray fluorescence spectrometer for light element analysis

    SciTech Connect

    Smolek, Stephan; Streli, Christina; Zoeger, Norbert; Wobrauschek, Peter

    2010-05-15

    Since most available micro x-ray fluorescence (micro-XRF) spectrometers operate in air, which does not allow the analysis of low-Z elements (Z{<=}14), a special micro-XRF spectrometer has been designed to extend the analytical range down to light elements (Z{>=}6). It offers improved excitation and detection conditions necessary for light element analysis. To eliminate absorption of the exciting and fluorescent radiation, the system operates under vacuum condition. Sample mapping is automated and controlled by specialized computer software developed for this spectrometer. Several different samples were measured to test and characterize the spectrometer. The spot size has been determined by scans across a 10 {mu}m Cu wire which resulted in a full width at half maximum of 31 {mu}m for Mo K{alpha} line (17.44 keV) and 44 {mu}m effective beam size for the Cu K edge and 71 {mu}m effective beam size for the Cu L edge. Lower limits of detection in the picogram range for each spot (or {mu}g/cm{sup 2}) were obtained by measuring various thin metal foils under different conditions. Furthermore, detection limits in the parts per million range were found measuring NIST621 standard reference material. Area scans of a microscopic laser print and NaF droplet were performed to show mapping capabilities.

  11. New developments in the manufacture of large freeform surfaces with micro-structures

    NASA Astrophysics Data System (ADS)

    Roblee, Jeff; Walter, Mark; Jacobs, Ben

    2015-10-01

    A new capability for simultaneously generating micro-structures and large freeform surfaces has been developed. Multiple axes of CNC coordinated motion have been integrated into an ultra precision machine platform, enabling a wide variety of optical mold masters to be created. Facilitated by a specially developed control system, freeform optical surfaces as large as 600 x 600 x 100 mm are possible. Some machine alignments are critical to the production of accurate parts and these will be discussed. A bridge construction reduces Abbe offsets, and oil hydrostatic linear slide ways provide sub-micron straightness. The linear axes are capable of accurate positioning by means of linear motors in combination with the non contact oil hydrostatic slide ways. Optical surface finishes are achieved with the stability of a large granite base supported by a high performance vibration isolation system. The machine includes a unique, self-compensating, patented oil bearing rotary axis. Critical machine errors are measured and corrected with integrated CNC machine compensation. The machine has accuracy and repeatability for the creation of precise, intersecting groove structures with multiple angles over large areas. Optical surfaces can be generated either by a ruling/shaping operation with a non-rotating tool, or by a flycutting tool rotating on a high speed air bearing spindle. The spindle can double as a positioning axis to generate variable angle grooves in ruling mode. A Fast Tool Servo can be utilized to create fine micro-structures. Work piece quality can be evaluated in-situ with metrology sensors.

  12. Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products Part 2: LED Manufacturing and Performance

    SciTech Connect

    Scholand, Michael; Dillon, Heather E.

    2012-05-01

    Part 2 of the project (this report) uses the conclusions from Part 1 as a point of departure to focus on two objectives: producing a more detailed and conservative assessment of the manufacturing process and providing a comparative LCA with other lighting products based on the improved manufacturing analysis and taking into consideration a wider range of environmental impacts. In this study, we first analyzed the manufacturing process for a white-light LED (based on a sapphire-substrate, blue-light, gallium-nitride LED pumping a yellow phosphor), to understand the impacts of the manufacturing process. We then conducted a comparative LCA, looking at the impacts associated with the Philips Master LEDbulb and comparing those to a CFL and an incandescent lamp. The comparison took into account the Philips Master LEDbulb as it is now in 2012 and then projected forward what it might be in 2017, accounting for some of the anticipated improvements in LED manufacturing, performance and driver electronics.

  13. High-temperature micro liquid chromatography for lipid molecular species analysis with evaporative light scattering detection.

    PubMed

    Hazotte, Aurélie; Libong, Danielle; Chaminade, Pierre

    2007-01-26

    The need for a rapid and sensitive chromatographic technique for analyzing lipid molecular species, has led to the development of an high-temperature micro liquid chromatographic system (HTLC) coupled to an evaporative light scattering detector. The increased diffusion coefficients and reduced viscosity at higher temperatures allowed lipids to be analyzed rapidly with solvents differing from those classically used in lipids chemistry. Hypercarb, a reverse phase material, was used for its different properties including heat resistance in high temperature micro HPLC. We have investigated the temperature effect on kinetic performances in HTLC, established pure solvents eluent strength at high temperature and studied different classes of lipids with seven pure solvents. We found that it was possible to use alcohols solvents in the mobile phase to elute lipids without the use of chlorinated solvents. A quick and simple method was developed to analyze a complex lipid simple, ceramide type III and type IV. PMID:17161844

  14. Investigation of Very Fast Light Detectors: Silicon Photomultiplier and Micro PMT for a Cosmic Ray Array

    NASA Astrophysics Data System (ADS)

    Cervantes, Omar; Reyes, Liliana; Hooks, Tyler; Perez, Luis; Ritt, Stefan

    2016-03-01

    To construct a cosmic detector array using 4 scintillation detectors, we investigated 2 recent light sensor technologies from Hamamatsu, as possible readout detectors. First, we investigated several homemade versions of the multipixel photon counter (MPPC) light sensors. These detectors were either biased with internal or external high voltage power supplies. We made extensive measurements to confirm for the coincidence of the MPPC devices. Each sensor is coupled to a wavelength shifting fiber (WSF) that is embedded along a plastic scintillator sheet (30cmx60cmx1/4''). Using energetic cosmic rays, we evaluated several of these homemade detector modules placed above one another in a light proof enclosure. Next, we assembled 2 miniaturized micro photomultiplier (micro PMT), a device recently marketed by Hamamatsu. These sensors showed very fast response times. With 3 WSF embedded in scintillator sheets, we performed coincidence experiments. The detector waveforms were captured using the 5GS/sec domino ring sampler, the DRS4 and our workflow using the CERN PAW package and data analysis results would be presented. Title V Grant.

  15. Multi-functional micro electromechanical devices and method of bulk manufacturing same

    NASA Technical Reports Server (NTRS)

    Okojie, Robert S. (Inventor)

    2004-01-01

    A method of bulk manufacturing SiC sensors is disclosed and claimed. Materials other than SiC may be used as the substrate material. Sensors requiring that the SiC substrate be pierced are also disclosed and claimed. A process flow reversal is employed whereby the metallization is applied first before the recesses are etched into or through the wafer. Aluminum is deposited on the entire planar surface of the metallization. Photoresist is spun onto the substantially planar surface of the Aluminum which is subsequently masked (and developed and removed). Unwanted Aluminum is etched with aqueous TMAH and subsequently the metallization is dry etched. Photoresist is spun onto the still substantially planar surface of Aluminum and oxide and then masked (and developed and removed) leaving the unimidized photoresist behind. Next, ITO is applied over the still substantially planar surface of Aluminum, oxide and unimidized photoresist. Unimidized and exposed photoresist and ITO directly above it are removed with Acetone. Next, deep reactive ion etching attacks exposed oxide not protected by ITO. Finally, hot phosphoric acid removes the Al and ITO enabling wires to connect with the metallization. The back side of the SiC wafer may be also be etched.

  16. 1-µm Micro-Lens Array on Flip-Chip Light-Emitting Diode

    NASA Astrophysics Data System (ADS)

    Hei Li, Kwai; Zhang, Qian; Choi, Hoi Wai

    2013-08-01

    The fabrication of hexagonally close-packed micro-lens array on sapphire face of flip-chip bonded LED by nanosphere lithography is demonstrated. Self-assembled silica spheres serve as an etch mask to transfer hemispherical geometry onto the sapphire. The optical and electrical properties are evaluated. Without degrading the current-voltage (I-V) properties, the lensed LED shows an enhancement of 27.8% on light output power, compared with unpatterned LED. The emission characteristic is also investigated by performing finite-difference time-domain simulation, which is found to be consistent with the experimental results.

  17. 1-μm Micro-Lens Array on Flip-Chip Light-Emitting Diode

    NASA Astrophysics Data System (ADS)

    Li, Kwai Hei; Zhang, Qian; Choi, Hoi Wai

    2013-08-01

    The fabrication of hexagonally close-packed micro-lens array on sapphire face of flip-chip bonded LED by nanosphere lithography is demonstrated. Self-assembled silica spheres serve as an etch mask to transfer hemispherical geometry onto the sapphire. The optical and electrical properties are evaluated. Without degrading the current--voltage (I--V) properties, the lensed LED shows an enhancement of 27.8% on light output power, compared with unpatterned LED. The emission characteristic is also investigated by performing finite-difference time-domain simulation, which is found to be consistent with the experimental results.

  18. Temperature-dependent efficiency droop of blue InGaN micro-light emitting diodes

    SciTech Connect

    Tian, Pengfei; McKendry, Jonathan J. D.; Herrnsdorf, Johannes; Ferreira, Ricardo; Watson, Ian M.; Gu, Erdan Dawson, Martin D.; Watson, Scott; Kelly, Anthony E.

    2014-10-27

    Temperature-dependent trends in radiative and Auger recombination coefficients have been determined at different injection carrier concentrations using InGaN micro-light emitting diodes 40 μm in diameter. The differential lifetime was obtained first from the measured modulation bandwidth and was then employed to calculate the carrier concentration in the quantum well active region. When the temperature increases, the carrier concentration increases, but both the radiative and Auger recombination coefficients decrease. In addition, the temperature dependence of radiative and Auger recombination coefficients is weaker at a higher injection carrier concentration, which is strongly related to phase space filling.

  19. Low cost and manufacturable complete microTAS for detecting bacteria.

    PubMed

    Sauer-Budge, Alexis F; Mirer, Paul; Chatterjee, Anirban; Klapperich, Catherine M; Chargin, David; Sharon, Andre

    2009-10-01

    In this paper, we present a fully integrated lab-on-a-chip and associated instrument for the detection of bacteria from liquid samples. The system conducts bacterial lysis, nucleic acid isolation and concentration, polymerase chain reaction (PCR), and end-point fluorescent detection. To enable truly low-cost manufacture of the single-use disposable chip, we designed the plastic chip in a planar format without any active components to be amenable to injection molding and utilized a novel porous polymer monolith (PPM) embedded with silica that has been shown to lyse bacteria and isolate the nucleic acids from clinical samples (M. D. Kulinski, M. Mahalanabis, S. Gillers, J. Y. Zhang, S. Singh and C. M. Klapperich, Biomed. Microdevices, 2009, 11, 671-678).(1) The chip is made of Zeonex(R), a thermoplastic with a high melting temperature to allow PCR, good UV transmissibility for UV-curing of the PPM, and low auto-fluorescence for fluorescence detection of the amplicon. We have built a prototype instrument to automate control of the fluids, temperature cycling, and optical detection with the capability of accommodating various chip designs. To enable fluid control without including valves or pumps on the chip, we utilized a remote valve switching technique. To allow fluid flow rate changes on the valveless chip, we incorporated speed changing fluid reservoirs. The PCR thermal cycling was achieved with a ceramic heater and air cooling, while end-point fluorescence detection was accomplished with an optical spectrometer; all integrated in the instrument. The chip seamlessly and automatically is mated to the instrument through an interface block that presses against the chip. The interface block aligns and ensures good contact of the chip to the temperature controlled region and the optics. The integrated functionality of the chip was demonstrated using Bacillus subtilis as a model bacterial target. A Taqman assay was employed on-chip to detect the isolated bacterial DNA

  20. Elastic light scattering from aerosol particles and direct coupling of micro-resonators

    NASA Astrophysics Data System (ADS)

    Fernandes, Gustavo Eddino

    Two unrelated topics are treated in this thesis. In Part I the measurement and interpretation of two-angle optical scattering (TAOS) patterns from aerosol particles in the respiratory size-range (1-10 microm) is discussed. Three experiments are presented. The first experiment introduces a different light-collection scheme than previously used, which allows for the simultaneous measurement of TAOS patterns in both the forward and backward scattering hemispheres of aerosols in real-time. In the second experiment, the collection of TAOS patterns in the near-backward hemisphere, which is important for remote sensing applications such as light detection and ranging (LIDAR) applications, is explored. In particular, a light collection scheme is introduced which allows for the simultaneous measurement of TAOS patterns in both parallel and perpendicular polarizations for single aerosol particles. Finally, a study that correlates the appearance of speckles in the TAOS patterns of aerosol aggregates with their surface roughness, and uses speckle characteristics to sort between several types of aerosol aggregates is presented. In Part 2, a study of semiconductor micro-disk resonators that are seamlessly (end-to-end) coupled to one another is presented. The seamless coupling scheme, referred to as "direct-coupling", enables coupling not only of the lasing modes, but also of the amplified spontaneous emission (ASE) produced in the resonators. The exchange of ASE between the elements in a coupled micro-disk device is shown to lead to many unique characteristics in the light output versus injection current (L-I) curves of' these devices. Devices consisting of two and three directly-coupled micro-disk elements are considered. In particular, it is shown that ON-OFF-ON switching of the output intensity as well as discontinuous shifts in the output wavelength as a function of increasing injected current in one of the elements can be achieved in the three-element devices. These

  1. Photovoltaic device with increased light absorption and method for its manufacture

    SciTech Connect

    Glatfelter, Troy; Vogeli, Craig; Call, Jon; Hammond, Ginger

    1993-07-20

    A photovoltaic cell having a light-directing optical element integrally formed in an encapsulant layer thereof. The optical element redirects light to increase the internal absorption of light incident on the photovoltaic device.

  2. Aging characteristics of blue InGaN micro-light emitting diodes at an extremely high current density of 3.5 kA cm-2

    NASA Astrophysics Data System (ADS)

    Tian, Pengfei; Althumali, Ahmad; Gu, Erdan; Watson, Ian M.; Dawson, Martin D.; Liu, Ran

    2016-04-01

    The aging characteristics of blue InGaN micro-light emitting diodes (micro-LEDs) with different sizes have been studied at an extremely high current density 3.5 kA cm-2 for emerging micro-LED applications including visible light communication (VLC), micro-LED pumped organic lasers and optogenetics. The light output power of micro-LEDs first increases and then decreases due to the competition of Mg activation in p-GaN layer and defect generation in the active region. The smaller micro-LEDs show less light output power degradation compared with larger micro-LEDs, which is attributed to the lower junction temperature of smaller micro-LEDs. It is found that the high current density without additional junction temperature cannot induce significant micro-LED degradation at room temperature but the combination of the high current density and high junction temperature leads to strong degradation. Furthermore, the cluster LEDs, composed of a micro-LED array, have been developed with both high light output power and less light output degradation for micro-LED applications in solid state lighting and VLC.

  3. Patterning and integration of polyfluorene polymers on micro-pixellated UV AlInGaN light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Guilhabert, B.; Gong, Z.; Zhang, H.; Belton, C.; Mack Intosh, A.; Gu, E.; Campoy-Quiles, M.; Stavrinou, P. N.; Bradley, D. D. C.; Pethrick, R. A.; Dawson, M. D.

    2008-05-01

    We report the integration of micro-patterned polyfluorene conjugated polymers onto GaN-based ultraviolet (UV) micro-pixellated light-emitting diode arrays (micro-LEDs). The 64 × 64 element matrix-addressable AlInGaN devices have a pixel size of 20 µm diameter on a 50 µm pitch, emitting at 368 nm. Each array is covered with a 2.5 µm thick photo-curable deep-UV-transparent polymer and a 30 nm thick polyfluorene film. This polymer bi-layer is subsequently patterned into an array of 28 µm diameter discs aligned with the pixels of the micro-LED array. Polymer down-converted visible emission from these pattern-programmable organic/inorganic electroluminescent micro-arrays is achieved.

  4. Analysis of micro-lens integrated flip-chip InGaN light-emitting diodes by confocal microscopy

    NASA Astrophysics Data System (ADS)

    Li, K. H.; Feng, C.; Choi, H. W.

    2014-02-01

    A hexagonally close-packed microlens array has been integrated onto the sapphire face of a flip-chip bonded InGaN light-emitting diode (LED). The micro-optics is formed by etching a self-assembled monolayer of 1-μm silica microspheres coated on the sapphire substrate, producing hemispherical sapphire lenses. Without degrading electrical characteristic, the light output power of the lensed LED is increased by more than a quarter compared with the unlensed LED. Enhanced light extraction via micro-optics is verified by rigorous coupled wave analysis. The focusing behavior of the micro-lenses, as well as the emission characteristics of the lensed LED, is studied by confocal microscopy.

  5. Subwavelength light confinement and quantum chaos in micro- and nano-structured metamaterials

    NASA Astrophysics Data System (ADS)

    Govyadinov, Alexander A.

    This dissertation concerns a broad range of unique phenomena related to the light propagation at nano- and micro-scales. To access the nano-domain, we introduce anisotropy-based waveguides with positive- and negative-index modes. These novel structures allow energy propagation in subwavelength regions and, in contrast to surface waves, have the mode structure identical to that of telecom fibers. We design multilayered meta-materials for far-IR to visible frequencies and develop analytical homogenization techniques for light transmission through these systems. Our numerical simulations demonstrate that tapered waveguides with anisotropic cores can efficiently transfer energy to and from regions as small as 1/45-th of the wavelength, substantially outperforming conventional techniques. We analyze the behavior of volume and surface modes in nano-waveguides and demonstrate theoretically that subwavelength geometry enables the unique control over modes' dispersive properties, unavailable in diffraction-limited systems. In particular, the inter-scale transition between "photonic-funnel" and "photonic-compressor" regimes in nano-structures allows versatile management of the group velocity of light pulses ranging from slow to superluminal values. As a control mechanism, we employ the material gain, previously suggested for loss compensation, and develop an analytical description of the relevant physics. We further study the prospects of gain-assisted dispersion management in passive and active negative index structures and formulate a universal approach for defining the causal direction of the wave vector of modes in optical metamaterials. This approach also determines signs of the refractive index and impedance. We employ the developed formalism to demonstrate a broadband dispersion-less index and impedance matching in the nanowire-based negative index materials. Finally, we address light scattering phenomena in asymmetric micro-cavity resonators. We introduce a novel

  6. Fully solution-processed organic light-emitting electrochemical cells (OLEC) with inkjet-printed micro-lenses for disposable lab-on-chip applications at ambient conditions

    NASA Astrophysics Data System (ADS)

    Shu, Zhe; Pabst, Oliver; Beckert, Erik; Eberhardt, Ramona; Tünnermann, Andreas

    2016-02-01

    Microfluidic lab-on-chip devices can be used for chemical and biological analyses such as DNA tests or environmental monitoring. Such devices integrate most of the basic functionalities needed for scientific analysis on a microfluidic chip. When using such devices, cost and space-intensive lab equipment is no longer necessary. However, in order to make a monolithic and cost-efficient/disposable microfluidic sensing device, direct integration of the excitation light source for fluorescent sensing is often required. To achieve this, we introduce a fully solution processable deviation of OLEDs, organic light-emitting electrochemical cells (OLECs), as a low-cost excitation light source for a disposable microfluidic sensing platform. By mixing metal ions and a solid electrolyte with light-emitting polymers as active materials, an in-situ doping and in-situ PN-junction can be generated within a three layer sandwich device. Thanks to this doping effect, work function adaptation is not necessary and air-stable electrode can be used. An ambient manufacturing process for fully solution-processed OLECs is presented, which consist of a spin-coated blue light-emitting polymer plus dopants on an ITO cathode and an inkjet-printed PEDOT:PSS transparent top anode. A fully transparent blue OLEC is able to obtain light intensity > 2500 cd/m2 under pulsed driving mode and maintain stable after 1000 cycles, which fulfils requirements for simple fluorescent on-chip sensing applications. However, because of the large refractive index difference between substrates and air, about 80% of emitted light is trapped inside the device. Therefore, inkjet printed micro-lenses on the rear side are introduced here to further increase light-emitting brightness.

  7. Light extraction efficiency enhancement for InGaN quantum wells light-emitting diodes with GaN micro-domes

    NASA Astrophysics Data System (ADS)

    Zhao, Peng; Han, Lu; Zhao, Hongping

    2013-03-01

    The enhancement of light extraction efficiency for thin-film-flip-chip (TFFC) InGaN QWs LEDs with GaN microdomes on n-GaN layer was studied. The three dimensional FDTD method was used to calculate the light extraction efficiency for the TFFC InGaN QWs LEDs emitting at visible spectral regime, as compared to that of the conventional TFFC InGaN QWs LEDs. The calculation indicates significant dependence of the p-GaN layer thickness on the light extraction efficiency. Significant enhancement of the light extraction efficiency (2.5-2.7 times for λpeak=460nm and 2.7- 2.8 times for λpeak=550nm) is achievable from LEDs with GaN micro-domes with optimized micro-dome diameter and height.

  8. Highly transparent sapphire micro-grating structures with large diffuse light scattering

    NASA Astrophysics Data System (ADS)

    Ko, Yeong Hwan; Yu, Jae Su

    2011-08-01

    The highly transparent micro-grating structures (MGSs) of sapphire substrate with large diffuse light scattering were theoretically and experimentally studied. From the finite difference time domain simulation, it was found that the degree of diffuse light scattering is strongly dependent on the size of grating structures. For a highly transparent property, the sapphire MGSs were optimally designed by the theoretical calculations using the rigorous coupled wave analysis method. The order of taper, geometry (i.e., width and height), and pitch length of MGSs were optimized to maximize their average total transmittance over a wide wavelength range of 300-1800 nm. Additionally, the influence of the deposition of low-refractive index material such as SiO2 onto sapphire MGSs on the transmittance characteristics was investigated. To verify experimentally the feasibility, the sapphire MGSs were fabricated by the conventional lithography and dry etching processes. The SiO2 deposited sapphire MGS exhibited a further increase in the total transmittance due to its relatively more graded refractive index profile while maintaining a significantly enhanced diffuse light scattering. The experimental data were in a reasonable agreement with the theoretical results.

  9. Bone regeneration by the osteoconductivity of porous titanium implants manufactured by selective laser melting: a histological and micro computed tomography study in the rabbit.

    PubMed

    de Wild, Michael; Schumacher, Ralf; Mayer, Kyrill; Schkommodau, Erik; Thoma, Daniel; Bredell, Marius; Kruse Gujer, Astrid; Grätz, Klaus W; Weber, Franz E

    2013-12-01

    The treatment of large bone defects still poses a major challenge in orthopaedic and cranio-maxillofacial surgery. One possible solution could be the development of personalized porous titanium-based implants that are designed to meet all mechanical needs with a minimum amount of titanium and maximum osteopromotive properties so that it could be combined with growth factor-loaded hydrogels or cell constructs to realize advanced bone tissue engineering strategies. Such implants could prove useful for mandibular reconstruction, spinal fusion, the treatment of extended long bone defects, or to fill in gaps created on autograft harvesting. The aim of this study was to determine the mechanical properties and potential of bone formation of light weight implants generated by selective laser melting (SLM). We mainly focused on osteoconduction, as this is a key feature in bone healing and could serve as a back-up for osteoinduction and cell transplantation strategies. To that end, defined implants were produced by SLM, and their surfaces were left untreated, sandblasted, or sandblasted/acid etched. In vivo bone formation with the different implants was tested throughout calvarial defects in rabbits and compared with untreated defects. Analysis by micro computed tomography (μCT) and histomorphometry revealed that all generatively produced porous Ti structures were well osseointegrated into the surrounding bone. The histomorphometric analysis revealed that bone formation was significantly increased in all implant-treated groups compared with untreated defects and significantly increased in sand blasted implants compared with untreated ones. Bone bridging was significantly increased in sand blasted acid-etched scaffolds. Therefore, scaffolds manufactured by SLM should be surface treated. Bone augmentation beyond the original bone margins was only seen in implant-treated defects, indicating an osteoconductive potential of the implants that could be utilized clinically for bone

  10. Hybrid noise control in a duct using a light micro-perforated plate.

    PubMed

    Wang, X N; Choy, Y S; Cheng, L

    2012-12-01

    A plate silencer consists of an expansion chamber with two side-branch cavities covered by light but extremely stiff plates. It works effectively with a wide stopband from low-to-medium frequencies only if the plate is extremely stiff, to ensure a strong reflection of acoustic wave to the upstream in the duct. However, a plate with a slightly weak bending stiffness will result in non-uniform transmission loss (TL) spectra with narrowed stopband. In this study, a hybrid silencer is proposed by introducing micro-perforations into the plate to elicit the sound absorption in order to compensate for the deficiency in the passband caused by the insufficient sound reflection in a certain frequency range due to weaker plate stiffness. A theoretical model, capable of dealing with the strong coupling between the vibrating micro-perforated plate and sound fields inside the cavity and the duct, is developed. Through proper balancing between the sound absorption and reflection, the proposed hybrid silencer provides a more flattened and uniform TL and a widened stopband by more than 20% while relaxing the harsh requirement on the bending stiffness of the plate. Theoretical predictions are validated by experimental data, with phenomenon explained through numerical analyses. PMID:23231108

  11. Over 1000 channel nitride-based micro-light-emitting diode arrays with tunnel junctions

    NASA Astrophysics Data System (ADS)

    Watanabe, Masahiro; Nakajima, Keisuke; Kaga, Mitsuru; Kuwano, Yuka; Minamikawa, Daichi; Suzuki, Tomoyuki; Yamashita, Kouji; Iwaya, Motoaki; Takeuchi, Tetsuya; Kamiyama, Satoshi; Akasaki, Isamu

    2014-01-01

    We fabricated nitride-based micro-LED arrays with a small number of fabrication process steps by using a combination of tunnel junctions and patterned n-GaN cathode lines. A use of the combination enables us to skip a couple of process steps required in standard LED array fabrication. A 10 × 10 channel matrix-addressable LED array with a 10 × 16 µm2 emission regions and a 25 µm pitch lengths showed uniform operating voltages and light output intensities, indicating good yield due to the small number of process steps used. In addition, microdisplay of over 1000 (14 × 72) channels was successfully demonstrated. The new array structure with the tunnel junction and n-GaN cathode line provides a high density and a high yield simultaneously.

  12. A Hybrid Micro-Pixel Based Deep Ultraviolet Light-Emitting Diode Lamp

    NASA Astrophysics Data System (ADS)

    Hwang, Seongmo; Islam, Monirul; Zhang, Bin; Lachab, Mohamed; Dion, Joe; Heidari, Ahmad; Nazir, Haseeb; Adivarahan, Vinod; Khan, Asif

    2011-01-01

    We report on the room temperature electrical and optical characterization of a multichip light-emitting diode (LED) lamp with peak emission at 281 nm. Four pairs of micro-pixel LED arrays were connected in series to fabricate the lamp, which delivered a pulsed output power of 235 mW at 1.18 A (duty cycle ˜0.5%), and attained a high external quantum efficiency of 4.63%. Under dc operation, the maximum power achieved by this lamp was ˜20 mW at a drive current of 220 mA. The peak output power improved 1.62-fold after a thermoelectric cooler was added to the device packaging assembly.

  13. GaN-based light-emitting diodes with hybrid micro/nano-textured indium-tin-oxide layer

    NASA Astrophysics Data System (ADS)

    Huamao, Huang; Jinyong, Hu; Hong, Wang

    2014-08-01

    Three types of textured indium-tin-oxide (ITO) surface, including nano-texturing and hybrid micro/nano-texturing with micro-holes (concave-hybrid-pattern) or micro-pillars (convex-hybrid-pattern), were applied to GaN-based light-emitting diodes (LEDs). The nano-texturing was realized by maskless wet-etching, and the micro-texturing was achieved by standard photolithography and wet-etching. Compared to LED chips with flat ITO surface, those with nano-pattern, concave-hybrid-pattern, and convex-hybrid-pattern exhibit enhancement of 11.3%, 15.8%, and 17.9%, respectively, for the light-output powers at 20 mA. The electrical performance has no degradation. Moreover, the convex-hybrid-pattern show higher light-output efficiency under small injection current, while the concave-hybrid-pattern exhibit better light-output efficiency at large injection current. The light-extraction efficiency is simulated by use of two-dimensional finite difference time domain method, and the numerical results are consistent with the experiments.

  14. Micro-light-pipe array with an excitation attenuation filter for lensless digital enzyme-linked immunosorbent assay

    NASA Astrophysics Data System (ADS)

    Takehara, Hironari; Nagasaki, Mizuki; Sasagawa, Kiyotaka; Takehara, Hiroaki; Noda, Toshihiko; Tokuda, Takashi; Ohta, Jun

    2016-03-01

    Digital enzyme-linked immunosorbent assay (ELISA) is used for detecting various biomarkers with hypersensitivity. We have been developing compact systems by replacing the fluorescence microscope with a CMOS image sensor. Here, we propose a micro-light-pipe array structure made of metal filled with dye-doped resin, which can be used as a fabrication substrate of the micro-reaction-chamber array of digital ELISA. The possibility that this structure enhances the coupling efficiency for fluorescence was simulated using a simple model. To realize the structure, we fabricated a 30-µm-thick micropipe array by copper electroplating around a thick photoresist pattern. The typical diameter of each fabricated micropipe was 10 µm. The pipes were filled with yellow-dye-doped epoxy resin. The transmittance ratio of fluorescence and excitation light could be controlled by adjusting the doping concentration. We confirmed that an angled excitation light incidence suppressed the leakage of excitation light.

  15. Micro and nano-structured green gallium indium nitride/gallium nitride light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Stark, Christoph J. M.

    Light-emitting diodes (LEDs) are commonly designed and studied based on bulk material properties. In this thesis different approaches based on patterns in the nano and micrometer length scale range are used to tackle low efficiency in the green spectral region, which is known as “green gap”. Since light generation and extraction are governed by microscopic processes, it is instructive to study LEDs with lateral mesa sizes scaled to the nanometer range. Besides the well-known case of the quantum size effect along the growth direction, a continuous lateral scaling could reveal the mechanisms behind the purported absence of a green gap in nanowire LEDs and the role of their extraction enhancement. Furthermore the possibility to modulate strain and piezoelectric polarization by post growth patterning is of practical interest, because the internal electric fields in conventional wurtzite GaN LEDs cause performance problems. A possible alternative is cubic phase GaN, which is free of built-in polarization fields. LEDs on cubic GaN could show the link between strong polarization fields and efficiency roll-off at high current densities, also known as droop. An additional problem for all nitride-based LEDs is efficient light extraction. For a planar GaN LED only roughly 8% of the generated light can be extracted. Novel lightextraction structures with extraction-favoring geometry can yield significant increase in light output power. To investigate the effect of scaling the mesa dimension, micro and nano-sized LED arrays of variable structure size were fabricated. The nano-LEDs were patterned by electron beam lithography and dry etching. They contained up to 100 parallel nano-stripe LEDs connected to one common contact area. The mesa width was varied over 1 μm, 200 nm, and 50 nm. These LEDs were characterized electrically and optically, and the peak emission wavelength was found to depend on the lateral structure size. An electroluminescence (EL) wavelength shift of 3 nm

  16. Enhancement of Light Output Power and Modification of Beam Profile in InGaN/GaN Light Emitting Diodes with Micro Polygon Column Shaped Transparent

    NASA Astrophysics Data System (ADS)

    Lee, Mi So; Kim, Hyung Gu; Hye Kang, Ji; Ryu, Jae Hyoung; Kim, Hyun Kyu; Kim, Hee Yun; Uthirakumar, Periyayya; Hong, Chang-Hee

    2010-11-01

    We report on the fabrication of GaN-based light-emitting diodes (LEDs) with micro-polygon columns (MPC) obtained by selective area growth (SAG) using the technique of metal organic chemical vapor deposition (MOCVD). The SAG makes it possible to control the density, size and position of the micro polygon columns. The facet structure consists of a polygon column covered with {1101} facets. Columns with rough occur on the (0001) surface. The light output power of the MPC-LED was 53% higher than conventional LED. In addition, the light extraction efficiency of InGaN/GaN LEDs is significantly improved owing to the photon path length is shorter. It is possible to modify the beam profile via shaped transparent layer. Thus, this structure can provide photons with multiple chances of escaping from the LEDs surfaces.

  17. White Light Modeling, Algorithm Development, and Validation on the Micro-arcsecond Metrology Testbed

    NASA Technical Reports Server (NTRS)

    Milman, Mark H.; Regher, Martin; Shen, Tsae Pyng

    2004-01-01

    The Space Interferometry Mission (SIM) scheduled for launch in early 2010, is an optical interferometer that will perform narrow angle and global wide angle astrometry with unprecedented accuracy, providing differential position accuracies of 1uas, and 4uas global accuracies in position, proper motion and parallax. The astrometric observations of the SIM instrument are performed via delay measurements provided by three Michelson-type, white light interferometers. Two 'guide' interferometers acquire fringes on bright guide stars in order to make highly precise measurements of variations in spacecraft attitude, while the third interferometer performs the science measurement. SIM derives its performance from a combination of precise fringe measurements of the interfered starlight (a few ten-thousandths of a wave) and very precise (tens of picometers) relative distance measurements made between a set of fiducials. The focus of the present paper is on the development and analysis of algorithms for accurate white light estimation, and on validating some of these algorithms on the MicroArcsecond Testbed.

  18. A Correlative Method for Imaging Identical Regions of Samples by Micro-CT, Light Microscopy, and Electron Microscopy

    PubMed Central

    Sengle, Gerhard; Tufa, Sara F.; Sakai, Lynn Y.; Zulliger, Martin A.

    2013-01-01

    We present a method in which a precise region of interest within an intact organism is spatially mapped in three dimensions by non-invasive micro-computed X-ray tomography (micro-CT), then further evaluated by light microscopy (LM) and transmission electron microscopy (TEM). Tissues are prepared as if for TEM including osmium fixation, which imparts soft tissue contrast in the micro-CT due to its strong X-ray attenuation. This method may therefore be applied to embedded, archived TEM samples. Upon selection of a two-dimensional (2-D) projection from a region of interest (ROI) within the three-dimensional volume, the epoxy-embedded sample is oriented for microtomy so that the sectioning plane is aligned with the micro-CT projection. Registration is verified by overlaying LM images with 2-D micro-CT projections. Structures that are poorly resolved in the micro-CT may be evaluated at TEM resolution by observing the next serial ultrathin section, thereby accessing the same ROI by all three imaging techniques. We compare white adipose tissue within the forelimbs of mice harboring a lipid-altering mutation with their littermate controls. We demonstrate that individual osmium-stained lipid droplets as small as 15 µm and separated by as little as 35 µm may be discerned as separate entities in the micro-CT, validating this to be a high-resolution, non-destructive technique for evaluation of fat content. PMID:23264636

  19. Environmental research brief: Pollution prevention assessment for a manufacturer of automotive lighting equipment and accessories

    SciTech Connect

    Fleischman, M.; Couch, B.; Handmaker, A.; Looby, G.P.

    1995-08-01

    The US Environmental Protection Agency (EPA) has funded a Pilot project to assist small and medium-size manufacture who want to minimize their generation of waste but who lac the expertise to do so. In an effort to assist these manufacturers Waste Minimization Assessment Centers (WMACs) we established at selected universities and procedures were adapted from the EPA Waste Minimization Opportunity Assessment Manual. The WMAC team at the University of Tennessee performed an assessment at a plant that manufactures outboard motors for water craft. Three basic subunits received from other manufacturing plants undergo primarily painting and assembly operations in order to produce the final product. The team`s report, detailing findings and recommendations, indicated that paint overspray waste and spent clean-up solvent are generated in large quantities and that significant cost savings could be achieved by installing robotic paint application equipment. This Research Brief was developed by the principal investigators and EPA`s National Risk Management Research Laboratory, Cincinnati, OH, to announce key findings of an ongoing research project that is fully documented in a separate report of the same title available from University City Science Center.

  20. Next Generation Print-based Manufacturing for Photovoltaics and Solid State Lighting

    SciTech Connect

    Sue A. Carter

    2012-09-07

    For the grand challenge of reducing our energy and carbon footprint, the development of renewable energy and energy efficient technologies offer a potential solution. Energy technologies can reduce our dependence on foreign oil as well as the energy consumed by the petroleum industry, the leading consumer of energy by a U.S. industry sector. Nonetheless, the manufacturing processes utilized to manufacture equipment for alternative energy technologies often involve energy-intensive processes. This undermines some of the advantages to moving to 'green' technologies in the first place. Our answer to the Industrial Technology Program's (ITP) Grand Challenge FOA was to develop a transformational low cost manufacturing process for plastic-based photovoltaics that will lower by over 50% both energy consumption and greenhouse emissions and offer a return-of-investment of over 20%. We demonstrated a Luminescent Solar Concentrator fabricated on a plastic acrylic substrate (i.e. no glass) that increases the power output of the PV cell by 2.2x with a 2% power efficiency as well as an LSC with a 7% power efficiency that increased the power output from the PV cells by 35%. S large area 20-inch x 60-inch building-integrated photovoltaic window was fabricated using contract manufacturing with a 4% power efficiency which improved the power output of the PV cell by over 50%. In addition, accelerated lifetimes of the luminescent material demonstrate lifetimes of 20-years.

  1. Manufacturing Challenges Implementing Material Changes for the Super Light Weight External Tank: A Welding Process Perspective

    NASA Technical Reports Server (NTRS)

    Lawless, K.; Jones, C.

    2001-01-01

    A viewgraph presentation gives an overview of the manufacturing challenges in implementing welding material changes for the super lightweight external tank. Details are given on the external tank configuration, the weld purging equipment used, planning the selection of weld filler wire alloy, the initial weld microstructure, the wide panel tensile testing, and the dome cap welding.

  2. ENVIRONMENTAL RESEARCH BRIEF: POLLUTION PREVENTION ASSESSMENT FOR A MANUFACTURER OF AUTOMOTIVE LIGHTING EQUIPMENT AND ACCESSORIES

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) has funded a pilot project to assist small-and medium-size manufacturers who want to minimize their generation of waste but who lack the expertise to do so. aste Minimization Assessment Centers (WMACS) were established at selected un...

  3. Simultaneously spatially and temporally focusing light for tailored ultrafast micro-machining

    NASA Astrophysics Data System (ADS)

    Thomas, Jens U.; Block, Erica; Greco, Michael; Meier, Amanda; Durfee, Charles G.; Squier, Jeffrey A.; Nolte, Stefan; Tünnermann, Andreas

    2014-03-01

    Simultaneous spatially and temporally focussing (SSTF) of ultrashort pulses allows for an unprecedented control of the intensity distribution of light. It has therefore a great potential for widespread applications ranging from nonlinear microscopy, ophthalmology to micro-machining. SSTF also allows to overcome many bottlenecks of ultrashort pulse micro-machining, especially non-linear effects like filamentation and self-focussing. Here, we describe and demonstrate in detail how SSTF offers an additional degree of freedom for shaping the focal volume. In order to obtain a SSTF beam, the output of an ultrafast laser is usually split by a grating into an array of copies of the original beam, which we refer to as beamlets. The ratio of the beamlet array width to the width of the invidual beamlet is the beam aspect ratio. The focal volume of the SSTF beam can now be tailored transversally by shaping the cross-section of the beamlets and axially by choosing the right beam aspect ratio. We will discuss the requirements of the setup for a successful implementation of this approach: Firstly, the group velocity dispersion and the third order dispersion have to be compensated in order to obtain a high axial confinement. Secondly, the beamlet size and their orientation should not vary too much spectrally. Thirdly, beamlet and SSTF focus should match. We will hence demonstrate how SSTF allows to inscribe tailored three-dimensional structures with fine control over their aspect ratio. We also show how the SSTF focus can be adapted for various glasses and crystals.

  4. Growth and characterizations of GaN micro-rods on graphene films for flexible light emitting diodes

    SciTech Connect

    Chung, Kunook; Beak, Hyeonjun; Tchoe, Youngbin; Oh, Hongseok; Yi, Gyu-Chul; Yoo, Hyobin; Kim, Miyoung

    2014-09-01

    We report the growth of GaN micro-rods and coaxial quantum-well heterostructures on graphene films, together with structural and optical characterization, for applications in flexible optical devices. Graphene films were grown on Cu foil by means of chemical vapor deposition, and used as the substrates for the growth of the GaN micro-rods, which were subsequently transferred onto SiO{sub 2}/Si substrates. Highly Si-doped, n-type GaN micro-rods were grown on the graphene films using metal–organic chemical vapor deposition. The growth and vertical alignment of the GaN micro-rods, which is a critical factor for the fabrication of high-performance light-emitting diodes (LEDs), were characterized using electron microscopy and X-ray diffraction. The GaN micro-rods exhibited promising photoluminescence characteristics for optoelectronic device applications, including room-temperature stimulated emission. To fabricate flexible LEDs, In{sub x}Ga{sub 1–x}N/GaN multiple quantum wells and a p-type GaN layer were deposited coaxially on the GaN micro-rods, and transferred onto Ag-coated polymer substrates using lift-off. Ti/Au and Ni/Au metal layers were formed to provide electrical contacts to the n-type and p-type GaN regions, respectively. The micro-rod LEDs exhibited intense emission of visible light, even after transfer onto the flexible polymer substrate, and reliable operation was achieved following numerous cycles of mechanical deformation.

  5. Investigation on Clarified Fruit Juice Composition by Using Visible Light Micro-Raman Spectroscopy

    PubMed Central

    Camerlingo, Carlo; Zenone, Flora; Delfino, Ines; Diano, Nadia; Mita, Damiano Gustavo; Lepore, Maria

    2007-01-01

    Liquid samples of clarified apple and apricot juices at different production stages were investigated using visible light micro-Raman spectroscopy in order to assess its potential in monitoring fruit juice production. As is well-known, pectin plays a strategic role in the production of clarified juice and the possibility of using Raman for its detection during production was therefore evaluated. The data analysis has enabled the clear identification of pectin. In particular, Raman spectra of apple juice samples from washed and crushed fruits revealed a peak at 845 cm-1 (typical of pectin) which disappears in the Raman spectra of depectinised samples. The fructose content was also revealed by the presence of four peaks at 823 cm-1, 872 cm-1, 918 cm-1 and 975 cm-1. In the case of apricot juice, several Raman fingerprints of β-carotene at 1008, 1159 and 1520 cm-1 were also highlighted. Present results resulted interesting for the exclusive use of optical methods for the quantitative determination of the above-mentioned substances in place of the biochemical assays generally used for this purpose, which are time consuming and require different chemical reagents for each of them.

  6. MEMS compatible micro-GRIN lenses for fiber to chip coupling of light

    NASA Astrophysics Data System (ADS)

    Zickar, Michael; Noell, Wilfried; Marxer, Cornel; de Rooij, Nico

    2006-05-01

    Graded-Index (GRIN) lenses with a diameter of 125 μm are presented. This diameter enables the assembly of the GRIN lenses onto an optical micro-system using the same passive alignment grooves as used for the light carrying optical fibers. In contrast to refractive lenses, GRIN lenses have flat endfaces and the focal distance of a GRIN lens is defined by its length. Therefore, GRIN lenses can be diced from a selected multimode optical fiber with a regular wafer dicing machine. The effects of the resulting surface roughness are reduced by immersing the optical parts into index matching oil, which can not be applied for refractive lenses. This has a further advantage since an anti-reflective coating becomes dispensable. The coupling efficiency of a collimator set-up using the GRIN lenses is studied using paraxial ray calculations. The calculated minimal coupling losses of less than 0.3 dB are in excellent agreement with the measured results. Losses smaller than 2 dB over a coupling length of 2 mm have been measured.

  7. MEMS compatible micro-GRIN lenses for fiber to chip coupling of light.

    PubMed

    Zickar, Michael; Noell, Wilfried; Marxer, Cornel; de Rooij, Nico

    2006-05-15

    Graded-Index (GRIN) lenses with a diameter of 125 mum are presented. This diameter enables the assembly of the GRIN lenses onto an optical micro-system using the same passive alignment grooves as used for the light carrying optical fibers. In contrast to refractive lenses, GRIN lenses have flat endfaces and the focal distance of a GRIN lens is defined by its length. Therefore, GRIN lenses can be diced from a selected multimode optical fiber with a regular wafer dicing machine. The effects of the resulting surface roughness are reduced by immersing the optical parts into index matching oil, which can not be applied for refractive lenses. This has a further advantage since an anti-reflective coating becomes dispensable. The coupling efficiency of a collimator set-up using the GRIN lenses is studied using paraxial ray calculations. The calculated minimal coupling losses of less than 0.3 dB are in excellent agreement with the measured results. Losses smaller than 2 dB over a coupling length of 2 mm have been measured. PMID:19516576

  8. Integration of Micro-Light-Emitting-Diode Arrays and Silicon Driver for Heterogeneous Optoelectronic Integrated Circuit Device

    NASA Astrophysics Data System (ADS)

    Shin, Sang-Baie; Iijima, Ko-Ichiro; Chiba, Jun-Ichi; Okada, Hiroshi; Iwayama, Sho; Wakahara, Akihiro

    2011-04-01

    In this paper, we proposed the possibility of implementing a single chip device for realizing optoelectronic integrated circuits (OEICs). Micro-light-emitting-diode (LED) arrays and a complementary metal-oxide-semiconductor (CMOS) pulse width modulation (PWM) silicon driver were proposed, designed, and fabricated on a single chip. The micro-LED arrays were separated by a dry etching method into 64 pixels of 8×8, each with a size of 30×30 µm2 and operated in 3 V at 100 µA. The PWM Si driver was well operated and modulated using various control signals. Furthermore, to investigate the driver for handling massive parallel information, a simple multifunctional driver was designed, fabricated, and flip-chip-bonded using a gold compliant bump and anisotropic conductive adhesive with micro-LED arrays.

  9. Measurement of manufacturing resolution for two photon polymerization structures with different manufacturing parameters

    NASA Astrophysics Data System (ADS)

    Chung, Tien-Tung; Li, Wan-Jou; Chen, Sheng-Yuan; Hoi, Chi-Hou

    2015-02-01

    This paper studied manufacturing resolutions of micro structures made by two photon polymerization (TPP) technology with different manufacturing parameters. The light source used for the TPP manufacturing system was a low-cost 532 nm Nd:YAG green laser, and the material used was commercial resin Photomer 3015. Two objective lenses, one with magnification of 100 times (100x) and numerical aperture (NA) of 1.3 and the other with 50x and NA0.8 were used in TPP production. The manufacturing resolution, which is also named as voxel size, changed with different manufacturing parameters such as laser power and exposure time. The measurement results of TPP structures manufactured with different manufacturing parameters indicated that the minimum line width produced by the 100x-NA1.3 lens could be reduced down to 67 nanometer (nm), which was quite good for TPP systems with low-cost Nd:YAG laser.

  10. Floating Light-Activated Micro Electrical Stimulators Tested in the Rat Spinal Cord

    PubMed Central

    Abdo, Ammar; Sahin, Mesut; Freedman, David S.; Cevik, Elif; Spuhler, Philipp S.; Unlu, M. Selim

    2011-01-01

    Microelectrodes of neural stimulation utilize fine wires for electrical connections to driving electronics. Breakage of these wires and the neural tissue response due to their tethering forces are major problems encountered with long term implantation of microelectrodes. The lifetime of an implant for neural stimulation can be substantially improved if the wire interconnects are eliminated. Thus, we proposed a floating light-activated micro electrical stimulator (FLAMES) for wireless neural stimulation. In this paradigm, a laser beam at near infrared (NIR) wavelengths will be used as a means of energy transfer to the device. In this study, microstimulators of various sizes were fabricated, with two cascaded GaAs p-i-n photodiodes, and tested in the rat spinal cord. A train of NIR pulses (0.2 ms, 50 Hz) was sent through the tissue to wirelessly activate the devices and generate the stimulus current. The forces elicited by intraspinal stimulation were measured from the ipsilateral forelimb with a force transducer. The largest forces were around 1.08N, a significant level of force for the rat forelimb motor function. These in vivo tests suggest that the FLAMES can be used for intraspinal microstimulation even for the deepest implant locations in the rat spinal cord. The power required to generate a threshold arm movement was investigated as the laser source was moved away from the microstimulator. The results indicate that the photon density does not decrease substantially for horizontal displacements of the source that are in the same order as the beam radius. This gives confidence that the stimulation threshold may not be very sensitive to small displacement of the spinal cord relative to the spine-mounted optical power source. PMID:21914931

  11. Advanced light source technologies that enable high-volume manufacturing of DUV lithography extensions

    NASA Astrophysics Data System (ADS)

    Cacouris, Theodore; Rao, Rajasekhar; Rokitski, Rostislav; Jiang, Rui; Melchior, John; Burfeindt, Bernd; O'Brien, Kevin

    2012-03-01

    Deep UV (DUV) lithography is being applied to pattern increasingly finer geometries, leading to solutions like double- and multiple-patterning. Such process complexities lead to higher costs due to the increasing number of steps required to produce the desired results. One of the consequences is that the lithography equipment needs to provide higher operating efficiencies to minimize the cost increases, especially for producers of memory devices that experience a rapid decline in sales prices of these products over time. In addition to having introduced higher power 193nm light sources to enable higher throughput, we previously described technologies that also enable: higher tool availability via advanced discharge chamber gas management algorithms; improved process monitoring via enhanced on-board beam metrology; and increased depth of focus (DOF) via light source bandwidth modulation. In this paper we will report on the field performance of these technologies with data that supports the desired improvements in on-wafer performance and operational efficiencies.

  12. First long term in vivo study on subdurally implanted micro-ECoG electrodes, manufactured with a novel laser technology.

    PubMed

    Henle, C; Raab, M; Cordeiro, J G; Doostkam, S; Schulze-Bonhage, A; Stieglitz, T; Rickert, J

    2011-02-01

    A novel computer aided manufacturing (CAM) method for electrocorticography (ECoG) microelectrodes was developed to be able to manufacture small, high density microelectrode arrays based on laser-structuring medical grade silicone rubber and high purity platinum. With this manufacturing process, we plan to target clinical applications, such as presurgical epilepsy monitoring, functional imaging during cerebral tumor resections and brain-computer interface control in paralysed patients, in the near future. This paper describes the manufacturing, implantation and long-term behaviour of such an electrode array. In detail, we implanted 8-channel electrode arrays subdurally over rat cerebral cortex over a period of up to 25 weeks. Our primary objective was to ascertain the electrode's stability over time, and to analyse the host response in vivo. For this purpose, impedance measurements were carried out at regular intervals over the first 18 weeks of the implantation period. The impedances changed between day 4 and day 7 after implantation, and then remained stable until the end of the implantation period, in accordance with typical behaviour of chronically implanted microelectrodes. A post-mortem histological examination was made to assess the tissue reaction due to the implantation. A mild, chronically granulated inflammation was found in the area of the implant, which was essentially restricted to the leptomeninges. Overall, these findings suggest that the concept of the presented ECoG-electrodes is promising for use in long-term implantations. PMID:20838900

  13. Three-dimensional optical digitizer system: working with white light for the manufacturing industry

    NASA Astrophysics Data System (ADS)

    Rodriguez-Larena, Jorge; Canal Bienzobas, Fernando; Campos, Fernando

    1999-11-01

    In this work, an optical system for digitizing 3D objects by using structured light is described. It is fast, contactless, highly accurate and it can work in strongly illuminated environments. An application for an industrial quality control set-up is presented, in which sand cores to be used in the car industry are automatically handled by a robot and analyzed by the 3D digitizer. After the analysis of each core presented by the robot, the digitizer sends an OK or KO instruction for the faultless or faulty piece to be placed by the robot in a different area. In order to perform all the calculations required for the analysis and for the hardware control, a specific software has been developed. A series of examples and result are shown with comments on the advantages of the method here described.

  14. Manufacture and Evaluation of Light Emitting Diode Package Substrate Using Flexible Printed Circuit Board.

    PubMed

    Park, Jung-Kab; Shin, Jin-Ha; Jung, Mun-Gi; Shigehisa, Tomabechi; Park, Hwa-Sun; Suh, Su-Jeong

    2015-10-01

    Unlike other light sources such as fluorescent lamps and incandescent bulbs, light-emitting diodes (LED) convert 70-80% of energy into heat. If the heat produced an LED chip is not effectively released, its luminous efficiency and lifespan are reduced. Therefore, as a method effectively release heat, an LED PKG substrate containing a heat-releasing material with excellent thermal conductance was fabricated, and its thermal resistance and luminous efficiency were analyzed. In this experiment, a thin polyimide film with excellent ductility was used to fabricate the LED PKG substrate. A 35-μm-thick Cu foil with excellent thermal conductance was subjected to high temperature and pressure and attached to both sides of the polyimide film. By electroplating Ag or Au, which has excellent thermal conductance, for us as the electrode and heat-releasing material, LED PKG substrate was fabricated with a thickness of approximately 170 μm. (-40 °C --> RT --> 120 °C). The results revealed that the LED PKG substrate having a Ag electrode with excellent thermal conductance had an excellent thermal resistance of approximately 4.2 °C/W (Au electrode: 5.6 °C/W). The luminous flux after 100 cycles in the thermal shock test was reduced by approximately 0.09% (Au electrode: 2.77%), indicating that the LED PKG substrate had excellent thermal resistance without any mechanical and material defects in a rapid-temperature-changing environment. The advantages and excellent thermal resistance can be exploited in cellular phones and LCD panels, and heat-releasing problems in thin panels be solved. PMID:26726375

  15. Spin-torque excited spin waves revealed by micro-focused Brillouin light scattering

    NASA Astrophysics Data System (ADS)

    Madami, Marco

    2012-02-01

    Since the discovery of the spin transfer torque (STT) effect [1,2] a great effort has been devoted to the realization and study of spin torque oscillators (STOs) because of their potential applications as spin waves injectors in magnonic devices or current-tunable broad-band microwave sources. More recently the possibility to synchronize multiple STOs [3,4] via the emitted spin waves, propagating in the magnetic ``free'' layer, envisioned a way to overcome their main limitation in the output power. For these reasons it's now crucial to obtain a detailed knowledge and understanding of the emitted spin waves properties like: their spatial distribution, their propagating or localized character, their decay length, wavelength and group velocity. In the last two years micro-focused Brillouin light scattering (μ-BLS) revealed to be a powerful tool in order to investigate several of this properties [5,6]. In this presentation we discuss the potentialities of μ-BLS to the study of emitted spin waves in STOs systems with particular focus on the results of our latest work [6]. Here we took advantage of our μ-BLS setup in order to study spin waves emitted by an out-of-plane magnetized nano-contact STO. Performing a ``wave-vector resolved'' μ-BLS experiment we provided the first direct experimental evidence of the propagating nature of SWs emitted from an out-of-plane magnetized STO. The decay of the propagating SW intensity up to several microns away from the nano-contact position showed great potential for STT based magnonic devices. We also investigated the STO tunability measuring the emitted SW frequency as a function of both the applied direct current and external field intensities. Micromagnetic simulations provided the theoretical support to quantitatively reproduce the results. [4pt] [1] Slonczewski, J. C. J. Magn. Magn. Mater. 159, L1 (1996).[0pt] [2] Berger, L. Phys. Rev. B 54, 9353 (1996).[0pt] [3] Kaka, S. et al. Nature 437, 389 (2005).[0pt] [4] Mancoff, F. B

  16. Adaptation of an evaporative light-scattering detector to micro and capillary liquid chromatography and response assessment.

    PubMed

    Gaudin, Karen; Baillet, Arlette; Chaminade, Pierre

    2004-10-01

    A commercially available evaporative light-scattering detection (ELSD) system was adapted for micro and capillary LC. Therefore the various parameters involved in the droplet formation during the nebulization step in the ELSD system were studied. It was shown that the velocity term in the Nukiyama Tanasawa equation remains constant, leading to droplets of the same order of magnitude for narrow bore and capillary columns. Consequently, the ELSD modification was performed by decreasing the internal diameter of the effluent capillary tube in the nebulizer nozzle and by keeping its external diameter constant. Next, response curves for a conventional and the developed micro and capillary LC were compared as to investigate why a linear ELSD response is often obtained when used in micro or capillary LC. By splitting the flow rate post column, we showed that the nebulization process was not at the origin of the phenomenon. For ceramide III and tripalmitin, the response curves were found to be non-linear. However the curvature was less significant when the columns internal diameter decreased. Calculated particle size profiles for micro or capillary LC suggest that the particle entering the detection chamber are bigger than under conventional LC conditions. Last, triethylamine and formic acid were used to increase the response of the detector. The response enhancement, expected from previous studies, was established for the two lipids involved in this study. PMID:15532554

  17. Stray light reduction in testing of NIRSpec subsystems: the focal plane array and micro-shutter assembly

    NASA Astrophysics Data System (ADS)

    Connelly, Joseph A.; Hadjimichael, Theo J.; Boucarut, Rene A.; Tveekrem, June L.; Mott, D. Brent

    2006-08-01

    The James Webb Space Telescope (JWST) is an infrared, space-based telescope scheduled for launch in 2013. JWST will hold four scientific instruments, including the Near Infrared Spectrograph (NIRSpec). NIRSpec operates in the wavelength range from 0.6 to 5 microns, and will be assembled by the European Space Agency. NASA/Goddard Space Flight Center (GSFC) is responsible for two NIRSpec subsystems: the detector subsystem, with the focal plane array (FPA), and the micro-shutter subsystem, with the micro-shutter assembly (MSA). The FPA consists of two side-by-side Rockwell Scientific HgCdTe 2Kx2K detectors, with the detectors and readout electronics optimized for low noise. The MSA is a GSFC developed micro-electro-mechanical system (MEMS) that serves as a programmable slit mask, allowing NIRSpec to obtain simultaneous spectra of >100 objects in a single field of view. We present the optical characterization test plan of the FPA. The test plan is driven by many requirements: cryogenic operating temperature, a flight-like beam shape, and multi-wavelength flux from 1 to 10,000 photons per second, thus low stray light is critical. We use commercial optical modeling software to predict stray light effects at the FPA. We also present the optical contrast test plan of the MSA. Each individual shutter element operates in an on/off state, and the most important optical metric is contrast. The MSA is designed to minimize stray and scattered light, and the test setup reduces stray light such that the optical contrast is measurable.

  18. A PIV study of light-driven tangential micro flows occurring near a decane-water interface

    NASA Astrophysics Data System (ADS)

    Cui, Nai-Yi; Zhang, Fan; Wan, Xuexiang

    2015-10-01

    It is observed that light radiation can drive tangential micro/mili-scale flows in vicinity of the liquid-liquid interface between two immiscible liquids. Particle Image Velocimetry (PIV) study for these newly-reported phenomena shows that the strength of these light-driven flows strongly depends on the radiation power of the excitation light used, the inclination of the liquid-liquid interface, the thickness of the top-layer liquid, and the concentrations of the liquid involved. The effect occurs only in the case that the thickness of the top-layer liquid is sufficiently thin and positionally non-uniform. For a decane-water dual layer liquid system with a particular geometry, a Gaussian-type CW IR laser with a radiation power of several tens mili-watts can maintain a micro-scale flow with its maximum flow speed of several millimeter per second at the fastest point of the flow stream. The strength of the flows increases with inclination of the liquid-liquid interface but decreases with the thickness of the top-layer liquid. Adding another solute liquid into water in the decane-water system weakens the strength of the flows remarkably. For interpretation, Marangoni effect in association with an asymmetric deflection of the excitation light may be employed as a driving mechanism behind these phenomena. However, some characteristic behaviors of these flows revealed by PIV data also suggest that the recoil effects due to the abrupt change in the momenta of photons, which also occur associated with asymmetric light deflection at the inclined interfaces of liquid media, may also contribute significantly. In terms of application, these phenomena suggest a novel technological principle, based on which direct mechanical actuation and manipulation of liquids of extensive quantity using light beams may be accomplished.

  19. Advanced manufacturing technologies for light-weight post- polished snap-together reflective optical system designs

    NASA Astrophysics Data System (ADS)

    Sweeney, Michael N.

    2002-09-01

    Fast, light weight, off-axis, aspheric, reflective optical designs are increasingly being designed and built for space-based remote sensing, fire control systems, aerial reconnaissance, cryovac instrumentation and laser scanning. Diamond point turning (DPT) is the technology of first resort for many of these applications. In many cases the best diamond machining technologies available cannot meet the desired requirements for system wavefront error and scatter. Aluminum, beryllium, AlBeMet and silicon carbide mirrors, layered with thin films of electroless nickel or silicon can be first diamond machined and then post polished to achieve greatly enhanced performance levels for surface scatter, wavefront error (WFE), and alignment registration. By application of post polishing using precise null testing techniques, the objectives of snap-together, or limited compensation alignment of aggressive reflective optical systems can be achieved that are well beyond the performance envelope achievable by diamond machining alone. This paper discusses the tradeoffs among materials and processes selection for post polished reflective systems and illustrates actual applications including telescopes for earth and Mars orbit, and a commercial, high speed, flat field scan engine.

  20. Design and fabrication of AlGaInP-based micro-light-emitting-diode array devices

    NASA Astrophysics Data System (ADS)

    Bao, Xingzhen; Liang, Jingqiu; Liang, Zhongzhu; Wang, Weibiao; Tian, Chao; Qin, Yuxin; Lü, Jinguang

    2016-04-01

    An integrated high-resolution (individual pixel size 80 μm×80 μm) solid-state self-emissive active matrix programmed with 320×240 micro-light-emitting-diode arrays structure was designed and fabricated on an AlGaInP semiconductor chip using micro electro-mechanical systems, microstructure and semiconductor fabricating techniques. Row pixels share a p-electrode and line pixels share an n-electrode. We experimentally investigated GaAs substrate thickness affects the electrical and optical characteristics of the pixels. For a 150-μm-thick GaAs substrate, the single pixel output power was 167.4 μW at 5 mA, and increased to 326.4 μW when current increase to 10 mA. The device investigated potentially plays an important role in many fields.

  1. X27A - A New Hard X-ray Micro-Spectroscopy Facility at the National Synchrtron Light Source

    SciTech Connect

    Ablett,J.; Kao, C.; Reeder, R.; Tang, Y.; Lanzirotti, A.

    2006-01-01

    A new hard X-ray micro-spectroscopy beamline has recently been installed at bending-magnet beamline X27A at the National Synchrotron Light Source, where the focus of research is primarily directed towards the environmental, geological and materials science communities. This instrument delivers moderate, {approx}10 {micro}m spatial resolution using achromatic dynamically bent Kirkpatrick-Baez mirrors, in addition to providing high X-ray flux throughput and selectable energy resolution. The balance between moderate spatial resolution and high flux throughput, in combination with a liquid nitrogen-cooled 13-element energy-dispersive high-purity germanium detector, is particularly well suited to the investigation of dilute and thin-film systems using the fluorescence X-ray absorption fine-structure mode of detection. In this paper, we report on the design and performance of this instrument and highlight a recent experimental study undertaken at this facility.

  2. Fibre coupled micro-light emitting diode array light source with integrated band-pass filter for fluorescence detection in miniaturised analytical systems.

    PubMed

    Vaculovičová, Markéta; Akther, Mahbub; Maaskant, Pleun; Brabazon, Dermot; Macka, Mirek

    2015-04-29

    In this work, a new type of miniaturized fibre-coupled solid-state light source is demonstrated as an excitation source for fluorescence detection in capillary electrophoresis. It is based on a parabolically shaped micro-light emitting diode (μ-LED) array with a custom band-pass optical interference filter (IF) deposited at the back of the LED substrate. The GaN μ-LED array consisted of 270 individual μ-LED elements with a peak emission at 470 nm, each about 14 μm in diameter and operated as a single unit. Light was extracted through the transparent substrate material, and coupled to an optical fibre (OF, 400 μm in diameter, numerical aperture NA=0.37), to form an integrated μ-LED-IF-OF light source component. This packaged μ-LED-IF-OF light source emitted approximately 225 μW of optical power at a bias current of 20 mA. The bandpass IF filter was designed to reduce undesirable LED light emissions in the wavelength range above 490 nm. Devices with and without IF were compared in terms of the optical power output, spectral characteristics as well as LOD values. While the IF consisted of only 7.5 pairs (15 layers) of SiO2/HfO2 layers, it resulted in an improvement of the baseline noise as well as the detection limit measured using fluorescein as test analyte, both by approximately one order of magnitude, with a LOD of 1×10(-8) mol L(-1) obtained under optimised conditions. The μ-LED-IF-OF light source was then demonstrated for use in capillary electrophoresis with fluorimetric detection. The limits of detection obtained by this device were compared to those obtained with a commercial fibre coupled LED device. PMID:25847165

  3. Research of micro-prism distribution on the bottom surface of the small-size integrated light guide plate.

    PubMed

    Xu, Ping; Huang, Yanyan; Su, Zhijie; Zhang, Xulin; Luo, Tongzheng; Peng, Wenda

    2015-02-23

    The luminance uniformity of the backlight module (BLM) importantly depends on the microstructure distribution on the bottom surface of the light guide plate (LGP). Based on the small-size integrated LGP (ILGP) proposed, we put forward a distribution expression of micro-prisms on the bottom surface of the ILGP, and present the relational expressions between the coefficients of the analytical expression and the structural parameters of the ILGP, such as the light guide length L, width of the ILGP W, thickness of the ILGP H, and space between light emitting diodes (LEDs) d. Then, the research results above are applied to the design of the small-size ILGPs. Not only can the micro-structure distributions on the bottom surface of the ILGPs be directly given, but also the simulation results show that the luminance uniformities of the integrated BLMs are higher than 85%. The research indicates that the expressions proposed in this paper are correct and effective, and have important guiding significances and referential value. PMID:25836524

  4. A novel technique for the production of electrospun scaffolds with tailored three-dimensional micro-patterns employing additive manufacturing.

    PubMed

    Rogers, Catherine M; Morris, Gavin E; Gould, Toby W A; Bail, Robert; Toumpaniari, Sotiria; Harrington, Helen; Dixon, James E; Shakesheff, Kevin M; Segal, Joel; Rose, Felicity R A J

    2014-09-01

    Electrospinning is a common technique used to fabricate fibrous scaffolds for tissue engineering applications. There is now growing interest in assessing the ability of collector plate design to influence the patterning of the fibres during the electrospinning process. In this study, we investigate a novel method to generate hybrid electrospun scaffolds consisting of both random fibres and a defined three-dimensional (3D) micro-topography at the surface, using patterned resin formers produced by rapid prototyping (RP). Poly(D,L-lactide-co-glycolide) was electrospun onto the engineered RP surfaces and the ability of these formers to influence microfibre patterning in the resulting scaffolds visualized by scanning electron microscopy. Electrospun scaffolds with patterns mirroring the microstructures of the formers were successfully fabricated. The effect of the resulting fibre patterns and 3D geometries on mammalian cell adhesion and proliferation was investigated by seeding enhanced green fluorescent protein labelled 3T3 fibroblasts onto the scaffolds. Following 24 h and four days of culture, the seeded scaffolds were visually assessed by confocal macro- and microscopy. The patterning of the fibres guided initial cell adhesion to the scaffold with subsequent proliferation over the geometry resulting in the cells being held in a 3D micro-topography. Such patterning could be designed to replicate a specific in vivo structure; we use the dermal papillae as an exemplar here. In conclusion, a novel, versatile and scalable method to produce hybrid electrospun scaffolds has been developed. The 3D directional cues of the patterned fibres have been shown to influence cell behaviour and could be used to culture cells within a similar 3D micro-topography as experienced in vivo. PMID:24722371

  5. A process to control light in a micro resonator through a coupling modulation by surface acoustic waves

    PubMed Central

    Fan, Guofang; Li, Yuan; Hu, Chunguang; Lei, Lihua; Guo, Yanchuan

    2016-01-01

    A novel process to control light through the coupling modulation by surface acoustic wave (SAW) is presented in an optical micro resonator. An optical waveguide modulator of a racetrack resonator on silicon-on-insulator (SOI) technology is took as an example to explore the mechanism. A finite-difference time-domain (FDTD) is developed to simulate the acousto-optical (AO) modulator using the mechanism. An analytical method is presented to verify our proposal. The results show that the process can work well as an optical modulator by SAW. PMID:27485470

  6. A process to control light in a micro resonator through a coupling modulation by surface acoustic waves

    NASA Astrophysics Data System (ADS)

    Fan, Guofang; Li, Yuan; Hu, Chunguang; Lei, Lihua; Guo, Yanchuan

    2016-08-01

    A novel process to control light through the coupling modulation by surface acoustic wave (SAW) is presented in an optical micro resonator. An optical waveguide modulator of a racetrack resonator on silicon-on-insulator (SOI) technology is took as an example to explore the mechanism. A finite-difference time-domain (FDTD) is developed to simulate the acousto-optical (AO) modulator using the mechanism. An analytical method is presented to verify our proposal. The results show that the process can work well as an optical modulator by SAW.

  7. A process to control light in a micro resonator through a coupling modulation by surface acoustic waves.

    PubMed

    Fan, Guofang; Li, Yuan; Hu, Chunguang; Lei, Lihua; Guo, Yanchuan

    2016-01-01

    A novel process to control light through the coupling modulation by surface acoustic wave (SAW) is presented in an optical micro resonator. An optical waveguide modulator of a racetrack resonator on silicon-on-insulator (SOI) technology is took as an example to explore the mechanism. A finite-difference time-domain (FDTD) is developed to simulate the acousto-optical (AO) modulator using the mechanism. An analytical method is presented to verify our proposal. The results show that the process can work well as an optical modulator by SAW. PMID:27485470

  8. Wafer-scale micro-optics fabrication

    NASA Astrophysics Data System (ADS)

    Voelkel, Reinhard

    2012-07-01

    Micro-optics is an indispensable key enabling technology for many products and applications today. Probably the most prestigious examples are the diffractive light shaping elements used in high-end DUV lithography steppers. Highly-efficient refractive and diffractive micro-optical elements are used for precise beam and pupil shaping. Micro-optics had a major impact on the reduction of aberrations and diffraction effects in projection lithography, allowing a resolution enhancement from 250 nm to 45 nm within the past decade. Micro-optics also plays a decisive role in medical devices (endoscopes, ophthalmology), in all laser-based devices and fiber communication networks, bringing high-speed internet to our homes. Even our modern smart phones contain a variety of micro-optical elements. For example, LED flash light shaping elements, the secondary camera, ambient light and proximity sensors. Wherever light is involved, micro-optics offers the chance to further miniaturize a device, to improve its performance, or to reduce manufacturing and packaging costs. Wafer-scale micro-optics fabrication is based on technology established by the semiconductor industry. Thousands of components are fabricated in parallel on a wafer. This review paper recapitulates major steps and inventions in wafer-scale micro-optics technology. The state-of-the-art of fabrication, testing and packaging technology is summarized.

  9. Contour scanning of textile preforms using a light-section sensor for the automated manufacturing of fibre-reinforced plastics

    NASA Astrophysics Data System (ADS)

    Schmitt, R.; Niggemann, C.; Mersmann, C.

    2008-04-01

    Fibre-reinforced plastics (FRP) are particularly suitable for components where light-weight structures with advanced mechanical properties are required, e.g. for aerospace parts. Nevertheless, many manufacturing processes for FRP include manual production steps without an integrated quality control. A vital step in the process chain is the lay-up of the textile preform, as it greatly affects the geometry and the mechanical performance of the final part. In order to automate the FRP production, an inline machine vision system is needed for a closed-loop control of the preform lay-up. This work describes the development of a novel laser light-section sensor for optical inspection of textile preforms and its integration and validation in a machine vision prototype. The proposed method aims at the determination of the contour position of each textile layer through edge scanning. The scanning route is automatically derived by using texture analysis algorithms in a preliminary step. As sensor output a distinct stage profile is computed from the acquired greyscale image. The contour position is determined with sub-pixel accuracy using a novel algorithm based on a non-linear least-square fitting to a sigmoid function. The whole contour position is generated through data fusion of the measured edge points. The proposed method provides robust process automation for the FRP production improving the process quality and reducing the scrap quota. Hence, the range of economically feasible FRP products can be increased and new market segments with cost sensitive products can be addressed.

  10. Novel light-curable materials containing experimental bioactive micro-fillers remineralise mineral-depleted bonded-dentine interfaces.

    PubMed

    Sauro, Salvatore; Osorio, Raquel; Osorio, Estrella; Watson, Timothy F; Toledano, Manuel

    2013-01-01

    This study aimed at evaluating the therapeutic remineralising effects of innovative light-curable materials (LCMs) containing two experimental calcium silicate-based micro-fillers (TCS) modified with β-TCP only or β-TCP, zinc oxide (ZnO)/polyacrylic acid (PAA) on mineral-depleted bonded-dentine interfaces in simulated body fluids (SBFS). Three experimental LCMs were formulated: (1) resin A, containing a β-TCP-modified TCS (βTCS) micro-filler; (2) resin B, containing a polycarboxylated β-TCP/ZnO-modified TCS (βZn-TCS) micro-filler; and 3) resin C, containing no filler (control). Acid-etched (35% H3PO4) dentine specimens were bonded using the three LCMs and submitted to atomic force microscope (AFM)/nano-indentation analysis to evaluate the modulus of elasticity (Ei) and hardness (Hi) across the interface after SBFS storage (24 h/1 m/3 m). The ultramorphology and micropermeability of the resin-dentine interface were evaluated using confocal laser microscopy. Resin-dentine sticks were created and submitted to microtensile bond strength (μTBS) test (SBFS: 24 h/3 m). Scanning electron microscopy (SEM) was performed after de-bonding. The LCMs containing the experimental bioactive micro-fillers reduced the micropermeability and induced a significant increase of the Ei and Hi along the bonding interface. The specimens created using the resin B (βZn-TCS) attained the highest μTBS values both after 24 h and 3 m of SBFS storage. In conclusion, the innovative bioactive light-curable materials tested in this study are able to induce a therapeutic remineralising effect on the nano-mechanical properties and on the sealing ability of mineral-depleted resin-dentine interfaces. The contemporary idea of minimally invasive operative treatment, where therapeutic restorations are performed to combat the carious process and remineralise the dental hard tissues, may be satisfied by using such resin-base systems, containing βTCS or βZn-TCS bioactive micro

  11. Light intensity modulation by coccoliths of Emiliania huxleyi as a micro-photo-regulator

    PubMed Central

    Mizukawa, Yuri; Miyashita, Yuito; Satoh, Manami; Shiraiwa, Yoshihiro; Iwasaka, Masakazu

    2015-01-01

    In this study, we present experimental evidence showing that coccoliths have light-scattering anisotropy that contributes to a possible control of solar light exposure in the ocean. Changing the angle between the incident light and an applied magnetic field causes differences in the light-scattering intensities of a suspension of coccoliths isolated from Emiliania huxleyi. The magnetic field effect is induced by the diamagnetic torque force directing the coccolith radial plane perpendicular to the applied magnetic fields at 400 to 500 mT. The developed technique reveals the light-scattering anisotropies in the 3-μm-diameter floating coccoliths by orienting themselves in response to the magnetic fields. The detached coccolith scatters radially the light incident to its radial plane. The experimental results on magnetically oriented coccoliths show that an individual coccolith has a specific direction of light scattering, although the possible physiological effect of the coccolith remains for further study, focusing on the light-scattering anisotropies of coccoliths on living cells. PMID:26323524

  12. 2 nm continuously tunable 488nm micro-integrated diode-laser-based SHG light source for Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Braune, M.; Maiwald, M.; Sumpf, B.; Tränkle, G.

    2016-04-01

    Raman spectroscopy in the visible spectral range is of great interest due to resonant Raman effects. Nevertheless, fluorescence and ambient light can mask the weak Raman lines. Shifted excitation Raman difference spectroscopy is a demonstrated tool to overcome this drawback. To apply this method, a light source with two alternating wavelengths is necessary. The spectral distance between these two wavelengths has to be adapted to the width of the Raman signal. According to the sample under investigation the width of the Raman signal could be in the range of 3 cm-1 - 12 cm-1. In this work, a micro-integrated light source emitting at 488 nm with a continuous wavelength tuning range up to 2 nm (83 cm-1) is presented. The pump source, a DFB laser emitting at 976 nm, and a periodically poled lithium niobate (PPLN) ridge waveguide crystal is used for the second harmonic generation (SHG). Both components are mounted on a μ-Peltier-element for temperature control. Here, a common wavelength tuning of the pump wavelength and the acceptance bandwidth of the SHG crystal via temperature is achieved. With the results the light source is suitable for portable Raman and SERDS experiments with a flexible spectral distance between both excitation wavelengths for SERDS with respect to the sample under investigation.

  13. Visible Light Driven Photocatalytic Reactor Based on Micro-structured Polymer Optical Fiber Preform

    NASA Astrophysics Data System (ADS)

    Li, Dong-Dong; She, Jiang-Bo; Wang, Chang-Shun; Peng, Bo

    2014-05-01

    A novel visible light driven photocatalytic reactor with 547 pieces of Ag/AgBr-film-modified capillaries is reported and it is derived from a microstructured polymer optical fiber (MPOF) preform. The MPOF preform not only plays the role of a light-transmitting media, but it is also a Ag/AgBr supporting and waste-water pipe to supply the photocatalytic degradation of dyes solute. The photocatalytic reactor has such a large surface area for Ag/AgBr loading, which is a visible light driven photocatalyst that photodegradation efficiency is enhanced.

  14. Light emission of metal halide lamps under micro- and hypergravity conditions

    SciTech Connect

    Stoffels, W.W.; Kemps, P.C.M.; Beckers, J.; Kroesen, G.M.W.; Haverlag, M.

    2005-12-12

    The wavelength-integrated light output from a metal halide discharge lamp is measured for gravity conditions varying from 0 to 1.8 g during parabolic flights. The results show that the changing gravity affects the convection flow in the lamp, which in turn changes the total light output. For vertically burning lamps, the sign and magnitude of the effect can be predicted using the demixing parameter: the ratio of typical diffusion to convection times. In horizontally burning lamps at 0 g, the absence of convective mixing results in a reduced light emission.

  15. Laser ablation of micro-photonic structures for efficient light collection and distribution

    NASA Astrophysics Data System (ADS)

    Shang, Xiaobing; Desmet, Andres; De Smet, Jelle; Joshi, Pankaj; Cuypers, Dieter; Van Put, Steven; Van Steenberge, Geert; Vervaeke, Michael; Thienpont, Hugo; De Smet, Herbert

    2015-06-01

    In this work we report the fabrication of polymer micro-photonic gratings for use in liquid-crystal based actively tunable electro-optic components. The gratings are produced by moving the sample surface sideways across a perpendicularly impinging KrF excimer laser beam (λ  =  248 nm), which is shaped by specially designed triangular and trapezoidal masks. To obtain correctly dimensioned and smooth grating surfaces, different materials (SU-8, polycarbonate, Epoclad and Epocore) are subjected to the laser ablation with optimized laser processing parameters. The resulting grating structures on Epocore exhibit the best surface roughness and dimensional fidelity. Optionally, spacers for maintaining the cell gap of the superimposed liquid crystal layer can also be fabricated in the same process. Two different methods were demonstrated: overlapping ablation and double mask ablation. Micro-grating structures were produced that deflect a monochromatic (543 nm) laser beam to the theoretically predicted 11th order with an angle of 7°.

  16. Fluorescent all-fiber light source based on micro-capillaries and on microstructured optical fibers terminated with a microbulb

    NASA Astrophysics Data System (ADS)

    Vladev, Veselin; Eftimov, Tinko; Bock, Wojtek

    2015-12-01

    An integrated fiber-optic fluorescent light source compatible with photonic-crystal and hollow-core fibers is presented in this paper. We have studied the dependence of the fluorescence spectra on the length of a micro-capillary filled with Rhodamine 6G dissolved in glycerin. As the capillary, we used a standard fiber-optic glass ferrule with two parallel holes having an inner diameter of 125 μm. One of the holes was filled with fluorescing solution, while an SMF-28 fiber polished at 45° with aluminum coating was placed in the second hole to serve as a pumping fiber. As the solution was pumped by continuous-wave laser light at 532 nm, the fluorescence was captured by a microstructured optical fiber immersed in the filled hole. To prevent the solution from penetrating into this receiving fiber, its end was capped by molten borosilicate glass forming a ball lens. Combining the spectra of several fluorescent organic dyes can create a broadband light source compatible with optical fibers that could be used for the development of compact photonic-crystal and hollow-core fiber sensors.

  17. The bio-gripper: a fluid-driven micro-manipulator of living tissue constructs for additive bio-manufacturing.

    PubMed

    Ip, Blanche C; Cui, Francis; Tripathi, Anubhav; Morgan, Jeffrey R

    2016-06-01

    thirty times with Q(c) corresponding to our simulation. Our bio-gripper was capable of stacking and aligning twenty microtissues. In summary, we successfully engineered a robust controllable fluid-driven bio-gripper to efficiently manipulate living microtissues and micro-objects in an aqueous environment. PMID:27221320

  18. Thin-film solar cells with InGaAs/GaAsP multiple quantum wells and a rear surface etched with light trapping micro-hole array

    NASA Astrophysics Data System (ADS)

    Watanabe, Kentaroh; Inoue, Tomoyuki; Sodabanlu, Hassanet; Sugiyama, Masakazu; Nakano, Yoshiaki

    2015-08-01

    A light trapping effect in GaAs p-i-n solar cells with InGaAs/GaAsP multiple quantum wells (MQWs) in the i-layer was demonstrated by applying a light scattering texture to the rear surface of the cell. A thin-film MQW solar cell was successfully fabricated by metal organic vapor phase epitaxy (MOVPE) to grow an inverted n-i-p photovoltaic (PV) structure; this structure was then transferred to a Si support substrate to prevent optical loss due to free carrier absorption. For the light scattering texture, the use of both the wet-etched micro-hole arrayed SiO2 dielectric layer on the rear surface of the cell and the secondarily etched micro hole array on the GaAs layer was attempted. On the SiO2 layer, the micro hole array pattern was obtained by the radio frequency sputtering of the layer followed by wet etching with photolithographic patterning. On the GaAs layer, the micro-hole array pattern was obtained by direct etching through a SiO2 template. Compared with the light scattering effects of the micro-hole-arrayed SiO2 layer, the secondarily etched GaAs rear contact layer showed a significant improvement in external quantum efficiency (EQE) in the wavelength range from 855 to 1000 nm that corresponds to the photon absorption wavelength in MQWs.

  19. 49 CFR 579.21 - Reporting requirements for manufacturers of 5,000 or more light vehicles annually.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... (electric battery power), FCP (fuel-cell power), HEV (hybrid electric vehicle), HCP (hydrogen combustion... vehicle manufactured during the reporting period and the nine model years prior to the earliest model year... manufacturer's vehicle, together with each incident involving one or more deaths occurring in a foreign...

  20. Method and apparatus for measuring micro structures, anisotropy and birefringence in polymers using laser scattered light

    DOEpatents

    Grek, Boris; Bartolick, Joseph; Kennedy, Alan D.

    2000-01-01

    A method and apparatus for measuring microstructures, anistropy and birefringence in polymers using laser scattered light includes a laser which provides a beam that can be conditioned and is directed at a fiber or film which causes the beam to scatter. Backscatter light is received and processed with detectors and beam splitters to obtain data. The data is directed to a computer where it is processed to obtain information about the fiber or film, such as the birefringence and diameter. This information provides a basis for modifications to the production process to enhance the process.

  1. Size-dependent magnetization dynamics in individual Ni80Fe20 disk using micro-focused Brillouin Light Scattering spectroscopy

    NASA Astrophysics Data System (ADS)

    Shimon, G.; Adeyeye, A. O.

    2015-09-01

    A direct and systematic investigation of the magnetization dynamics in individual circular Ni80Fe20 disk of diameter (D) in the range from 300 nm to 1 μm measured using micro-focused Brillouin Light Scattering (μ-BLS) spectroscopy is presented. At high field, when the disks are in a single domain state, the resonance frequency of the uniform center mode is observed to reduce with reducing disk's diameter. For D = 300 nm, additional edge and end-domains resonant modes are observed due to size effects. At low field, when the disks are in a vortex state, a systematic increase of resonant frequency of magnetostatic modes in a vortex state with the square root of the disks' aspect ratio (thickness divided by radius) is observed. Such dependence diminishes for disks with larger aspect ratio due to an increasing exchange energy contribution. Micromagnetic simulations are in excellent agreement with the experiments.

  2. Enhanced light emission from carbon nanotubes integrated in silicon micro-resonator

    NASA Astrophysics Data System (ADS)

    Noury, Adrien; Le Roux, Xavier; Vivien, Laurent; Izard, Nicolas

    2015-08-01

    Single-walled carbon nanotubes are considered a fascinating nanomaterial for photonic applications and are especially promising for efficient light emitters in the telecommunication wavelength range. Furthermore, their hybrid integration with silicon photonic structures makes them an ideal platform to explore their intrinsic properties. Here we report on the strong photoluminescence enhancement from carbon nanotubes integrated in silicon ring resonator circuits under two pumping configurations: surface-illuminated pumping at 735 nm and collinear pumping at 1.26 μ {{m}}. Extremely efficient rejection of the non-resonant photoluminescence was obtained. In the collinear approach, an emission efficiency enhancement by a factor of 26 has been demonstrated in comparison with the classical pumping scheme. This demonstration paves the way for the development of integrated light sources in silicon based on carbon nanotubes.

  3. Micro-focused Brillouin light scattering: imaging spin waves at the nanoscale

    NASA Astrophysics Data System (ADS)

    Sebastian, Thomas; Schultheiss, Katrin; Obry, Björn; Hillebrands, Burkard; Schultheiss, Helmut; Obry, Björn

    2015-06-01

    Spin waves constitute an important part of research in the field of magnetization dynamics. Spin waves are the elementary excitations of the spin system in a magnetically ordered material state and magnons are their quasi particles. In the following article, we will discuss the optical method of Brillouin light scattering (BLS) spectroscopy which is a now a well established tool for the characterization of spin waves. BLS is the inelastic scattering of light from spin waves and confers several benefits: the ability to map the spin wave intensity distribution with spatial resolution and high sensitivity as well as the potential to simultaneously measure the frequency and the wave vector and, therefore, the dispersion properties. For several decades, the field of spin waves gained huge interest by the scientific community due to its relevance regarding fundamental issues of spindynamics in the field of solid states physics. The ongoing research in recent years has put emphasis on the high potential of spin waves regarding information technology. In the emerging field of textit{magnonics}, several concepts for a spin-wave based logic have been proposed and realized. Opposed to charge-based schemes in conventional electronics and spintronics, magnons are charge-free currents of angular momentum, and, therefore, less subject to scattering processes that lead to heating and dissipation. This fact is highlighted by the possibility to utilize spin waves as information carriers in electrically insulating materials. These developments have propelled the quest for ways and mechanisms to guide and manipulate spin-wave transport. In particular, a lot of effort is put into the miniaturization of spin-wave waveguides and the excitation of spin waves in structures with sub-micrometer dimensions. For the further development of potential spin-wave-based devices, the ability to directly observe spin-wave propagation with spatial resolution is crucial. As an optical technique BLS do

  4. Microscopic vision modeling method by direct mapping analysis for micro-gripping system with stereo light microscope.

    PubMed

    Wang, Yuezong; Zhao, Zhizhong; Wang, Junshuai

    2016-04-01

    We present a novel and high-precision microscopic vision modeling method, which can be used for 3D data reconstruction in micro-gripping system with stereo light microscope. This method consists of four parts: image distortion correction, disparity distortion correction, initial vision model and residual compensation model. First, the method of image distortion correction is proposed. Image data required by image distortion correction comes from stereo images of calibration sample. The geometric features of image distortions can be predicted though the shape deformation of lines constructed by grid points in stereo images. Linear and polynomial fitting methods are applied to correct image distortions. Second, shape deformation features of disparity distribution are discussed. The method of disparity distortion correction is proposed. Polynomial fitting method is applied to correct disparity distortion. Third, a microscopic vision model is derived, which consists of two models, i.e., initial vision model and residual compensation model. We derive initial vision model by the analysis of direct mapping relationship between object and image points. Residual compensation model is derived based on the residual analysis of initial vision model. The results show that with maximum reconstruction distance of 4.1mm in X direction, 2.9mm in Y direction and 2.25mm in Z direction, our model achieves a precision of 0.01mm in X and Y directions and 0.015mm in Z direction. Comparison of our model with traditional pinhole camera model shows that two kinds of models have a similar reconstruction precision of X coordinates. However, traditional pinhole camera model has a lower precision of Y and Z coordinates than our model. The method proposed in this paper is very helpful for the micro-gripping system based on SLM microscopic vision. PMID:26924646

  5. The genomics of wild yeast populations sheds light on the domestication of man's best (micro) friend.

    PubMed

    Eberlein, Chris; Leducq, Jean-Baptiste; Landry, Christian R

    2015-11-01

    The domestication of plants, animals and microbes by humans are the longest artificial evolution experiments ever performed. The study of these long-term experiments can teach us about the genomics of adaptation through the identification of the genetic bases underlying the traits favoured by humans. In laboratory evolution, the characterization of the molecular changes that evolved specifically in some lineages is straightforward because the ancestors are readily available, for instance in the freezer. However, in the case of domesticated species, the ancestor is often missing, which leads to the necessity of going back to nature in order to infer the most likely ancestral state. Significant and relatively recent examples of this approach include wolves as the closest wild relative to domestic dogs (Axelsson et al. 2013) and teosinte as the closest relative to maize (reviewed in Hake & Ross-Ibarra 2015). In both cases, the joint analysis of domesticated lineages and their wild cousins has been key in reconstructing the molecular history of their domestication. While the identification of closest wild relatives has been done for many plants and animals, these comparisons represent challenges for micro-organisms. This has been the case for the budding yeast Saccharomyces cerevisiae, whose natural ecological niche is particularly challenging to define. For centuries, this unicellular fungus has been the cellular factory for wine, beer and bread crafting, and currently for bioethanol and drug production. While the recent development of genomics has lead to the identification of many genetic elements associated with important wine characteristics, the historical origin of some of the domesticated wine strains has remained elusive due to the lack of knowledge of their close wild relatives. In this issue of Molecular Ecology, Almeida et al. (2015) identified what is to date the closest known wild population of the wine yeast. This population is found associated with

  6. Multi-wavelength phase-shifting interferometry for micro-structures measurement based on color image processing in white light interference

    NASA Astrophysics Data System (ADS)

    Guo, Tong; Li, Feng; Chen, Jinping; Fu, Xing; Hu, Xiaotang

    2016-07-01

    Conventional multi-wavelength phase-shifting interferometry utilizes two or three monochromatic light sources, such as lasers, to realize the measurement of the surface topography with large discontinuity. In this paper, the white light source, with a single-chip CCD color camera, is used to accomplish multi-wavelength phase-shifting interferometry. In addition, we propose an algorithm which combines white light phase-shifting algorithm, equivalent wavelength method and fringe order method to achieve measuring and calibrating the micro-structures ranging from nanometer scale to micrometer scale. Finally, the proposed method is validated by a traceable step height standard.

  7. A study on the analysis method of shape quality and the micro burr removal on a micro pyramid pattern using the micro MR fluid jet polishing system

    NASA Astrophysics Data System (ADS)

    Lee, J. W.; Ha, S. J.; Hong, K. P.; Cho, Y. K.; Kim, K. B.; Kim, B. C.; Cho, M. W.

    2016-04-01

    Recently, micro square pyramid patterns which can be obtained by a light diffusion effect have been widely studied and examined. However, micro pyramid patterns are difficult to fabricate, because of a deburring problem. Therefore, a micro machining technology for the fabrication of micro pyramid patterns has emerged as an essential element. Burr can almost be generated on the edge of the micro pattern when the micro square pyramid pattern is manufactured by a mechanical cutting process. The micro pyramid pattern shape is difficult to maintain as an original form when the burrs are removed. So various methods have been used in an attempt to remove the burrs. A micro magnetorheological (MR) fluid jet polishing process is one of various methods to remove burrs. The process can control shear force for material removing it by a controlled viscosity of the MR fluid due to magnetic-field adjusting. In this paper, magnetic analysis and the deburring process were carried out to fabricate a micro square pyramid pattern on brass (non-magnetic material) and nickel (ferromagnetic material) using a micro MR fluid jet polishing system. Finally, the deburring characteristics and the shape analysis of micro pyramid patterns were investigated by using a micro MR fluid jet polishing system.

  8. Lighting.

    SciTech Connect

    United States. Bonneville Power Administration.

    1992-09-01

    Since lighting accounts for about one-third of the energy used in commercial buildings, there is opportunity to conserve. There are two ways to reduce lighting energy use: modify lighting systems so that they used less electricity and/or reduce the number of hours the lights are used. This booklet presents a number of ways to do both. Topics covered include: reassessing lighting levels, reducing lighting levels, increasing bulb & fixture efficiency, using controls to regulate lighting, and taking advantage of daylight.

  9. Tunable multicolor and white-light upconversion luminescence in Yb3+/Tm3+/Ho3+ tri-doped NaYF4 micro-crystals.

    PubMed

    Lin, Hao; Xu, Dekang; Teng, Dongdong; Yang, Shenghong; Zhang, Yueli

    2015-09-01

    NaYF4 micro-crystals with various concentrations of Yb(3+) /Tm(3+) /Ho(3+) were prepared successfully via a simple and reproducible hydrothermal route using EDTA as the chelating agent. Their phase structure and surface morphology were studied using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD patterns revealed that all the samples were pure hexagonal phase NaYF4. SEM images showed that Yb(3+)/Tm(3+)/Ho(3+) tri-doped NaYF4 were hexagonal micro-prisms. Upconversion photoluminescence spectra of Yb(3+)/Tm(3+)/Ho(3+) tri-doped NaYF4 micro-crystals with various dopant concentrations under 980 nm excitation with a 665 mW pump power were studied. Tunable multicolor (purple, purplish blue, yellowish green, green) and white light were achieved by simply adjusting the Ho(3+) concentration in 20%Yb(3+)/1%Tm(3+)/xHo(3+) tri-doped NaYF4 micro-crystals. Furthermore, white-light emissions could be obtained using different pump powers in 20%Yb(3+)/1%Tm(3+)/1%Ho(3+) tri-doped NaYF4 micro-crystals at 980 nm excitation. The pump power-dependent intensity relationship was studied and relevant energy transfer processes were discussed in detail. The results suggest that Yb(3+)/Tm(3+) Ho(3+) tri-doped NaYF4 micro-crystals have potential applications in optoelectronic devices such as photovoltaic, plasma display panel and white-light-emitting diodes. PMID:25377774

  10. POLLUTION PREVENTION ASSESSMENT FOR A MANUFACTURER OF AUTOMOTIVE LIGHTING EQUIPMENT AND ACCESSORIES (EPA/600/S-95/012)

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) has funded a pilot project to assist small and medium-size manufacturers who want to minimize their generation of waste but who lack the expertise to do so. Waste Minimization Assessment Centers (WMACs) were established at selected u...

  11. InGaN based micro light emitting diodes featuring a buried GaN tunnel junction

    SciTech Connect

    Malinverni, M. Martin, D.; Grandjean, N.

    2015-08-03

    GaN tunnel junctions (TJs) are grown by ammonia molecular beam epitaxy. High doping levels are achieved with a net acceptor concentration close to ∼10{sup 20 }cm{sup −3}, thanks to the low growth temperature. This allows for the realization of p-n junctions with ultrathin depletion width enabling efficient interband tunneling. n-p-n structures featuring such a TJ exhibit low leakage current densities, e.g., <5 × 10{sup −5} A cm{sup −2} at reverse bias of 10 V. Under forward bias, the voltage is 3.3 V and 4.8 V for current densities of 20 A cm{sup −2} and 2000 A cm{sup −2}, respectively. The specific series resistance of the whole device is 3.7 × 10{sup −4} Ω cm{sup 2}. Then micro-light emitting diodes (μ-LEDs) featuring buried TJs are fabricated. Excellent current confinement is demonstrated together with homogeneous electrical injection, as seen on electroluminescence mapping. Finally, the I-V characteristics of μ-LEDs with various diameters point out the role of the access resistance at the current aperture edge.

  12. InGaN based micro light emitting diodes featuring a buried GaN tunnel junction

    NASA Astrophysics Data System (ADS)

    Malinverni, M.; Martin, D.; Grandjean, N.

    2015-08-01

    GaN tunnel junctions (TJs) are grown by ammonia molecular beam epitaxy. High doping levels are achieved with a net acceptor concentration close to ˜1020 cm-3, thanks to the low growth temperature. This allows for the realization of p-n junctions with ultrathin depletion width enabling efficient interband tunneling. n-p-n structures featuring such a TJ exhibit low leakage current densities, e.g., <5 × 10-5 A cm-2 at reverse bias of 10 V. Under forward bias, the voltage is 3.3 V and 4.8 V for current densities of 20 A cm-2 and 2000 A cm-2, respectively. The specific series resistance of the whole device is 3.7 × 10-4 Ω cm2. Then micro-light emitting diodes (μ-LEDs) featuring buried TJs are fabricated. Excellent current confinement is demonstrated together with homogeneous electrical injection, as seen on electroluminescence mapping. Finally, the I-V characteristics of μ-LEDs with various diameters point out the role of the access resistance at the current aperture edge.

  13. Application of light-weight filtration media in an anoxic biofilter for nitrate removal from micro-polluted surface water.

    PubMed

    Wang, Zheng; Fei, Xiang; He, Shengbing; Huang, Jungchen; Zhou, Weili

    2016-01-01

    The research investigated nitrate removal from micro-polluted surface water by the single-stage process of anoxic biofilter using light-weight polystyrene beads as filtration media. In this study, sodium acetate was used as an external carbon source and the nitrate removal efficiency under different regimes of hydraulic loading rate (HLR), water temperature, and C/N ratio was studied. In addition, the effect of backwash on denitrification efficiency was investigated. The results show that the biofilter achieved a high nitrate removal efficiency in 2 weeks at water temperatures ranging between 22 and 25 °C at a C/N ratio (COD:NO3(-)-N) of 6:1. Besides, the average removal efficiency of nitrate at HLRs of 5.66, 7.07 and 8.49 m(3) m(-2) h(-1) were 87.5, 87.3 and 87.1%, respectively. The average removal efficiency of nitrate nitrogen was 13.9% at a HLR of 5.66 m(3) m(-2) h(-1) at water temperatures of 12-14 °C, then it increased to 93.7% when the C/N ratio increased to 10. It suggests that the optimal hydraulic retention time is at water temperatures of 8-10 °C. The water consumption rate of backwash was about 0.2-0.3%, and denitrification efficiency returned to the normal level in 12 h after backwash. PMID:27533875

  14. Manufacturing technology

    SciTech Connect

    Blaedel, K L

    1998-01-01

    The mission of the Manufacturing Technology thrust area at Lawrence Livermore National Laboratory (LLNL) has been to have an adequate base of manufacturing technology, not necessarily resident at LLNL, to conduct their future business. The specific goals were (1) to develop an understanding of fundamental fabrication processes; (2) to construct general purpose process models that have wide applicability; (3) to document their findings and models in journals; (4) to transfer technology to LLNL programs, industry, and colleagues; and (5) to develop continuing relationships with the industrial and academic communities to advance their collective understanding of fabrication processes. In support of this mission, two projects were reported here, each of which explores a way to bring higher precision to the manufacturing challenges that we face over the next few years. The first, ''A Spatial-Frequency-Domain Approach to Designing a Precision Machine Tools,'' is an overall view of how they design machine tools and instruments to make or measure workpieces that are specified in terms of the spatial frequency content of the residual errors of the workpiece surface. This represents an improvement of an ''error budget,'' a design tool that saw significant development in the early 1980's, and has been in active use since then. The second project, ''Micro-Drilling of ICF Capsules,'' is an attempt to define the current state in commercial industry for drilling small holes, particularly laser-drilling. The report concludes that 1-{micro}m diameter holes cannot currently be drilled to high aspect ratios, and then defines the engineering challenges that will have to be overcome to machine holes small enough for NIF capsules.

  15. Assessment of Possible Cycle Lengths for Fully-Ceramic Micro-Encapsulated Fuel-Based Light Water Reactor Concepts

    SciTech Connect

    R. Sonat Sen; Michael A. Pope; Abderrafi M. Ougouag; Kemal O. Pasamehmetoglu

    2012-04-01

    The tri-isotropic (TRISO) fuel developed for High Temperature reactors is known for its extraordinary fission product retention capabilities [1]. Recently, the possibility of extending the use of TRISO particle fuel to Light Water Reactor (LWR) technology, and perhaps other reactor concepts, has received significant attention [2]. The Deep Burn project [3] currently focuses on once-through burning of transuranic fissile and fissionable isotopes (TRU) in LWRs. The fuel form for this purpose is called Fully-Ceramic Micro-encapsulated (FCM) fuel, a concept that borrows the TRISO fuel particle design from high temperature reactor technology, but uses SiC as a matrix material rather than graphite. In addition, FCM fuel may also use a cladding made of a variety of possible material, again including SiC as an admissible choice. The FCM fuel used in the Deep Burn (DB) project showed promising results in terms of fission product retention at high burnup values and during high-temperature transients. In the case of DB applications, the fuel loading within a TRISO particle is constituted entirely of fissile or fissionable isotopes. Consequently, the fuel was shown to be capable of achieving reasonable burnup levels and cycle lengths, especially in the case of mixed cores (with coexisting DB and regular LWR UO2 fuels). In contrast, as shown below, the use of UO2-only FCM fuel in a LWR results in considerably shorter cycle length when compared to current-generation ordinary LWR designs. Indeed, the constraint of limited space availability for heavy metal loading within the TRISO particles of FCM fuel and the constraint of low (i.e., below 20 w/0) 235U enrichment combine to result in shorter cycle lengths compared to ordinary LWRs if typical LWR power densities are also assumed and if typical TRISO particle dimensions and UO2 kernels are specified. The primary focus of this summary is on using TRISO particles with up to 20 w/0 enriched uranium kernels loaded in Pressurized Water

  16. Volume shrinkage of bone, brain and muscle tissue in sample preparation for micro-CT and light sheet fluorescence microscopy (LSFM).

    PubMed

    Buytaert, Jan; Goyens, Jana; De Greef, Daniel; Aerts, Peter; Dirckx, Joris

    2014-08-01

    Two methods are especially suited for tomographic imaging with histological detail of macroscopic samples that consist of multiple tissue types (bone, muscle, nerve or fat): Light sheet (based) fluorescence microscopy (LSFM) and micro-computed tomography (micro-CT). Micro-CT requires staining with heavy chemical elements (and thus fixation and sometimes dehydration) in order to make soft tissue imageable when measured alongside denser structures. LSMF requires fixation, decalcification, dehydration, clearing and staining with a fluorescent dye. The specimen preparation of both imaging methods is prone to shrinkage, which is often not mentioned, let alone quantified. In this paper the presence and degree of shrinkage are quantitatively identified for the selected preparation methods/stains. LSFM delivers a volume shrinkage of 17% for bone, 56% for muscle and 62% for brain tissue. The three most popular micro-CT stains (phosphotungstic acid, iodine with potassium iodide, and iodine in absolute ethanol) deliver a volume shrinkage ranging from 10 to 56% for muscle and 27-66% for brain, while bone does not shrink in micro-CT preparation. PMID:24963987

  17. New ArF immersion light source introduces technologies for high-volume 14nm manufacturing and beyond

    NASA Astrophysics Data System (ADS)

    Cacouris, T.; Conley, W.; Thornes, J.; Bibby, T.; Melchior, J.; Aggarwal, T.; Gross, E.

    2015-03-01

    Semiconductor market demand for improved performance at lower cost continues to drive enhancements in excimer light source technologies. Multi-patterning lithography solutions to extend deep-UV (DUV) immersion have driven requirements such as higher throughput and higher efficiencies to maximize the utilization of leading-edge lithography equipment. Three key light source parameters have direct influence on patterning performance - energy, wavelength and bandwidth stability - and they have been the primary areas of continuous improvement. With 14nm node development, a number of studies have shown the direct influence of bandwidth stability on CD uniformity for certain patterns and geometries, leading to the desire for further improvements in this area. More recent studies also examined the impact of bandwidth on 10nm logic node patterning [1]. Alongside these drivers, increasing cost per patterning layer continues to demand further improvements in operating costs and efficiencies from the lithography tools, and the light source can offer further gains in these areas as well. This paper introduces several light source technologies that are embodied in a next-generation light source, the Cymer XLR® 700ix, which is an extension of the ring laser architecture introduced 8 years ago. These technologies enable a significant improvement in bandwidth stability as well as notable reductions in operating costs through more efficient gas management algorithms and lower facilities costs.

  18. Wide angle light collection with ultralow reflection and super scattering by silicon micro-nanostructures for thin crystalline silicon solar cell applications

    NASA Astrophysics Data System (ADS)

    Das, Sonali; Kundu, Avra; Saha, Hiranmay; Datta, Swapan K.

    2016-01-01

    Conventional c-Si solar cells employ micron-sized pyramids for achieving reduced reflection (˜10%) and enhanced light trapping by multiple bounces (maximum 3) of the incident light. Alternatively, bio-mimetic, moth-eye sub-wavelength nanostructures offer broadband antireflection properties (˜3%) suitable for solar cell applications in the optical regime. However, such structures do not provide any advantage in the charge carrier extraction process as radial junctions cannot be formed in such sub-wavelength dimensions and they have high surface area causing increased charged carrier recombination. The choice of the geometry for achieving optimum photon-electron harvesting for solar applications is therefore very critical. Cross-fertilization of the conventional solar cell light-trapping techniques and the sub-wavelength nanostructures results in unique micro-nanostructures (structures having sub-wavelength dimensions as well as dimensions of the order of few microns) which provide advanced light management capabilities along with the ability of realizing radial junctions. It is seen that an ultralow reflection along with wide angle light collection is obtained which enables such structures to overcome the morning, evening and winter light losses in solar cells. Further, super-scattering in the structures offer enhanced light trapping not only in the structure itself but also in the substrate housing the structure. Ray and wave optics have been used to understand the optical benefits of the structures. It is seen that the aspect ratio of the structures plays the most significant role for achieving such light management capabilities, and efficiencies as high as 12% can be attained. Experiments have been carried out to fabricate a unique micro-nanomaze-like structure instead of a periodic array of micro-nanostructures with the help of nanosphere lithography and the MacEtch technique. It is seen that randomized micro-nanomaze geometry offers very good antireflection

  19. MQWs InGaN/GaN LED with embedded micro-mirror array in the epitaxial-lateral-overgrowth gallium nitride for light extraction enhancement.

    PubMed

    Huang, Chen-Yang; Ku, Hao-Min; Liao, Chen-Zi; Chao, Shiuh

    2010-05-10

    Multi-quantum wells (MQWs) InGaN/GaN LEDs, 300 microm x 300 microm chip size, were fabricated with Ta(2)O(5) / SiO(2) dielectric multi-layer micro-mirror array (MMA) embedded in the epitaxiallateral- overgrowth (ELOG) gallium nitride (GaN) on the c-plane sapphire substrate. MQWs InGaN/GaN LEDs with ELOG embedded patterned SiO(2) array (P-SiO(2)) of the same dimension as the MMA were also fabricated for comparison. Dislocation density was reduced for the ELOG samples. 75.2% light extraction enhancement for P-SiO(2)-LED and 102.6% light extraction enhancement for MMA-LED were obtained over the standard LED. We showed that multiple-diffraction with high intensity from the MMA redirected the trap lights to escape from the LED causing the light extraction enhancement. PMID:20588920

  20. Fabrication of spherical mitigation pit on KH2PO4 crystal by micro-milling and modeling of its induced light intensification.

    PubMed

    Cheng, Jian; Chen, Mingjun; Liao, Wei; Wang, Haijun; Xiao, Yong; Li, Mingquan

    2013-07-15

    Micro-machining is the most promising method for KH(2)PO(4) crystal to mitigate the surface damage growth in high power laser system. In this work, spherical mitigation pit is fabricated by micro-milling with an efficient machining procedure. The light intensification caused by rear surface features before and after mitigation is numerically modeled based on the finite-difference time-domain method. The results indicate that the occurrence of total internal reflections should be responsible for the largest light intensification inside the crystal. For spherical pits after mitigation, the light intensification can be greatly alleviated by preventing the occurrence of total internal reflections. The light intensification caused by spherical mitigation pit is strongly dependent on the width-depth ratio and it is suggested that the width-depth ratio of spherical mitigation pit must be devised to be larger than 5.0 to achieve the minimal light intensification for the mitigation of surface damage growth. Laser damage tests for KH(2)PO(4) crystal validate that the laser damage resistance of initially damaged surface can be retrieved to near the level of ideal surface by replacing initial damage site with predesigned mitigation pit. PMID:23938531

  1. Arrays of MicroLEDs and Astrocytes: Biological Amplifiers to Optogenetically Modulate Neuronal Networks Reducing Light Requirement

    PubMed Central

    Berlinguer-Palmini, Rolando; Narducci, Roberto; Merhan, Kamyar; Dilaghi, Arianna; Moroni, Flavio; Masi, Alessio; Scartabelli, Tania; Landucci, Elisa; Sili, Maria; Schettini, Antonio; McGovern, Brian; Maskaant, Pleun; Degenaar, Patrick; Mannaioni, Guido

    2014-01-01

    In the modern view of synaptic transmission, astrocytes are no longer confined to the role of merely supportive cells. Although they do not generate action potentials, they nonetheless exhibit electrical activity and can influence surrounding neurons through gliotransmitter release. In this work, we explored whether optogenetic activation of glial cells could act as an amplification mechanism to optical neural stimulation via gliotransmission to the neural network. We studied the modulation of gliotransmission by selective photo-activation of channelrhodopsin-2 (ChR2) and by means of a matrix of individually addressable super-bright microLEDs (μLEDs) with an excitation peak at 470 nm. We combined Ca2+ imaging techniques and concurrent patch-clamp electrophysiology to obtain subsequent glia/neural activity. First, we tested the μLEDs efficacy in stimulating ChR2-transfected astrocyte. ChR2-induced astrocytic current did not desensitize overtime, and was linearly increased and prolonged by increasing μLED irradiance in terms of intensity and surface illumination. Subsequently, ChR2 astrocytic stimulation by broad-field LED illumination with the same spectral profile, increased both glial cells and neuronal calcium transient frequency and sEPSCs suggesting that few ChR2-transfected astrocytes were able to excite surrounding not-ChR2-transfected astrocytes and neurons. Finally, by using the μLEDs array to selectively light stimulate ChR2 positive astrocytes we were able to increase the synaptic activity of single neurons surrounding it. In conclusion, ChR2-transfected astrocytes and μLEDs system were shown to be an amplifier of synaptic activity in mixed corticalneuronal and glial cells culture. PMID:25265500

  2. Arrays of microLEDs and astrocytes: biological amplifiers to optogenetically modulate neuronal networks reducing light requirement.

    PubMed

    Berlinguer-Palmini, Rolando; Narducci, Roberto; Merhan, Kamyar; Dilaghi, Arianna; Moroni, Flavio; Masi, Alessio; Scartabelli, Tania; Landucci, Elisa; Sili, Maria; Schettini, Antonio; McGovern, Brian; Maskaant, Pleun; Degenaar, Patrick; Mannaioni, Guido

    2014-01-01

    In the modern view of synaptic transmission, astrocytes are no longer confined to the role of merely supportive cells. Although they do not generate action potentials, they nonetheless exhibit electrical activity and can influence surrounding neurons through gliotransmitter release. In this work, we explored whether optogenetic activation of glial cells could act as an amplification mechanism to optical neural stimulation via gliotransmission to the neural network. We studied the modulation of gliotransmission by selective photo-activation of channelrhodopsin-2 (ChR2) and by means of a matrix of individually addressable super-bright microLEDs (μLEDs) with an excitation peak at 470 nm. We combined Ca2+ imaging techniques and concurrent patch-clamp electrophysiology to obtain subsequent glia/neural activity. First, we tested the μLEDs efficacy in stimulating ChR2-transfected astrocyte. ChR2-induced astrocytic current did not desensitize overtime, and was linearly increased and prolonged by increasing μLED irradiance in terms of intensity and surface illumination. Subsequently, ChR2 astrocytic stimulation by broad-field LED illumination with the same spectral profile, increased both glial cells and neuronal calcium transient frequency and sEPSCs suggesting that few ChR2-transfected astrocytes were able to excite surrounding not-ChR2-transfected astrocytes and neurons. Finally, by using the μLEDs array to selectively light stimulate ChR2 positive astrocytes we were able to increase the synaptic activity of single neurons surrounding it. In conclusion, ChR2-transfected astrocytes and μLEDs system were shown to be an amplifier of synaptic activity in mixed corticalneuronal and glial cells culture. PMID:25265500

  3. 49 CFR 579.21 - Reporting requirements for manufacturers of 5,000 or more light vehicles annually.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... (electric battery power), FCP (fuel-cell power), HEV (hybrid electric vehicle), HCP (hydrogen combustion... (compression ignition fuel), EBP (electric battery power), FCP (fuel-cell power), HEV (hybrid electric vehicle... submit information separately with respect to each make, model, and model year of light...

  4. Study on visible-light-curable polycarprolactone and poly(ethylene glycol) diacrylate for LCD-projected maskless additive manufacturing system

    NASA Astrophysics Data System (ADS)

    Cheng, Yih-Lin; Kao, Hao-Lun

    2015-09-01

    Photopolymers have been applied in many Additive Manufacturing (AM) systems and mostly are cured by UV light. Biodegradable photo-curable polymers are very limited and are not commercially available. DLP-projected maskless AM systems become more and more popular nowadays, but its working area is limited if the part resolution is required. For larger working envelope purpose, liquid crystal display (LCD) panel has great potentials, and LCD's resolution has been improved significantly in the past few years due to the smart phone application. Therefore, in this research, LCD panel is used to replace DLP for a maskless AM system to cure biodegradable materials, Polycarprolactone (PCL) and Poly(ethylene glycol) diacrylate (PEG-DA). Due to the characteristics of LCD panel, the material systems should be sensitive and photo-polymerized in visible-light range, particularly in RGB. In this study, various percentages of visiblelight photoinitiator, Irgacure 784, in the material systems were investigated. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were utilized to characterize cured biomaterials. Because of the use of photoinitiator, the biocompatibility of the cured materials was also concerned, and hence, MTT assay tests were performed. The preliminary tests of fabrication, using the LCD-projected maskless AM system, cured grid patterns to illustrate the feasibility. The visible-light-curable PCL and PEG-DA will be able to be adopted in tissue engineering scaffold applications in the future.

  5. Validating continuous digital light processing (cDLP) additive manufacturing accuracy and tissue engineering utility of a dye-initiator package.

    PubMed

    Wallace, Jonathan; Wang, Martha O; Thompson, Paul; Busso, Mallory; Belle, Vaijayantee; Mammoser, Nicole; Kim, Kyobum; Fisher, John P; Siblani, Ali; Xu, Yueshuo; Welter, Jean F; Lennon, Donald P; Sun, Jiayang; Caplan, Arnold I; Dean, David

    2014-03-01

    This study tested the accuracy of tissue engineering scaffold rendering via the continuous digital light processing (cDLP) light-based additive manufacturing technology. High accuracy (i.e., <50 µm) allows the designed performance of features relevant to three scale spaces: cell-scaffold, scaffold-tissue, and tissue-organ interactions. The biodegradable polymer poly (propylene fumarate) was used to render highly accurate scaffolds through the use of a dye-initiator package, TiO2 and bis (2,4,6-trimethylbenzoyl)phenylphosphine oxide. This dye-initiator package facilitates high accuracy in the Z dimension. Linear, round, and right-angle features were measured to gauge accuracy. Most features showed accuracies between 5.4-15% of the design. However, one feature, an 800 µm diameter circular pore, exhibited a 35.7% average reduction of patency. Light scattered in the x, y directions by the dye may have reduced this feature's accuracy. Our new fine-grained understanding of accuracy could be used to make further improvements by including corrections in the scaffold design software. Successful cell attachment occurred with both canine and human mesenchymal stem cells (MSCs). Highly accurate cDLP scaffold rendering is critical to the design of scaffolds that both guide bone regeneration and that fully resorb. Scaffold resorption must occur for regenerated bone to be remodeled and, thereby, achieve optimal strength. PMID:24429508

  6. MicroRNA408 Is Critical for the HY5-SPL7 Gene Network That Mediates the Coordinated Response to Light and Copper[C][W

    PubMed Central

    Zhang, Huiyong; Zhao, Xin; Li, Jigang; Cai, Huaqing; Deng, Xing Wang; Li, Lei

    2014-01-01

    Light and copper are important environmental determinants of plant growth and development. Despite the wealth of knowledge on both light and copper signaling, the molecular mechanisms that integrate the two pathways remain poorly understood. Here, we use Arabidopsis thaliana to demonstrate an interaction between SQUAMOSA PROMOTER BINDING PROTEIN-LIKE7 (SPL7) and ELONGATED HYPOCOTYL5 (HY5), which mediate copper and light signaling, respectively. Through whole-genome chromatin immunoprecipitation and RNA sequencing analyses, we elucidated the SPL7 regulon and compared it with that of HY5. We found that the two transcription factors coregulate many genes, including those involved in anthocyanin accumulation and photosynthesis. Moreover, SPL7 and HY5 act coordinately to transcriptionally regulate MIR408, which results in differential expression of microRNA408 (miR408) and its target genes in response to changing light and copper conditions. We demonstrate that this regulation is tied to copper allocation to the chloroplast and plastocyanin levels. Finally, we found that constitutively activated miR408 rescues the distinct developmental defects of the hy5, spl7, and hy5 spl7 mutants. These findings revealed the existence of crosstalk between light and copper, mediated by a HY5-SPL7 network. Furthermore, integration of transcriptional and posttranscriptional regulation is critical for governing proper metabolism and development in response to combined copper and light signaling. PMID:25516599

  7. Temperature characteristics of epitaxially grown InAs quantum dot micro-disk lasers on silicon for on-chip light sources

    NASA Astrophysics Data System (ADS)

    Wan, Yating; Li, Qiang; Liu, Alan Y.; Gossard, Arthur C.; Bowers, John E.; Hu, Evelyn L.; Lau, Kei May

    2016-07-01

    Temperature characteristics of optically pumped micro-disk lasers (MDLs) incorporating InAs quantum dot active regions are investigated for on-chip light sources. The InAs quantum dot MDLs were grown on V-groove patterned (001) silicon, fully compatible with the prevailing complementary metal oxide-semiconductor technology. By combining the high-quality whispering gallery modes and 3D confinement of injected carriers in quantum dot micro-disk structures, we achieved lasing operation from 10 K up to room temperature under continuous optical pumping. Temperature dependences of the threshold, lasing wavelength, slope efficiency, and mode linewidth are examined. An excellent characteristic temperature To of 105 K has been extracted.

  8. On-chip copper-dielectric interference filters for manufacturing of ambient light and proximity CMOS sensors.

    PubMed

    Frey, Laurent; Masarotto, Lilian; D'Aillon, Patrick Gros; Pellé, Catherine; Armand, Marilyn; Marty, Michel; Jamin-Mornet, Clémence; Lhostis, Sandrine; Le Briz, Olivier

    2014-07-10

    Filter technologies implemented on CMOS image sensors for spectrally selective applications often use a combination of on-chip organic resists and an external substrate with multilayer dielectric coatings. The photopic-like and near-infrared bandpass filtering functions respectively required by ambient light sensing and user proximity detection through time-of-flight can be fully integrated on chip with multilayer metal-dielectric filters. Copper, silicon nitride, and silicon oxide are the materials selected for a technological proof-of-concept on functional wafers, due to their immediate availability in front-end semiconductor fabs. Filter optical designs are optimized with respect to specific performance criteria, and the robustness of the designs regarding process errors are evaluated for industrialization purposes. PMID:25090070

  9. Manufacturing Success

    ERIC Educational Resources Information Center

    Reese, Susan

    2007-01-01

    According to the National Association of Manufacturers (NAM), "manufacturing is the engine that drives American prosperity". When NAM and its research and education arm, The Manufacturing Institute, released the handbook, "The Facts About Modern Manufacturing," in October 2006, NAM President John Engler noted, that manufacturing output in America…

  10. Micro-textures for efficient light trapping and improved electrical performance in thin-film nanocrystalline silicon solar cells

    NASA Astrophysics Data System (ADS)

    Tan, Hairen; Psomadaki, Efthymia; Isabella, Olindo; Fischer, Marinus; Babal, Pavel; Vasudevan, Ravi; Zeman, Miro; Smets, Arno H. M.

    2013-10-01

    Micro-textures with large opening angles and smooth U-shape are applied to nanocrystalline silicon (nc-Si:H) solar cells. The micro-textured substrates result in higher open-circuit-voltage (Voc) and fill-factor (FF) than nano-textured substrates. For thick solar cells, high Voc and FF are maintained. Particularly, the Voc only drops from 564 to 541 mV as solar cell thickness increases from 1 to 5 μm. The improvement in electrical performance of solar cells is ascribed to the growth of dense nc-Si:H layers free from defective filaments on micro-textured substrates. Thereby, micromorph tandem solar cells with an initial efficiency of 13.3%, Voc = 1.464 V, and FF = 0.759 are obtained.

  11. Identification of unwanted photoproducts of cosmetic preservatives in personal care products under ultraviolet-light using solid-phase microextraction and micro-matrix solid-phase dispersion.

    PubMed

    Alvarez-Rivera, Gerardo; Llompart, Maria; Garcia-Jares, Carmen; Lores, Marta

    2015-04-17

    The photochemical transformation of widely used cosmetic preservatives including benzoates, parabens, BHA, BHT and triclosan has been investigated in this work applying an innovative double-approach strategy: identification of transformation products in aqueous photodegradation experiments (UV-light, 254nm), followed by targeted screening analysis of such photoproducts in UV-irradiated cosmetic samples. Solid-phase microextraction (SPME) was applied, using different fiber coatings, in order to widen the range of detectable photoproducts in water, whereas UV-irradiated personal care products (PCPs) containing the target preservatives were extracted by micro-matrix solid-phase dispersion (micro-MSPD). Both SPME and micro-MSPD-based methodologies were successfully optimized and validated. Degradation kinetics of parent species, and photoformation of their transformation by-products were monitored by gas chromatography coupled to mass spectrometry (GC-MS). Thirty nine photoproducts were detected in aqueous photodegradation experiments, being tentatively identified based on their mass spectra. Transformation pathways between structurally related by-products, consistent with their kinetic behavior were postulated. The photoformation of unexpected photoproducts such as 2- and 4-hydroxybenzophenones, and 2,8-dichlorodibenzo-p-dioxin in PCPs are reported in this work for the first time. PMID:25757820

  12. Laser printing and femtosecond laser structuring of electrode materials for the manufacturing of 3D lithium-ion micro-batteries

    NASA Astrophysics Data System (ADS)

    Smyrek, P.; Kim, H.; Zheng, Y.; Seifert, H. J.; Piqué, A.; Pfleging, W.

    2016-04-01

    Recently, three-dimensional (3D) electrode architectures have attracted great interest for the development of lithium-ion micro-batteries applicable for Micro-Electro-Mechanical Systems (MEMS), sensors, and hearing aids. Since commercial available micro-batteries are mainly limited in overall cell capacity by their electrode footprint, new processing strategies for increasing both capacity and electrochemical performance have to be developed. In case of such standard microbatteries, two-dimensional (2D) electrode arrangements are applied with thicknesses up to 200 μm. These electrode layers are composed of active material, conductive agent, graphite, and polymeric binder. Nevertheless, with respect to the type of active material, the active material to conductive agent ratio, and the film thickness, such thick-films suffer from low ionic and electronic conductivities, poor electrolyte accessibility, and finally, limited electrochemical performance under challenging conditions. In order to overcome these drawbacks, 3D electrode arrangements are under intense investigation since they allow the reduction of lithium-ion diffusion pathways in between inter-digitated electrodes, even for electrodes with enhanced mass loadings. In this paper, we present how to combine laser-printing and femtosecond laser-structuring for the development of advanced 3D electrodes composed of Li(Ni1/3Mn1/3Co1/3)O2 (NMC). In a first step, NMC thick-films were laser-printed and calendered to achieve film thicknesses in the range of 50 μm - 80 μm. In a second step, femtosecond laser-structuring was carried out in order to generate 3D architectures directly into thick-films. Finally, electrochemical cycling of laser-processed films was performed in order to evaluate the most promising 3D electrode designs suitable for application in long life-time 3D micro-batteries.

  13. Micro-cavity lasers with large device size for directional emission

    NASA Astrophysics Data System (ADS)

    Yan, Chang-ling; Li, Peng; Shi, Jian-wei; Feng, Yuan; Hao, Yong-qin; Zhu, Dongda

    2014-10-01

    Optical micro-cavity structures, which can confine light in a small mode volume with high quality factors, have become an important platform not only for optoelectronic applications with densely integrated optical components, but also for fundamental studies such as cavity quantum electrodynamics and nonlinear optical processes. Micro-cavity lasers with directional emission feature are becoming a promising resonator for the compact laser application. In this paper, we presented the limason-shaped cavity laser with large device size, and fabricated this type of micro-cavity laser with quantum cascade laser material. The micro-cavity laser with large device size was fabricated by using InP based InGaAs/InAlAs quantum cascade lasers material at about 10um emitting wavelength, and the micro-cavity lasers with the large device size were manufactured and characterized with light output power, threshold current, and the far-field pattern.

  14. Micro-Square-Array InGaN-Based Light-Emitting Diode with an Insulated Ga2O3 Layer through a Photoelectrochemical Process

    NASA Astrophysics Data System (ADS)

    Lin, Chia-Feng; Lin, Chun-Min; Jiang, Ren-Hao

    2012-01-01

    InGaN-based micro-square-array light emitting diode (MSA-LED) was fabricated by filling with an insulated Ga2O3 layer around the individual micro-square patterns for a metal interconnected process. The Ga2O3 layer formed at the mesa sidewall and the bottom etched surface of the n-type GaN layer in the LED structure through a selective photoelectrochemical (PEC) wet oxidation process in H2O solution. The 25- and 15-µm-square mesa patterns of the MSA-LED structures were defined by the plasma dry and the PEC wet etching processes that a conventional broad-area LED (BA-LED) was closed to the MSA-LED for comparison. The peak wavelength blueshift of the electroluminescence spectra and the enhancement of the light output power were measured at 1.0 nm/41% and 2.5 nm/22% for the 25- and 15-µm-MSA-LED, respectively, compared with the BA-LED. The reverse leakage current of both MSA-LED structures was about 2.5×10-11 A that was lower than the BA-LED (8.3×10-9 A) at -5 V reverse bias. The PEC Ga2O3 layer acted a passivation layer to prevent the leakage current from the mesa sidewall surface and an interconnect process in the MSA-LED structures.

  15. Growth of micro-crystals in solution by in-situ heating via continuous wave infrared laser light and an absorber

    NASA Astrophysics Data System (ADS)

    Pathak, Shashank; Dharmadhikari, Jayashree A.; Thamizhavel, A.; Mathur, Deepak; Dharmadhikari, Aditya K.

    2016-01-01

    We report on growth of micro-crystals such as sodium chloride (NaCl), copper sulphate (CuSO4), potassium di-hydrogen phosphate (KDP) and glycine (NH2CH2COOH) in solution by in-situ heating using continuous wave Nd:YVO4 laser light. Crystals are grown by adding single walled carbon nanotubes (SWNT). The SWNTs absorb 1064 nm light and act as an in-situ heat source that vaporizes the solvent producing microcrystals. The temporal dynamics of micro-crystal growth is investigated by varying experimental parameters such as SWNT bundle size and incident laser power. We also report crystal growth without SWNT in an absorbing medium: copper sulphate in water. Even though the growth dynamics with SWNT and copper sulphate are significantly different, our results indicate that bubble formation is necessary for nucleation. Our simple method may open up new vistas for rapid growth of seed crystals especially for examining the crystallizability of inorganic and organic materials.

  16. A method for edge detection of textile preforms using a light-section sensor for the automated manufacturing of fibre-reinforced plastics

    NASA Astrophysics Data System (ADS)

    Schmitt, Robert; Orth, Alexandre; Niggemann, Christian

    2007-06-01

    The present work describes a new method to measure the contour position of plane reinforcement fabrics for the manufacturing of structural composite parts. The pursued approach uses optical metrology based on laser light-section technology. In detail, a laser line is projected over the edge of a fabric layer and acquired with a digital camera, which is located under an offset angle to the laser sensor. This leads to a distinctive displacement of the laser line in the acquired image, which is proportional to the distance between the sensor and the fabric layer. The distorted line can be described as a step profile, to which an analytical function is fitted to calculate the horizontal edge position with sub-pixel accuracy. To measure the whole layer position, the edges are scanned with the laser sensor to provide multiple contour points. This allows the interpolation of the object contour. The interpolated contour can be compared with the specified position and dimension of the textile layer. This enables a closed-loop control of the cutting and build-up process of the preform. Thus, an efficient production process of fibre-reinforced plastics through an automated inline measurement is possible.

  17. Eat-by-light: fiber-optic and micro-optic devices for food safety and quality assessment

    NASA Astrophysics Data System (ADS)

    Mignani, A. G.; Ciaccheri, L.; Cucci, C.; Mencaglia, A. A.; Cimato, A.; Attilio, C.; Thienpont, H.; Ottevaere, H.; Paolesse, R.; Mastroianni, M.; Monti, D.; Buonocore, G.; Del Nobile, A.; Mentana, A.; Dall'Asta, C.; Faccini, A.; Galaverna, G.; Dossena, A.

    2007-07-01

    A selection of fiber-optic and micro-optic devices is presented designed and tested for monitoring the quality and safety of typical foods, namely the extra virgin olive oil, the beer, and the milk. Scattered colorimetry is used for the authentication of various types of extra virgin olive oil and beer, while a fiber-optic-based device for UV-VIS-NIR absorption spectroscopy is exploited in order to obtain the hyperspectral optical signature of olive oil. This is done not only for authentication purposes, but also so as to correlate the spectral data with the content of fatty acids that are important nutritional factors. A micro-optic sensor for the detection of olive oil aroma is presented. It is capable of distinguishing different ageing levels of extra virgin olive oil. It shows effective potential for acting as a smart cap of bottled olive oil in order to achieve a non-destructive olfactory perception of oil ageing. Lastly, a compact portable fluorometer is experimented for the rapid monitoring of the carcinogenic M1 aflatoxin in milk.

  18. Eat-by-light fiber-optic and micro-optic devices for food quality and safety assessment

    NASA Astrophysics Data System (ADS)

    Mignani, A. G.; Ciaccheri, L.; Cucci, C.; Mencaglia, A. A.; Cimato, A.; Attilio, C.; Thienpont, H.; Ottevaere, H.; Paolesse, R.; Mastroianni, M.; Monti, D.; Buonocore, G.; Del Nobile, A.; Mentana, A.; Grimaldi, M. F.; Dall'Asta, C.; Faccini, A.; Galaverna, G.; Dossena, A.

    2007-06-01

    A selection is presented of fiber-optic and micro-optic devices that have been designed and tested for guaranteeing the quality and safety of typical foods, such as extra virgin olive oil, beer, and milk. Scattered colorimetry is used to authenticate various types of extra virgin olive oil and beer, while a fiber-optic-based device for UV-VIS-NIR absorption spectroscopy is exploited in order to obtain the hyperspectral optical signature of olive oil. This is done not only for authentication purposes, but also so as to correlate the spectral data with the content of fatty acids, which are important nutritional factors. A micro-optic sensor for the detection of olive oil aroma that is capable of distinguishing different ageing levels of extra virgin olive oil is also presented. It shows effective potential for acting as a smart cap of bottled olive oil in order to achieve a non-destructive olfactory perception of oil ageing. Lastly, a compact portable fluorometer for the rapid monitoring of the carcinogenic M1 aflatoxin in milk, is experimented.

  19. Efficacy of UV-Pit-light traps for discerning micro-habitat-specific beetle and ant species related with different oil palm age stands and tropical annual seasons for accurate ecology and diversity interpretations

    NASA Astrophysics Data System (ADS)

    Ahmad Bukhary, A. K.; Ruslan, M. Y.; Mohd. Fauzi, M. M.; Nicholas, S.; Muhamad Fahmi, M. H.; Izfa Riza, H.; Idris, A. B.

    2015-09-01

    A newly innovated and efficient UV-Pit-light Trap is described and the results of the experiments on its efficacy that were carried out within different oil palm age stands of the year 2013 were evaluated and compared with previous study year of 2010, with out the implementation of the UV-Pit-light Trap. In 2013 the UV-Pit-light Traps, the Malaise Traps, and the Pit-fall Traps were employed, while in 2010, the conventional canopy-height UV-Light Traps, Malaise Traps, and the Pit-fall Traps were employed. The UV-Pit-light traps caught more beetle and ant families, morpho-species, and individuals per species compared with the passive Pit-fall traps. The UV-Pit-light Trap targets different subsets of the oil palm beetles and ants' communities, specifying on epigaeic-related micro-habitats, with different oil palm age stands have different compositions of micro-habitats. The UV-Pit-light Traps have the dual quality for satisfying both the biological and statistical data requirements and evaluations. There were no significant difference between the UV-Pit-light Traps and the passive Pit-fall Traps, while the trapping difference with the Malaise traps for different seasons of the year 2013. The UV-Pit-light Traps and the Malaise Traps were complementary to each other, detecting the activities of beetles and ants around the epigaeic-related micro-habitats or having active flight activities respectively according to annual seasons. The UV-Pit-light Trap is an oil-palm specific type of passive trapping system, focusing on the insect species dwelling the upper-ground/epigaeic micro-habitats.

  20. Design, development and use of the spectrometer for investigating coherent THz radiation produced by micro-bunching instabilities at Diamond Light Source

    NASA Astrophysics Data System (ADS)

    Finn, Aiveen; Karataev, Pavel; Rehm, Guenther

    2016-07-01

    Schottky barrier diodes (SBDs) are known for their low noise, ultra-fast response and excellent sensitivity. They are often implemented as detectors in the millimetre wavelength regime. Micro-bunch instabilities (MBI) have been detected at many light sources around the world including the Diamond Light Source, UK. These MBI can result in bursts of coherent synchrotron radiation (CSR) with millimetre wavelengths. More research needs to be carried out with regards to the dynamics of MBI in order to confirm the simulations and to eventually harness the power of the CSR bursts. A single shot spectrometer has been designed and is under operation at the Diamond Light Source (DLS). It is composed of eight SBDs ranging from 33-1000 GHz. Unlike previous measurements carried out, each of the SBDs has been individually characterised thus making the results obtained comparable to simulations. In this paper, we present the assessment of each SBD in the spectrometer and the first results of the spectrometer's use in the beam.

  1. Hybrid optical fiber add-drop filter based on wavelength dependent light coupling between micro/nano fiber ring and side-polished fiber

    NASA Astrophysics Data System (ADS)

    Yu, Jianhui; Jin, Shaoshen; Wei, Qingsong; Zang, Zhigang; Lu, Huihui; He, Xiaoli; Luo, Yunhan; Tang, Jieyuan; Zhang, Jun; Chen, Zhe

    2015-01-01

    In this paper, we report our experimental study on directly coupling a micro/nano fiber (MNOF) ring with a side-polished fiber(SPF). As a result of the study, the behavior of an add-drop filter was observed. The demonstrated add-drop filter explored the wavelength dependence of light coupling between a MNOF ring and a SPF. The characteristics of the filter and its performance dependence on the MNOF ring diameter were investigated experimentally. The investigation resulted in an empirically obtained ring diameter that showed relatively good filter performance. Since light coupling between a (MNOF) and a conventional single mode fiber has remained a challenge in the photonic integration community, the present study may provide an alternative way to couple light between a MNOF device and a conventional single mode fiber based device or system. The hybridization approach that uses a SPF as a platform to integrate a MNOF device may enable the realization of other all-fiber optical hybrid devices.

  2. Plasma-aided manufacturing

    NASA Astrophysics Data System (ADS)

    Shohet, J. L.

    1993-12-01

    Plasma-aided manufacturing is used for producing new materials with unusual and superior properties, for developing new chemical compounds and processes, for machining, and for altering and refining materials and surfaces. Plasma-aided manufacturing has direct applications to semiconductor fabrication, materials synthesis, welding, lighting, polymers, anti-corrosion coatings, machine tools, metallurgy, electrical and electronics devices, hazardous waste removal, high performance ceramics, and many other items in both the high-technology and the more traditional industries in the United States.

  3. Lighting

    SciTech Connect

    Audin, L.

    1994-12-31

    EPAct covers a vast territory beyond lighting and, like all legislation, also contains numerous {open_quotes}favors,{close_quotes} compromises, and even some sleight-of-hand. Tucked away under Title XIX, for example, is an increase from 20% to 28% tax on gambling winnings, effective January 1, 1993 - apparently as a way to help pay for new spending listed elsewhere in the bill. Overall, it is a landmark piece of legislation, about a decade overdue. It remains to be seen how the Federal Government will enforce upgrading of state (or even their own) energy codes. There is no mention of funding for {open_quotes}energy police{close_quotes} in EPAct. Merely creating such a national standard, however, provides a target for those who sincerely wish to create an energy-efficient future.

  4. Assessing the effectiveness of low-pressure ultraviolet light for inactivating Mycobacterium avium complex (MAC) micro-organisms

    EPA Science Inventory

    Aims: To assess low-pressure ultraviolet light (LP-UV) inactivation kinetics of Mycobacterium avium complex (MAC) strains in a water matrix using collimated beam apparatus. Methods and Results: Strains of M. avium (n = 3) and Mycobacterium intracellulare (n = 2) were exposed t...

  5. Lithographic measurement of EUV flare in the 0.3-NA Micro ExposureTool optic at the Advanced Light Source

    SciTech Connect

    Cain, Jason P.; Naulleau, Patrick; Spanos, Costas J.

    2005-01-01

    The level of flare present in a 0.3-NA EUV optic (the MET optic) at the Advanced Light Source at Lawrence Berkeley National Laboratory is measured using a lithographic method. Photoresist behavior at high exposure doses makes analysis difficult. Flare measurement analysis under scanning electron microscopy (SEM) and optical microscopy is compared, and optical microscopy is found to be a more reliable technique. In addition, the measured results are compared with predictions based on surface roughness measurement of the MET optical elements. When the fields in the exposure matrix are spaced far enough apart to avoid influence from surrounding fields and the data is corrected for imperfect mask contrast and aerial image proximity effects, the results match predicted values quite well. The amount of flare present in this optic ranges from 4.7% for 2 {micro}m features to 6.8% for 500 nm features.

  6. A new on-axis micro-spectrophotometer for combining Raman, fluorescence and UV/Vis absorption spectroscopy with macromolecular crystallography at the Swiss Light Source

    PubMed Central

    Pompidor, Guillaume; Dworkowski, Florian S. N.; Thominet, Vincent; Schulze-Briese, Clemens; Fuchs, Martin R.

    2013-01-01

    The combination of X-ray diffraction experiments with optical methods such as Raman, UV/Vis absorption and fluorescence spectroscopy greatly enhances and complements the specificity of the obtained information. The upgraded version of the in situ on-axis micro-spectrophotometer, MS2, at the macromolecular crystallography beamline X10SA of the Swiss Light Source is presented. The instrument newly supports Raman and resonance Raman spectroscopy, in addition to the previously available UV/Vis absorption and fluorescence modes. With the recent upgrades of the spectral bandwidth, instrument stability, detection efficiency and control software, the application range of the instrument and its ease of operation were greatly improved. Its on-axis geometry with collinear X-ray and optical axes to ensure optimal control of the overlap of sample volumes probed by each technique is still unique amongst comparable facilities worldwide and the instrument has now been in general user operation for over two years. PMID:23955041

  7. Light-Weight Sensor Package for Precision 3d Measurement with Micro Uavs E.G. Power-Line Monitoring

    NASA Astrophysics Data System (ADS)

    Kuhnert, K.-D.; Kuhnert, L.

    2013-08-01

    The paper describes a new sensor package for micro or mini UAVs and one application that has been successfully implemented with this sensor package. It is intended for 3D measurement of landscape or large outdoor structures for mapping or monitoring purposes. The package can be composed modularly into several configurations. It may contain a laser-scanner, camera, IMU, GPS and other sensors as required by the application. Also different products of the same sensor type have been integrated. Always it contains its own computing infrastructure and may be used for intelligent navigation, too. It can be operated in cooperation with different drones but also completely independent of the type of drone it is attached to. To show the usability of the system, an application in monitoring high-voltage power lines that has been successfully realised with the package is described in detail.

  8. Preliminary Commissioning and Performance of the Soft X-ray Micro-characterization Beamline at the Canadian Light Source

    SciTech Connect

    Hu, Y. F.; Coulthard, I.; Chevrier, D.; Wright, G.; Igarashi, R.; Sitnikov, A.; Yates, B. W.; Hallin, E. L.; Sham, T. K.; Reininger, R.

    2010-06-23

    The Soft X-ray Micro-characterization Beamline (SXRMB) is a medium energy, bending magnet based beamline, designed to cover an energy range of 1.7-10 keV using two sets of crystals--InSb(111) and Si(111). The design goal is to deliver a flux of 2x10{sup 11} photons sec{sup -1}/100 mA with a resolution up to 10,000 for X-ray Absorption Spectroscopy. A KB mirror stage is designed to provide microprobe capability, with a spot size of 10x10 {mu}m{sup 2} and a flux of >10{sup 9} at the microprobe station. The beamline has been in the commissioning phase since 2008, and access to the X-ray absorption endstation is now open to general users. The optical commissioning and performance of the beamline is presented with some early experimental results.

  9. Study on Surface Modification of Indium Tin Oxide and Resist Surfaces Using CF4/O2 Plasma for Manufacturing Organic Light-Emitting Diodes by Inkjet Printing

    NASA Astrophysics Data System (ADS)

    Ikagawa, Masakuni; Tohno, Ichiro; Shinmura, Tadashi; Takagi, Shigeyuki; Kataoka, Yoshinori; Fujihira, Masamichi

    2008-12-01

    We studied a surface modification technique for indium tin oxide (ITO) anodes without precleaning and resist banks for manufacturing organic light-emitting diodes (OLEDs) by inkjet printing. The ITO surface modified by inductively coupled plasma (ICP) with an optimized CF4/O2 (7:3) gas mixture improved both its hydrophilicity and its work function, while the resist surface treated by the plasma became hydrophobic. The resist and ITO surfaces treated by plasmas of various gas mixtures (i.e., CF4, CF4/Ar (1:2), CF4/O2 (x:1; x=1, 7/3, 4, and 9) were analyzed by X-ray photoelectron spectroscopy (XPS) of the C 1s, F 1s, O 1s, and In 3d5/2 core levels. On the uncleaned ITO surfaces modified by CF4/O2 plasmas, organic contaminants were removed more efficiently and the deposition of CFx on the remaining contaminants decreased with increasing oxygen. The amount of F in the form of InFx increased using the CF4/O2 (7:3) plasma in comparison with that using the CF4/Ar and CF4 plasmas. We investigated the effect of adding oxygen to CF4 on the change in gaseous species produced in the plasma chamber by mass spectrometry. In the CF4/O2 (7:3) plasma, the peak intensities of F+, HF+, F2+, O+, and O2+ were higher than those in the CF4 plasma. The results suggest that In2O3 was generated by the oxidation of indium with O, and InFx was generated by the fluoridation of indium with HF. By introducing InFx onto ITO surfaces using the CF4/O2 plasma, the hole-injection energy barrier could be reduced.

  10. Manufacturing technologies

    NASA Astrophysics Data System (ADS)

    The Manufacturing Technologies Center is at the core of Sandia National Laboratories' advanced manufacturing effort which spans the entire product realization process. The center's capabilities in product and process development are summarized in the following disciplines: (1) mechanical - rapid prototyping, manufacturing engineering, machining and computer-aided manufacturing, measurement and calibration, and mechanical and electronic manufacturing liaison; (2) electronics - advanced packaging for microelectronics, printed circuits, and electronic fabrication; and (3) materials - ceramics, glass, thin films, vacuum technology, brazing, polymers, adhesives, composite materials, and process analysis.

  11. The Lantern: an ultra-light micro-drive for multi-tetrode recordings in mice and other small animals.

    PubMed

    Battaglia, Francesco P; Kalenscher, Tobias; Cabral, Henrique; Winkel, Jasper; Bos, Jeroen; Manuputy, Ron; van Lieshout, Theo; Pinkse, Frans; Beukers, Harry; Pennartz, Cyriel

    2009-04-15

    In vivo electrophysiological recordings from groups of distinguishable neurons in behaving mice is a technique with a rapidly growing appeal, particularly because it can be combined with gene targeting techniques. This methodology is deemed essential for achieving a flexible and versatile coupling of molecular-genetic manipulations with behavioral and system level analyses of the nervous system. One major obstacle in obtaining this technological integration is the relatively high weight and bulk size of the available implantable devices for ensemble recordings as compared to the size of the animal. This imposes considerable physical stress on the animals and may prevent them from performing complex behavioral tasks for more than a few minutes. We developed a novel micro-drive which allows independent day-to-day positioning of up to 6 tetrodes in the mouse brain, with an extremely reduced weight and size. The system is based on an "exoskeleton" as its structural element, and allows a completely rectilinear path of the electrodes inside the drive and into the brain. Tests showed that mice can tolerate the chronically implanted device very well up to 12 weeks after implantation, while exhibiting normal behavior. Cell yields and stability obtained with this drive in two different brain areas (the hippocampus and orbitofrontal cortex) were comparable to those of traditional recording systems, usually applied to rats. The device may greatly expand possibilities to combine gene targeting and ensemble recording techniques, in behaviorally varied as well as cognitively demanding settings. PMID:19152807

  12. Depth-resolved confocal micro-Raman spectroscopy for characterizing GaN-based light emitting diode structures

    SciTech Connect

    Chen, Wei-Liang; Lee, Yu-Yang; Chang, Yu-Ming; Chang, Chiao-Yun; Huang, Huei-Min; Lu, Tien-Chang

    2013-11-15

    In this work, we demonstrate that depth-resolved confocal micro-Raman spectroscopy can be used to characterize the active layer of GaN-based LEDs. By taking the depth compression effect due to refraction index mismatch into account, the axial profiles of Raman peak intensities from the GaN capping layer toward the sapphire substrate can correctly match the LED structural dimension and allow the identification of unique Raman feature originated from the 0.3 μm thick active layer of the studied LED. The strain variation in different sample depths can also be quantified by measuring the Raman shift of GaN A{sub 1}(LO) and E{sub 2}(high) phonon peaks. The capability of identifying the phonon structure of buried LED active layer and depth-resolving the strain distribution of LED structure makes this technique a potential optical and remote tool for in operando investigation of the electronic and structural properties of nitride-based LEDs.

  13. Enhanced Light Scattering of the Forbidden longitudinal Optical Phonon Mode Studied by Micro-Raman Spectroscopy on Single InN nanowires

    SciTech Connect

    Sutter, E.; Schafer-Nolte, E.O.; Stoica T.; Gotschke, T.; Limbach, F.A.; Sutter, P.; Grutzmacher, D.; Calarco, R.

    2010-08-06

    In the literature, there are controversies on the interpretation of the appearance in InN Raman spectra of a strong scattering peak in the energy region of the unscreened longitudinal optical (LO) phonons, although a shift caused by the phonon-plasmon interaction is expected for the high conductance observed in this material. Most measurements on light scattering are performed on ensembles of InN nanowires (NWs). However, it is important to investigate the behavior of individual nanowires and here we report on micro-Raman measurements on single nanowires. When changing the polarization direction of the incident light from parallel to perpendicular to the wire, the expected reduction of the Raman scattering was observed for transversal optical (TO) and E2 phonon scattering modes, while a strong symmetry-forbidden LO mode was observed independently on the laser polarization direction. Single Mg- and Si-doped crystalline InN nanowires were also investigated. Magnesium doping results in a sharpening of the Raman peaks, while silicon doping leads to an asymmetric broadening of the LO peak. The results can be explained based on the influence of the high electron concentration with a strong contribution of the surface accumulation layer and the associated internal electric field.

  14. Highly energy-efficient agricultural lighting by B+R LEDs with beam shaping using micro-lens diffuser

    NASA Astrophysics Data System (ADS)

    Lee, Xuan-Hao; Chang, Yu-Yu; Sun, Ching-Cherng

    2013-03-01

    This paper presents a high-performance LED agricultural luminaire that uses a beam-shaping diffuser to achieve high optical efficiency and energy saving. The agricultural luminaire performs an optical efficiency as high as 84.2%. The beam shaping effect also obtains irradiance uniformity of 1/2.56 and excellent spatial color uniformity. The enhancement ratio of optical utilization factor in the proposed agricultural luminaire is 360% in comparison with traditional lighting. Under the designed case, the total utilization factor, including optical utilization factor and spectral utilization factor, of the B+R LED lamp can save 86.1% of power consumption in comparison with compact fluorescent bulbs.

  15. Near-field-enhanced, off-resonant laser sintering of semiconductor particles for additive manufacturing of dispersed Au-ZnO-micro/nano hybrid structures

    NASA Astrophysics Data System (ADS)

    Lau, Marcus; Niemann, Ralf G.; Bartsch, Mathias; O'Neill, William; Barcikowski, Stephan

    2014-03-01

    Off-resonant near-field enhancement by gold nanoparticles adsorbed on crystalline zinc oxide significantly increases the energy efficiency of infrared laser sintering. In detail, ten different gold mass loads on zinc oxide were exposed to 1,064 nm cw-laser radiation. Variation of scan speed, laser power, and spot size showed that the energy threshold required for sintering decreases and sintering process window widens compared to laser sintering of pure zinc oxide powder. Transmission electron microscope analysis after focused ion beam cross sectioning of the sintered particles reveals that supported gold nanoparticles homogenously resolidify in the sintered semiconductor matrix. The enhanced sintering process with ligand-free gold nanoparticles gives access to metal-semiconductor hybrid materials with potential application in light harvesting or energy conversion.

  16. Applications of the BAE SYSTEMS MicroIR uncooled infrared thermal imaging cameras

    NASA Astrophysics Data System (ADS)

    Wickman, Heather A.; Henebury, John J., Jr.; Long, Dennis R.

    2003-09-01

    MicroIR uncooled infrared imaging modules (based on VOx microbolometers), developed and manufactured at BAE SYSTEMS, are integrated into ruggedized, weatherproof camera systems and are currently supporting numerous security and surveillance applications. The introduction of uncooled thermal imaging has permitted the expansion of traditional surveillance and security perimeters. MicroIR cameras go beyond the imagery limits of visible and low-light short wavelength infrared sensors, providing continual, uninterrupted, high quality imagery both day and night. Coupled with an appropriate lens assembly, MicroIR cameras offer exemplary imagery performance that lends itself to a more comprehensive level of surveillance. With the current increased emphasis on security and surveillance, MicroIR Cameras are evolving as an unquestionably beneficial instrument in the security and surveillance arenas. This paper will elaborate on the attributes of the cameras, and discuss the development and the deployment, both present and future, of BAE SYSTEMS MicroIR Cameras.

  17. Cable manufacture

    NASA Technical Reports Server (NTRS)

    Gamble, P.

    1972-01-01

    A survey is presented of flat electrical cable manufacturing, with particular reference to patented processes. The economics of manufacture based on an analysis of material and operating costs is considered for the various methods. Attention is given to the competitive advantages of the several processes and their resulting products. The historical area of flat cable manufacture is presented to give a frame of reference for the survey.

  18. Electrical, spectral and optical performance of yellow-green and amber micro-pixelated InGaN light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Gong, Z.; Liu, N. Y.; Tao, Y. B.; Massoubre, D.; Xie, E. Y.; Hu, X. D.; Chen, Z. Z.; Zhang, G. Y.; Pan, Y. B.; Hao, M. S.; Watson, I. M.; Gu, E.; Dawson, M. D.

    2012-01-01

    Micro-pixelated InGaN LED arrays operating at 560 and 600 nm, respectively, are demonstrated for what the authors believe to be the first time. Such devices offer applications in areas including bioinstrumentation, visible light communications and optoelectronic tweezers. The devices reported are based on new epitaxial structures, retaining conventional (0 0 0 1) orientation, but incorporating electron reservoir layers which enhance the efficiency of radiative combination in the active regions. A measured output optical power density up to 8 W cm-2 (4.4 W cm-2) has been achieved from a representative pixel of the yellow-green (amber) LED array, substantially higher than that from conventional broad-area reference LEDs fabricated from the same wafer material. Furthermore, these micro-LEDs can sustain a high current density, up to 4.5 kA cm-2, before thermal rollover. A significant blueshift of the emission wavelength with increasing injection current is observed, however. This blueshift saturates at 45 nm (50 nm) for the yellow-green (amber) LED array, and numerical simulations have been used to gain insight into the responsible mechanisms in this microstructured format of device. In the relatively low-current-density regime (<3.5 kA cm-2) the blueshift is attributable to both the screening of the piezoelectric field by the injected carriers and the band-filling effect, whereas in the high-current regime, it is mainly due to band-filling. Further development of the epitaxial wafer material is expected to improve the current-dependent spectral stability.

  19. Phosphorus-Doped Carbon Nitride Tubes with a Layered Micro-nanostructure for Enhanced Visible-Light Photocatalytic Hydrogen Evolution.

    PubMed

    Guo, Shien; Deng, Zhaopeng; Li, Mingxia; Jiang, Baojiang; Tian, Chungui; Pan, Qingjiang; Fu, Honggang

    2016-01-26

    Phosphorus-doped hexagonal tubular carbon nitride (P-TCN) with the layered stacking structure was obtained from a hexagonal rod-like single crystal supramolecular precursor (monoclinic, C2/m). The production process of P-TCN involves two steps: 1) the precursor was prepared by self-assembly of melamine with cyanuric acid from in situ hydrolysis of melamine under phosphorous acid-assisted hydrothermal conditions; 2) the pyrolysis was initiated at the center of precursor under heating, thus giving the hexagonal P-TCN. The tubular structure favors the enhancement of light scattering and active sites. Meanwhile, the introduction of phosphorus leads to a narrow band gap and increased electric conductivity. Thus, the P-TCN exhibited a high hydrogen evolution rate of 67 μmol h(-1) (0.1 g catalyst, λ >420 nm) in the presence of sacrificial agents, and an apparent quantum efficiency of 5.68 % at 420 nm, which is better than most of bulk g-C3 N4 reported. PMID:26692105

  20. Manufacturing Technology.

    ERIC Educational Resources Information Center

    Barnes, James L.

    This curriculum guide is designed to assist junior high school industrial arts teachers in planning new courses and revising existing courses in manufacturing technology. Addressed in the individual units of the guide are the following topics: introduction to manufacturing, materials processing, personnel management, production management,…

  1. Manufacturing technologies

    SciTech Connect

    1995-09-01

    The Manufacturing Technologies Center is an integral part of Sandia National Laboratories, a multiprogram engineering and science laboratory, operated for the Department of Energy (DOE) with major facilities at Albuquerque, New Mexico, and Livermore, California. Our Center is at the core of Sandia`s Advanced Manufacturing effort which spans the entire product realization process.

  2. Micro/Nanomanufacturing in Support of Materials Science

    SciTech Connect

    Jian, L. K.; Chen, A.; Heussler, S. P.; Liu, G.; Mahmood, Shahrain bin; Kalaiselvi, S. M. P.; Maniam, S. M.; Virasawmy, Selven; Ren, Y. P.; Moser, H. O.; Barrett, M. D.; Dhanapaul, A. L.

    2009-01-29

    With its LiMiNT facility (Lithography for Micro- and Nanotechnology), Singapore Synchrotron Light Source (SSLS) provides a one-stop shop for micro/nano fabrication on large areas (typically 4'' diameter). Synchrotron deep X-ray lithography, eventually enhanced by the super-resolution process, is used to simultaneously pattern large numbers of micro/nano structures into a resist. Laser direct writer or electron beam serve as primary pattern generators, in particular, for mask making. Structure heights of >1 mm, aspect ratios of >200, and minimum sizes of <200 nm have been achieved, not necessarily simultaneously. Such structures may be replicated into a variety of metals and plastics. Tilting, rotating of the mask-substrate stack during exposure enables the parallel production of nearly 3D structures. Application fields include electromagnetic metamaterials, X-ray and infrared optics, photonics, lasers, quantum technology, precision manufacturing, and fluidics. SSLS is serving a growing community of users and customers.

  3. Micro-focused Brillouin light scattering study of the magnetization dynamics driven by Spin Hall effect in a transversely magnetized NiFe nanowire

    SciTech Connect

    Madami, M. Carlotti, G.; Gubbiotti, G.; Tacchi, S.; Siracusano, G.; Finocchio, G.; Carpentieri, M.

    2015-05-07

    We employed micro-focused Brillouin light scattering to study the amplification of the thermal spin wave eigenmodes by means of a pure spin current, generated by the spin-Hall effect, in a transversely magnetized Pt(4 nm)/NiFe(4 nm)/SiO{sub 2}(5 nm) layered nanowire with lateral dimensions 500 × 2750 nm{sup 2}. The frequency and the cross section of both the center (fundamental) and the edge spin wave modes have been measured as a function of the intensity of the injected dc electric current. The frequency of both modes exhibits a clear redshift while their cross section is greatly enhanced on increasing the intensity of the injected dc. A threshold-like behavior is observed for a value of the injected dc of 2.8 mA. Interestingly, an additional mode, localized in the central part of the nanowire, appears at higher frequency on increasing the intensity of the injected dc above the threshold value. Micromagnetic simulations were used to quantitatively reproduce the experimental results and to investigate the complex non-linear dynamics induced by the spin-Hall effect, including the modification of the spatial profile of the spin wave modes and the appearance of the extra mode above the threshold.

  4. Comparison of prosthetic models produced by traditional and additive manufacturing methods

    PubMed Central

    Park, Jin-Young; Kim, Hae-Young; Kim, Ji-Hwan; Kim, Jae-Hong

    2015-01-01

    PURPOSE The purpose of this study was to verify the clinical-feasibility of additive manufacturing by comparing the accuracy of four different manufacturing methods for metal coping: the conventional lost wax technique (CLWT); subtractive methods with wax blank milling (WBM); and two additive methods, multi jet modeling (MJM), and micro-stereolithography (Micro-SLA). MATERIALS AND METHODS Thirty study models were created using an acrylic model with the maxillary upper right canine, first premolar, and first molar teeth. Based on the scan files from a non-contact blue light scanner (Identica; Medit Co. Ltd., Seoul, Korea), thirty cores were produced using the WBM, MJM, and Micro-SLA methods, respectively, and another thirty frameworks were produced using the CLWT method. To measure the marginal and internal gap, the silicone replica method was adopted, and the silicone images obtained were evaluated using a digital microscope (KH-7700; Hirox, Tokyo, Japan) at 140X magnification. Analyses were performed using two-way analysis of variance (ANOVA) and Tukey post hoc test (α=.05). RESULTS The mean marginal gaps and internal gaps showed significant differences according to tooth type (P<.001 and P<.001, respectively) and manufacturing method (P<.037 and P<.001, respectively). Micro-SLA did not show any significant difference from CLWT regarding mean marginal gap compared to the WBM and MJM methods. CONCLUSION The mean values of gaps resulting from the four different manufacturing methods were within a clinically allowable range, and, thus, the clinical use of additive manufacturing methods is acceptable as an alternative to the traditional lost wax-technique and subtractive manufacturing. PMID:26330976

  5. Micro-laser

    DOEpatents

    Hutchinson, Donald P.; Richards, Roger K.

    2003-07-22

    A micro-laser is disclosed which includes a waveguide, a first and a second subwavelength resonant grating in the waveguide, and at least one photonic band gap resonant structure (PBG) in the waveguide and at least one amplifying medium in the waveguide. PBG features are positioned between the first and second subwavelength resonant gratings and allow introduction of amplifying mediums into the highly resonant guided micro-laser microcavity. The micro-laser may be positioned on a die of a bulk substrate material with one or more electronic and optical devices and may be communicably connected to the same. A method for fabricating a micro-laser is disclosed. A method for tuning the micro-laser is also disclosed. The micro-laser may be used as an optical regenerator, or a light source for data transfer or for optical computing.

  6. Manufacturing technology

    SciTech Connect

    Blaedel, K.L.

    1997-02-01

    The specific goals of the Manufacturing Technology thrust area are to develop an understanding of fundamental fabrication processes, to construct general purpose process models that will have wide applicability, to document our findings and models in journals, to transfer technology to LLNL programs, industry, and colleagues, and to develop continuing relationships with industrial and academic communities to advance our collective understanding of fabrication processes. Advances in four projects are described here, namely Design of a Precision Saw for Manufacturing, Deposition of Boron Nitride Films via PVD, Manufacturing and Coating by Kinetic Energy Metallization, and Magnet Design and Application.

  7. Energy consumption in manufacturing

    NASA Astrophysics Data System (ADS)

    Schmid, S. R.

    2012-04-01

    Energy sources, in the form of coal, oil, natural gas, solar or nuclear power, are global commodities, and as demand is projected to rise in the coming decades, so will costs. As such, an understanding of the energy needs of manufacturing processes and the ability to reduce the energy and carbon footprints are essential for sustainability reasons. Energy source effects are quantified in a number of measures. Models of energy needs by manufacturing processes are then examined, along with models incorporating the use of ancillary equipment such as pumps, filters, blowers, lighting, etc. Finally, the successful application of the tribological principles to influence energy consumption is discussed.

  8. Smart Manufacturing.

    PubMed

    Davis, Jim; Edgar, Thomas; Graybill, Robert; Korambath, Prakashan; Schott, Brian; Swink, Denise; Wang, Jianwu; Wetzel, Jim

    2015-01-01

    Historic manufacturing enterprises based on vertically optimized companies, practices, market share, and competitiveness are giving way to enterprises that are responsive across an entire value chain to demand dynamic markets and customized product value adds; increased expectations for environmental sustainability, reduced energy usage, and zero incidents; and faster technology and product adoption. Agile innovation and manufacturing combined with radically increased productivity become engines for competitiveness and reinvestment, not simply for decreased cost. A focus on agility, productivity, energy, and environmental sustainability produces opportunities that are far beyond reducing market volatility. Agility directly impacts innovation, time-to-market, and faster, broader exploration of the trade space. These changes, the forces driving them, and new network-based information technologies offering unprecedented insights and analysis are motivating the advent of smart manufacturing and new information technology infrastructure for manufacturing. PMID:25898070

  9. Array servo scanning micro EDM of 3D micro cavities

    NASA Astrophysics Data System (ADS)

    Tong, Hao; Li, Yong; Yi, Futing

    2010-12-01

    Micro electro discharge machining (Micro EDM) is a non-traditional processing technology with the special advantages of low set-up cost and few cutting force in machining any conductive materials regardless of their hardness. As well known, die-sinking EDM is unsuitable for machining the complex 3D micro cavity less than 1mm due to the high-priced fabrication of 3D microelectrode itself and its serous wear during EDM process. In our former study, a servo scanning 3D micro-EDM (3D SSMEDM) method was put forward, and our experiments showed it was available to fabricate complex 3D micro-cavities. In this study, in order to improve machining efficiency and consistency accuracy for array 3D micro-cavities, an array-servo-scanning 3D micro EDM (3D ASSMEDM) method is presented considering the complementary advantages of the 3D SSMEDM and the array micro electrodes with simple cross-section. During 3D ASSMEDM process, the array cavities designed by CAD / CAM system can be batch-manufactured by servo scanning layer by layer using array-rod-like micro tool electrodes, and the axial wear of the array electrodes is compensated in real time by keeping discharge gap. To verify the effectiveness of the 3D ASSMEDM, the array-triangle-micro cavities (side length 630 μm) are batch-manufactured on P-doped silicon by applying the array-micro-electrodes with square-cross-section fabricated by LIGA process. Our exploratory experiment shows that the 3D ASSMEDM provides a feasible approach for the batch-manufacture of 3D array-micro-cavities of conductive materials.

  10. Array servo scanning micro EDM of 3D micro cavities

    NASA Astrophysics Data System (ADS)

    Tong, Hao; Li, Yong; Yi, Futing

    2011-05-01

    Micro electro discharge machining (Micro EDM) is a non-traditional processing technology with the special advantages of low set-up cost and few cutting force in machining any conductive materials regardless of their hardness. As well known, die-sinking EDM is unsuitable for machining the complex 3D micro cavity less than 1mm due to the high-priced fabrication of 3D microelectrode itself and its serous wear during EDM process. In our former study, a servo scanning 3D micro-EDM (3D SSMEDM) method was put forward, and our experiments showed it was available to fabricate complex 3D micro-cavities. In this study, in order to improve machining efficiency and consistency accuracy for array 3D micro-cavities, an array-servo-scanning 3D micro EDM (3D ASSMEDM) method is presented considering the complementary advantages of the 3D SSMEDM and the array micro electrodes with simple cross-section. During 3D ASSMEDM process, the array cavities designed by CAD / CAM system can be batch-manufactured by servo scanning layer by layer using array-rod-like micro tool electrodes, and the axial wear of the array electrodes is compensated in real time by keeping discharge gap. To verify the effectiveness of the 3D ASSMEDM, the array-triangle-micro cavities (side length 630 μm) are batch-manufactured on P-doped silicon by applying the array-micro-electrodes with square-cross-section fabricated by LIGA process. Our exploratory experiment shows that the 3D ASSMEDM provides a feasible approach for the batch-manufacture of 3D array-micro-cavities of conductive materials.