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Sample records for microfabricated magnetic sifter

  1. Effect of Magnetic Field Gradient on Effectiveness of the Magnetic Sifter for Cell Purification.

    PubMed

    Ooi, Chinchun; Earhart, Christopher M; Wilson, Robert J; Wang, Shan X

    2013-01-01

    In our experiments with NCI-H1650 lung cancer cell lines labeled with magnetic nanoparticles via the Epithelial Cell Adhesion Molecule (EpCAM) antigen, we demonstrate capture efficiencies above 90% even at sample flow rates of 5 ml/h through our microfabricated magnetic sifter. We also improve the elution efficiencies from between 50% and 60% to close to 90% via optimization of the permanent magnet size and position used to magnetize the sifter. We then explain our observations via the use of finite element software for magnetic field and field gradient distributions, and a particle tracing algorithm, illustrating the impact of magnetic field gradients on the performance of the magnetic sifter. The high capture and elution efficiencies observed here is especially significant for magnetic separation of biologically interesting but rare moieties such as cancer stem cells for downstream analysis. PMID:23515873

  2. Effect of Magnetic Field Gradient on Effectiveness of the Magnetic Sifter for Cell Purification

    PubMed Central

    Ooi, Chinchun; Earhart, Christopher M.; Wilson, Robert J.; Wang, Shan X.

    2013-01-01

    In our experiments with NCI-H1650 lung cancer cell lines labeled with magnetic nanoparticles via the Epithelial Cell Adhesion Molecule (EpCAM) antigen, we demonstrate capture efficiencies above 90% even at sample flow rates of 5 ml/h through our microfabricated magnetic sifter. We also improve the elution efficiencies from between 50% and 60% to close to 90% via optimization of the permanent magnet size and position used to magnetize the sifter. We then explain our observations via the use of finite element software for magnetic field and field gradient distributions, and a particle tracing algorithm, illustrating the impact of magnetic field gradients on the performance of the magnetic sifter. The high capture and elution efficiencies observed here is especially significant for magnetic separation of biologically interesting but rare moieties such as cancer stem cells for downstream analysis. PMID:23515873

  3. Magnetic sifters and biochips for early diagnosis and therapy monitoring of cancer

    NASA Astrophysics Data System (ADS)

    Earhart, Chris

    2008-03-01

    Magnetic nanoparticles conjugated with biomolecules or recognition moieties are finding wide applications in medicine. In this context, we are developing a micromachined magnetic sifter and magnetic nanoparticles aimed for sample preparation applications in early diagnosis of cancer. The microfabricated sifter consisting of arrays of micron sized slits etched through a silicon wafer. A magnetic film is deposited on the wafer, producing high magnetic field gradients, comparable in magnitude to gradients in planar flow devices. As the solution flows through the die, magnetic particles are captured by the magnetic material surrounding the slits. The large number of slits allows for processing of large volumes of liquid, much greater than that of planar microfluidic devices. The sifters can be simply attached to a syringe or tube, resulting in a portable and user-friendly tool for molecular biology. Separation efficiencies of ˜ 50% for one pass through the sifter have been achieved. We have also designed and fabricated several types of magnetic biochips consisting of arrays of giant magnetoresistive (GMR) spin valve detectors with appropriate dimensions, surface chemistry, and microfluidics. An advanced electronic test station has been set up as a demonstration vehicle for the integrated evaluation of our magnetic biochips with commercial and custom magnetic nanoparticle labels for DNA or protein biomarkers. The magnetic biochip is capable of detecting down to 1-30 nanotags. Real-time detection of DNA signatures and protein targets in buffer and serum samples has been successfully performed in our laboratories, suggesting that magnetic biochips hold great promises for molecular diagnostics of cancer and other diseases. In collaboration with Chris M. Earhart, Wei Hu, Robert J. Wilson, Sebastian J. Osterfeld, Robert L. White, Nader Pourmand, and Shan X. Wang @ Stanford University. This work was supported by grants from NIH (1U54CA119367-01) and DARPA/Navy (N00014-02-1-0807).

  4. Isolation and mutational analysis of circulating tumor cells from lung cancer patients with magnetic sifters and biochips†

    PubMed Central

    Earhart, Christopher M.; Hughes, Casey E.; Gaster, Richard S.; Ooi, Chin Chun; Wilson, Robert J.; Zhou, Lisa Y.; Humke, Eric W.; Xu, Lingyun; Wong, Dawson J.; Willingham, Stephen B.; Schwartz, Erich J.; Weissman, Irving L.; Jeffrey, Stefanie S.; Neal, Joel W.; Rohatgi, Rajat; Wakelee, Heather A.; Wang, Shan X.

    2014-01-01

    Detection and characterization of circulating tumor cells (CTCs) may reveal insights into the diagnosis and treatment of malignant disease. Technologies for isolating CTCs developed thus far suffer from one or more limitations, such as low throughput, inability to release captured cells, and reliance on expensive instrumentation for enrichment or subsequent characterization. We report a continuing development of a magnetic separation device, the magnetic sifter, which is a miniature microfluidic chip with a dense array of magnetic pores. It offers high efficiency capture of tumor cells, labeled with magnetic nanoparticles, from whole blood with high throughput and efficient release of captured cells. For subsequent characterization of CTCs, an assay, using a protein chip with giant magnetoresistive nanosensors, has been implemented for mutational analysis of CTCs enriched with the magnetic sifter. The use of these magnetic technologies, which are separate devices, may lead the way to routine preparation and characterization of “liquid biopsies” from cancer patients. PMID:23969419

  5. Spin annihilations of and spin sifters for transverse electric and transverse magnetic waves in co- and counter-rotations

    PubMed Central

    Mok, Jinsik

    2014-01-01

    Summary This study is motivated in part to better understand multiplexing in wireless communications, which employs photons carrying varying angular momenta. In particular, we examine both transverse electric (TE) and transverse magnetic (TM) waves in either co-rotations or counter-rotations. To this goal, we analyze both Poynting-vector flows and orbital and spin parts of the energy flow density for the combined fields. Consequently, we find not only enhancements but also cancellations between the two modes. To our surprise, the photon spins in the azimuthal direction exhibit a complete annihilation for the counter-rotational case even if the intensities of the colliding waves are of different magnitudes. In contrast, the orbital flow density disappears only if the two intensities satisfy a certain ratio. In addition, the concepts of spin sifters and enantiomer sorting are illustrated. PMID:25383300

  6. Rapid Characterization of Magnetic Moment of Cells for Magnetic Separation

    PubMed Central

    Ooi, Chinchun; Earhart, Christopher M.; Wilson, Robert J.; Wang, Shan X.

    2014-01-01

    NCI-H1650 lung cancer cell lines labeled with magnetic nanoparticles via the Epithelial Cell Adhesion Molecule (EpCAM) antigen were previously shown to be captured at high efficiencies by a microfabricated magnetic sifter. If fine control and optimization of the magnetic separation process is to be achieved, it is vital to be able to characterize the labeled cells’ magnetic moment rapidly. We have thus adapted a rapid prototyping method to obtain the saturation magnetic moment of these cells. This method utilizes a cross-correlation algorithm to analyze the cells’ motion in a simple fluidic channel to obtain their magnetophoretic velocity, and is effective even when the magnetic moments of cells are small. This rapid characterization is proven useful in optimizing our microfabricated magnetic sifter procedures for magnetic cell capture. PMID:24771946

  7. Rapid Characterization of Magnetic Moment of Cells for Magnetic Separation.

    PubMed

    Ooi, Chinchun; Earhart, Christopher M; Wilson, Robert J; Wang, Shan X

    2013-07-01

    NCI-H1650 lung cancer cell lines labeled with magnetic nanoparticles via the Epithelial Cell Adhesion Molecule (EpCAM) antigen were previously shown to be captured at high efficiencies by a microfabricated magnetic sifter. If fine control and optimization of the magnetic separation process is to be achieved, it is vital to be able to characterize the labeled cells' magnetic moment rapidly. We have thus adapted a rapid prototyping method to obtain the saturation magnetic moment of these cells. This method utilizes a cross-correlation algorithm to analyze the cells' motion in a simple fluidic channel to obtain their magnetophoretic velocity, and is effective even when the magnetic moments of cells are small. This rapid characterization is proven useful in optimizing our microfabricated magnetic sifter procedures for magnetic cell capture. PMID:24771946

  8. Microfabricated atomic vapor cell arrays for magnetic field measurements

    SciTech Connect

    Woetzel, S.; Schultze, V.; IJsselsteijn, R.; Schulz, T.; Anders, S.; Stolz, R.; Meyer, H.-G.

    2011-03-15

    We describe a method for charging atomic vapor cells with cesium and buffer gas. By this, it is possible to adjust the buffer gas pressure in the cells with good accuracy. Furthermore, we present a new design of microfabricated vapor cell arrays, which combine silicon wafer based microfabrication and ultrasonic machining to achieve the arrays of thermally separated cells with 50 mm{sup 3} volume. With cells fabricated in the outlined way, intrinsic magnetic field sensitivities down to 300 fT/Hz{sup 1/2} are reached.

  9. Microfabrication of High Resolution X-ray Magnetic Calorimeters

    SciTech Connect

    Hsieh, W.-T.; Stevenson, Thomas R.; Bandler, Simon R.; Kelly, Daniel P.; Porst, Jan P.; Rotzinger, Hannes; Seidel, George M.

    2009-12-16

    Metallic magnetic calorimeter (MMC) is one of the most promising x-ray detector technologies for providing the very high energy resolution needed for future astronomical x-ray imaging spectroscopy. For this purpose, we have developed micro-fabricated 5x5 arrays of MMC of which each individual pixel has excellent energy resolution as good as 3.4 eV at 6 keV x-ray. Here we report on the fabrication techniques developed to achieve good resolution and high efficiency. These include: processing of a thin insulation layer for strong magnetic coupling between the AuEr sensor film and the niobium pick-up coil; production of overhanging absorbers for enhanced efficiency of x-ray absorption; fabrication on SiN membranes to minimize the effects on energy resolution from athermal phonon loss. We have also improved the deposition of the magnetic sensor film such that the film magnetization is nearly completely that is expected from the AuEr sputter target bulk material. In addition, we have included a study of a positional sensitive design, the Hydra design, which allows thermal coupling of four absorbers to a common MMC sensor and circuit.

  10. Microfabrication of High Resolution X-ray Magnetic Calorimeters

    NASA Astrophysics Data System (ADS)

    Hsieh, Wen-Ting; Bandler, Simon R.; Kelly, Daniel P.; Porst, Jan P.; Rotzinger, Hannes; Seidel, George M.; Stevenson, Thomas R.

    2009-12-01

    Metallic magnetic calorimeter (MMC) is one of the most promising x-ray detector technologies for providing the very high energy resolution needed for future astronomical x-ray imaging spectroscopy. For this purpose, we have developed micro-fabricated 5×5 arrays of MMC of which each individual pixel has excellent energy resolution as good as 3.4 eV at 6 keV x-ray. Here we report on the fabrication techniques developed to achieve good resolution and high efficiency. These include: processing of a thin insulation layer for strong magnetic coupling between the AuEr sensor film and the niobium pick-up coil; production of overhanging absorbers for enhanced efficiency of x-ray absorption; fabrication on SiN membranes to minimize the effects on energy resolution from athermal phonon loss. We have also improved the deposition of the magnetic sensor film such that the film magnetization is nearly completely that is expected from the AuEr sputter target bulk material. In addition, we have included a study of a positional sensitive design, the Hydra design, which allows thermal coupling of four absorbers to a common MMC sensor and circuit.

  11. Microfabricated Ion Beam Drivers for Magnetized Target Fusion

    NASA Astrophysics Data System (ADS)

    Persaud, Arun; Seidl, Peter; Ji, Qing; Ardanuc, Serhan; Miller, Joseph; Lal, Amit; Schenkel, Thomas

    2015-11-01

    Efficient, low-cost drivers are important for Magnetized Target Fusion (MTF). Ion beams offer a high degree of control to deliver the required mega joules of driver energy for MTF and they can be matched to several types of magnetized fuel targets, including compact toroids and solid targets. We describe an ion beam driver approach based on the MEQALAC concept (Multiple Electrostatic Quadrupole Array Linear Accelerator) with many beamlets in an array of micro-fabricated channels. The channels consist of a lattice of electrostatic quadrupoles (ESQ) for focusing and of radio-frequency (RF) electrodes for ion acceleration. Simulations with particle-in-cell and beam envelope codes predict >10x higher current densities compared to state-of-the-art ion accelerators. This increase results from dividing the total ion beam current up into many beamlets to control space charge forces. Focusing elements can be biased taking advantage of high breakdown electric fields in sub-mm structures formed using MEMS techniques (Micro-Electro-Mechanical Systems). We will present results on ion beam transport and acceleration in MEMS based beamlets. Acknowledgments: This work is supported by the U.S. DOE under Contract No. DE-AC02-05CH11231.

  12. 7 CFR 58.224 - Sifters.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Sifters. 58.224 Section 58.224 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE...

  13. 7 CFR 58.224 - Sifters.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Sifters. 58.224 Section 58.224 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE...

  14. Evaluation of Magnetic Resonance Imaging Issues for Implantable Microfabricated Magnetic Actuators

    PubMed Central

    Lee, Hyowon; Xu, Qing; Shellock, Frank G.; Bergsneider, Marvin; Judy, Jack W.

    2013-01-01

    The mechanical robustness of microfabricated torsional magnetic actuators in withstanding the strong static fields (7 T) and time-varying field gradients (17 T/m) produced by an MR system was studied in this investigation. The static and dynamic mechanical characteristics of 30 devices were quantitatively measured before and after exposure to both strong uniform and non-uniform magnetic fields. The results showed no statistically significant change in both the static and dynamic mechanical performance, which mitigate concerns about the mechanical stability of these devices in association with MR systems under the conditions used for this assessment. The MR-induced heating was also measured in a 3-T/128-MHz MR system. The results showed a minimal increase (1.6 °C) in temperature due to the presence of the magnetic microactuator array. Finally, the size of the MR-image artifacts created by the magnetic microdevices were quantified. The signal loss caused by the devices was approximately four times greater than the size of the device. PMID:24077662

  15. Development of Microfabricated Magnetic Actuators for Removing Cellular Occlusion

    PubMed Central

    Lee, Selene A.; Lee, Hyowon; Pinney, James R; Khialeeva, Elvira; Bergsneider, Marvin; Judy, Jack W.

    2011-01-01

    Here we report on the development of torsional magnetic microactuators for displacing biological materials in implantable catheters. Static and dynamic behaviors of the devices were characterized in air and in fluid using optical experimental methods. The devices were capable of achieving large deflections (>60°) and had resonant frequencies that ranged from 70 Hz to 1.5 kHz in fluid. The effect of long-term actuation (>2.5 · 108 cycles) was quantified using resonant shift as the metric (Δf < 2%). Cell-clearing capabilities of the devices were evaluated by examining the effect of actuation on a layer of aggressively growing adherent cells. On average, actuated microdevices removed 37.4% of the adherent cell layer grown over the actuator surface. The effect of actuation time, deflection angle, and beam geometry were evaluated. The experimental results indicate that physical removal of adherent cells at the microscale is feasible using magnetic microactuation. PMID:21886945

  16. A microfabricated coil for implantable applications of magnetic spinal cord stimulation.

    PubMed

    Yu-Min Fu; Che-Yu Chen; Xin-Hong Qian; Yu-Ting Cheng; Chung-Yu Wu; Jui-Sheng Sun; Chien-Chun Huang; Chao-Kai Hu

    2015-08-01

    In this paper, a microfabricated inductive coil comprising of 125-turn coil windings and a MnZn-based magnetic core in a volume of 200 mm(3) is presented for the magnetic neural stimulation in a spinal cord. The coil winding with the parallel-linkage design instead of the typical serial-linkage one is proposed not only to provide better design flexibility to the current mode driving circuit but also to simplify the fabrication process of the 3-D inductive coil, which can further advance the coil miniaturization. Experimental results show the microcoil with a 1.5 A, 1 kHz square-wave current input can induce a voltages of ~220 μV on the conducting wire with an impedance of ~0.2 Ω @ 1 kHz, 1 mm separation. PMID:26737882

  17. SIFTER search: a web server for accurate phylogeny-based protein function prediction.

    PubMed

    Sahraeian, Sayed M; Luo, Kevin R; Brenner, Steven E

    2015-07-01

    We are awash in proteins discovered through high-throughput sequencing projects. As only a minuscule fraction of these have been experimentally characterized, computational methods are widely used for automated annotation. Here, we introduce a user-friendly web interface for accurate protein function prediction using the SIFTER algorithm. SIFTER is a state-of-the-art sequence-based gene molecular function prediction algorithm that uses a statistical model of function evolution to incorporate annotations throughout the phylogenetic tree. Due to the resources needed by the SIFTER algorithm, running SIFTER locally is not trivial for most users, especially for large-scale problems. The SIFTER web server thus provides access to precomputed predictions on 16 863 537 proteins from 232 403 species. Users can explore SIFTER predictions with queries for proteins, species, functions, and homologs of sequences not in the precomputed prediction set. The SIFTER web server is accessible at http://sifter.berkeley.edu/ and the source code can be downloaded. PMID:25979264

  18. SIFTER search: a web server for accurate phylogeny-based protein function prediction

    SciTech Connect

    Sahraeian, Sayed M.; Luo, Kevin R.; Brenner, Steven E.

    2015-05-15

    We are awash in proteins discovered through high-throughput sequencing projects. As only a minuscule fraction of these have been experimentally characterized, computational methods are widely used for automated annotation. Here, we introduce a user-friendly web interface for accurate protein function prediction using the SIFTER algorithm. SIFTER is a state-of-the-art sequence-based gene molecular function prediction algorithm that uses a statistical model of function evolution to incorporate annotations throughout the phylogenetic tree. Due to the resources needed by the SIFTER algorithm, running SIFTER locally is not trivial for most users, especially for large-scale problems. The SIFTER web server thus provides access to precomputed predictions on 16 863 537 proteins from 232 403 species. Users can explore SIFTER predictions with queries for proteins, species, functions, and homologs of sequences not in the precomputed prediction set. Lastly, the SIFTER web server is accessible at http://sifter.berkeley.edu/ and the source code can be downloaded.

  19. SIFTER search: a web server for accurate phylogeny-based protein function prediction

    DOE PAGESBeta

    Sahraeian, Sayed M.; Luo, Kevin R.; Brenner, Steven E.

    2015-05-15

    We are awash in proteins discovered through high-throughput sequencing projects. As only a minuscule fraction of these have been experimentally characterized, computational methods are widely used for automated annotation. Here, we introduce a user-friendly web interface for accurate protein function prediction using the SIFTER algorithm. SIFTER is a state-of-the-art sequence-based gene molecular function prediction algorithm that uses a statistical model of function evolution to incorporate annotations throughout the phylogenetic tree. Due to the resources needed by the SIFTER algorithm, running SIFTER locally is not trivial for most users, especially for large-scale problems. The SIFTER web server thus provides access tomore » precomputed predictions on 16 863 537 proteins from 232 403 species. Users can explore SIFTER predictions with queries for proteins, species, functions, and homologs of sequences not in the precomputed prediction set. Lastly, the SIFTER web server is accessible at http://sifter.berkeley.edu/ and the source code can be downloaded.« less

  20. A microfabricated magnetic actuation device for mechanical conditioning of arrays of 3D microtissues.

    PubMed

    Xu, Fan; Zhao, Ruogang; Liu, Alan S; Metz, Tristin; Shi, Yu; Bose, Prasenjit; Reich, Daniel H

    2015-06-01

    This paper describes an approach to actuate magnetically arrays of microtissue constructs for long-term mechanical conditioning and subsequent biomechanical measurements. Each construct consists of cell/matrix material self-assembled around a pair of flexible poly(dimethylsiloxane) (PDMS) pillars. The deflection of the pillars reports the tissues' contractility. Magnetic stretching of individual microtissues via magnetic microspheres mounted on the cantilevers has been used to elucidate the tissues' elastic modulus and response to varying mechanical boundary conditions. This paper describes the fabrication of arrays of micromagnetic structures that can transduce an externally applied uniform magnetic field to actuate simultaneously multiple microtissues. These structures are fabricated on silicon-nitride coated Si wafers and contain electrodeposited Ni bars. Through-etched holes provide optical and culture media access when the devices are mounted on the PDMS microtissue scaffold devices. Both static and AC forces (up to 20 μN on each microtissue) at physiological frequencies are readily generated in external fields of 40 mT. Operation of the magnetic arrays was demonstrated via measurements of elastic modulus and dynamic stiffening in response to AC actuation of fibroblast populated collagen microtissues. PMID:25959132

  1. A microfabricated magnetic actuation device for mechanical conditioning of arrays of 3D microtissues

    PubMed Central

    Xu, Fan; Zhao, Ruogang; Liu, Alan S.; Metz, Tristin; Shi, Yu; Bose, Prasenjit; Reich, Daniel H.

    2015-01-01

    This paper describes an approach to actuate magnetically arrays of microtissue constructs for long-term mechanical conditioning and subsequent biomechanical measurements. Each construct consists of cell/matrix material self-assembled around a pair of flexible poly(dimethylsiloxane) (PDMS) pillars. The deflection of the pillars reports the tissues’ contractility. Magnetic stretching of individual microtissues via magnetic microspheres mounted on the cantilevers has been used to elucidate the tissues’ elastic modulus and response to varying mechanical boundary conditions. This paper describes the fabrication of arrays of micromagnetic structures that can transduce an externally applied uniform magnetic field to actuate simultaneously multiple microtissues. These structures are fabricated on silicon-nitride coated Si wafers and contain electrodeposited Ni bars. Through-etched holes provide optical and culture media access when the devices are mounted on the PDMS microtissue scaffold devices. Both static and AC forces (up to 20 μN on each microtissue) at physiological frequencies are readily generated in external fields of 40 mT. Operation of the magnetic arrays was demonstrated via measurements of elastic modulus and dynamic stiffening in response to AC actuation of fibroblast populated collagen microtissues. PMID:25959132

  2. Probing cellular traction forces with magnetic nanowires and microfabricated force sensor arrays

    NASA Astrophysics Data System (ADS)

    Lin, Yi-Chia; Kramer, Corinne M.; Chen, Christopher S.; Reich, Daniel H.

    2012-02-01

    In this paper, the use of magnetic nanowires for the study of cellular response to force is demonstrated. High-aspect ratio Ni rods with diameter 300 nm and lengths up to 20 μm were bound to or internalized by pulmonary artery smooth muscle cells (SMCs) cultured on arrays of flexible micropost force sensors. Forces and torques were applied to the cells by driving the nanowires with AC magnetic fields in the frequency range 0.1-10 Hz, and the changes in cellular contractile forces were recorded with the microposts. These local stimulations yield global force reinforcement of the cells’ traction forces, but this contractile reinforcement can be effectively suppressed upon addition of a calcium channel blocker, ruthenium red, suggesting the role of calcium channels in the mechanical response. The responsiveness of the SMCs to actuation depends on the frequency of the applied stimulation. These results show that the combination of magnetic nanoparticles and micropatterned, flexible substrates can provide new approaches to the study of cellular mechanotransduction.

  3. 7 CFR 58.246 - Cleaning of dryers, collectors, conveyors, ducts, sifters and storage bins.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Cleaning of dryers, collectors, conveyors, ducts, sifters and storage bins. 58.246 Section 58.246 Agriculture Regulations of the Department of Agriculture... Inspection and Grading Service 1 Operations and Operating Procedures § 58.246 Cleaning of dryers,...

  4. 7 CFR 58.246 - Cleaning of dryers, collectors, conveyors, ducts, sifters and storage bins.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Cleaning of dryers, collectors, conveyors, ducts, sifters and storage bins. 58.246 Section 58.246 Agriculture Regulations of the Department of Agriculture... Inspection and Grading Service 1 Operations and Operating Procedures § 58.246 Cleaning of dryers,...

  5. 7 CFR 58.246 - Cleaning of dryers, collectors, conveyors, ducts, sifters and storage bins.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Cleaning of dryers, collectors, conveyors, ducts, sifters and storage bins. 58.246 Section 58.246 Agriculture Regulations of the Department of Agriculture... Inspection and Grading Service 1 Operations and Operating Procedures § 58.246 Cleaning of dryers,...

  6. 7 CFR 58.246 - Cleaning of dryers, collectors, conveyors, ducts, sifters and storage bins.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Cleaning of dryers, collectors, conveyors, ducts, sifters and storage bins. 58.246 Section 58.246 Agriculture Regulations of the Department of Agriculture... Inspection and Grading Service 1 Operations and Operating Procedures § 58.246 Cleaning of dryers,...

  7. Microfabricated thermionic detector

    DOEpatents

    Lewis, Patrick R; Manginell, Ronald P; Wheeler, David R; Trudell, Daniel E

    2012-10-30

    A microfabricated TID comprises a microhotplate and a thermionic source disposed on the microhotplate. The microfabricated TID can provide high sensitivity and selectivity to nitrogen- and phosphorous-containing compounds and other compounds containing electronegative function groups. The microfabricated TID can be microfabricated with semiconductor-based materials. The microfabricated TID can be combined with a microfabricated separation column and used in microanalytical system for the rapid on-site detection of pesticides, chemical warfare agents, explosives, pharmaceuticals, and other organic compounds that contain nitrogen or phosphorus.

  8. Laser processes for precise microfabrication of magnetic disk-drive components

    NASA Astrophysics Data System (ADS)

    Tam, Andrew C.

    2000-11-01

    The technique of laser micro-processing has recently found several important and widespread applications in the manufacturing of disk-drive components. Examples provided here include the cleaning of surface contaminants, the formation of nano-bumps on disk surfaces for controlled surface texturing or for making glide height standards, and the micro-bending of magnetic head sliders for flight-height controls. Short-pulsed laser irradiation at suitable wavelength, fluence, and incidence direction can be used to clean off particulate and organic-film contaminants from surfaces of critical components, for example, the slider and the disk. Controlled disk texturing is needed to alleviate the problem of stiction which occurs when the disk stop spinning and the super smooth slider comes into stationary contact with the super smooth disk. A compact laser operating at high pulse repetition rate can be used to produce a low-stiction racetrack composed of typically a million nano-bumps. This can be done both for NiP/aluminum disks, or for glass disks. Single isolated bump with a specified height for providing height-standard can also be tailor-made. Very recently, we have developed a 'laser curvature adjust technique' and implemented it into production of magnetic head sliders. Here, microscopic adjustments of the curvature of air bearing surface of sliders can be produced by suitable laser scribing at the back side of the ceramic slider.

  9. Micro-fabricated Helmholtz coil featuring disposable microfluidic sample inserts for applications in nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Spengler, N.; Moazenzadeh, A.; Meier, R. Ch; Badilita, V.; Korvink, J. G.; Wallrabe, U.

    2014-03-01

    In this study, we report on a novel, multi-use, high-resolution NMR/MRI micro-detection probe for the screening of flat samples. It is based on a Helmholtz coil pair in the centre of the probe, built out of two 1.5 mm diameter wirebonded copper coils, resulting in a homogeneous distribution of the magnetic field. For liquids and suspensions, custom fabricated, disposable sample inserts are placed inside the pair and aligned automatically, preventing the sensor and the samples from contamination. The sensor was successfully tested in a 500 MHz (11.7 T) spectrometer where we achieved a linewidth of 1.79 Hz (3.58 ppb) of a water phantom. Nutation experiments revealed an overall B1-field uniformity of 92% (ratio in signal intensity at flip angles of 810°/90°), leading to a homogeneous excitation of concentration limited samples. To demonstrate the imaging capabilities of the detector, we acquired images of a solid and a liquid sample—of a piece of leaf, directly inserted into the probe and of a sample insert, filled with a suspension of 50 μm diameter polymer beads and deionized water, with in-plane resolutions of 20 × 20 μ m2 and 10 × 10 μ m2, respectively.

  10. Real-time thickness measurement of biological tissues using a microfabricated magnetically-driven lens actuator.

    PubMed

    Mansoor, Hadi; Zeng, Haishan; Chiao, Mu

    2011-08-01

    A fiber optic confocal catheter with a micro scanning lens was developed for real-time and non-contact thickness measurement of biological tissue. The catheter has an outer diameter and rigid length of 4.75 mm and 30 mm respectively and is suitable for endoscopic applications. The catheter incorporates a lens actuator that is fabricated using microelectromechanical systems (MEMS) technology. The lens is mounted on a folded flexure made of nickel and is actuated by magnetic field. Thickness measurements are performed by positioning the catheter in front of the tissue and actuating the lens scanner in the out-of-plane direction. A single-mode optical fiber (SMF) is used to deliver a 785 nm laser beam to the tissue and relay back the reflected light from the tissue to a photomultiplier tube (PMT). When the focal point of the scanning lens passes tissue boundaries, intensity peaks are detected in the reflecting signal. Tissue thickness is calculated using its index of refraction and the lens displacement between intensity peaks. The utility of the confocal catheter was demonstrated by measuring the cornea and skin thicknesses of a mouse. Measurement uncertainty of 8.86 µm within 95% confidence interval has been achieved. PMID:21468630

  11. Microfabricated Spin Polarized Atomic Magnetometers

    NASA Astrophysics Data System (ADS)

    Jimenez Martinez, Ricardo

    Spin polarized atomic magnetometers involve the preparation of atomic spins and their detection for monitoring magnetic fields. Due to the fact that magnetic fields are ubiquitous in our world, spin polarized atomic magnetometers are used in a wide range of applications from the detection of magnetic fields generated by the human heart and brain to the detection of nuclear magnetic resonance. In this thesis we developed microfabricated spin polarized atomic magnetometers. These sensors are based on optical pumping and spin-exchange collisions between alkali atoms and noble gases contained in microfabricated millimeter-scale vapor cells. In the first part of the thesis, we improved different features of current microfabricated optical magnetometers. Specifically, we improved the bandwidth of these devices, without degrading their magnetic field sensitivity, by broadening their magnetic resonance through spin-exchange collisions between alkali atoms. We also implemented all-optical excitation techniques to avoid problems, such as the magnetic perturbation of the environment, induced by the radio-frequency fields used in some of these sensors. In the second part of the thesis we demonstrated a microfluidic chip for the optical production and detection of hyperpolarized Xe gas through spin-exchange collisions with optically pumped Rb atoms. These devices are critical for the widespread use of spin polarized atomic magnetometers in applications requiring simple, compact, low-cost, and portable instrumentation.

  12. The CHAPS, SIFTER, and TAPS-R as Predictors of (C)AP Skills and (C)APD

    ERIC Educational Resources Information Center

    Wilson, Wayne J.; Jackson, Alison; Pender, Alice; Rose, Carla; Wilson, Jacqueline; Heine, Chyrisse; Khan, Asad

    2011-01-01

    Purpose: In this study, the authors investigated the relationships between 3 tests used to screen for (central) auditory processing disorder ([C]APD)--the Children's Auditory Performance Scale (CHAPS; W. J. Smoski, M. A. Brunt, & J. C. Tannahill, 1998), the Screening Instrument for Targeting Educational Risk (SIFTER; K. Anderson, 1989), and the…

  13. Microfabricated teeter-totter resonator

    DOEpatents

    Adkins, Douglas Ray; Heller, Edwin J.; Shul, Randy J.

    2004-11-23

    A microfabricated teeter-totter resonator comprises a frame, a paddle pivotably anchored to the frame by pivot arms that define an axis of rotation, a current conductor line on a surface of the paddle, means for applying a static magnetic field substantially perpendicular to the rotational axis and in the plane of the paddle, and means for energizing the current conductor line with an alternating current. A Lorentz force is generated by the interaction of the magnetic field with the current flowing in the conductor line, causing the paddle to oscillate about the axis of rotation. The teeter-totter resonator can be fabricated with micromachining techniques with materials used in the integrated circuits manufacturing industry. The microfabricated teeter-totter resonator has many varied applications, both as an actuation device and as a sensor. When used as a chemical sensor, a chemically sensitive coating can be disposed on one or both surfaces of the paddle to enhance the absorption of chemical analytes from a fluid stream. The resulting mass change can be detected as a change in the resonant frequency or phase of the oscillatory motion of the paddle.

  14. Microfabricated ion trap array

    DOEpatents

    Blain, Matthew G.; Fleming, James G.

    2006-12-26

    A microfabricated ion trap array, comprising a plurality of ion traps having an inner radius of order one micron, can be fabricated using surface micromachining techniques and materials known to the integrated circuits manufacturing and microelectromechanical systems industries. Micromachining methods enable batch fabrication, reduced manufacturing costs, dimensional and positional precision, and monolithic integration of massive arrays of ion traps with microscale ion generation and detection devices. Massive arraying enables the microscale ion traps to retain the resolution, sensitivity, and mass range advantages necessary for high chemical selectivity. The reduced electrode voltage enables integration of the microfabricated ion trap array with on-chip circuit-based rf operation and detection electronics (i.e., cell phone electronics). Therefore, the full performance advantages of the microfabricated ion trap array can be realized in truly field portable, handheld microanalysis systems.

  15. Microfabricated AC impedance sensor

    DOEpatents

    Krulevitch, Peter; Ackler, Harold D.; Becker, Frederick; Boser, Bernhard E.; Eldredge, Adam B.; Fuller, Christopher K.; Gascoyne, Peter R. C.; Hamilton, Julie K.; Swierkowski, Stefan P.; Wang, Xiao-Bo

    2002-01-01

    A microfabricated instrument for detecting and identifying cells and other particles based on alternating current (AC) impedance measurements. The microfabricated AC impedance sensor includes two critical elements: 1) a microfluidic chip, preferably of glass substrates, having at least one microchannel therein and with electrodes patterned on both substrates, and 2) electrical circuits that connect to the electrodes on the microfluidic chip and detect signals associated with particles traveling down the microchannels. These circuits enable multiple AC impedance measurements of individual particles at high throughput rates with sufficient resolution to identify different particle and cell types as appropriate for environmental detection and clinical diagnostic applications.

  16. Microfabricated diffusion source

    DOEpatents

    Oborny, Michael C.; Frye-Mason, Gregory C.; Manginell, Ronald P.

    2008-07-15

    A microfabricated diffusion source to provide for a controlled diffusion rate of a vapor comprises a porous reservoir formed in a substrate that can be filled with a liquid, a headspace cavity for evaporation of the vapor therein, a diffusion channel to provide a controlled diffusion of the vapor, and an outlet to release the vapor into a gas stream. The microfabricated diffusion source can provide a calibration standard for a microanalytical system. The microanalytical system with an integral diffusion source can be fabricated with microelectromechanical systems technologies.

  17. Micro-Fabrication and Circuit Optimization for Magnetic Components of High-Efficiency DC-DC Converters

    NASA Astrophysics Data System (ADS)

    Tian, Rui

    Magnetic components are essential parts of power converters. Inductors with magnetic cores are investigated. An eddy current loss model for pot-core inductors is developed with finite elemental analysis (FEA). The reliability of inductors using magnetic cores in a high-temperature environment is investigated. Working in up to 150°C circumstance for a short periods is not destructive for the inductors. Optimization of toroidal inductors in a DC-DC converter is investigated. Parasitic capacitance and the capacitive loss in toroidal inductors are modeled. Standard circuit optimization is performed to explore the energy conversion efficiency of the toroidal inductors. Thermal analysis, light-load efficiency and relative permeability of the toroidal inductor design are also investigated. The toroidal inductor can achieve about 85% efficiency for 3 A DC current and 1 W/mm2 power density. Inductor-only efficiency of toroidal inductors is investigated with revised model. At 100 MHz operating frequency, toroidal inductors can achieve more than 97% inductor efficiency with power density range of 0.7 W/mm2 to 6 W/mm2. The performance of our nanograngular magnetic core is dependent on the angle of the poling magnetic field compared to the field during operation. Experiments on a serious of samples show that the poling angle can deviate by up to 15 degrees from ideal with only a small penalty in performance. The field-angle experiment is intended to prove integrated toroidal inductor process possible. A magnetic fixture model is proposed for large-scale toroidal inductor processing.

  18. Program of research on microfabrication techniques for VLSI magnetic devices. Final report, 1 October 1983-30 September 1984

    SciTech Connect

    Kryder, M.H.; Alex, M.; Artman, J.; Bauer, L.; Campbell, R.

    1984-11-01

    New materials, new fabrication techniques and new device structures for high density magnetic bubble devices were developed. The main focus of the work has been to develop ion-implanted contiguous disk devices offering sixteen times the bit density of presently manufactured bubble devices and chip capacities of 64 Mbit. Under this contract, the authors developed a computer program for modeling magnetic bubble garnet materials and applied it to the design of bubble materials having isotropic magnetostriction. They have previously show that such materials would provide better device operating characteristics. During the past year they also modeled the anisotropic stresses around ion-implanted propagation patterns and showed how they produce nonuniform anisotropies due to magnetostrictive effects.

  19. Program of research on microfabrication techniques for vlsi magnetic devices. Interim progress report 30 Sep 1981-29 Sep 1982

    SciTech Connect

    Kryder, M.H.; Bauer, C.L.; Rayne, J.A.; Guzman, A.

    1982-10-01

    Means of fabricating, selectively modifying, and characterizing single crystal epitaxial garnet and amorphous magnetic thin films are being investigated with the intention of developing new materials and processes for magnetic devices including bubble, recording, magneto-optic, and micro-wave devices. Submicron ion unimplantable garnets have been developed for ion-implanted contiguous disk devices. A wideband ferromagnetic resonance spectrometer and a high resolution magneto-optic photometer were developed and used to measure the magneto-striction and crystalline anisotropy constants of these materials. It was found that ion implantation dramatically reduces the crystalline anisotropy field and that a large portion of the change in uniaxial anisotropy of garnets is produced by non-stress related mechanisms which became more important as bubble size is reduced. Transmission electron microscopy investigations of ion implanted garnets have revealed clearly observable changes in stress and structure produced by implantation. Amorphous magnetic materials have been developed which support submicrometer sized domains for bubble and magneto-optic device applications. A number of high density bubble devices have been designed and fabricated: 2-4 micrometers period ion-implanted contiguous disk devices, 4-8 micrometer period current-acessed devices, and 2-6 micrometer period current-accessed ion implanted devices with 4 to 16 times lower power dissipation than earlier current-accessed devices.

  20. Microfabricated particle focusing device

    DOEpatents

    Ravula, Surendra K.; Arrington, Christian L.; Sigman, Jennifer K.; Branch, Darren W.; Brener, Igal; Clem, Paul G.; James, Conrad D.; Hill, Martyn; Boltryk, Rosemary June

    2013-04-23

    A microfabricated particle focusing device comprises an acoustic portion to preconcentrate particles over large spatial dimensions into particle streams and a dielectrophoretic portion for finer particle focusing into single-file columns. The device can be used for high throughput assays for which it is necessary to isolate and investigate small bundles of particles and single particles.

  1. Microfabricated bragg waveguide

    DOEpatents

    Fleming, James G.; Lin, Shawn-Yu; Hadley, G. Ronald

    2004-10-19

    A microfabricated Bragg waveguide of semiconductor-compatible material having a hollow core and a multilayer dielectric cladding can be fabricated by integrated circuit technologies. The microfabricated Bragg waveguide can comprise a hollow channel waveguide or a hollow fiber. The Bragg fiber can be fabricated by coating a sacrificial mandrel or mold with alternating layers of high- and low-refractive-index dielectric materials and then removing the mandrel or mold to leave a hollow tube with a multilayer dielectric cladding. The Bragg channel waveguide can be fabricated by forming a trench embedded in a substrate and coating the inner wall of the trench with a multilayer dielectric cladding. The thicknesses of the alternating layers can be selected to satisfy the condition for minimum radiation loss of the guided wave.

  2. SIFTER: Scintillating Fiber Telescopes for Energetic Radiation, Gamma-Ray Applications

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.

    2002-01-01

    The research project "SIFTER: Scintillating Fiber Telescopes for Energetic Radiation, Gamma-Ray Applications" approved under the NASA High Energy Astrophysics Research Program. The principal investigator of the proposal was Prof. Geoffrey N. Pendleton, who is currently on extended leave from UAH. Prof. William S. Paciesas administered the grant during Dr. Pendleton's absence. The project was originally funded for one year from 6/8/2000 to 6/7/2001. Due to conflicts with other commitments by the PI, the period of performance was extended at no additional cost until 6/30/2002. The goal of this project was to study scintillating fiber pair-tracking gamma-ray telescope configurations specifically designed to perform imaging and spectroscopy in the 5 - 250 MeV energy range. The main efforts were concentrated in two areas: 1) development of tracking techniques and event reconstruction algorithms, with particular emphasis on angular resolution; and 2) investigation of coded apertures as a means to improve the instrument angular resolution at low energies.

  3. Microfabricated Formaldehyde Gas Sensors

    PubMed Central

    Flueckiger, Jonas; Ko, Frank K.; Cheung, Karen C.

    2009-01-01

    Formaldehyde is a volatile organic compound that is widely used in textiles, paper, wood composites, and household materials. Formaldehyde will continuously outgas from manufactured wood products such as furniture, with adverse health effects resulting from prolonged low-level exposure. New, microfabricated sensors for formaldehyde have been developed to meet the need for portable, low-power gas detection. This paper reviews recent work including silicon microhotplates for metal oxide-based detection, enzyme-based electrochemical sensors, and nanowire-based sensors. This paper also investigates the promise of polymer-based sensors for low-temperature, low-power operation. PMID:22291561

  4. Microfabricated ion frequency standard

    DOEpatents

    Schwindt, Peter; Biedermann, Grant; Blain, Matthew G.; Stick, Daniel L.; Serkland, Darwin K.; Olsson, III, Roy H.

    2010-12-28

    A microfabricated ion frequency standard (i.e. an ion clock) is disclosed with a permanently-sealed vacuum package containing a source of ytterbium (Yb) ions and an octupole ion trap. The source of Yb ions is a micro-hotplate which generates Yb atoms which are then ionized by a ultraviolet light-emitting diode or a field-emission electron source. The octupole ion trap, which confines the Yb ions, is formed from suspended electrodes on a number of stacked-up substrates. A microwave source excites a ground-state transition frequency of the Yb ions, with a frequency-doubled vertical-external-cavity laser (VECSEL) then exciting the Yb ions up to an excited state to produce fluorescent light which is used to tune the microwave source to the ground-state transition frequency, with the microwave source providing a precise frequency output for the ion clock.

  5. Silicon microfabricated beam expander

    SciTech Connect

    Othman, A. Ibrahim, M. N.; Hamzah, I. H.; Sulaiman, A. A.; Ain, M. F.

    2015-03-30

    The feasibility design and development methods of silicon microfabricated beam expander are described. Silicon bulk micromachining fabrication technology is used in producing features of the structure. A high-precision complex 3-D shape of the expander can be formed by exploiting the predictable anisotropic wet etching characteristics of single-crystal silicon in aqueous Potassium-Hydroxide (KOH) solution. The beam-expander consist of two elements, a micromachined silicon reflector chamber and micro-Fresnel zone plate. The micro-Fresnel element is patterned using lithographic methods. The reflector chamber element has a depth of 40 µm, a diameter of 15 mm and gold-coated surfaces. The impact on the depth, diameter of the chamber and absorption for improved performance are discussed.

  6. Microfabricated therapeutic actuators

    SciTech Connect

    Lee, Abraham P.; Northrup, M. Allen; Ciarlo, Dino R.; Krulevitch, Peter A.; Benett, William J.

    1999-01-01

    Microfabricated therapeutic actuators are fabricated using a shape memory polymer (SMP), a polyurethane-based material that undergoes a phase transformation at a specified temperature (Tg). At a temperature above temperature Tg material is soft and can be easily reshaped into another configuration. As the temperature is lowered below temperature Tg the new shape is fixed and locked in as long as the material stays below temperature Tg. Upon reheating the material to a temperature above Tg, the material will return to its original shape. By the use of such SMP material, SMP microtubing can be used as a release actuator for the delivery of embolic coils through catheters into aneurysms, for example. The microtubing can be manufactured in various sizes and the phase change temperature Tg is determinate for an intended temperature target and intended use.

  7. Microfabricated therapeutic actuators

    DOEpatents

    Lee, A.P.; Northrup, M.A.; Ciarlo, D.R.; Krulevitch, P.A.; Benett, W.J.

    1999-06-15

    Microfabricated therapeutic actuators are fabricated using a shape memory polymer (SMP), a polyurethane-based material that undergoes a phase transformation at a specified temperature (Tg). At a temperature above temperature Tg material is soft and can be easily reshaped into another configuration. As the temperature is lowered below temperature Tg the new shape is fixed and locked in as long as the material stays below temperature Tg. Upon reheating the material to a temperature above Tg, the material will return to its original shape. By the use of such SMP material, SMP microtubing can be used as a release actuator for the delivery of embolic coils through catheters into aneurysms, for example. The microtubing can be manufactured in various sizes and the phase change temperature Tg is determinate for an intended temperature target and intended use. 8 figs.

  8. Silicon microfabricated beam expander

    NASA Astrophysics Data System (ADS)

    Othman, A.; Ibrahim, M. N.; Hamzah, I. H.; Sulaiman, A. A.; Ain, M. F.

    2015-03-01

    The feasibility design and development methods of silicon microfabricated beam expander are described. Silicon bulk micromachining fabrication technology is used in producing features of the structure. A high-precision complex 3-D shape of the expander can be formed by exploiting the predictable anisotropic wet etching characteristics of single-crystal silicon in aqueous Potassium-Hydroxide (KOH) solution. The beam-expander consist of two elements, a micromachined silicon reflector chamber and micro-Fresnel zone plate. The micro-Fresnel element is patterned using lithographic methods. The reflector chamber element has a depth of 40 µm, a diameter of 15 mm and gold-coated surfaces. The impact on the depth, diameter of the chamber and absorption for improved performance are discussed.

  9. Microfabricated triggered vacuum switch

    DOEpatents

    Roesler, Alexander W.; Schare, Joshua M.; Bunch, Kyle

    2010-05-11

    A microfabricated vacuum switch is disclosed which includes a substrate upon which an anode, cathode and trigger electrode are located. A cover is sealed over the substrate under vacuum to complete the vacuum switch. In some embodiments of the present invention, a metal cover can be used in place of the trigger electrode on the substrate. Materials used for the vacuum switch are compatible with high vacuum, relatively high temperature processing. These materials include molybdenum, niobium, copper, tungsten, aluminum and alloys thereof for the anode and cathode. Carbon in the form of graphitic carbon, a diamond-like material, or carbon nanotubes can be used in the trigger electrode. Channels can be optionally formed in the substrate to mitigate against surface breakdown.

  10. Microfabricated High-Moment Micrometer-sized MRI Contrast Agents

    PubMed Central

    Zabow, Gary; Dodd, Stephen J.; Shapiro, Erik; Moreland, John; Koretsky, Alan P.

    2010-01-01

    While chemically synthesized superparamagnetic microparticles have enabled much new research based on MRI-tracking of magnetically labeled cells, signal-to-noise levels still limit the potential range of applications. Here it is shown how, through top-down microfabrication, contrast agent relaxivity can be increased several-fold, which should extend the sensitivity of such cell tracking studies. Microfabricated agents can benefit from both higher magnetic moments and higher uniformity than their chemically synthesized counterparts, implying increased label visibility and more quantitative image analyses. To assess the performance of microfabricated micrometer-sized contrast agent particles, analytic models and numerical simulations are developed and tested against new microfabricated agents described in this paper, as well as against results of previous imaging studies of traditional chemically synthesized microparticle agents. Experimental data showing signal effects of 500-nanometer thick, 2-micrometer diameter, gold-coated iron and gold-coated nickel disks verify the simulations. Additionally, it is suggested that measures of location better than the pixel resolution can be obtained and that these are aided using well-defined contrast agent particles achievable through microfabrication techniques. PMID:20928829

  11. Implantation of microfabricated immunoisolating biocapsules

    NASA Astrophysics Data System (ADS)

    Desai, Tejal A.; Chu, Wen Hwa; Ferrari, Mauro; Rasi, Guido; Sinibaldi-Vallebona, Paola; Borboni, Patrizia; Beattie, G.; Hayek, A.

    1998-03-01

    Silicon-based biocapsules have been microfabricated with uniform and well-controlled pore dimensions in the tens of nanometer range to provide effective immunoisolation of cell xenografts. Surface and bulk micromachining were integrated in the fabrication process, resulting in a diffusion membrane with mechanical and chemical stability, surrounded by an anisotropically-etched silicon wafer, which serves as the encapsulation cavity. The membrane allows the diffusion of essential nutrients while blocking the passage of immune molecules, which may destroy cellular transplants. Preliminary short term studies on both primary pancreatic islets and insulinoma cell lines encapsulated within microfabricated biocapsules were conducted to determine the toxicity and biocompatibility of biocapsules, the viability and functionality of encapsulated cells, as well as the overall immunoprotective capabilities of the biocapsule. Results seem to indicate that microfabricated biocapsules are non-toxic and do not elicit any adverse inflammatory reactions when implanted. Furthermore, encapsulated insulinoma cells remained viable and functional within microfabricated environments in vivo. These results show the feasibility and potential application of microfabricated biocapsules for several pathologies.

  12. Microfabricated Genomic Analysis System

    NASA Technical Reports Server (NTRS)

    Gonda, Steve; Elms, Rene

    2005-01-01

    Genetic sequencing and many genetic tests and assays require electrophoretic separation of DNA. In this technique, DNA fragments are separated by size as they migrate through a sieving gel under the influence of an applied electric field. In order to conduct these analyses on-orbit, it is essential to acquire the capability to efficiently perform electrophoresis in a microgravity environment. Conventional bench top electrophoresis equipment is large and cumbersome and does not lead itself to on-orbit utilization. Much of the previous research regarding on-orbit electrophoresis involved altering conventional electrophoresis equipment for bioprocessing, purification, and/or separation technology applications. A new and more efficient approach to on-orbit electrophoresis is the use of a microfabricated electrophoresis platform. These platforms are much smaller, less expensive to produce and operate, use less power, require smaller sample sizes (nanoliters), and achieve separation in a much shorter distance (a few centimeters instead of 10 s or 100 s of centimeters.) In contrast to previous applications, this platform would be utilized as an analytical tool for life science/medical research, environmental monitoring, and medical diagnoses. Identification of infectious agents as well as radiation related damage are significant to NASA s efforts to maintain, study, and monitor crew health during and in support of near-Earth and interplanetary missions. The capability to perform genetic assays on-orbit is imperative to conduct relevant and insightful biological and medical research, as well as continuing NASA s search for life elsewhere. This technology would provide an essential analytical tool for research conducted in a microgravity environment (Shuttle, ISS, long duration/interplanetary missions.) In addition, this technology could serve as a critical and invaluable component of a biosentinel system to monitor space environment genotoxic insults to include radiation.

  13. Microfabrication using soft lithography

    NASA Astrophysics Data System (ADS)

    Zhao, Xiao-Mei

    Soft Lithography is a group of non-photolithographic techniques currently being explored in our group. Four such techniques-microcontact printing (μCP), replica molding (REM), micromolding in capillaries (MIMIC), and microtransfer molding (μTM)-have been demonstrated for fabricating micro- and nanostructures of a variety of materials with dimension >=30 nm. Part I (Chapters 1-5) reviews several aspects of the three molding techniques REM, MIMIC, and μTM. Chapters 1-3 describe μTM and MIMIC, and the use of these techniques in the fabrication of functional devices. μTM is capable of generating μm-scale structures over large areas, on both planar and contoured surfaces, and is able to make 3-dimensional structures layer by layer. The capability of μTM and MIMIC has been demonstrated in the fabrication of single-mode waveguides, waveguide couplers and interferometers. The coupling between waveguides can be tailored by waveguide spacing or the differential in curing time between the waveguides and the cladding. Chapters 4-5 demonstrate the combination of REM and shrinkable polystyrene (PS) films to reduce the feature size of microstructures and to generate microstructures with high aspect ratios on both planar and curved surfaces. A shrinkable PS film is patterned with relief structures, and then heated and shrinks. Thermal shrinkage results in a 100-fold increase in the aspect ratio of the patterned microstructures in the PS film. The microstructures in the shrunken PS films can be transferred to many other materials by REM. Part II (Chapters 6-7) focuses on two issues in the microfabrication using self-assembled monolayers (SAMs) as ultrathin resists. Chapter 6 describes a selective etching solution for transferring patterns of SAMs of alkanethiolates into the underlying layers (e.g., gold, silver, and copper). This etching solution uses thiosulfate as the ligand that coordinates to the metal ions, and ferricyanide as the oxidant. It has been demonstrated to be

  14. Microfabricated Optically-Pumped Magnetometers for Biomagnetic Applications

    NASA Astrophysics Data System (ADS)

    Knappe, Svenja; Alem, Orang; Sheng, Dong; Kitching, John

    2016-06-01

    We report on the progress in developing microfabricated optically-pumped magnetometer arrays for imaging applications. We have improved our sensitivities by several orders of magnitude in the last ten years. Now, our zero-field magnetometers reach noise values below 15 fT/Hz1/2. Recently, we have also developed gradiometers to reject ambient magnetic field noise. We have built several imaging arrays and validated them for biomedical measurements of brain and heart activity.

  15. Infrared microthermography of microfabricated devices

    NASA Astrophysics Data System (ADS)

    Furstenberg, Robert; Kendziora, C. A.; Stepnowski, Stanley V.; McGill, R. Andrew

    2007-06-01

    We report a new experimental apparatus for infrared microthermography applicable to a wide class of samples including semitransparent ones and perforated devices. This setup is particularly well suited for the thermography of microfabricated devices. Traditionally, temperature calibration is performed using calibration hot plates, but this is not applicable to transmissive samples. In this work a custom designed miniature calibration oven in conjunction with spatial filtering is used to obtain accurate static and transient temperature maps of actively heated devices. The procedure does not require prior knowledge of the emissivity. Calibration and image processing algorithms are discussed and analyzed. We show that relatively inexpensive uncooled bolometer arrays can be a suitable detector choice in certain radiometric applications. As an example, we apply this method in the analysis of temperature profiles of an actively heated microfabricated preconcentrator device that incorporates a perforated membrane and is used in trace detection of illicit substances.

  16. Infrared microthermography of microfabricated devices

    SciTech Connect

    Furstenberg, Robert; Kendziora, C. A.; Stepnowski, Stanley V.; McGill, R. Andrew

    2007-06-15

    We report a new experimental apparatus for infrared microthermography applicable to a wide class of samples including semitransparent ones and perforated devices. This setup is particularly well suited for the thermography of microfabricated devices. Traditionally, temperature calibration is performed using calibration hot plates, but this is not applicable to transmissive samples. In this work a custom designed miniature calibration oven in conjunction with spatial filtering is used to obtain accurate static and transient temperature maps of actively heated devices. The procedure does not require prior knowledge of the emissivity. Calibration and image processing algorithms are discussed and analyzed. We show that relatively inexpensive uncooled bolometer arrays can be a suitable detector choice in certain radiometric applications. As an example, we apply this method in the analysis of temperature profiles of an actively heated microfabricated preconcentrator device that incorporates a perforated membrane and is used in trace detection of illicit substances.

  17. Microfabricated injectable drug delivery system

    DOEpatents

    Krulevitch, Peter A.; Wang, Amy W.

    2002-01-01

    A microfabricated, fully integrated drug delivery system capable of secreting controlled dosages of multiple drugs over long periods of time (up to a year). The device includes a long and narrow shaped implant with a sharp leading edge for implantation under the skin of a human in a manner analogous to a sliver. The implant includes: 1) one or more micromachined, integrated, zero power, high and constant pressure generating osmotic engine; 2) low power addressable one-shot shape memory polymer (SMP) valves for switching on the osmotic engine, and for opening drug outlet ports; 3) microfabricated polymer pistons for isolating the pressure source from drug-filled microchannels; 4) multiple drug/multiple dosage capacity, and 5) anisotropically-etched, atomically-sharp silicon leading edge for penetrating the skin during implantation. The device includes an externally mounted controller for controlling on-board electronics which activates the SMP microvalves, etc. of the implant.

  18. Infrared microthermography of microfabricated devices.

    PubMed

    Furstenberg, Robert; Kendziora, C A; Stepnowski, Stanley V; McGill, R Andrew

    2007-06-01

    We report a new experimental apparatus for infrared microthermography applicable to a wide class of samples including semitransparent ones and perforated devices. This setup is particularly well suited for the thermography of microfabricated devices. Traditionally, temperature calibration is performed using calibration hot plates, but this is not applicable to transmissive samples. In this work a custom designed miniature calibration oven in conjunction with spatial filtering is used to obtain accurate static and transient temperature maps of actively heated devices. The procedure does not require prior knowledge of the emissivity. Calibration and image processing algorithms are discussed and analyzed. We show that relatively inexpensive uncooled bolometer arrays can be a suitable detector choice in certain radiometric applications. As an example, we apply this method in the analysis of temperature profiles of an actively heated microfabricated preconcentrator device that incorporates a perforated membrane and is used in trace detection of illicit substances. PMID:17614631

  19. Temperature programmable microfabricated gas chromatography column

    DOEpatents

    Manginell, Ronald P.; Frye-Mason, Gregory C.

    2003-12-23

    A temperature programmable microfabricated gas chromatography column enables more efficient chemical separation of chemical analytes in a gas mixture by the integration of a resistive heating element and temperature sensing on the microfabricated column. Additionally, means are provided to thermally isolate the heated column from their surroundings. The small heat capacity and thermal isolation of the microfabricated column improves the thermal time response and power consumption, both important factors for portable microanalytical systems.

  20. Microfabricated fuel heating value monitoring device

    DOEpatents

    Robinson, Alex L.; Manginell, Ronald P.; Moorman, Matthew W.

    2010-05-04

    A microfabricated fuel heating value monitoring device comprises a microfabricated gas chromatography column in combination with a catalytic microcalorimeter. The microcalorimeter can comprise a reference thermal conductivity sensor to provide diagnostics and surety. Using microfabrication techniques, the device can be manufactured in production quantities at a low per-unit cost. The microfabricated fuel heating value monitoring device enables continuous calorimetric determination of the heating value of natural gas with a 1 minute analysis time and 1.5 minute cycle time using air as a carrier gas. This device has applications in remote natural gas mining stations, pipeline switching and metering stations, turbine generators, and other industrial user sites. For gas pipelines, the device can improve gas quality during transfer and blending, and provide accurate financial accounting. For industrial end users, the device can provide continuous feedback of physical gas properties to improve combustion efficiency during use.

  1. DNA electrophoresis in microfabricated devices

    NASA Astrophysics Data System (ADS)

    Dorfman, Kevin D.

    2010-10-01

    Picking up at the conclusion of Viovy’s review of the physics of gel electrophoresis [J.-L. Viovy, Rev. Mod. Phys. 72, 813 (2000)10.1103/RevModPhys.72.813], this review synthesizes the experimental data, theoretical models, and simulation results for DNA electrophoresis in microfabricated and nanofabricated devices appearing since the seminal paper by Volkmuth and Austin [Nature (London) 358, 600 (1992)10.1038/358600a0]. Prototype versions of these devices separate DNA by molecular weight at a rate far superior to gel electrophoresis. After providing an overview of the requisite background material in polymer physics, electrophoresis, and microfluidic device fabrication, the focus is on the following three generic problems: (i) collision with an isolated post, (ii) transport in an array of posts, and (iii) entropic trapping and filtration in the slit-well motif. The transport phenomena are examined here in the context of the length and time scales characterizing the DNA, the device, and the applied electric field.

  2. Microfabrication techniques for semiconductor lasers

    NASA Astrophysics Data System (ADS)

    Tamanuki, Takemasa; Tadokoro, T.; Morito, Ken; Koyama, Fumio; Iga, Kenichi

    1991-03-01

    Several important techniques for fabricating micro-cavity semiconductor lasers including surface emitting lasers have been developed. Reactive ion beam etch (RIBE) for GaA1As and GaInAsP is employed and its condition for vertical fine etch under low damages and removal of residual damages are made clear. Passivation by sulfur is introduced to the fabrication process. Regrowth techniques for DII structures by LPE and MOCVD has been established. Some device applications are discussed. 1. MICRO-ETCHING PROCESS Micro-cavity lasers including a vertical cavity surface emitting laser1 are attracting the research interest for optical parallel processing and parallel light wave systems. In order to realize micron-order or sub-micron laserdevices the technology of micro-fabrication must be established. In this study the total fabrication technology has been almost completed. First fine and low damage etching condition by ultrahigh vacuum background RIBE using a Cl2 gas has been made clear. We have found an isotropic etching condition for the vertical side wall formation and good mask traceability i. e. the acceleration voltage is 500 V and substrate temperature is 150 C with a 5000A thickness Si02 mask. Residual damages induced on the surface and the side wall are characterized by photo-luminescence and making stripe lasers. Figure 1 is the histogram of the nominal threshold current density for (a) oxide-defined stripe lasers (b) RIBE etched and LPE regrown BH-lasers using an LPE grown DII wafer (LPE/LPE) and (c) RIBE etched

  3. Microfabricated environments to study collective cell behaviors.

    PubMed

    Vedula, Sri Ram Krishna; Ravasio, Andrea; Anon, Ester; Chen, Tianchi; Peyret, Grégoire; Ashraf, Mohammed; Ladoux, Benoit

    2014-01-01

    Coordinated cell movements in epithelial layers are essential for proper tissue morphogenesis and homeostasis. Microfabrication techniques have proven to be very useful for studies of collective cell migration in vitro. In this chapter, we briefly review the use of microfabricated substrates in providing new insights into collective cell behaviors. We first describe the development of micropatterned substrates to study the influence of geometrical constraints on cell migration and coordinated movements. Then, we present an alternative method based on microfabricated pillar substrates to create well-defined gaps within cell sheets and study gap closure. We also provide a discussion that presents possible pitfalls and sheds light onto the important parameters that allow the study of long-term cell culture on substrates of well-defined geometries. PMID:24484669

  4. Processing Nanostructured Sensors Using Microfabrication Techniques

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.; VanderWal, Randall L.; Evans, Laura J.; Xu, Jennifer C.

    2010-01-01

    Standard microfabrication techniques can be implemented and scaled to help assemble nanoscale microsensors. Currently nanostructures are often deposited onto materials primarily by adding them to a solution, then applying the solution in a thin film. This results in random placement of the nanostructures with no controlled order, and no way to accurately reproduce the placement. This method changes the means by which microsensors with nanostructures are fabricated. The fundamental advantage to this approach is that it enables standard microfabrication techniques to be applied in the repeated manufacture of nanostructured sensors on a microplatform.

  5. Micro-fabrication Techniques for Target Components

    SciTech Connect

    Miles, R; Hamilton, J; Crawford, J; Ratti, S; Trevino, J; Graff, T; Stockton, C; Harvey, C

    2008-06-10

    Micro-fabrication techniques, derived from the semi-conductor industry, can be used to make a variety of useful mechanical components for targets. A selection of these components including supporting cooling arms for prototype cryogenic inertial confinement fusion targets, stepped and graded density targets for materials dynamics experiments are described. Micro-fabrication enables cost-effective, simultaneous fabrication of multiple high-precision components with complex geometries. Micro-fabrication techniques such as thin-film deposition, photo-lithographic patterning and etch processes normally used in the semi-conductor manufacture industry, can be exploited to make useful mechanical target components. Micro-fabrication processes have in recent years been used to create a number of micro-electro-mechanical systems (MEMS) components such as pressure sensors, accelerometers, ink jet printer heads, microfluidics platforms and the like. These techniques consist primarily of deposition of thin films of material, photo-lithographic patterning and etching processes performed sequentially to produce three dimensional structures using essentially planar processes. While the planar technology can be limiting in terms of the possible geometries of the final product, advantages of using these techniques include the ability to make multiple complex structures simultaneously and cost-effectively. Target components fabricated using these techniques include the supporting cooling arms for cryogenic prototype fusion ignition targets, stepped targets for equation-of-state experiments, and graded density reservoirs for material strength experiments.

  6. Microfabricated pressure and shear stress sensors

    NASA Technical Reports Server (NTRS)

    Liu, Chang (Inventor); Chen, Jack (Inventor); Engel, Jonathan (Inventor)

    2009-01-01

    A microfabricated pressure sensor. The pressure sensor comprises a raised diaphragm disposed on a substrate. The diaphragm is configured to bend in response to an applied pressure difference. A strain gauge of a conductive material is coupled to a surface of the raised diaphragm and to at least one of the substrate and a piece rigidly connected to the substrate.

  7. Microfabricated field calibration assembly for analytical instruments

    DOEpatents

    Robinson, Alex L.; Manginell, Ronald P.; Moorman, Matthew W.; Rodacy, Philip J.; Simonson, Robert J.

    2011-03-29

    A microfabricated field calibration assembly for use in calibrating analytical instruments and sensor systems. The assembly comprises a circuit board comprising one or more resistively heatable microbridge elements, an interface device that enables addressable heating of the microbridge elements, and, in some embodiments, a means for positioning the circuit board within an inlet structure of an analytical instrument or sensor system.

  8. Processing of Nanostructured Devices Using Microfabrication Techniques

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W (Inventor); Xu, Jennifer C (Inventor); Evans, Laura J (Inventor); Kulis, Michael H (Inventor); Berger, Gordon M (Inventor); Vander Wal, Randall L (Inventor)

    2014-01-01

    Systems and methods that incorporate nanostructures into microdevices are discussed herein. These systems and methods can allow for standard microfabrication techniques to be extended to the field of nanotechnology. Sensors incorporating nanostructures can be fabricated as described herein, and can be used to reliably detect a range of gases with high response.

  9. Microfabrication Technologies for Oral Drug Delivery

    PubMed Central

    Sant, Shilpa; Tao, Sarah L.; Fisher, Omar; Xu, Qiaobing; Peppas, Nicholas A.; Khademhosseini, Ali

    2012-01-01

    Micro-/nanoscale technologies such as lithographic techniques and microfluidics offer promising avenues to revolutionalize the fields of tissue engineering, drug discovery, diagnostics and personalized medicine. Microfabrication techniques are being explored for drug delivery applications due to their ability to combine several features such as precise shape and size into a single drug delivery vehicle. They also offer to create unique asymmetrical features incorporated into single or multiple reservoir systems maximizing contact area with the intestinal lining. Combined with intelligent materials, such microfabricated platforms can be designed to be bioadhesive and stimuli-responsive. Apart from drug delivery devices, microfabrication technologies offer exciting opportunities to create biomimetic gastrointestinal tract models incorporating physiological cell types, flow patterns and brush-border like structures. Here we review the recent developments in this field with a focus on the applications of microfabrication in the development of oral drug delivery devices and biomimetic gastrointestinal tract models that can be used to evaluate the drug delivery efficacy. PMID:22166590

  10. Microfabricated mirrors for space applications

    NASA Astrophysics Data System (ADS)

    Bayat, Dara; Ataman, Caglar; Guldimann, Benedikt; Lani, Sébastien; Noell, Wilfried; de Rooij, Nico

    2011-03-01

    We report on the advances towards the design and fabrication of a system consisting of two 10mm mirrors, one actuated magnetically and the other electrostatically. The system will be used for beam steering. The maximum resonant frequencies and deflection angle of each of the actuators will be reviewed and compared.

  11. Optical pumping in a microfabricated Rb vapor cell using a microfabricated Rb discharge light source

    SciTech Connect

    Venkatraman, V.; Kang, S.; Affolderbach, C.; Mileti, G.; Shea, H.

    2014-02-03

    Miniature (microfabricated alkali vapor resonance cell using (1) a microfabricated Rb discharge lamp light source, as well as (2) a conventional glass-blown Rb discharge lamp. The microfabricated Rb lamp cell is a dielectric barrier discharge (DBD) light source, having the same inner cell volume of around 40 mm{sup 3} as that of the resonance cell, both filled with suitable buffer gases. A miniature (∼2 cm{sup 3} volume) test setup based on the M{sub z} magnetometer interrogation technique was used for observation of optical-radiofrequency double-resonance signals, proving the suitability of the microfabricated discharge lamp to introduce efficient optical pumping. The pumping ability of this light source was found to be comparable to or even better than that of a conventional glass-blown lamp. The reported results indicate that the micro-fabricated DBD discharge lamp has a high potential for the development of a new class of miniature atomic clocks, magnetometers, and quantum sensors.

  12. Microfabricated bulk wave acoustic bandgap device

    DOEpatents

    Olsson, Roy H.; El-Kady, Ihab F.; McCormick, Frederick; Fleming, James G.; Fleming, Carol

    2010-06-08

    A microfabricated bulk wave acoustic bandgap device comprises a periodic two-dimensional array of scatterers embedded within the matrix material membrane, wherein the scatterer material has a density and/or elastic constant that is different than the matrix material and wherein the periodicity of the array causes destructive interference of the acoustic wave within an acoustic bandgap. The membrane can be suspended above a substrate by an air or vacuum gap to provide acoustic isolation from the substrate. The device can be fabricated using microelectromechanical systems (MEMS) technologies. Such microfabricated bulk wave phononic bandgap devices are useful for acoustic isolation in the ultrasonic, VHF, or UHF regime (i.e., frequencies of order 1 MHz to 10 GHz and higher, and lattice constants of order 100 .mu.m or less).

  13. Microfabricated bulk wave acoustic bandgap device

    DOEpatents

    Olsson, Roy H.; El-Kady, Ihab F.; McCormick, Frederick; Fleming, James G.; Fleming, legal representative, Carol

    2010-11-23

    A microfabricated bulk wave acoustic bandgap device comprises a periodic two-dimensional array of scatterers embedded within the matrix material membrane, wherein the scatterer material has a density and/or elastic constant that is different than the matrix material and wherein the periodicity of the array causes destructive interference of the acoustic wave within an acoustic bandgap. The membrane can be suspended above a substrate by an air or vacuum gap to provide acoustic isolation from the substrate. The device can be fabricated using microelectromechanical systems (MEMS) technologies. Such microfabricated bulk wave phononic bandgap devices are useful for acoustic isolation in the ultrasonic, VHF, or UHF regime (i.e., frequencies of order 1 MHz to 10 GHz and higher, and lattice constants of order 100 .mu.m or less).

  14. Trapping of branched DNA in microfabricated structures.

    PubMed Central

    Volkmuth, W D; Duke, T; Austin, R H; Cox, E C

    1995-01-01

    We have observed electrostatic trapping of tribranched DNA molecules undergoing electrophoresis in a microfabricated pseudo-two-dimensional array of posts. Trapping occurs in a unique transport regimen in which the electrophoretic mobility is extremely sensitive to polymer topology. The arrest of branched polymers is explained by considering their center-of-mass motion; in certain conformations, owing to the constraints imposed by the obstacles a molecule cannot advance without the center of mass first moving a short distance backwards. The depth of the resulting local potential well can be much greater than the thermal energy so that escape of an immobilized molecule can be extremely slow. We summarize the expected behavior of the mobility as a function of field strength and topology and point out that the microfabricated arrays are highly suitable for detecting an extremely small number of branched molecules in a very large population of linear molecules. Images Fig. 2 PMID:7624337

  15. Enabling Systems Biology Approaches Through Microfabricated Systems

    PubMed Central

    Zhan, Mei; Chingozha, Loice; Lu, Hang

    2014-01-01

    With the experimental tools and knowledge that have accrued from a long history of reductionist biology, we can now start to put the pieces together and begin to understand how biological systems function as an integrated whole. Here, we describe how microfabricated tools have demonstrated promise in addressing experimental challenges in throughput, resolution and sensitivity to support systems-based approaches to biological understanding. PMID:23984862

  16. Optical properties of fluids in microfabricated channels

    SciTech Connect

    French, T.; Gourley, P.L.; McDonald, A.E.

    1997-03-01

    Microfabricated channels are widely thought to be the key to realizing chemical analysis on a microscopic scale. Chemical and biological information in the microchannels is often probed with optical techniques such as fluorescence, Raman and absorption spectroscopy. However, the optical effects of a microchannel are not well characterized. For example, it is important to understand the optics of the channel in order to optimize optical coupling efficiency. The authors consider various designs for enhancing the sensitivity of fluorescence detection in a microchannel.

  17. Evaluation of microfabricated deformable mirror systems

    NASA Astrophysics Data System (ADS)

    Cowan, William D.; Lee, Max K.; Bright, Victor M.; Welsh, Byron M.

    1998-09-01

    This paper presents recent result for aberration correction and beam steering experiments using polysilicon surface micromachined piston micromirror arrays. Microfabricated deformable mirrors offer a substantial cost reduction for adaptive optic systems. In addition to the reduced mirror cost, microfabricated mirrors typically require low control voltages, thus eliminating high voltage amplifiers. The greatly reduced cost per channel of adaptive optic systems employing microfabricated deformable mirrors promise high order aberration correction at low cost. Arrays of piston micromirrors with 128 active elements were tested. Mirror elements are on a 203 micrometers 12 by 12 square grid. The overall array size is 2.4 mm square. The arrays were fabricated in the commercially available DARPA supported MUMPs surface micromachining foundry process. The cost per mirror array in this prototyping process is less than 200 dollars. Experimental results are presented for a hybrid correcting element comprised of a lenslet array and piston micromirror array, and for a piston micromirror array only. Also presented is a novel digital deflection micromirror which requires no digital to analog converters, further reducing the cost of adaptive optics system.

  18. Integration of micro-fabricated atomic magnetometers on military systems

    NASA Astrophysics Data System (ADS)

    Schultz, Gregory; Mhaskar, Rahul; Prouty, Mark; Miller, Jonathan

    2016-05-01

    A new generation of ultra-high sensitivity magnetic sensors based on innovative micro-electromechanical systems (MEMS) are being developed and incorporated into military systems. Specifically, we are currently working to fully integrate the latest generation of MicroFabricated Atomic Magnetometers (MFAMs) developed by Geometrics on defense mobility systems such as unmanned systems, military vehicles and handheld units. Recent reductions in size, weight, and power of these sensors has enabled new deployment opportunities for improved sensitivity to targets of interest, but has also introduced new challenges associated with noise mitigation, mission configuration planning, and data processing. Our work is focused on overcoming the practical aspects of integrating these sensors with various military platforms. Implications associated with utilizing these combined sensor systems in working environments are addressed in order to optimize signal-to-noise ratios, detection probabilities, and false alarm mitigation. Specifically, we present collaborative work that bridges the gap between commercial specialists and operation platform integration organizations including magnetic signature characterization and mitigation as well as the development of simulation tools that consider a wide array of sensor, environmental, platform, and mission-level parameters. We discuss unique deployment concepts for explosive hazard target geolocation, and data processing. Applications include configurations for undersea and underground threat detection - particularly those associated with stationary or mobile explosives and compact metallic targets such as munitions, subsea threats, and other hazardous objects. We show the potential of current and future features of miniaturized magnetic sensors including very high magnetic field sensitivities, bandwidth selectivity, and array processing.

  19. Microfabrication of hybrid fluid membrane for microengines

    NASA Astrophysics Data System (ADS)

    Chutani, R.; Formosa, F.; de Labachelerie, M.; Badel, A.; Lanzetta, F.

    2015-12-01

    This paper describes the microfabrication and dynamic characterization of thick membranes providing a technological solution for microengines. The studied membranes are called hybrid fluid-membrane (HFM) and consist of two thin membranes that encapsulate an incompressible fluid. This work details the microelectromechanical system (MEMS) scalable fabrication and characterization of HFMs. The membranes are composite structures based on Silicon spiral springs embedded in a polymer (RTV silicone). The anodic bonding of multiple stacks of Si/glass structures, the fluid filling and the sealing have been demonstrated. Various HFMs were successfully fabricated and their dynamic characterization demonstrates the agreement between experimental and theoretical results.

  20. Microfabricated electromagnetic filters for millikelvin experiments

    NASA Astrophysics Data System (ADS)

    le Sueur, Hélène; Joyez, Philippe

    2006-11-01

    In this article we report on the design, fabrication, and tests of microfabricated broadband filters suitable for proper electromagnetic thermalization of electrical lines connected to sensitive quantum electronics experiments performed at dilution fridge temperatures. Compared to previous such miniature filters, the new design improves on performance and reliability. These filters can be packed in space-saving cases with either single or multicontact connector. Measured performance in the accessible range compares well to simulations. We use these simulations to discuss the effectiveness of these filters for electromagnetic thermalization at 30mK.

  1. Microfabricated linear Paul-Straubel ion trap

    DOEpatents

    Mangan, Michael A.; Blain, Matthew G.; Tigges, Chris P.; Linker, Kevin L.

    2011-04-19

    An array of microfabricated linear Paul-Straubel ion traps can be used for mass spectrometric applications. Each ion trap comprises two parallel inner RF electrodes and two parallel outer DC control electrodes symmetric about a central trap axis and suspended over an opening in a substrate. Neighboring ion traps in the array can share a common outer DC control electrode. The ions confined transversely by an RF quadrupole electric field potential well on the ion trap axis. The array can trap a wide array of ions.

  2. Trends in Microfabrication Capabilities & Device Architectures.

    SciTech Connect

    Bauer, Todd; Jones, Adam; Lentine, Anthony L.; Mudrick, John; Okandan, Murat; Rodrigues, Arun F.

    2015-06-01

    The last two decades have seen an explosion in worldwide R&D, enabling fundamentally new capabilities while at the same time changing the international technology landscape. The advent of technologies for continued miniaturization and electronics feature size reduction, and for architectural innovations, will have many technical, economic, and national security implications. It is important to anticipate possible microelectronics development directions and their implications on US national interests. This report forecasts and assesses trends and directions for several potentially disruptive microfabrication capabilities and device architectures that may emerge in the next 5-10 years.

  3. Microfabricated microengine with constant rotation rate

    DOEpatents

    Romero, Louis A.; Dickey, Fred M.

    1999-01-01

    A microengine uses two synchronized linear actuators as a power source and converts oscillatory motion from the actuators into constant rotational motion via direct linkage connection to an output gear or wheel. The microengine provides output in the form of a continuously rotating output gear that is capable of delivering drive torque at a constant rotation to a micromechanism. The output gear can have gear teeth on its outer perimeter for directly contacting a micromechanism requiring mechanical power. The gear is retained by a retaining means which allows said gear to rotate freely. The microengine is microfabricated of polysilicon on one wafer using surface micromachining batch fabrication.

  4. Overtaking method based on sand-sifter mechanism: Why do optimistic value functions find optimal solutions in multi-armed bandit problems?

    PubMed

    Ochi, Kento; Kamiura, Moto

    2015-09-01

    A multi-armed bandit problem is a search problem on which a learning agent must select the optimal arm among multiple slot machines generating random rewards. UCB algorithm is one of the most popular methods to solve multi-armed bandit problems. It achieves logarithmic regret performance by coordinating balance between exploration and exploitation. Since UCB algorithms, researchers have empirically known that optimistic value functions exhibit good performance in multi-armed bandit problems. The terms optimistic or optimism might suggest that the value function is sufficiently larger than the sample mean of rewards. The first definition of UCB algorithm is focused on the optimization of regret, and it is not directly based on the optimism of a value function. We need to think the reason why the optimism derives good performance in multi-armed bandit problems. In the present article, we propose a new method, which is called Overtaking method, to solve multi-armed bandit problems. The value function of the proposed method is defined as an upper bound of a confidence interval with respect to an estimator of expected value of reward: the value function asymptotically approaches to the expected value of reward from the upper bound. If the value function is larger than the expected value under the asymptote, then the learning agent is almost sure to be able to obtain the optimal arm. This structure is called sand-sifter mechanism, which has no regrowth of value function of suboptimal arms. It means that the learning agent can play only the current best arm in each time step. Consequently the proposed method achieves high accuracy rate and low regret and some value functions of it can outperform UCB algorithms. This study suggests the advantage of optimism of agents in uncertain environment by one of the simplest frameworks. PMID:26166266

  5. Microfabricated structures for integrated DNA analysis.

    PubMed Central

    Burns, M A; Mastrangelo, C H; Sammarco, T S; Man, F P; Webster, J R; Johnsons, B N; Foerster, B; Jones, D; Fields, Y; Kaiser, A R; Burke, D T

    1996-01-01

    Photolithographic micromachining of silicon is a candidate technology for the construction of high-throughput DNA analysis devices. However, the development of complex silicon microfabricated systems has been hindered in part by the lack of a simple, versatile pumping method for integrating individual components. Here we describe a surface-tension-based pump able to move discrete nanoliter drops through enclosed channels using only local heating. This thermocapillary pump can accurately mix, measure, and divide drops by simple electronic control. In addition, we have constructed thermal-cycling chambers, gel electrophoresis channels, and radiolabeled DNA detectors that are compatible with the fabrication of thermocapillary pump channels. Since all of the components are made by conventional photolithographic techniques, they can be assembled into more complex integrated systems. The combination of pump and components into self-contained miniaturized devices may provide significant improvements in DNA analysis speed, portability, and cost. The potential of microfabricated systems lies in the low unit cost of silicon-based construction and in the efficient sample handling afforded by component integration. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:8643614

  6. Microfabrication and Nanotechnology in Stent Design

    PubMed Central

    Martinez, Adam W.; Chaikof, Elliot L.

    2012-01-01

    Intravascular stents were first introduced in the 1980s as an adjunct to primary angioplasty for management of early complications, including arterial dissection, or treatment of an inadequate technical outcome due to early elastic recoil of the atherosclerotic lesion. Despite the beneficial effects of stenting, persistent high rates of restenosis motivated the design of drug eluting stents for delivery of agents to limit the proliferative and other inflammatory responses within the vascular wall that contribute to the development of a restenotic lesion. These strategies have yielded a significant reduction in the incidence of restenosis, but challenges remain, including incomplete repair of the endothelium at the site of vascular wall injury that may be associated with a late risk of thrombosis. A failure of vessel wall healing has been attributed to primarily to the use of polymeric stent coatings, but the effects of the eluted drug and other material properties or design features of the stent cannot be excluded. Improvements in stent microfabrication, as well as the introduction of alternative materials may help to address those limitations that inhibit stent performance. This review describes the application of novel microfabrication processes and the evolution of new nanotechnologies that hold significant promise in eliminating existing shortcomings of current stent platforms. PMID:21462356

  7. Microfabricated wire arrays for Z-pinch.

    SciTech Connect

    Spahn, Olga Blum; Rowen, Adam M.; Cich, Michael Joseph; Peake, Gregory Merwin; Arrington, Christian L.; Nash, Thomas J.; Klem, John Frederick; Romero, Dustin Heinz

    2008-10-01

    Microfabrication methods have been applied to the fabrication of wire arrays suitable for use in Z. Self-curling GaAs/AlGaAs supports were fabricated as an initial route to make small wire arrays (4mm diameter). A strain relief structure that could be integrated with the wire was designed to allow displacements of the anode/cathode connections in Z. Electroplated gold wire arrays with integrated anode/cathode bus connections were found to be sufficiently robust to allow direct handling. Platinum and copper plating processes were also investigated. A process to fabricate wire arrays on any substrate with wire thickness up to 35 microns was developed. Methods to handle and mount these arrays were developed. Fabrication of wire arrays of 20mm diameter was demonstrated, and the path to 40mm array fabrication is clear. With some final investment to show array mounting into Z hardware, the entire process to produce a microfabricated wire array will have been demonstrated.

  8. Integration of microfabricated low resistance and thousand-turn coils for vibration energy harvesting

    NASA Astrophysics Data System (ADS)

    Zhang, Qian; Wang, Yufeng; Zhao, Lurui; Sok Kim, Eun

    2016-02-01

    This paper presents two microfabrication approaches for multi-layer coils for vibration-energy harvesters. A magnet array is arranged with alternating north- and south-orientation to provide a rapidly changing magnetic field for high electromagnetic energy conversion. Multi-turn spiral coils on silicon wafer are aligned to the magnet array for maximum magnetic flux change. One type of coil is made out of 300 μm-thick copper that is electroplated with silicon mold, and the other is built on 25 μm-thick copper electroplated with photoresist mold. The low resistive coils fabricated by the first approach are integrated in a microfabricated energy harvester of 17  ×  7  ×  1.7 mm3 (=0.2 cm3) weighing 0.8 g, which generates 14.3 μW power output (into 0.7 Ω load) from vibration amplitude of 6 μm at 250 Hz. The latter approach is used to make a 1080-turn coil for a microfabricated electromagnetic energy harvester with magnet array and plastic spring. Though the size and weight of the harvester are only 44  ×  20  ×  6 mm3 (=5.3 cm3) and 12 g, respectively, it generates 1.04 mW power output (into 190 Ω load) when it is vibrated at 75 Hz with vibration amplitude of 220 μm.

  9. Microfabricated Inserts for Magic Angle Coil Spinning (MACS) Wireless NMR Spectroscopy

    PubMed Central

    Badilita, Vlad; Fassbender, Birgit; Kratt, Kai; Wong, Alan; Bonhomme, Christian; Sakellariou, Dimitris; Korvink, Jan G.; Wallrabe, Ulrike

    2012-01-01

    This article describes the development and testing of the first automatically microfabricated probes to be used in conjunction with the magic angle coil spinning (MACS) NMR technique. NMR spectroscopy is a versatile technique for a large range of applications, but its intrinsically low sensitivity poses significant difficulties in analyzing mass- and volume-limited samples. The combination of microfabrication technology and MACS addresses several well-known NMR issues in a concerted manner for the first time: (i) reproducible wafer-scale fabrication of the first-in-kind on-chip LC microresonator for inductive coupling of the NMR signal and reliable exploitation of MACS capabilities; (ii) improving the sensitivity and the spectral resolution by simultaneous spinning the detection microcoil together with the sample at the “magic angle” of 54.74° with respect to the direction of the magnetic field (magic angle spinning – MAS), accompanied by the wireless signal transmission between the microcoil and the primary circuit of the NMR spectrometer; (iii) given the high spinning rates (tens of kHz) involved in the MAS methodology, the microfabricated inserts exhibit a clear kinematic advantage over their previously demonstrated counterparts due to the inherent capability to produce small radius cylindrical geometries, thus tremendously reducing the mechanical stress and tearing forces on the sample. In order to demonstrate the versatility of the microfabrication technology, we have designed MACS probes for various Larmor frequencies (194, 500 and 700 MHz) testing several samples such as water, Drosophila pupae, adamantane solid and LiCl at different magic angle spinning speeds. PMID:22936994

  10. Microfabricated inserts for magic angle coil spinning (MACS) wireless NMR spectroscopy.

    PubMed

    Badilita, Vlad; Fassbender, Birgit; Kratt, Kai; Wong, Alan; Bonhomme, Christian; Sakellariou, Dimitris; Korvink, Jan G; Wallrabe, Ulrike

    2012-01-01

    This article describes the development and testing of the first automatically microfabricated probes to be used in conjunction with the magic angle coil spinning (MACS) NMR technique. NMR spectroscopy is a versatile technique for a large range of applications, but its intrinsically low sensitivity poses significant difficulties in analyzing mass- and volume-limited samples. The combination of microfabrication technology and MACS addresses several well-known NMR issues in a concerted manner for the first time: (i) reproducible wafer-scale fabrication of the first-in-kind on-chip LC microresonator for inductive coupling of the NMR signal and reliable exploitation of MACS capabilities; (ii) improving the sensitivity and the spectral resolution by simultaneous spinning the detection microcoil together with the sample at the "magic angle" of 54.74° with respect to the direction of the magnetic field (magic angle spinning - MAS), accompanied by the wireless signal transmission between the microcoil and the primary circuit of the NMR spectrometer; (iii) given the high spinning rates (tens of kHz) involved in the MAS methodology, the microfabricated inserts exhibit a clear kinematic advantage over their previously demonstrated counterparts due to the inherent capability to produce small radius cylindrical geometries, thus tremendously reducing the mechanical stress and tearing forces on the sample. In order to demonstrate the versatility of the microfabrication technology, we have designed MACS probes for various Larmor frequencies (194, 500 and 700 MHz) testing several samples such as water, Drosophila pupae, adamantane solid and LiCl at different magic angle spinning speeds. PMID:22936994

  11. A microfabricated sensor for thin dielectric layers.

    PubMed

    Fierlinger, P; DeVoe, R; Flatt, B; Gratta, G; Green, M; Kolkowitz, S; Leport, F; Montero Diez, M; Neilson, R; O'Sullivan, K; Pocar, A; Wodin, J

    2008-04-01

    We describe a sensor for the measurement of thin dielectric layers capable of operation in a variety of environments. The sensor is obtained by microfabricating a capacitor with interleaved aluminum fingers, exposed to the dielectric to be measured. In particular, the device can measure thin layers of solid frozen from a liquid or gaseous medium. Sensitivity to single atomic layers is achievable in many configurations and, by utilizing fast, high sensitivity capacitance readout in a feedback system onto environmental parameters; coatings of few layers can be dynamically maintained. We discuss the design, readout, and calibration of several versions of the device optimized in different ways. We specifically dwell on the case in which atomically thin solid xenon layers are grown and stabilized, in cryogenic conditions, from a liquid xenon bath. PMID:18447546

  12. Micro-fabricated stylus ion trap.

    PubMed

    Arrington, Christian L; McKay, Kyle S; Baca, Ehren D; Coleman, Jonathan J; Colombe, Yves; Finnegan, Patrick; Hite, Dustin A; Hollowell, Andrew E; Jördens, Robert; Jost, John D; Leibfried, Dietrich; Rowen, Adam M; Warring, Ulrich; Weides, Martin; Wilson, Andrew C; Wineland, David J; Pappas, David P

    2013-08-01

    An electroformed, three-dimensional stylus Paul trap was designed to confine a single atomic ion for use as a sensor to probe the electric-field noise of proximate surfaces. The trap was microfabricated with the UV-LIGA technique to reduce the distance of the ion from the surface of interest. We detail the fabrication process used to produce a 150 μm tall stylus trap with feature sizes of 40 μm. We confined single, laser-cooled, (25)Mg(+) ions with lifetimes greater than 2 h above the stylus trap in an ultra-high-vacuum environment. After cooling a motional mode of the ion at 4 MHz close to its ground state ( = 0.34 ± 0.07), the heating rate of the trap was measured with Raman sideband spectroscopy to be 387 ± 15 quanta/s at an ion height of 62 μm above the stylus electrodes. PMID:24007096

  13. Microfabricated structures with electrical isolation and interconnections

    NASA Technical Reports Server (NTRS)

    Clark, William A. (Inventor); Juneau, Thor N. (Inventor); Roessig, Allen W. (Inventor); Lemkin, Mark A. (Inventor)

    2001-01-01

    The invention is directed to a microfabricated device. The device includes a substrate that is etched to define mechanical structures at least some of which are anchored laterally to the remainder of the substrate. Electrical isolation at points where mechanical structures are attached to the substrate is provided by filled isolation trenches. Filled trenches may also be used to electrically isolate structure elements from each other at points where mechanical attachment of structure elements is desired. The performance of microelectromechanical devices is improved by 1) having a high-aspect-ratio between vertical and lateral dimensions of the mechanical elements, 2) integrating electronics on the same substrate as the mechanical elements, 3) good electrical isolation among mechanical elements and circuits except where electrical interconnection is desired.

  14. Microfabricated devices in microbial bioenergy sciences.

    PubMed

    Han, Arum; Hou, Huijie; Li, Lei; Kim, Hyun Soo; de Figueiredo, Paul

    2013-04-01

    Microbes provide a platform for the synthesis of clean energy from renewable resources. Significant investments in discovering new microbial systems and capabilities, discerning the molecular mechanisms that mediate microbial bioenergy production, and optimizing existing microbial bioenergy systems have been made. However, further development is needed to achieve the economically feasible large-scale production of value-added energy products. Microfabricated lab-on-a-chip systems provide cost- and time-efficient opportunities for analyzing microbe-mediated bioenergy synthesis. Here, we review developments in the application of lab-on-a-chip systems to the bioenergy sciences. We focus on systems that support the analysis of microbial generation of bioelectricity, biogas, and liquid transportation fuels. We conclude by suggesting possible future directions. PMID:23453527

  15. Microfabricated Platforms for Mechanically Dynamic Cell Culture

    PubMed Central

    Moraes, Christopher; Sun, Yu; Simmons, Craig A.

    2010-01-01

    The ability to systematically probe in vitro cellular response to combinations of mechanobiological stimuli for tissue engineering, drug discovery or fundamental cell biology studies is limited by current bioreactor technologies, which cannot simultaneously apply a variety of mechanical stimuli to cultured cells. In order to address this issue, we have developed a series of microfabricated platforms designed to screen for the effects of mechanical stimuli in a high-throughput format. In this protocol, we demonstrate the fabrication of a microactuator array of vertically displaced posts on which the technology is based, and further demonstrate how this base technology can be modified to conduct high-throughput mechanically dynamic cell culture in both two-dimensional and three-dimensional culture paradigms. PMID:21206477

  16. Level set method for microfabrication simulations

    NASA Astrophysics Data System (ADS)

    Baranski, Maciej; Kasztelanic, Rafal; Albero, Jorge; Nieradko, Lukasz; Gorecki, Christophe

    2010-05-01

    The article describes application of Level Set method for two different microfabrication processes. First is shape evolution of during reflow of the glass structure. Investigated problem were approximated by viscous flow of material thus kinetics of the process were known from physical model. Second problem is isotropic wet etching of silicon. Which is much more complicated because dynamics of the shape evolution is strongly coupled with time and geometry shapes history. In etching simulations Level Set method is coupled with Finite Element Method (FEM) that is used for calculation of etching acid concentration that determine geometry evolution of the structure. The problem arising from working with FEM with time varying boundaries was solved with the use of the dynamic mesh technique employing the Level Set formalism of higher dimensional function for geometry description. Isotropic etching was investigated in context of mico-lenses fabrication. Model was compared with experimental data obtained in etching of the silicon moulds used for micro-lenses fabrication.

  17. Non-planar microfabricated gas chromatography column

    DOEpatents

    Lewis, Patrick R.; Wheeler, David R.

    2007-09-25

    A non-planar microfabricated gas chromatography column comprises a planar substrate having a plurality of through holes, a top lid and a bottom lid bonded to opposite surfaces of the planar substrate, and inlet and outlet ports for injection of a sample gas and elution of separated analytes. A plurality of such planar substrates can be aligned and stacked to provide a longer column length having a small footprint. Furthermore, two or more separate channels can enable multi-channel or multi-dimensional gas chromatography. The through holes preferably have a circular cross section and can be coated with a stationary phase material or packed with a porous packing material. Importantly, uniform stationary phase coatings can be obtained and band broadening can be minimized with the circular channels. A heating or cooling element can be disposed on at least one of the lids to enable temperature programming of the column.

  18. Guiding neuronal development with in situ microfabrication

    NASA Astrophysics Data System (ADS)

    Kaehr, Bryan; Allen, Richard; Javier, David J.; Currie, John; Shear, Jason B.

    2004-11-01

    We report the ability to modify microscopic 3D topographies within dissociated cultures, providing a means to alter the development of neurons as they extend neurites and establish interconnections. In this approach, multiphoton excitation is used to focally excite noncytotoxic photosensitizers that promote protein crosslinking, such as BSA, into matrices having feature sizes 250 nm. Barriers, growth lanes, and pinning structures comprised of crosslinked proteins are fabricated under conditions that do not compromise the viability of neurons both on short time scales and over periods of days. In addition, the ability to fabricate functional microstructures from crosslinked avidin enables submicrometer localization of controllable quantities of biotinylated ligands, such as indicators and biological effectors. Feasibility is demonstrated for using in situ microfabrication to guide the contact position of cortical neurons with micrometer accuracy, opening the possibility for engineering well defined sets of synaptic interactions. biofabrication | multiphoton cell patterning | growth cone

  19. Microfabricated instrument for tissue biopsy and analysis

    DOEpatents

    Krulevitch, Peter A.; Lee, Abraham P.; Northrup, M. Allen; Benett, William J.

    2001-01-01

    A microfabricated biopsy/histology instrument which has several advantages over the conventional procedures, including minimal specimen handling, smooth cutting edges with atomic sharpness capable of slicing very thin specimens (approximately 2 .mu.m or greater), micro-liter volumes of chemicals for treating the specimens, low cost, disposable, fabrication process which renders sterile parts, and ease of use. The cutter is a "cheese-grater" style design comprising a block or substrate of silicon and which uses anisotropic etching of the silicon to form extremely sharp and precise cutting edges. As a specimen is cut, it passes through the silicon cutter and lies flat on a piece of glass which is bonded to the cutter. Microchannels are etched into the glass or silicon substrates for delivering small volumes of chemicals for treating the specimen. After treatment, the specimens can be examined through the glass substrate.

  20. Magnetoencephalography of epilepsy with a microfabricated atomic magnetrode.

    PubMed

    Alem, Orang; Benison, Alex M; Barth, Daniel S; Kitching, John; Knappe, Svenja

    2014-10-22

    Magnetoencephalography has long held the promise of providing a noninvasive tool for localizing epileptic seizures in humans because of its high spatial resolution compared with the scalp EEG. Yet, this promise has been elusive, not because of a lack of sensitivity or spatial resolution but because the large size and immobility of present cryogenic (superconducting) technology prevent long-term telemetry required to capture these very infrequent epileptiform events. To circumvent this limitation, we used Micro-Electro-Mechanical Systems technology to construct a noncryogenic (room temperature) microfabricated atomic magnetometer ("magnetrode") based on laser spectroscopy of rubidium vapor and similar in size and flexibility to scalp EEG electrodes. We tested the magnetrode by measuring the magnetic signature of epileptiform discharges in a rat model of epilepsy. We were able to measure neuronal currents of single epileptic discharges and more subtle spontaneous brain activity with a high signal-to-noise ratio approaching that of present superconducting sensors. These measurements are a promising step toward the goal of high-resolution noninvasive telemetry of epileptic events in humans with seizure disorders. PMID:25339745

  1. Microfabrics in Siliceous Hotsprings: Yellowstone National Park, Wyoming

    NASA Technical Reports Server (NTRS)

    Guidry, S. A.; Chafetz, H. S.; Westall, F.

    2001-01-01

    Microfabrics shed light on the mechanisms governing siliceous sinter precipitation, the profound effects of microorganisms, as well as a conventional facies model for siliceous hotsprings. Additional information is contained in the original extended abstract.

  2. Microfabricated instrument for tissue biopsy and analysis

    DOEpatents

    Krulevitch, Peter A.; Lee, Abraham P.; Northrup, M. Allen; Benett, William J.

    1999-01-01

    A microfabricated biopsy/histology instrument which has several advantages over the conventional procedures, including minimal specimen handling, smooth cutting edges with atomic sharpness capable of slicing very thin specimens (approximately 2 .mu.m or greater), micro-liter volumes of chemicals for treating the specimens, low cost, disposable, fabrication process which renders sterile parts, and ease of use. The cutter is a "cheese-grater" style design comprising a block or substrate of silicon and which uses anisotropic etching of the silicon to form extremely sharp and precise cutting edges. As a specimen is cut, it passes through the silicon cutter and lies flat on a piece of glass which is bonded to the cutter. Microchannels are etched into the glass or silicon substrates for delivering small volumes of chemicals for treating the specimen. After treatment, the specimens can be examined through the glass substrate. For automation purposes, microvalves and micropumps may be incorporated. Also, specimens in parallel may be cut and treated with identical or varied chemicals. The instrument is disposable due to its low cost and thus could replace current expensive microtome and histology equipment.

  3. Microfabricated electrochemical sensors for combustion applications

    NASA Astrophysics Data System (ADS)

    Vulcano Rossi, Vitor A.; Mullen, Max R.; Karker, Nicholas A.; Zhao, Zhouying; Kowarz, Marek W.; Dutta, Prabir K.; Carpenter, Michael A.

    2015-05-01

    A new design for the miniaturization of an existing oxygen sensor is proposed based on the application of silicon microfabrication technologies to a cm sized O2 sensor demonstrated by Argonne National Laboratory and The Ohio State University which seals a metal/metal oxide within the structure to provide an integrated oxygen reference. The structural and processing changes suggested will result in a novel MEMS-based device meeting the semiconductor industry standards for cost efficiency and mass production. The MEMS design requires thin film depositions to create a YSZ membrane, palladium oxide reference and platinum electrodes. Pt electrodes are studied under operational conditions ensuring film conductivity over prolonged usage. SEM imaging confirms void formation after extended tests, consistent with the literature. Furthermore, hydrophilic bonding of pairs of silicon die samples containing the YSZ membrane and palladium oxide is discussed in order to create hermetic sealed cavities for oxygen reference. The introduction of tensile Si3N4 films to the backside of the silicon die generates bowing of the chips, compromising bond quality. This effect is controlled through the application of pressure during the initial bonding stages. In addition, KOH etching of the bonded die samples is discussed, and a YSZ membrane that survives the etching step is characterized by Raman spectroscopy.

  4. Characterization of implantable microfabricated fluid delivery devices.

    PubMed

    Rathnasingham, Ruben; Kipke, Daryl R; Bledsoe, Sanford C; McLaren, John D

    2004-01-01

    The formal characterization of the performance of microfluidic delivery devices is crucial for reliable in vivo application. A comprehensive laboratory technique was developed and used to optimize, calibrate and validate microfabricated fluid delivery devices. In vivo experiments were carried out to verify the accuracy and reliability of the pressure driven devices. Acute guinea pig experiments were conducted to measure the response to alpha-amino-3-hydroxy-5-methyl-4-isoxalone propionic acid, an excitatory neurotransmitter, at multiple locations in the inferior colliculus. A nondimensional parameter, Q, was successfully used to classify devices in terms of geometry alone (i.e., independent of fluid properties). Functional devices exhibited long-term linearity and reliability in delivering single phase, Newtonian fluids, in discrete volumes with a resolution of 500 picoliters at less than 0.45 lbf/in2 (30 mbar) pressure drop. Results for non-Newtonian fluids are not presented here. The acute results showed a proportional increase in the firing rate for delivered volumes of 2 nL up to 10 nL (at rates of between 0.1 and 1 nL/s). Flow characteristics are maintained during acute experiments and post-implant. A control experiment conducted with Ringer solution produced negligible effects, suggesting the results to be truly pharmacological. The experimental techniques employed have proven to be reliable and will be used for future calibration and testing of next generation chronic microfluidic delivery devices. PMID:14723503

  5. Microfabricated instrument for tissue biopsy and analysis

    SciTech Connect

    Krulevitch, P.A.; Lee, A.P.; Northrup, M.A.; Benett, W.J.

    1999-11-16

    This invention relates to a microfabricated biopsy/histology instrument which has several advantages over the conventional procedures. The advantages include: minimal specimen handling; smooth cutting edges with atomic sharpness capable of slicing very thin specimens (approximately 2 {mu}m or greater); micro-liter volumes of chemicals for treating the specimens; low cost; disposable; fabrication process which renders sterile parts; and ease of use. The cutter is a cheese-grater style design comprising a block or substrate of silicon and which uses anisotropic etching of the silicon to form extremely sharp and precise cutting edges. As a specimen is cut, it passes through the silicon cutter and lies flat on a piece of glass which is bonded to the cutter. Microchannels are etched into the glass or silicon substrates for delivering small volumes of chemicals for treating the specimen. After treatment, the specimens can be examined through the glass substrate. For automation purposes, microvalves and micropumps may be incorporated. Also, specimens in parallel may be cut and treated with identical or varied chemicals. The instrument is disposable due to its low cost and thus could replace current expensive microtome and histology equipment.

  6. Microfabricated adhesive mimicking gecko foot-hair

    NASA Astrophysics Data System (ADS)

    Geim, A. K.; Dubonos, S. V.; Grigorieva, I. V.; Novoselov, K. S.; Zhukov, A. A.; Shapoval, S. Yu.

    2003-07-01

    The amazing climbing ability of geckos has attracted the interest of philosophers and scientists alike for centuries. However, only in the past few years has progress been made in understanding the mechanism behind this ability, which relies on submicrometre keratin hairs covering the soles of geckos. Each hair produces a miniscule force ~10-7 N (due to van der Waals and/or capillary interactions) but millions of hairs acting together create a formidable adhesion of ~10 N cm-2: sufficient to keep geckos firmly on their feet, even when upside down on a glass ceiling. It is very tempting to create a new type of adhesive by mimicking the gecko mechanism. Here we report on a prototype of such 'gecko tape' made by microfabrication of dense arrays of flexible plastic pillars, the geometry of which is optimized to ensure their collective adhesion. Our approach shows a way to manufacture self-cleaning, re-attachable dry adhesives, although problems related to their durability and mass production are yet to be resolved.

  7. Microfabricated therapeutic actuators and release mechanisms therefor

    DOEpatents

    Lee, Abraham P.; Fitch, Joseph P.; Schumann, Daniel L.; Da Silva, Luiz; Benett, William J.; Krulevitch, Peter A.

    2000-01-01

    Microfabricated therapeutic actuators are fabricated using a shape memory polymer (SMP), a polyurethane-based material that undergoes a phase transformation at a specified temperature (Tg). At a temperature above temperature Tg material is soft and can be easily reshaped into another configuration. As the temperature is lowered below temperature Tg the new shape is fixed and locked in as long as the material stays below temperature Tg. Upon reheating the material to a temperature above Tg, the material will return to its original shape. By the use of such SMP material, SMP microtubing can be used as a retaining/release actuator for the delivery of material, such as embolic coils, for example, through catheters into aneurysms, for example. The microtubing can be manufactured in various sizes and the phase change temperature Tg is determinate for an intended temperature target and intended use. The SMP microtubing can be positioned around or within an end of a deposit material. Various heating arrangements can be utilized with the SMP release mechanism, and the SMP microtubing can include a metallic coating for enhanced light absorption.

  8. Fetal magnetocardiography measurements with an array of microfabricated optically pumped magnetometers

    NASA Astrophysics Data System (ADS)

    Alem, Orang; Sander, Tilmann H.; Mhaskar, Rahul; LeBlanc, John; Eswaran, Hari; Steinhoff, Uwe; Okada, Yoshio; Kitching, John; Trahms, Lutz; Knappe, Svenja

    2015-06-01

    Following the rapid progress in the development of optically pumped magnetometer (OPM) technology for the measurement of magnetic fields in the femtotesla range, a successful assembly of individual sensors into an array of nearly identical sensors is within reach. Here, 25 microfabricated OPMs with footprints of 1 cm3 were assembled into a conformal array. The individual sensors were inserted into three flexible belt-shaped holders and connected to their respective light sources and electronics, which reside outside a magnetically shielded room, through long optical and electrical cables. With this setup the fetal magnetocardiogram of a pregnant woman was measured by placing two sensor belts over her abdomen and one belt over her chest. The fetal magnetocardiogram recorded over the abdomen is usually dominated by contributions from the maternal magnetocardiogram, since the maternal heart generates a much stronger signal than the fetal heart. Therefore, signal processing methods have to be applied to obtain the pure fetal magnetocardiogram: orthogonal projection and independent component analysis. The resulting spatial distributions of fetal cardiac activity are in good agreement with each other. In a further exemplary step, the fetal heart rate was extracted from the fetal magnetocardiogram. Its variability suggests fetal activity. We conclude that microfabricated optically pumped magnetometers operating at room temperature are capable of complementing or in the future even replacing superconducting sensors for fetal magnetocardiography measurements.

  9. Fetal magnetocardiography measurements with an array of microfabricated optically pumped magnetometers.

    PubMed

    Alem, Orang; Sander, Tilmann H; Mhaskar, Rahul; LeBlanc, John; Eswaran, Hari; Steinhoff, Uwe; Okada, Yoshio; Kitching, John; Trahms, Lutz; Knappe, Svenja

    2015-06-21

    Following the rapid progress in the development of optically pumped magnetometer (OPM) technology for the measurement of magnetic fields in the femtotesla range, a successful assembly of individual sensors into an array of nearly identical sensors is within reach. Here, 25 microfabricated OPMs with footprints of 1 cm(3) were assembled into a conformal array. The individual sensors were inserted into three flexible belt-shaped holders and connected to their respective light sources and electronics, which reside outside a magnetically shielded room, through long optical and electrical cables. With this setup the fetal magnetocardiogram of a pregnant woman was measured by placing two sensor belts over her abdomen and one belt over her chest. The fetal magnetocardiogram recorded over the abdomen is usually dominated by contributions from the maternal magnetocardiogram, since the maternal heart generates a much stronger signal than the fetal heart. Therefore, signal processing methods have to be applied to obtain the pure fetal magnetocardiogram: orthogonal projection and independent component analysis. The resulting spatial distributions of fetal cardiac activity are in good agreement with each other. In a further exemplary step, the fetal heart rate was extracted from the fetal magnetocardiogram. Its variability suggests fetal activity. We conclude that microfabricated optically pumped magnetometers operating at room temperature are capable of complementing or in the future even replacing superconducting sensors for fetal magnetocardiography measurements. PMID:26041047

  10. Microfabricated glucose biosensor for culture well operation.

    PubMed

    Pemberton, R M; Cox, T; Tuffin, R; Sage, I; Drago, G A; Biddle, N; Griffiths, J; Pittson, R; Johnson, G; Xu, J; Jackson, S K; Kenna, G; Luxton, R; Hart, J P

    2013-04-15

    A water-based carbon screen-printing ink formulation, containing the redox mediator cobalt phthalocyanine (CoPC) and the enzyme glucose oxidase (GOx), was investigated for its suitability to fabricate glucose microbiosensors in a 96-well microplate format: (1) the biosensor ink was dip-coated onto a platinum (Pt) wire electrode, leading to satisfactory amperometric performance; (2) the ink was deposited onto the surface of a series of Pt microelectrodes (10-500 μm diameter) fabricated on a silicon substrate using MEMS (microelectromechanical systems) microfabrication techniques: capillary deposition proved to be successful; a Pt microdisc electrode of ≥100 μm was required for optimum biosensor performance; (3) MEMS processing was used to fabricate suitably sized metal (Pt) tracks and pads onto a silicon 96 well format base chip, and the glucose biosensor ink was screen-printed onto these pads to create glucose microbiosensors. When formed into microwells, using a 340 μl volume of buffer, the microbiosensors produced steady-state amperometric responses which showed linearity up to 5 mM glucose (CV=6% for n=5 biosensors). When coated, using an optimised protocol, with collagen in order to aid cell adhesion, the biosensors continued to show satisfactory performance in culture medium (linear range to 2 mM, dynamic range to 7 mM, CV=5.7% for n=4 biosensors). Finally, the operation of these collagen-coated microbiosensors, in 5-well 96-well format microwells, was tested using a 5-channel multipotentiostat. A relationship between amperometric response due to glucose, and cell number in the microwells, was observed. These results indicate that microphotolithography and screen-printing techniques can be combined successfully to produce microbiosensors capable of monitoring glucose metabolism in 96 well format cell cultures. The potential application areas for these microbiosensors are discussed. PMID:23265827

  11. Development of neutral atom traps based on a microfabricated waveguide

    NASA Astrophysics Data System (ADS)

    Jau, Yuan-Yu; Lee, Jongmin; Biedermann, Grant; Siddiqui, Aleem; Eichenfield, Matt; Dougla, Erica

    2016-05-01

    Implementation of trapping neutral atoms in the evanescent fields generated by a nano-structure, such as a nanofiber or a microfabricated nano-waveguide, will naturally enable strong atom-photon interactions, which serve the key mechanisms for different type of quantum controls. At Sandia National Labs, we are aiming to develop a platform based on this concept to eventually trap cesium atoms with a microfabricated waveguide. Although, neutral atom traps using optical nanofiber has been demonstrated, there are several key issues that need to be resolved to realize trapping atoms with microfabricated structure. The subjects include the material for making the waveguide, optical power handling capability, surface adsorption of alkali-metal atoms, surface roughness of the nano-structure, cold-atom source for loading the atoms into the evanescent-field traps, etc. We will discuss our studies on these related subjects and report our latest progress.

  12. Parylene C as a Sacrificial Material for Microfabrication

    NASA Technical Reports Server (NTRS)

    Beamesderfer, Michael

    2005-01-01

    Parylene C has been investigated for use as a sacrificial material in microfabrication. Although Parylene C cannot be patterned lithographically like photoresists, it nevertheless extends the range of processing options by offering a set of properties that are suitable for microfabrication and are complementary to those of photoresists. The compatibility of Parylene C with several microfabrication processes was demonstrated in experiments in which a thin film of Parylene C was deposited on a silicon wafer, then several thin metal films were deposited and successfully patterned, utilizing the Parylene C pads as a sacrificial layer. The term "parylene" -- a contraction of "poly(para-xylene)" -- denotes a family of vapor-deposited polymers. In Parylene C (the most common form of parylene), a chlorine atom is substituted for one of the hydrogen atoms on the benzene ring of each para-xylene moiety. Heretofore, parylenes have been used as conformal coating materials in diverse applications.

  13. Microfabricated Segmented-Involute-Foil Regenerator for Stirling Engines

    NASA Technical Reports Server (NTRS)

    Ibrahim, Mounir; Danila, Daniel; Simon, Terrence; Mantell, Susan; Sun, Liyong; Gedeon, David; Qiu, Songgang; Wood, Gary; Kelly, Kevin; McLean, Jeffrey

    2010-01-01

    An involute-foil regenerator was designed, microfabricated, and tested in an oscillating-flow test rig. The concept consists of stacked involute-foil nickel disks (see figure) microfabricated via a lithographic process. Test results yielded a performance of about twice that of the 90-percent random-fiber currently used in small Stirling converters. The segmented nature of the involute- foil in both the axial and radial directions increases the strength of the structure relative to wrapped foils. In addition, relative to random-fiber regenerators, the involute-foil has a reduced pressure drop, and is expected to be less susceptible to the release of metal fragments into the working space, thus increasing reliability. The prototype nickel involute-foil regenerator was adequate for testing in an engine with a 650 C hot-end temperature. This is lower than that required by larger engines, and high-temperature alloys are not suited for the lithographic microfabrication approach.

  14. Microfabrication of IPMC cilia for bio-inspired flow sensing

    NASA Astrophysics Data System (ADS)

    Lei, Hong; Li, Wen; Tan, Xiaobo

    2012-04-01

    As the primary flow sensing organ for fishes, the lateral line system plays a critical role in fish behavior. Analogous to its biological counterpart, an artificial lateral line system, consisting of arrays of micro flow sensors, is expected to be instrumental in the navigation and control of underwater robots. In this paper we investigate the microfabrication of ionic polymer-metal composite (IPMC) cilia for the purpose of flow sensing. While existing macro- and microfabrication methods for IPMCs have predominantly focused on planar structures, we propose a device where micro IPMC beams stand upright on a substrate to effectively interact with the flow. Challenges in the casting of 3D Nafion structure and selective formation of electrodes are discussed, and potential solutions for addressing these challenges are presented together with preliminary microfabrication results.

  15. Microfabricated biocapsules for the immunoisolation of pancreatic islets of Langerhans

    NASA Astrophysics Data System (ADS)

    Desai, Tejal Ashwin

    1998-08-01

    A silicon-based microfabricated biocapsule was developed and evaluated for use in the immunoisolation of transplanted cells, specifically pancreatic islets of Langerhans for the treatment of Type I diabetes. The transplantation of cells with specific functions is a promising therapy for a wide variety of pathologies including diabetes, Parkinson's, and hemophilia. Such transplanted cells, however, are sensitive to both cellular and humoral immune rejection as well as damage by autoimmune activity, without chronic immunosuppression. The research presented in this dissertation investigated whether microfabricated silicon-based biocapsules, with uniform membrane pore sizes in the tens of nanometer range, could provide an immunoprotective environment for pancreatic islets and other insulin-secreting cell lines, while maintaining cell viability and functionality. By utilizing fabrication techniques commonly employed in the microelectronics industry (MEMS), membranes were fabricated with precisely controlled and uniform pore sizes, allowing the optimization of biocapsule membrane parameters for the encapsulation of specific hormone-secreting cell types. The biocapsule-forming process employed bulk micromachining to define cell-containing chambers within single crystalline silicon wafers. These chambers interface with the surrounding biological environment through polycrystalline silicon filter membranes, which were surface micromachined to present a high density of uniform pores to allow sufficient permeability to oxygen, glucose, and insulin. Both in vitro and in vivo experiments established the biocompatibility of the microfabricated biocapsule, and demonstrated that encapsulated cells could live and function normally in terms of insulin-secretion within microfabricated environments for extended periods of time. This novel research shows the potential of using microfabricated biocapsules for the encapsulation of several different cell xenografts. The semipermeability

  16. Microfabricated Chemical Sensors for Safety and Emission Control Applications

    NASA Technical Reports Server (NTRS)

    Hunter, G. W.; Neudeck, P. G.; Chen, L.-Y.; Knight, D.; Liu, C. C.; Wu, Q. H.

    1998-01-01

    Chemical sensor technology is being developed for leak detection, emission monitoring, and fire safety applications. The development of these sensors is based on progress in two types of technology: 1) Micromachining and microfabrication (MicroElectroMechanical Systems (MEMS)-based) technology to fabricate miniaturized sensors. 2) The development of high temperature semiconductors, especially silicon carbide. Using these technologies, sensors to measure hydrogen, hydrocarbons, nitrogen oxides, carbon monoxide, oxygen, and carbon dioxide are being developed. A description is given of each sensor type and its present stage of development. It is concluded that microfabricated sensor technology has significant potential for use in a range of aerospace applications.

  17. Microfabricated suspensions for electrical connections on the tunable elastomer membrane

    NASA Astrophysics Data System (ADS)

    Hung, Paul J.; Jeong, Kihun; Liu, Gang L.; Lee, Luke P.

    2004-12-01

    Electrical connections through microfabricated suspensions on a pneumatically pumped elastomer membrane were demonstrated. A method to fabricate the suspensions on the elastomer membrane was developed. The elastomer membrane was 1 mm in diameter and 120 μm in thickness. Resistances of the microfabricated suspensions measured across the elastomer membrane were within 1% difference when the membrane's center deflection ranged from 0 to 100 μm, which corresponded to a numerical aperture change from 0 to 0.2 as well as a 2.6% elongation of the elastomer.

  18. Microfabrics in depleted mantle plaeotransform (New Caledonia)

    NASA Astrophysics Data System (ADS)

    Teyssier, Christian; Chatzaras, Vasileios; Von Der Handt, Anette

    2016-04-01

    The New Caledonia ophiolite contains several wrench zones that have been interpreted as paleotransforms. These transform-ridge systems developed at the transition between ridge development and intra-oceanic subduction that resulted in depleted mantle (about 18 % melt according to olivine Mg# - spinel Cr#). The most prominent is the Bogota Peninsula paleotransform, a 10 km wide shear zone in which strain localizes in the 2 km wide Ouassé mylonite zone. This strain gradient is associated with microstructure and microfabric evolution that informs the relationship between hydration and strain in mantle mylonite. Olivine recrystallized grain size varies from about 1 mm to about 0.2 mm toward the mylonite zone. The strain gradient is also demonstrated by increasing deformation of orthopyroxene (opx) grains that become elongate porphyroclasts in the mylonite zone. Orthopyroxene geothermometry reveals T ~ 1050-1000 C (Ca-opx) and 950-850 C (Cr-Al-opx) in the least deformed rocks. In the mylonite zone a wider range of T is recorded, with minima reaching 850 C (Ca-opx) and 750 C (Cr-Al-opx). Electron microprobe analysis also detects the presence of 20-200 micron interstitial, high-temperature amphibole (pargasite), with modal abundance increasing in the mylonite zone; this suggests that high-temperature pervasive fluid flow may have played a role in strain localization and mylonitization. Olivine crystallographic fabrics include A-type and E-type, the latter possibly reflecting hydration of shear zone tectonites. E-type fabrics are present in both mylonite and less deformed rocks, and appear to be more common in rocks with olivine grain size < 400 microns. A correlation between E-type fabrics and amphibole mode is being investigated. The shear zone protolith was depleted mantle in which the ridge-transform system was permeated by fluids. These fluids initially originated at the subduction interface, but during the transform evolution, ocean water likely permeated the shear

  19. Microfabricated Tactile Sensors for Biomedical Applications: A Review

    PubMed Central

    Saccomandi, Paola; Schena, Emiliano; Oddo, Calogero Maria; Zollo, Loredana; Silvestri, Sergio; Guglielmelli, Eugenio

    2014-01-01

    During the last decades, tactile sensors based on different sensing principles have been developed due to the growing interest in robotics and, mainly, in medical applications. Several technological solutions have been employed to design tactile sensors; in particular, solutions based on microfabrication present several attractive features. Microfabrication technologies allow for developing miniaturized sensors with good performance in terms of metrological properties (e.g., accuracy, sensitivity, low power consumption, and frequency response). Small size and good metrological properties heighten the potential role of tactile sensors in medicine, making them especially attractive to be integrated in smart interfaces and microsurgical tools. This paper provides an overview of microfabricated tactile sensors, focusing on the mean principles of sensing, i.e., piezoresistive, piezoelectric and capacitive sensors. These sensors are employed for measuring contact properties, in particular force and pressure, in three main medical fields, i.e., prosthetics and artificial skin, minimal access surgery and smart interfaces for biomechanical analysis. The working principles and the metrological properties of the most promising tactile, microfabricated sensors are analyzed, together with their application in medicine. Finally, the new emerging technologies in these fields are briefly described. PMID:25587432

  20. Nano- and microfabrication for overcoming drug delivery challenges

    PubMed Central

    Kam, Kimberly R.

    2013-01-01

    This highlight article describes current nano- and microfabrication techniques for creating drug delivery devices. We first review the main physiological barriers to delivering therapeutic agents. Then, we describe how novel fabrication methods can be utilized to combine many features into a single physiologically relevant device to overcome drug delivery challenges. PMID:23730504

  1. Recent progress of laser precision microfabrication in China

    NASA Astrophysics Data System (ADS)

    Cheng, Zhaogu; Xu, Guoliang; Zhao, Quanzhong; Liu, Cuiqing

    2002-02-01

    Review on recent progress of laser precision microfabrication in China is given in this paper. The universal fields of the LPM mostly using short pulse and short wavelength lasers in China are as follows: new materials, advanced manufacturing technology, information technology, biological technology, medical treatment and so on, which are given priority to the development in high-tech fields in China.

  2. Experimental Characterization of Microfabricated VirtualImpactor Efficiency

    EPA Science Inventory

    The Air-Microfluidics Group is developing a microelectromechanical systems-based direct reading particulate matter (PM) mass sensor. The sensor consists of two main components: a microfabricated virtual impactor (VI) and a PM mass sensor. The VI leverages particle inertia to sepa...

  3. Sub-picotesla Scalar Atomic Magnetometer with a Microfabricated Vapor Cell

    NASA Astrophysics Data System (ADS)

    Zhang, Rui; Mhaskar, Rahul

    2016-05-01

    We explore the sensitivity limits of scalar atomic magnetometry with a micro-fabricated Cs vapor cell. The millimeter-scale cell is fabricated using silicon Micro-Electro-Mechanical Systems (MEMS) technology. The atomic spin procession is driven by an amplitude-modulated circularly polarized pump laser resonant with the D1 transition in Cs atoms. The precession is detected by an off-resonant linearly polarized probe laser using a balanced polarimeter setup. The probe light is spatially split into two beams to perform a gradiometer measurement. In a magnetic field of magnitude within the range of the earth magnetic field, we measure a sensitivity of less than 150 fT/ √Hz in the gradiometer mode, which shows that the magnetometer by itself can achieve sub-100 fT/ √Hz sensitivitiy. In addition to its high sensitivity, the magnetometer has a bandwidth of nearly 1 kHz due to the broad magnetic resonance inside the small cell. Our experiment suggests the feasibility of a portable, low-power and high-performance magnetometer, which can be operated in the earth's magnetic field. Such a device will greatly expand the range of applications for atomic magnetometers, such as the detection of nuclear magnetic resonance in an unshielded environment.

  4. ANKA, a customer-oriented synchrotron radiation facility for microfabrication and analytical services

    NASA Astrophysics Data System (ADS)

    Pea Anka Project Group; Buth, G.; Doyle, S.; Einfeld, D.; Hagelstein, M.; Hermle, S.; Huttel, E.; Krüssel, A.; Lange, M.; Mathis, Y.-L.; Mexner, W.; Moser, H. O.; Pellegrin, E.; Ristau, U.; Rossmanith, R.; Schaper, J.; Schieler, H.; Simon, R.; Steininger, R.; Voigt, S.; Walther, R.; Perez, F.; Pont, M.; Plesko, M.

    1998-03-01

    ANKA (Angströmquelle Karlsruhe) is a state-of-the-art synchrotron radiation facility under construction at the Forschungszentrum Karlsruhe. Based on a 2.5 GeV electron storage ring it will deliver photons predominantly in the hard X-ray range but it will also feature both XUV and infrared beamlines. In its first operational phase the radiation will be taken out of normal-conducting dipole bending magnets, while five free long straight sections are foreseen to accommodate insertion devices later on. ANKA has a novel mission, namely to provide synchrotron-radiation based services to industrial and other customers, in the fields of microfabrication and materials analysis. A limited liability company, ANKA GmbH, is being founded to operate the facility. Although commercial services to customers will represent more than half of the overall activity, these services will be complemented by providing beam time for research users.

  5. Solid state synthesis of chitosan and its unsaturated derivatives for laser microfabrication of 3D scaffolds

    NASA Astrophysics Data System (ADS)

    Akopova, T. A.; Demina, T. S.; Bagratashvili, V. N.; Bardakova, K. N.; Novikov, M. M.; Selezneva, I. I.; Istomin, A. V.; Svidchenko, E. A.; Cherkaev, G. V.; Surin, N. M.; Timashev, P. S.

    2015-07-01

    Chitosans with various degrees of deacetylation and molecular weights and their allyl substituted derivatives were obtained through a solvent-free reaction under shear deformation in an extruder. Structure and physical-chemical analysis of the samples were carried out using nuclear magnetic resonance (NMR), ultraviolet (UV) and infrared radiation (IR) spectroscopy. Photosensitive materials based on the synthesized polymers were successfully used for microfabrication of 3D well-defined architectonic structures by laser stereolithography. Study on the metabolic activity of NCTC L929 cultured in the presence of the cured chitosan extracts indicates that the engineered biomaterials could support adhesion, spreading and growth of adherent-dependent cells, and thus could be considered as biocompatible scaffolds.

  6. Method For Chemical Sensing Using A Microfabricated Teeter-Totter Resonator

    DOEpatents

    Adkins, Douglas Ray; Heller, Edwin J.; Shul, Randy J.

    2004-11-30

    A method for sensing a chemical analyte in a fluid stream comprises providing a microfabricated teeter-totter resonator that relies upon a Lorentz force to cause oscillation in a paddle, applying a static magnetic field substantially aligned in-plane with the paddle, energizing a current conductor line on a surface of the paddle with an alternating electrical current to generate the Lorentz force, exposing the resonator to the analyte, and detecting the response of the oscillatory motion of the paddle to the chemical analyte. Preferably, a chemically sensitive coating is disposed on at least one surface of the paddle to enhance the sorption of the analyte by the paddle. The concentration of the analyte in a fluid stream can be determined by measuring the change in the resonant frequency or phase of the teeter-totter resonator as the chemical analyte is added to or removed from the paddle.

  7. Microfabricated devices for performing chemical and biochemical analysis

    SciTech Connect

    Ramsey, J.M.; Jacobson, S.C.; Foote, R.S.

    1997-05-01

    There is growing interest in microfabricated devices that perform chemical and biochemical analysis. The general goal is to use microfabrication tools to construct miniature devices that can perform a complete analysis starting with an unprocessed sample. Such devices have been referred to as lab-on-a-chip devices. Initial efforts on microfluidic laboratory-on-a-chip devices focused on chemical separations. There are many potential applications of these fluidic microchip devices. Some applications such as chemical process control or environmental monitoring would require that a chip be used over an extended period of time or for many analyses. Other applications such as forensics, clinical diagnostics, and genetic diagnostics would employ the chip devices as single use disposable devices.

  8. Guided Homing of Cells in Multi-Photon Microfabricated Bioscaffolds.

    PubMed

    Skylar-Scott, Mark A; Liu, Man-Chi; Wu, Yuelong; Dixit, Atray; Yanik, Mehmet Fatih

    2016-05-01

    Tissues contain exquisite vascular microstructures, and patterns of chemical cues for directing cell migration, homing, and differentiation for organ development and function. 3D microfabrication by multi-photon photolithography is a flexible, high-resolution tool for generating 3D bioscaffolds. However, the combined fabrication of scaffold microstructure simultaneously with patterning of cues to create both geometrically and chemically defined microenvironments remains to be demonstrated. This study presents a high-speed method for micron-resolution fabrication of scaffold microstructure and patterning of protein cues simultaneously using native scaffold materials. By the simultaneous microfabrication of arbitrary microvasculature geometries, and patterning selected regions of the microvasculature with the homing ligand P-selectin, this study demonstrates adhesion, rolling, and selective homing of cells in defined 3D regions. This novel ability to generate high-resolution geometries replete with patterned cues at high speed enables the construction of biomimetic microenvironments for complex 3D assays of cellular behavior. PMID:27059425

  9. Microfabricated cantilever-based detector for molecular beam experiments

    NASA Astrophysics Data System (ADS)

    Bachels, T.; Schäfer, R.

    1998-11-01

    A low cost detector for particles in molecular beam experiments is presented which can easily be mounted in a molecular beam apparatus. The detector is based on microfabricated cantilevers, which can be employed either as single sensors or as sensor arrays. The single cantilever technique has been used to measure the absolute number of atoms coming out of a pulsed laser vaporization cluster source. The particles are detected by the shift of the thermally excited resonance frequency of the cantilever due to the cluster deposition. We have determined with the single cantilever the ratio of neutral to ionized clusters and we have investigated the cluster generation at different source conditions. In addition to this, a microfabricated cantilever array has been used to measure molecular beam profiles, which opens new possibilities for molecular beam deflection experiments.

  10. Multilayered Ge/SiGe Material in Microfabricated Thermoelectric Modules

    NASA Astrophysics Data System (ADS)

    Samarelli, A.; Llin, L. Ferre; Cecchi, S.; Chrastina, D.; Isella, G.; Etzelstorfer, T.; Stangl, J.; Gubler, E. Muller; Weaver, J. M. R.; Dobson, P.; Paul, D. J.

    2014-10-01

    Results for low dimensional p-type Ge/SiGe superlattices with Ge quantum wells of 3.43 nm are presented. A range of microfabricated test structures have been developed to characterise the cross-plane electrical and thermal properties of the Ge/SiGe heterostructures. These superlattices were directly grown on 100-mm-diameter silicon wafers by a chemical vapour deposition growth system with rates up to 6 nm/s. Quantum well and quantum mechanical tunnel barriers with dimensions down to nm have been designed, grown and tested; they demonstrate a ZT of 0.08 ± 0.011 and power factor of 1.34 ± 0.15 m W m-1 K-2 at 300 K. A complete microfabricated module using indium bump-bonding is reported together with preliminary results on unoptimised material and leg dimensions. Routes to optimise the material and modules are discussed.

  11. Multilayer Interconnects for Microfabricated Surface Electrode Ion Traps

    NASA Astrophysics Data System (ADS)

    Amini, Jason; Seidelin, Signe; Wesenberg, Janus; Britton, Joe; Blakestad, Brad; Brown, Kenton; Epstein, Ryan; Home, Jonathan; Jost, John; Langer, Chris; Leibfried, Dietrich; Ozeri, Roee; Wineland, David

    2007-06-01

    Microfabricated surface electrode traps for ions are a promising technology for building scalable trapping geometries for quantum information processing. We have expanded upon our single layer gold-on-fused-silica surface electrode trap [1] to include a second patterned conducting layer under the trapping electrodes and have demonstrated the fabrication of this architecture using standard microfabrication techniques. The multilayer approach allows for a significant increase in multi-zone trapping complexity and permits improved trapping structures that are otherwise unattainable in single layer designs without vertical interconnects through the wafer. Using improved calculational methods [2], we are in the process of optimizing the planar designs to create modular elements that can be joined into larger multi-zone trapping structures. Work supported by DTO and NIST. 1. S. Seidelin et al., Phys. Rev. Lett. 96, 253003 (2006). Also, see the abstract by S. Seidelin. 2. See the abstract by J. H. Wesenberg.

  12. Impact of microfabrication technology on x-ray optics

    SciTech Connect

    Ceglio, N.M.

    1981-08-01

    X-ray optics stands on the threshold of realizing its early promise: precision analysis of microstructure on the scale of the x-ray wavelength. The achievement of this exciting goal will depend in large part on advances in microfabrication technology making possible the precision fabrication of periodic microstructures. A review of recent advances in, as well as future prospects for: x-ray microscopy, coded imaging, and space-time resolved spectroscopy, resulting from improved microstructure fabrication capabilities is presented.

  13. SEM microfabric analysis of glacial varves, Geneseo, N. Y

    SciTech Connect

    Pietraszek, S.R. . Geology Dept.)

    1993-03-01

    A detailed study of the microfabric of Pleistocene varved silty-clay from Geneseo Valley (Geneseo, N.Y.) indicates rapid deposition of sediment in a flocculated state into a glacial lake. Ten varve couplets of a 10 cm thick sample were studied using the Scanning Electron Microscope to determine their microfabric. Each varve ranges from 0.5 cm to 2.0 cm and represents an annual ( ) deposit. Varves consists of a lower light colored, coarse zone of silt and clay, and an upper darker colored, organic fine clayey zone. Graded bedding is observed in each couplet, and random clay particle orientation is dominant throughout a varve, with the exception of the top 0.5 mm of the fine layer. The upper and lower contacts are sharp. Fabric features are instrumental in reconstructing a depositional environment. Microfabric results of the glacial unit indicate that an initial heavy concentration of clay and silt was introduced into the basin in a single pulse during spring runoff. The majority of silt settled together with clay in a flocculated or aggregated state, forming the lower coarse zone of random orientation. As the silt concentration diminished, the clay continued to flocculate and settled as a fine clay aggregate. It is proposed that the settling took place during the spring and summer months. Finally, during the winter months, the sediment surface of the varve was disturbed by nemotode burrows, which reoriented the clay flakes into a zone of preferred fabric. Microfabric analysis of these glacial varves, thus suggests that sediment was rapidly deposited in a flocculated state.

  14. Micro-Fabricated DC Comparison Calorimeter for RF Power Measurement

    PubMed Central

    Neji, Bilel; Xu, Jing; Titus, Albert H.; Meltzer, Joel

    2014-01-01

    Diode detection and bolometric detection have been widely used to measure radio frequency (RF) power. However, flow calorimeters, in particular micro-fabricated flow calorimeters, have been mostly unexplored as power meters. This paper presents the design, micro-fabrication and characterization of a flow calorimeter. This novel device is capable of measuring power from 100 μW to 200 mW. It has a 50-Ohm load that is heated by the RF source, and the heat is transferred to fluid in a microchannel. The temperature change in the fluid is measured by a thermistor that is connected in one leg of a Wheatstone bridge. The output voltage change of the bridge corresponds to the RF power applied to the load. The microfabricated device measures 25.4 mm × 50.8 mm, excluding the power supplies, microcontroller and fluid pump. Experiments demonstrate that the micro-fabricated sensor has a sensitivity up to 22 × 10−3 V/W. The typical resolution of this micro-calorimeter is on the order of 50 μW, and the best resolution is around 10 μW. The effective efficiency is 99.9% from 0–1 GHz and more than 97.5% at frequencies up to 4 GHz. The measured reflection coefficient of the 50-Ohm load and coplanar wave guide is less than −25 dB from 0–2 GHz and less than −16 dB at 2–4 GHz. PMID:25350509

  15. A microfabrication-based approach to quantitative isothermal titration calorimetry.

    PubMed

    Wang, Bin; Jia, Yuan; Lin, Qiao

    2016-04-15

    Isothermal titration calorimetry (ITC) directly measures heat evolved in a chemical reaction to determine equilibrium binding properties of biomolecular systems. Conventional ITC instruments are expensive, use complicated design and construction, and require long analysis times. Microfabricated calorimetric devices are promising, although they have yet to allow accurate, quantitative ITC measurements of biochemical reactions. This paper presents a microfabrication-based approach to integrated, quantitative ITC characterization of biomolecular interactions. The approach integrates microfabricated differential calorimetric sensors with microfluidic titration. Biomolecules and reagents are introduced at each of a series of molar ratios, mixed, and allowed to react. The reaction thermal power is differentially measured, and used to determine the thermodynamic profile of the biomolecular interactions. Implemented in a microdevice featuring thermally isolated, well-defined reaction volumes with minimized fluid evaporation as well as highly sensitive thermoelectric sensing, the approach enables accurate and quantitative ITC measurements of protein-ligand interactions under different isothermal conditions. Using the approach, we demonstrate ITC characterization of the binding of 18-Crown-6 with barium chloride, and the binding of ribonuclease A with cytidine 2'-monophosphate within reaction volumes of approximately 0.7 µL and at concentrations down to 2mM. For each binding system, the ITC measurements were completed with considerably reduced analysis times and material consumption, and yielded a complete thermodynamic profile of the molecular interaction in agreement with published data. This demonstrates the potential usefulness of our approach for biomolecular characterization in biomedical applications. PMID:26655185

  16. Microelectrode arrays fabricated using a novel hybrid microfabrication method.

    PubMed

    Merlo, Mark W; Snyder, Russell L; Middlebrooks, John C; Bachman, Mark

    2012-02-01

    We present novel hybrid microfabrication methods for microelectrode arrays that combine microwire assembly, microelectromechanical systems (MEMS) manufacturing techniques and precision tool-based micromachining. This combination enables hybrid microfabrication to produce complex geometries and structures, increase material selection, and improve integration. A 32-channel shank microelectrode array was fabricated to highlight the hybrid microfabrication techniques. The electrode shank was 130 μm at its narrowest, had a 127 μm thickness and had iridium oxide electrode sites that were 25 μm in diameter with 150 μm spacing. Techniques used to fabricate this electrode include microassembly of insulated gold wires into a micromold, micromolding the microelectrode shank, post molding machining, sacrificial release of the microelectrode and electrodeposition of iridium oxide onto the microelectrode sites. Electrode site position accuracy was shown to have a standard deviation of less than 4 μm. Acute in vivo recordings with the 32-channel shank microelectrode array demonstrated comparable performance to that obtained with commercial microelectrode arrays. This new approach to microelectrode array fabrication will enable new microelectrodes, such as multi-sided arrays, drug eluding electrodes and biodegradable shanks. PMID:21979567

  17. Microelectrode arrays fabricated using a novel hybrid microfabrication method

    PubMed Central

    Merlo, Mark W.; Snyder, Russell L.; Middlebrooks, John C.; Bachman, Mark

    2011-01-01

    We present novel hybrid microfabrication methods for microelectrode arrays that combine microwire assembly, microelectromechanical systems (MEMS) manufacturing techniques and precision tool-based micromachining. This combination enables hybrid microfabrication to produce complex geometries and structures, increase material selection, and improve integration. A 32-channel shank microelectrode array was fabricated to highlight the hybrid microfabrication techniques. The electrode shank was 130 μm at its narrowest, had a 127 μm thickness and had iridium oxide electrode sites that were 25 μm in diameter with 150 μm spacing. Techniques used to fabricate this electrode include microassembly of insulated gold wires into a micromold, micromolding the microelectrode shank, post molding machining, sacrificial release of the microelectrode and electrodeposition of iridium oxide onto the microelectrode sites. Electrode site position accuracy was shown to have a standard deviation of less than 4 μm. Acute in vivo recordings with the 32-channel shank microelectrode array demonstrated comparable performance to that obtained with commercial microelectrode arrays . This new approach to microelectrode array fabrication will enable new microelectrodes, such as multi-sided arrays, drug eluding electrodes and biodegradable shanks. PMID:21979567

  18. Applied Geophysics in the world of tomorrow - Microfabrication arrives

    NASA Astrophysics Data System (ADS)

    Johnson, R. M.

    2012-12-01

    Instrument manufacturers have a unique perspective on the design and use of geophysical equipment. The field instrument must provide reliable and repeatable performance in every climate condition and environmental extreme. The gear must be easy to use and more importantly easy to understand for non-native English speakers. I have traveled the world installing, repairing, commissioning and demonstrating geophysical survey systems. Everywhere I have traveled there is one unassailable fact - our geophysicist compatriots in developed and developing countries are hungry for information and hungry for technology. They want more and better systems to help improve their understanding of the subsurface. And they want to serve their countries by helping to exploit natural resources. I hold up for your review the first highly successful portable magnetometer, the G-856. Designed in 1981 with over 5000 sold, it is still produced in record numbers today for use all over the world. How could it be that a rather simple device could be so long lived, and make such an impact in exploration programs for 32 years? The answer is in producing reliable and easy to use equipment that is affordable. One might compare it to the iPad or Android device of today. The innovative and no-frills interface has attracted users from all markets including mining, oil/gas, archaeology, environmental, UXO/military and forensics. Powerful ancillary software to process the data has always been included at no charge, offering geoscientists a solution rather than a black box. Many of our technologies are poised for dramatic breakthroughs in miniaturization and interconnectivity. I point specifically to the micro-fabrication of the cesium vapor magnetometer. Initiated 5 years ago in conjunction with NIST, Geometrics has embarked on a high stakes game of minimizing size, weight, power consumption and price while eliminating dead zones and maintaining or increasing sensitivity and sample speed. These new

  19. Microfabricated sensors for the measurement of electromagnetic fields in biological tissues

    NASA Astrophysics Data System (ADS)

    Monberg, James; Henning, Albert K.

    1995-09-01

    Public awareness of the risks of exposure to electromagnetic radiation has grown over the past ten yeras. The effects of power lines on human and animal health have drawn particular attention. Some longitudinal studies of cancer rates near power lines show a significant correlation, while others show a null result. The studies have suffered from inadequate sensors for the measurement of electromagnetic radiation in vivo. In this work, we describe the design, construction, and testing of electrically passive, microfabricated single-pole antennas and coils. These sensors will be used in vivo to study the effects of electromagnetic radiation on animals. Our testing to date has been limited to in vitro studies of the magnetic field probes. Magnetic field pickup coils were fabricated with up to 100 turns, over a length of up to 1000 micrometers . Measurements were carried out with the sensors in air, and in water of various saline concentrations. Magnetic fields were applied using a Helmholtz coil. Both dc and ac fields were applied. The results indicate that small-area measurements of electromagnetic fields in vitro can be made successfully, provided adequate shielding and amplification are used.

  20. Microfabricated, flowthrough porous apparatus for discrete detection of binding reactions

    DOEpatents

    Beattie, Kenneth L.

    1998-01-01

    An improved microfabricated apparatus for conducting a multiplicity of individual and simultaneous binding reactions is described. The apparatus comprises a substrate on which are located discrete and isolated sites for binding reactions. The apparatus is characterized by discrete and isolated regions that extend through said substrate and terminate on a second surface thereof such that when a test sample is allowed to the substrate, it is capable of penetrating through each such region during the course of said binding reaction. The apparatus is especially useful for sequencing by hybridization of DNA molecules.

  1. Enhanced adhesion for LIGA microfabrication by using a buffer layer

    DOEpatents

    Bajikar, Sateesh S.; De Carlo, Francesco; Song, Joshua J.

    2001-01-01

    The present invention is an improvement on the LIGA microfabrication process wherein a buffer layer is applied to the upper or working surface of a substrate prior to the placement of a resist onto the surface of the substrate. The buffer layer is made from an inert low-Z material (low atomic weight), a material that absorbs secondary X-rays emissions from the substrate that are generated from the substrate upon exposure to a primary X-rays source. Suitable materials for the buffer layer include polyamides and polyimide. The preferred polyimide is synthesized form pyromellitic anhydride and oxydianiline (PMDA-ODA).

  2. Enhanced adhesion for LIGA microfabrication by using a buffer layer

    SciTech Connect

    Bajikar, Sateesh S.; De Carlo, Francesco; Song, Joshua J.

    2004-01-27

    The present invention is an improvement on the LIGA microfabrication process wherein a buffer layer is applied to the upper or working surface of a substrate prior to the placement of a resist onto the surface of the substrate. The buffer layer is made from an inert low-Z material (low atomic weight), a material that absorbs secondary X-rays emissions from the substrate that are generated from the substrate upon exposure to a primary X-rays source. Suitable materials for the buffer layer include polyamides and polyimide. The preferred polyimide is synthesized form pyromellitic anhydride and oxydianiline (PMDA-ODA).

  3. Concentrating Genomic Length DNA in a Microfabricated Array

    NASA Astrophysics Data System (ADS)

    Chen, Yu; Abrams, Ezra S.; Boles, T. Christian; Pedersen, Jonas N.; Flyvbjerg, Henrik; Austin, Robert H.; Sturm, James C.

    2015-05-01

    We demonstrate that a microfabricated bump array can concentrate genomic-length DNA molecules efficiently at continuous, high flow velocities, up to 40 μ m /s , if the single-molecule DNA globule has a sufficiently large shear modulus. Increase in the shear modulus is accomplished by compacting the DNA molecules to minimal coil size using polyethylene glycol (PEG) derived depletion forces. We map out the sweet spot, where concentration occurs, as a function of PEG concentration and flow speed using a combination of theoretical analysis and experiment. Purification of DNA from enzymatic reactions for next-generation DNA-sequencing libraries will be an important application of this development.

  4. Near-field optical microscopy based on microfabricated probes.

    PubMed

    Eckert, R; Freyland, J M; Gersen, H; Heinzelmann, H; Schürmann, G; Noell, W; Staufer, U; De Rooij, N F

    2001-04-01

    We demonstrate high resolution imaging with microfabricated, cantilevered probes, consisting of solid quartz tips on silicon levers. The tips are covered by a 60-nm thick layer of aluminium, which appears to be closed at the apex when investigated by transmission electron microscopy. An instrument specifically built for cantilever probes was used to record images of latex bead projection patterns in transmission as well as single molecule fluorescence. All images were recorded in constant height mode and show optical resolutions down to 32 nm. PMID:11298861

  5. Microfabrication and Applications of Opto-Microfluidic Sensors

    PubMed Central

    Zhang, Daiying; Men, Liqiu; Chen, Qiying

    2011-01-01

    A review of research activities on opto-microfluidic sensors carried out by the research groups in Canada is presented. After a brief introduction of this exciting research field, detailed discussion is focused on different techniques for the fabrication of opto-microfluidic sensors, and various applications of these devices for bioanalysis, chemical detection, and optical measurement. Our current research on femtosecond laser microfabrication of optofluidic devices is introduced and some experimental results are elaborated. The research on opto-microfluidics provides highly sensitive opto-microfluidic sensors for practical applications with significant advantages of portability, efficiency, sensitivity, versatility, and low cost. PMID:22163904

  6. Cell lysis and DNA extraction in microfabricated devices

    NASA Astrophysics Data System (ADS)

    Prinz, Christelle; Tegenfeldt, Jonas; Austin, Robert

    2002-03-01

    We are developing a microfabricated device to lyse single cells and extract the DNA. The chip consists of two parts: a diffuse mixer combined with a dielectrophoretic trap. We are working with E. coli which have been made osmoticaly unstable before loading into the chip. The cells are lysed by osmotic shock in the mixer. The lysate is then passed to the dielectrophoretic trap. Attempts to separate the genomic DNA from the lysate fragments by selectively trapping the DNA using dielectrophoresis have been made. We have encountered cell sticking problems and are investingating surface modifications using Polyethylene glycol to solve this problem.

  7. Imaging of relaxation times and microwave field strength in a microfabricated vapor cell

    NASA Astrophysics Data System (ADS)

    Horsley, Andrew; Du, Guan-Xiang; Pellaton, Matthieu; Affolderbach, Christoph; Mileti, Gaetano; Treutlein, Philipp

    2013-12-01

    We present a characterization technique for atomic vapor cells, combining time-domain measurements with absorption imaging to obtain spatially resolved information on decay times, atomic diffusion, and coherent dynamics. The technique is used to characterize a 5-mm-diameter, 2-mm-thick microfabricated Rb vapor cell, with N2 buffer gas, placed inside a microwave cavity. Time-domain Franzen and Ramsey measurements are used to produce high-resolution images of the population (T1) and coherence (T2) lifetimes in the cell, while Rabi measurements yield images of the σ-, π, and σ+ components of the applied microwave magnetic field. For a cell temperature of 90∘C, the T1 times across the cell center are found to be a roughly uniform 265μs, while the T2 times peak at around 350μs. We observe a “skin” of reduced T1 and T2 times around the edge of the cell due to the depolarization of Rb after collisions with the silicon cell walls. Our observations suggest that these collisions are far from being 100% depolarizing, consistent with earlier observations made with Na and glass walls. Images of the microwave magnetic field reveal regions of optimal field homogeneity, and thus coherence. Our technique is useful for vapor cell characterization in atomic clocks, atomic sensors, and quantum information experiments.

  8. The Intersection of Flow Cytometry with Microfluidics and Microfabrication

    PubMed Central

    Piyasena, Menake E.; Graves, Steven W.

    2014-01-01

    A modern flow cytometer can analyze and sort particles on a one by one basis at rates of 50,000 particles per second. Flow cytometers can also measure as many as 17 channels of fluorescence, several angles of scattered light, and other non-optical parameters such as particle impedance. More specialized flow cytometers can provide even greater analysis power, such as single molecule detection, imaging, and full spectral collection, at reduced rates. These capabilities have made flow cytometers an invaluable tool for numerous applications including cellular immunophenotyping, CD4+ T-cell counting, multiplex microsphere analysis, high-throughput screening, and rare cell analysis and sorting. Many bio-analytical techniques have been influenced by the advent of microfluidics as a component in analytical tools and flow cytometry is no exception. Here we detail the functions and uses of a modern flow cytometer, review the recent and historical contributions of microfluidics and microfabricated devices to field of flow cytometry, examine current application areas, and suggest opportunities for the synergistic application of microfabrication approaches to modern flow cytometry. PMID:24488050

  9. A Scalable Microfabricated Ion Trap for Quantum Information Processing

    NASA Astrophysics Data System (ADS)

    Maunz, Peter; Haltli, Raymond; Hollowell, Andrew; Lobser, Daniel; Mizrahi, Jonathan; Rembetski, John; Resnick, Paul; Sterk, Jonathan D.; Stick, Daniel L.; Blain, Matthew G.

    2016-05-01

    Trapped Ion Quantum Information Processing (QIP) relies on complex microfabricated trap structures to enable scaling of the number of quantum bits. Building on previous demonstrations of surface-electrode ion traps, we have designed and characterized the Sandia high-optical-access (HOA-2) microfabricated ion trap. This trap features high optical access, high trap frequencies, low heating rates, and negligible charging of dielectric trap components. We have observed trap lifetimes of more than 100h, measured trap heating rates for ytterbium of less than 40quanta/s, and demonstrated shuttling of ions from a slotted to an above surface region and through a Y-junction. Furthermore, we summarize demonstrations of high-fidelity single and two-qubit gates realized in this trap. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000. This work was supported by the Intelligence Advanced Research Projects Activity (IARPA).

  10. Microfabrication of transparent materials using filamented femtosecond laser beams

    NASA Astrophysics Data System (ADS)

    Butkus, S.; Paipulas, D.; Gaižauskas, Eugenijus; KaškelytÄ--, D.; Sirutkaitis, V.

    2014-05-01

    Glass drilling realized with the help of femtosecond lasers attract industrial attention, however, desired tasks may require systems employing high numerical aperture (NA) focusing conditions, low repetition rate lasers and complex fast motion translation stages. Due to the sensitivity of such systems, slight instabilities in parameter values can lead to crack formations, severe fabrication rate decrement and poor quality overall results. A microfabrication system lacking the stated disadvantages was constructed and demonstrated in this report. An f-theta lens was used in combination with a galvanometric scanner, in addition, a water pumping system that enables formation of water films of variable thickness in real time on the samples. Water acts as a medium for filament formation, which in turn decreases the focal spot diameter and increases fluence and axial focal length. This article demonstrates the application of a femtosecond (280fs) laser towards rapid cutting of different transparent materials. Filament formation in water gives rise to strong ablation at the surface of the sample, moreover, the water, surrounding the ablated area, adds increased cooling and protection from cracking. The constructed microfabrication system is capable of drilling holes in thick soda-lime, hardened glasses and sapphire. The fabrication time varies depending on the diameter of the hole and spans from a few to several hundred seconds. Moreover, complex-shape fabrication was demonstrated.

  11. Microcontact printing of self-assembled monolayers: applications in microfabrication

    NASA Astrophysics Data System (ADS)

    Wilbur, James L.; Kumar, Amit; Biebuyck, Hans A.; Kim, Enoch; Whitesides, George M.

    1996-12-01

    This paper describes applications in microfabrication using patterned self-assembled monolayers (SAMs) formed by microcontact printing. Microcontact printing 0957-4484/7/4/028/img1 is a flexible new technique that forms patterned SAMs with regions terminated by different chemical functionalities (and thus different physical and chemical properties), in patterns with 0957-4484/7/4/028/img2 dimensions. Patterns of SAM are formed using an alkanethiol as an `ink', and printing the alkanethiol on a metal support with elastomeric `stamp'. We fabricate the stamp by moulding a silicone elastomer using a master prepared by optical or x-ray microlithography or by other techniques. SAMs of long-chain alkanethiolates on gold and other metals can act as nanometer resists by protecting the supporting metal from corrosion by appropriately formulated etchants: the fabrication of microstructures of gold and silicon demonstrates the utility of patterned SAMs (formed by 0957-4484/7/4/028/img3) as nm resists. Patterned SAMs formed by 0957-4484/7/4/028/img3 can also control the wettability of a surface on the 0957-4484/7/4/028/img2 scale. The organization of liquids in patterned arrays with 0957-4484/7/4/028/img2 dimensions, and the patterned deposition of microcrystals and microcrystal arrays illustrate the use of controlled wettability for microfabrication.

  12. Ball-grid array architecture for microfabricated ion traps

    SciTech Connect

    Guise, Nicholas D. Fallek, Spencer D.; Stevens, Kelly E.; Brown, K. R.; Volin, Curtis; Harter, Alexa W.; Amini, Jason M.; Higashi, Robert E.; Lu, Son Thai; Chanhvongsak, Helen M.; Nguyen, Thi A.; Marcus, Matthew S.; Ohnstein, Thomas R.; Youngner, Daniel W.

    2015-05-07

    State-of-the-art microfabricated ion traps for quantum information research are approaching nearly one hundred control electrodes. We report here on the development and testing of a new architecture for microfabricated ion traps, built around ball-grid array (BGA) connections, that is suitable for increasingly complex trap designs. In the BGA trap, through-substrate vias bring electrical signals from the back side of the trap die to the surface trap structure on the top side. Gold-ball bump bonds connect the back side of the trap die to an interposer for signal routing from the carrier. Trench capacitors fabricated into the trap die replace area-intensive surface or edge capacitors. Wirebonds in the BGA architecture are moved to the interposer. These last two features allow the trap die to be reduced to only the area required to produce trapping fields. The smaller trap dimensions allow tight focusing of an addressing laser beam for fast single-qubit rotations. Performance of the BGA trap as characterized with {sup 40}Ca{sup +} ions is comparable to previous surface-electrode traps in terms of ion heating rate, mode frequency stability, and storage lifetime. We demonstrate two-qubit entanglement operations with {sup 171}Yb{sup +} ions in a second BGA trap.

  13. Microfabricated Chemical Sensors for Aerospace Fire Detection Applications

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.; Neudeck, Philip G.; Fralick, Gustave; Thomas, Valarie; Makel, D.; Liu, C. C.; Ward, B.; Wu, Q. H.

    2001-01-01

    The detection of fires on-board commercial aircraft is extremely important for safety reasons. Although dependable fire detection equipment presently exists within the cabin, detection of fire within the cargo hold has been less reliable and susceptible to false alarms. A second, independent method of fire detection to complement the conventional smoke detection techniques, such as the measurement of chemical species indicative of a fire, will help reduce false alarms and improve aircraft safety. Although many chemical species are indicative of a fire, two species of particular interest are CO and CO2. This paper discusses microfabricated chemical sensor development tailored to meet the needs of fire safety applications. This development is based on progress in three types of technology: 1) Micromachining and microfabrication (Microsystem) technology to fabricate miniaturized sensors. 2) The use of nanocrystalline materials to develop sensors with improved stability combined with higher sensitivity. 3) The development of high temperature semiconductors, especially silicon carbide. The individual sensor being developed and their level of maturity will be presented.

  14. Microfabricated, amperometric, enzyme-based biosensors for in vivo applications.

    PubMed

    Weltin, Andreas; Kieninger, Jochen; Urban, Gerald A

    2016-07-01

    Miniaturized electrochemical in vivo biosensors allow the measurement of fast extracellular dynamics of neurotransmitter and energy metabolism directly in the tissue. Enzyme-based amperometric biosensing is characterized by high specificity and precision as well as high spatial and temporal resolution. Aside from glucose monitoring, many systems have been introduced mainly for application in the central nervous system in animal models. We compare the microsensor principle with other methods applied in biomedical research to show advantages and drawbacks. Electrochemical sensor systems are easily miniaturized and fabricated by microtechnology processes. We review different microfabrication approaches for in vivo sensor platforms, ranging from simple modified wires and fibres to fully microfabricated systems on silicon, ceramic or polymer substrates. The various immobilization methods for the enzyme such as chemical cross-linking and entrapment in polymer membranes are discussed. The resulting sensor performance is compared in detail. We also examine different concepts to reject interfering substances by additional membranes, aspects of instrumentation and biocompatibility. Practical considerations are elaborated, and conclusions for future developments are presented. Graphical Abstract ᅟ. PMID:26935934

  15. Microfabricated Chemical Gas Sensors and Sensor Arrays for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.

    2005-01-01

    Aerospace applications require the development of chemical sensors with capabilities beyond those of commercially available sensors. In particular, factors such as minimal sensor size, weight, and power consumption are particularly important. Development areas which have potential aerospace applications include launch vehicle leak detection, engine health monitoring, and fire detection. Sensor development for these applications is based on progress in three types of technology: 1) Micromachining and microfabrication (Microsystem) technology to fabricate miniaturized sensors; 2) The use of nanocrystalline materials to develop sensors with improved stability combined with higher sensitivity; 3) The development of high temperature semiconductors, especially silicon carbide. This presentation discusses the needs of space applications as well as the point-contact sensor technology and sensor arrays being developed to address these needs. Sensors to measure hydrogen, hydrocarbons, nitrogen oxides (NO,), carbon monoxide, oxygen, and carbon dioxide are being developed as well as arrays for leak, fire, and emissions detection. Demonstrations of the technology will also be discussed. It is concluded that microfabricated sensor technology has significant potential for use in a range of aerospace applications.

  16. Microfabricated capillary electrophoresis amino acid chirality analyzer for extraterrestrial exploration

    NASA Technical Reports Server (NTRS)

    Hutt, L. D.; Glavin, D. P.; Bada, J. L.; Mathies, R. A.

    1999-01-01

    Chiral separations of fluorescein isothiocyanate-labeled amino acids have been performed on a microfabricated capillary electrophoresis chip to explore the feasibility of using such devices to analyze for extinct or extant life signs in extraterrestrial environments. The test system consists of a folded electrophoresis channel (19.0 cm long x 150 microns wide x 20 microns deep) that was photolithographically fabricated in a 10-cm-diameter glass wafer sandwich, coupled to a laser-excited confocal fluorescence detection apparatus providing subattomole sensitivity. Using a sodium dodecyl sulfate/gamma-cyclodextrin pH 10.0 carbonate electrophoresis buffer and a separation voltage of 550 V/cm at 10 degrees C, baseline resolution was observed for Val, Ala, Glu, and Asp enantiomers and Gly in only 4 min. Enantiomeric ratios were determined for amino acids extracted from the Murchison meteorite, and these values closely matched values determined by HPLC. These results demonstrate the feasibility of using microfabricated lab-on-a-chip systems to analyze extraterrestrial samples for amino acids.

  17. Microfabricated Instrumentation for Chemical Sensing in Industrial Process Control

    SciTech Connect

    Ramsey, J. M.

    2000-06-01

    The monitoring of chemical constituents in manufacturing processes is of economic importance to most industries. The monitoring and control of chemical constituents may be of importance for product quality control or, in the case of process effluents, of environmental concern. The most common approach now employed for chemical process control is to collect samples which are returned to a conventional chemical analysis laboratory. This project attempts to demonstrate the use of microfabricated structures, referred to as 'lab-on-a-chip' devices, that accomplish chemical measurement tasks that emulate those performed in the conventional laboratory. The devices envisioned could be used as hand portable chemical analysis instruments where samples are analyzed in the field or as emplaced sensors for continuous 'real-time' monitoring. This project focuses on the development of filtration elements and solid phase extraction elements that can be monolithically integrated onto electrophoresis and chromatographic structures pioneered in the laboratory. Successful demonstration of these additional functional elements on integrated microfabricated devices allows lab-on-a-chip technologies to address real world samples that would be encountered in process control environments. The resultant technology has a broad application to industrial environmental monitoring problems. such as monitoring municipal water supplies, waste water effluent from industrial facilities, or monitoring of run-off from agricultural activities. The technology will also be adaptable to manufacturing process control scenarios. Microfabricated devices integrating sample filtration, solid phase extraction, and chromatographic separation with solvent programming were demonstrated. Filtering of the sample was accomplished at the same inlet with an array of seven channels each 1 {micro}m deep and 18 {micro}m wide. Sample concentration and separation were performed on channels 5 {micro}m deep and 25 {micro

  18. Sub-to super-ambient temperature programmable microfabricated gas chromatography column

    DOEpatents

    Robinson, Alex L.; Anderson, Lawrence F.

    2004-03-16

    A sub- to super-ambient temperature programmable microfabricated gas chromatography column enables more efficient chemical separation of chemical analytes in a gas mixture by combining a thermoelectric cooler and temperature sensing on the microfabricated column. Sub-ambient temperature programming enables the efficient separation of volatile organic compounds and super-ambient temperature programming enables the elution of less volatile analytes within a reasonable time. The small heat capacity and thermal isolation of the microfabricated column improves the thermal time response and power consumption, both important factors for portable microanalytical systems.

  19. Rapid microfabrication of transparent materials using filamented femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Butkus, S.; Gaižauskas, E.; Paipulas, D.; Viburys, Ž.; Kaškelyė, D.; Barkauskas, M.; Alesenkov, A.; Sirutkaitis, V.

    2014-01-01

    Microfabrication of transparent materials using femtosecond laser pulses has showed good potential towards industrial application. Maintaining pulse energies exceeding the critical self-focusing threshold by more than 100-fold produced filaments that were used for micromachining purposes. This article demonstrates two different micromachining techniques using femtosecond filaments generated in different transparent media (water and glass). The stated micromachining techniques are cutting and welding of transparent samples. In addition, cutting and drilling experiments were backed by theoretical modelling giving a deeper insight into the whole process. We demonstrate cut-out holes in soda-lime glass having thickness up to 1 mm and aspect ratios close to 20, moreover, the fabrication time is of the order of tens of seconds, in addition, grooves and holes were fabricated in hardened 1.1 mm thick glass (Corning Gorilla glass). Glass welding was made possible and welded samples were achieved after several seconds of laser fabrication.

  20. Techniques For Microfabricating Coils For Microelectromechanical Systems Applications

    SciTech Connect

    Woods, R. C.; Powell, A. L.

    2008-01-21

    The advanced technology necessary for building future space exploration vehicles includes microfabricated coils for making possible self-inductances integrated with other passive and active electronic components. Integrated inductances make possible significant improvements in reliability over the traditional arrangement of using external discrete inductances, as well as allowing significant size (volume) reductions (also important in space vehicles). Two possible fabrication techniques (one using proprietary branded 'Foturan' glass, the other using silicon wafer substrates) for microscopic coils are proposed, using electroplating into channels. The techniques have been evaluated for fabricating the planar electrical coils needed for typical microelectromechanical systems applications. There remain problems associated with processing using 'Foturan' glass, but coil fabrication on silicon wafers was successful. Fabrication methods such as these are expected to play an important part in the development of systems and subsystems for forthcoming space exploration missions.

  1. Microfabrication of Fresnel zone plates by laser induced solid ablation

    NASA Astrophysics Data System (ADS)

    Rodrigues, Vanessa R. M.; Thomas, John; Santhosh, Chidangil; Ramachandran, Hema; Mathur, Deepak

    2016-07-01

    A novel and simple single-step method of inscribing optical elements on metal-coated transparent substrates is demonstrated. Laser induced solid ablation (LISA) demands very low laser energies (nJ), as can be amply provided by a femtosecond laser oscillator. Here, LISA is used to write Fresnel zone plates on indium and tungsten coated glass. With up to 100 zones, remarkable agreement is obtained between measured and expected values of the focal length. LISA has enabled attainment of focal spot sizes that are 38% smaller than what would be obtained using conventional lenses of the same numerical aperture. The simplicity with which a high degree of automation can readily be achieved using LISA makes this cost-effective method amenable to a wide variety of applications related to microfabrication of optical elements.

  2. Microfabricated Gas Sensors Demonstrated in Fire and Emission Applications

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.

    2003-01-01

    A range of microfabricated chemical sensors are being developed to meet the needs of fire detection and emission monitoring in aerospace applications. These sensors have the advantages over traditional technology of minimal size, weight, and power consumption as well as the ability to be placed closer to where the measurements need to be made. Sensor arrays are being developed to address detection needs in environments where multiple species need to be measured. For example, the monitoring of chemical species such as carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons, and other species is important in the detection of fires on airplanes and spacecraft. In contrast, different sensors are necessary for characterizing some aircraft engine designs where the monitoring of nitrogen oxides (NO(x)) and CO is of high interest. Demonstration of both fire and emission microsensor technology was achieved this year in a collaborative effort undertaken by the NASA Glenn Research Center, Case Western Reserve University, and Makel Engineering, Inc.

  3. Microfabricated multi-frequency particle impedance characterization system

    SciTech Connect

    Fuller, C K; Hamilton, J; Ackler, H; Krulevitch, P; Boser, B; Eldredge, A; Becker, F; Yang, J; Gascoyne, P

    2000-03-01

    We have developed a microfabricated flow-through impedance characterization system capable of performing AC, multi-frequency measurements on cells and other particles. The sensor measures both the resistive and reactive impedance of passing particles, at rates of up to 100 particles per second. Its operational bandwidth approaches 10 MHz with a signal-to-noise ratio of approximately 40 dB. Particle impedance is measured at three or more frequencies simultaneously, enabling the derivation of multiple particle parameters. This constitutes an improvement to the well-established technique of DC particle sizing via the Coulter Principle. Human peripheral blood granulocyte radius, membrane capacitance, and cytoplasmic conductivity were measured (r = 4.1 {micro}m, C{sub mem} = 0.9 {micro}F/cm{sup 2}, {sigma}{sub int} = 0.66 S/m) and were found to be consistent with published values.

  4. Thermal and Structural Analysis of Micro-Fabricated Involute Regenerators

    NASA Astrophysics Data System (ADS)

    Qiu, Songgang; Augenblick, Jack E.

    2005-02-01

    Long-life, high-efficiency power generators based on free-piston Stirling engines are an energy conversion solution for future space power generation and commercial applications. As part of the efforts to further improve Stirling engine efficiency and reliability, a micro-fabricated, involute regenerator structure is proposed by a Cleveland State University-led regenerator research team. This paper reports on thermal and structural analyses of the involute regenerator to demonstrate the feasibility of the proposed regenerator. The results indicate that the involute regenerator has extremely high axial stiffness to sustain reasonable axial compression forces with negligible lateral deformation. The relatively low radial stiffness may impose some challenges to the appropriate installation of the in-volute regenerators.

  5. Development of a hydrogen gas sensor using microfabrication technology

    NASA Technical Reports Server (NTRS)

    Liu, Chung-Chiun; Wu, Qinghai; Stuczynski, Matthew; Madzsar, George C.

    1992-01-01

    Microfabrication and micromachining technologies are used to produce a hydrogen gas sensor based on a palladium-silver film. The sensor uses a heater that is fabricated by diffusing p-type borones into the substrate, forming a resistance heater. A diode for temperature measurement is produced using p-type boron and n-type phosphor diffused into the substrate. A thickness of the palladium-silver film is approximately 300 arcsec. The hydrogen gas sensor employs the proven palladium-silver diode structure and is surrounded by a phosphor doped resistance heater which can be heated up to a temperature of 250 C. Experimental results show that the sensor is capable of operating over a wide range of hydrogen concentration levels between 0-95 percent without any hysteresis effects.

  6. A Microfabricated Involute-Foil Regenerator for Stirling Engines

    NASA Technical Reports Server (NTRS)

    Tew, Roy; Ibrahim, Mounir; Danila, Daniel; Simon, Terry; Mantell, Susan; Sun, Liyong; Gedeon, David; Kelly, Kevin; McLean, Jeffrey; Wood, Gary; Qiu, Songgang

    2007-01-01

    A segmented involute-foil regenerator has been designed, microfabricated and tested in an oscillating-flow rig with excellent results. During the Phase I effort, several approximations of parallel-plate regenerator geometry were chosen as potential candidates for a new microfabrication concept. Potential manufacturers and processes were surveyed. The selected concept consisted of stacked segmented-involute-foil disks (or annular portions of disks), originally to be microfabricated from stainless-steel via the LiGA (lithography, electroplating, and molding) process and EDM (electric discharge machining). During Phase II, re-planning of the effort led to test plans based on nickel disks, microfabricated via the LiGA process, only. A stack of nickel segmented-involute-foil disks was tested in an oscillating-flow test rig. These test results yielded a performance figure of merit (roughly the ratio of heat transfer to pressure drop) of about twice that of the 90% random fiber currently used in small 100 W Stirling space-power convertors in the Reynolds Number range of interest (50-100). A Phase III effort is now underway to fabricate and test a segmented-involute-foil regenerator in a Stirling convertor. Though funding limitations prevent optimization of the Stirling engine geometry for use with this regenerator, the Sage computer code will be used to help evaluate the engine test results. Previous Sage Stirling model projections have indicated that a segmented-involute-foil regenerator is capable of improving the performance of an optimized involute-foil engine by 6-9%; it is also anticipated that such involute-foil geometries will be more reliable and easier to manufacture with tight-tolerance characteristics, than random-fiber or wire-screen regenerators. Beyond the near-term Phase III regenerator fabrication and engine testing, other goals are (1) fabrication from a material suitable for high temperature Stirling operation (up to 850 C for current engines; up to

  7. Microfabricated rubber microscope using soft solid immersion lenses

    NASA Astrophysics Data System (ADS)

    Gambin, Yann; Legrand, Olivier; Quake, Stephen R.

    2006-04-01

    We show here a technique of soft lithography to microfabricate efficient solid immersion lenses (SIL) out of rubber elastomers. The light collection efficiency of a lens system is described by its numerical aperture (NA), and is critical for applications as epifluorescence microscopy [B. Herman, Fluorescence Microscopy (BIOS Scientific, Oxford/Springer, United Kingdom, 1998). While most simple lens systems have numerical apertures less than 1, the lenses described here have NA =1.25. Better performance can be engineered though the use of compound designs; we used this principle to make compound solid immersion lenses (NA=1.32). An important application of these lenses will be as integrated optics for microfluidic devices. We incorporated them into a handheld rubber microscope for microfluidic flow cytometry and imaged single E. Coli cells by fluorescence.

  8. Progress Towards Quantum Simulation Using Micro-fabricated Ion Traps

    NASA Astrophysics Data System (ADS)

    Wright, K.; Ji, G.; Rickerd, C.; Collins, K.; Monroe, C.

    2015-05-01

    We report on current experimental progress towards using a surface electrode trap for quantum simulation. We use a micro-fabricated trap developed collaboratively between the Georgia Tech Research Institute (GTRI) and Honeywell International known as the Ball Grid Array (BGA) trap. This trap features 96 electrodes for fine control of the DC potential as well as a small footprint allowing for tight focusing of interaction lasers. We discuss the experimental system which utilizes the BGA trap, loading of Yb171 ions in this trap, and deterministic loading of chains of five or more ions. We hope to take advantage of the features of this new trap architecture in order to perform a small scale Boson Sampling experiment. This work is performed in collaboration with the GTRI Ion Trap Group and supported by ARO with funding from the IARPA MQCO program, and the AFOSR STTR on Atom Trap Chips.

  9. How to Concentrate Genomic Length DNA in a Microfabricated Array

    NASA Astrophysics Data System (ADS)

    Chen, Yu; Abrams, Ezra; Boles, Christian; Pedersen, Jonas; Flyvbjerg, Henrik; Sturm, James; Austin, Robert

    We demonstrate that a microfabricated bump array can concentrate genomic-length DNA molecules efficiently at continuous, high flow velocities, up to 40 ?m/s, if the single-molecule DNA globule has a sufficiently large shear modulus.. Increase in the shear modulus is accomplished by compacting the DNA molecules to minimal coil-size using polyethylene glycol (PEG) derived depletion forces. We map out the sweet spot where concentration occurs as a function of PEG con- centration, flow speed, and bump array parameters using a combination of theoretical analysis and experiment. Purification of DNA from enzymatic reactions for next-generation DNA-sequencing libraries will be an important application of this development.

  10. Solid-state microscale lithium batteries prepared with microfabrication processes

    NASA Astrophysics Data System (ADS)

    Song, Jie; Yang, Xi; Zeng, Shuang-Shuang; Cai, Min-Zhen; Zhang, Liang-Tang; Dong, Quan-Feng; Zheng, Ming-Sen; Wu, Sun-Tao; Wu, Qi-Hui

    2009-04-01

    The miniaturization of power sources is important for meeting the requirements of low power, mass and volume for nano- or microelectronics and MEMS devices. In this paper a dexterous microfabrication process was developed for preparing microscale solid-state lithium batteries. The active size of a single microbattery is 500 µm × 500 µm and its thickness is 1.5 µm. LiCoO2 films prepared by RF sputtering, then annealed at moderate temperature (500 °C), were employed as a cathode electrode, and LiPON and Al films were used as a solid electrolyte and an anode electrode, respectively. An individual microbattery delivers a capacity of about 17 nAh at a current of 5 nA at the initial cycles, and can be operated at as high as 40 nA discharge current.

  11. A Microfabricated Involute-Foil Regenerator for Stirling Engines

    NASA Technical Reports Server (NTRS)

    Tew, Roy; Ibrahim, Mounir; Danila, Daniel; Simon, Terrence; Mantell, Susan; Sun, Liyong; Gedeon, David; Kelly, Kevin; McLean, Jeffrey; Qiu, Songgang

    2007-01-01

    A segmented involute-foil regenerator has been designed, microfabricated and tested in an oscillating-flow rig with excellent results. During the Phase I effort, several approximations of parallel-plate regenerator geometry were chosen as potential candidates for a new microfabrication concept. Potential manufacturers and processes were surveyed. The selected concept consisted of stacked segmented-involute-foil disks (or annular portions of disks), originally to be microfabricated from stainless-steel via the LiGA (lithography, electroplating, and molding) process and EDM. During Phase II, re-planning of the effort led to test plans based on nickel disks, microfabricated via the LiGA process, only. A stack of nickel segmented-involute-foil disks was tested in an oscillating-flow test rig. These test results yielded a performance figure of merit (roughly the ratio of heat transfer to pressure drop) of about twice that of the 90 percent random fiber currently used in small approx.100 W Stirling space-power convertors-in the Reynolds Number range of interest (50 to 100). A Phase III effort is now underway to fabricate and test a segmented-involute-foil regenerator in a Stirling convertor. Though funding limitations prevent optimization of the Stirling engine geometry for use with this regenerator, the Sage computer code will be used to help evaluate the engine test results. Previous Sage Stirling model projections have indicated that a segmented-involute-foil regenerator is capable of improving the performance of an optimized involute-foil engine by 6 to 9 percent; it is also anticipated that such involute-foil geometries will be more reliable and easier to manufacture with tight-tolerance characteristics, than random-fiber or wire-screen regenerators. Beyond the near-term Phase III regenerator fabrication and engine testing, other goals are (1) fabrication from a material suitable for high temperature Stirling operation (up to 850 C for current engines; up to 1200 C

  12. A review of microfabrication techniques and dielectrophoretic microdevices for particle manipulation and separation

    NASA Astrophysics Data System (ADS)

    Li, M.; Li, W. H.; Zhang, J.; Alici, G.; Wen, W.

    2014-02-01

    The development of lab-on-a-chip (LOC) devices over the past decade has attracted growing interest. LOC devices aim to achieve the miniaturization, integration, automation and parallelization of biological and chemical assays. One of the applications, the ability to effectively and accurately manipulate and separate micro- and nano-scale particles in an aqueous solution, is particularly appealing in biological, chemical and medical fields. Among the technologies that have been developed and implemented in microfluidic microsystems for particle manipulation and separation (such as mechanical, inertial, hydrodynamic, acoustic, optical, magnetic and electrical methodologies), dielectrophoresis (DEP) may prove to be the most popular because of its label-free nature, ability to manipulate neutral bioparticles, analyse with high selectivity and sensitivity, compatibility with LOC devices, and easy and direct interface with electronics. The required spatial electric non-uniformities for the DEP effect can be generated by patterning microelectrode arrays within microchannels, or placing insulating obstacles within a microchannel and curving the microchannels. A wide variety of electrode- and insulator-based DEP microdevices have been developed, fabricated, and successfully employed to manipulate and separate bioparticles (i.e. DNA, proteins, bacteria, viruses, mammalian and yeast cells). This review provides an overview of the state-of-the-art of microfabrication techniques and of the structures of dielectrophoretic microdevices aimed towards different applications. The techniques used for particle manipulation and separation based on microfluidics are provided in this paper. In addition, we also present the theoretical background of DEP.

  13. Microfabrication of the UV transparent polymer CYTOP using a conventional pulsed green laser

    NASA Astrophysics Data System (ADS)

    Ogawa, Tatsuya; Hanada, Yasutaka

    2016-03-01

    We report the surface microfabrication of CYTOP, an amorphous UV transparent fluoric polymer, using a conventional pulsed green laser. Fluorine-based polymers have unique characteristics, including high transparency from the deep-UV to the IR wavelengths, chemical stability and low refractive indices, and thus are expected to have a number of industrial applications. However, CYTOP and other fluoric polymers are generally very difficult to microfabricate. Therefore, we have developed a technique for the crack-free surface microfabrication of a CYTOP substrate based on ablation with a pulsed green laser followed by successive wet etching and annealing. In this work, the fundamental surface characteristics of the fabricated area were investigated. Following the surface microfabrication of CYTOP, a three-dimensional biochip was fabricated using a conventional bonding technique to demonstrate that a CYTOP biochip is superior to conventional transparent biochips with regard to the microscopic observation of cell motion.

  14. DETERMINATION OF HETEROGENEOUS ELECTRON TRANSFER RATE CONSTANTS AT MICROFABRICATED IRIDIUM ELECTRODES. (R825511C022)

    EPA Science Inventory

    There has been an increasing use of both solid metal and microfabricated iridium electrodes as substrates for various types of electroanalysis. However, investigations to determine heterogeneous electron transfer rate constants on iridium, especially at an electron beam evapor...

  15. DEM microfabrication technique and its applications in bioscience and microfluidic systems

    NASA Astrophysics Data System (ADS)

    Chen, Di; Yang, Fan; Tang, Min; Li, Yigui; Zhu, Jun; Zhang, Dacheng

    2001-10-01

    A new LIGA-like microfabrication technique was developed by present authors. DEM (deepetching, electroforming and microreplication) is the abbreviation of three main process steps in this new microfabrication technique. In contrast to LIGA technique, DEM technique has the advantages of lower cost and shorter process period. Microfluidic systems like plastic capillary electrophoresis chips, micro flowmeters and three-dimensional DNA chips were developed using DEM technique. DEM technique offers a new way for fabrication of MEMS and MOEMS components.

  16. Use of atomic force microscopy (AFM) for microfabric study of cohesive soils.

    PubMed

    Sachan, A

    2008-12-01

    Microfabric reflects the imprints of the geologic and stress history of the soil deposit, the depositional environment and weathering history. Many investigators have been concerned with the fundamental problem of how the engineering properties of clay depend on the microfabric, which can be defined as geometric arrangement of particles within the soil mass. It is believed that scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are the only techniques that can reveal particle arrangements of clayey soils directly; however, current research introduces a novel and more advanced technique, atomic force microscopy, to evaluate the microfabric of cohesive materials. The atomic force microscopy has several advantages over SEM/TEM for characterizing cohesive particles at the sub-micrometre range by providing 3D images and 2D images with Z-information used in quantitative measurements of soil microfabric using SPIP software, and having the capability of obtaining images in all environments (ambient air, liquids and vacuums). This paper focuses on the use of atomic force microscopy technique to quantify the microfabric of clayey soils by developing the criteria for average and maximum values of angle of particle orientation within the soil mass using proposed empirical equations for intermediate and extreme microfabrics (dispersed, flocculated). PMID:19094019

  17. A microfabricated scanning confocal optical microscope for in situ imaging

    NASA Astrophysics Data System (ADS)

    Dickensheets, David Lee

    Scanning confocal optical microscopes are well suited for imaging living tissue because of their ability to 'cross section' intact tissue. They are not, however, well suited for imaging tissues in situ. This dissertation describes a new, miniature, mirror scanned, high resolution confocal optical microscope that operates in real time. It is small enough to fit into an endoscope, and may eventually be incorporated into a hypodermic needle. Such a device would provide immediate in-situ tissue assessment at the cellular level and may enable, for example, biopsy without tissue removal. Non-medical applications may include process monitoring and endoscopic inspection. The microfabricated confocal optical scanning microscope, or μCOSM, incorporates single mode optical fiber illumination, silicon torsional scan mirrors, and an off- axis micro diffractive lens. The prototype device is monochromatic, at 633 nm, with a 1.1 mm working distance and 0.25 NA. It achieves a line response of 0.98 μm FWHM, and an axial response of 11.1 μm FWHM. The first part of the dissertation describes the opto- mechanical design of the microscope, which was chosen to be compatible with the microfabrication technologies used for its construction. Then the imaging properties of the off-axis diffractive objective lens are developed, including the aberrations of second and third order which constrain its use. The lens is a surface relief phase grating, and a rigorous electromagnetic analysis is employed to specify the pupil function of the microscope. Then the image forming properties of the μCOSM are derived and compared to experimental results. The second part of the dissertation describes the fabrication of the individual elements of the μCOSM, and their assembly into an imaging instrument. The lens is constructed using electron beam lithography and reactive ion etching of a fused silica substrate. The scanning mirrors for the microscope, which comprise a single crystal silicon plate

  18. Fluid and Cell Transport Through a Microfabricated Flow Chamber.

    NASA Astrophysics Data System (ADS)

    Brody, James Patrick

    We use silicon processing techniques to construct microfabricated fluid flow chambers. Custom designed silicon wafers with feature sizes of 1-10 μm and etch depths from 0.5-5 μm are anodically bonded to Pyrex glass to create a hermetically sealed chamber. A pressure gradient is placed across the chamber to induce bulk fluid flow. Properties of fluid flow and red blood cells are recorded using video microscopy. The human red blood cell is ideal for studying cellular membranes. It is an 8 μm diameter biconcave disc containing a membrane and associated cytoskeleton which surrounds a thick solution of hemoglobin. The material properties of individual red blood cells have been extensively studied in the past using micropipettes. However, we can get statistics on hundreds of red blood cells by fabricating an array of narrow channels 4 mu m x 4 μm in cross-section (the diameter of the smallest capillaries in the human body) and 13 μm long. These narrow channels are followed by an open space. This geometry forces red cells to repeatedly fold and unfold. Using these arrays, we show that the shear modulus of the membrane does not have a unique value, but has a distribution that ranges from 3-12 times 10 ^{-6} N/m. The surprisingly wide distribution is not due to cell size or cell age. It does seem to be correlated with intracellular Ca^ {2+}<=vels, leading us to believe that cell rigidity is controlled by some active process. We also report observations on red blood cells changing their rigidity by factors of fifty over tens of seconds. These microfabricated flow chambers are ideal for studying fluid flow through porous media. We construct custom designed two-dimensional environments with micron size features. These environments can be described by simple analytical theories which also attempt to describe flow through rock. For example, we image viscous imbibition of water into a percolation grid with 5 mu m edges in real time, and measure the permeability as a function

  19. Microfabrication and Test of a Three-Dimensional Polymer Hydro-focusing Unit for Flow Cytometry Applications

    NASA Technical Reports Server (NTRS)

    Yang, Ren; Feeback, Daniel L.; Wang, Wanjun

    2004-01-01

    This paper details a novel three-dimensional (3D) hydro-focusing micro cell sorter for micro flow cytometry applications. The unit was microfabricated by means of SU-8 3D lithography. The 3D microstructure for coaxial sheathing was designed, microfabricated, and tested. Three-dimensional hydro-focusing capability was demonstrated with an experiment to sort labeled tanned sheep erythrocytes (red blood cells). This polymer hydro-focusing microstructure is easily microfabricated and integrated with other polymer microfluidic structures.

  20. High sensitivity, low power, microfabricated electrochemical sensor for CO

    SciTech Connect

    Neuzil, P.; Kayvani, D.; Maclay, G.J.

    1996-12-31

    CO is a toxic byproduct of incomplete combustion. Improperly vented fireplaces and faulty furnaces cause a estimated 400 deaths in the US each year. The presence of high CO levels may also indicate the presence of a fire. Hence, improved CO detection is of great interest and in the last several years commercial CO detectors have been released. The two most common methods of CO detection in commercial systems for residential use are (1) optical colorometric method, and (2) tin oxide sensor. The colorometric method has the advantage of low power, but the devices tend to give an alarm condition when exposed to low CO levels for a long time period, are difficult to reset, and have a lifetime of about 1 year. The tin oxide sensors have limited stability and high power requirement since the sensor must be heated. There is a need for a stable, sensitive, low power, low cost CO sensor. The authors have developed a planar amperometric sensor for CO detection using microfabrication technology.

  1. Microfabrication of High-Resolution Porous Membranes for Cell Culture

    PubMed Central

    Kim, Monica Y.; Li, David Jiang; Pham, Long K.; Wong, Brandon G.

    2014-01-01

    Microporous membranes are widely utilized in cell biology to study cell-cell signaling and cell migration. However, the thickness and low porosity of commercial track-etched membranes limit the quality of cell imaging and the degree of cell-cell contact that can be achieved on such devices. We employ photolithography-based microfabrication to achieve porous membranes with pore diameter as small as 0.9 μm, up to 40% porosity, and less than 5% variation in pore size. Through the use of a soap release layer, membranes as thin as 1 μm can be achieved. The thin membranes minimally disrupt contrast enhancement optics, thus allowing good quality imaging of unlabeled cells under white light, unlike commercial membranes. In addition, the polymer membrane materials display low autofluorescence even after patterning, facilitating high quality fluorescence microscopy. Finally, confocal imaging suggests that substantial cell-cell contact is possible through the pores of these thin membranes. This membrane technology can enhance existing uses of porous membranes in cell biology as well as enable new types of experiments. PMID:24567663

  2. Microresonator Brillouin laser stabilization using a microfabricated rubidium cell

    NASA Astrophysics Data System (ADS)

    Loh, William; Hummon, Matthew T.; Leopardi, Holly F.; Fortier, Tara M.; Quinlan, Frank; Kitching, John; Papp, Scott B.; Diddams, Scott A.

    2016-06-01

    We frequency stabilize the output of a miniature stimulated Brillouin scattering (SBS) laser to rubidium atoms in a microfabricated cell to realize a laser system with frequency stability at the $10^{-11}$ level over seven decades in averaging time. In addition, our system has the advantages of robustness, low cost and the potential for integration that would lead to still further miniaturization. The SBS laser operating at 1560 nm exhibits a spectral linewidth of 820 Hz, but its frequency drifts over a few MHz on the 1 hour timescale. By locking the second harmonic of the SBS laser to the Rb reference, we reduce this drift by a factor of $10^3$ to the level of a few kHz over the course of an hour. For our combined SBS and Rb laser system, we measure a frequency noise of $4\\times10^4$ $Hz^2/Hz$ at 10 Hz offset frequency which rapidly rolls off to a level of 0.2 $Hz^2/Hz$ at 100 kHz offset. The corresponding Allan deviation is $\\leq2\\times10^{-11}$ for averaging times spanning $10^{-4}$ to $10^3$ s. By optically dividing the signal of the laser down to microwave frequencies, we generate an RF signal at 2 GHz with phase noise at the level of -76 dBc/Hz and -140 dBc/Hz at offset frequencies of 10 Hz and 10 kHz, respectively.

  3. A microfabricated nanocalorimeter: design, characterization, and chemical calibration.

    PubMed

    Xu, Junkai; Reiserer, Ron; Tellinghuisen, Joel; Wikswo, John P; Baudenbacher, Franz J

    2008-04-15

    A microfabricated titration calorimeter having nanowatt sensitivity is presented. The device is achieved by modifying a commercial, suspended-membrane, thin-film thermopile infrared sensor. Chemical reactions are studied by placing a 50.0 nL droplet of one reagent directly on the sensor and injecting nanoliter droplets of a second reagent through a micropipette by means of a pressure-driven droplet injector with 1% reliability in volume delivery. External thermal noise is minimized by a two-layer thermal shielding system. Evaporation is prevented by positioning the micropipette through a tiny hole in a cover glass, sealed by a drop of oil. The device is calibrated using two acid-base reactions: H2SO4 + HEPES buffer, and NaOH + HCl. The measured power sensitivity is 2.90(4) V/W, giving a detection limit of 22 nW. The 1/e time constant for a single injection is 1.1 s. The day-to-day power sensitivity is reproducible to approximately 2%. A computational model of the sensor reproduces the power sensitivity within 10% and the time constant within 20%. For a 50 nL sample and 0.8-1.5 nL titrant injection volumes, the heat uncertainty of 44 nJ corresponds to a 3sigma detection limit of 132 nJ, or the binding energy associated with 2.9 pM of IgG-protein A complex. PMID:18351750

  4. DNA separations in microfabricated devices with automated capillary sample introduction.

    PubMed

    Smith, E M; Xu, H; Ewing, A G

    2001-01-01

    A novel method is presented for automated injection of DNA samples into microfabricated separation devices via capillary electrophoresis. A single capillary is used to electrokinetically inject discrete plugs of DNA into an array of separation lanes on a glass chip. A computer-controlled micromanipulator is used to automate this injection process and to repeat injections into five parallel lanes several times over the course of the experiment. After separation, labeled DNA samples are detected by laser-induced fluorescence. Five serial separations of 6-carboxyfluorescein (FAM)-labeled oligonucleotides in five parallel lanes are shown, resulting in the analysis of 25 samples in 25 min. It is estimated that approximately 550 separations of these same oligonucleotides could be performed in one hour by increasing the number of lanes to 37 and optimizing the rate of the manipulator movement. Capillary sample introduction into chips allows parallel separations to be continuously performed in serial, yielding high throughput and minimal need for operator intervention. PMID:11288906

  5. Continuous-Flow Bioseparation Using Microfabricated Anisotropic Nanofluidic Sieving Structures

    PubMed Central

    Fu, Jianping; Mao, Pan; Han, Jongyoon

    2010-01-01

    The anisotropic nanofluidic filter (nanofilter) array (ANA) is a unique molecular sieving structure for separating biomolecules. Here we describe fabrication of planar and vertical ANA chips and how to perform continuous-flow bioseparation using them. This protocol is most useful for bioengineers that are interested in developing automated multistep chip-based bioanalysis systems and assumes prior cleanroom microfabrication knowledge. The ANA consists of a two-dimensional periodic nanofilter array, and the designed structural anisotropy of the ANA causes different sized- or charged-biomolecules to follow distinct trajectories under applied electric fields, leading to efficient continuous-flow separation. Using microfluidic channels surrounding the ANA, the fractionated biomolecule streams are collected and routed to different fluid channels or reservoirs for convenient sample recovery and downstream bioanalysis. The ANA is physically robust and can be reused repeatedly. Compared to conventional gel-based separation techniques, the ANA offers the potential for faster separation, higher throughput, and more convenient sample recovery. PMID:19876028

  6. Design and microfabrication of a lateral excited gallium arsenide biosensor

    NASA Astrophysics Data System (ADS)

    Bienaime, A.; Liu, L.; Elie-Caille, C.; Leblois, T.

    2012-02-01

    GaAs crystal presents some interesting perspectives for resonant biosensors due to its piezoelectric and good mechanical properties and the opportunity to bio-functionalize the surface. Moreover, GaAs can be micromachined by wet etching in several solutions, which constitutes a batch and low-cost process of fabrication. The lateral field excitation (LFE) is used to generate bulk acoustic waves. The main advantage of LFE is the possibility to measure in liquid media, moreover reduced aging and increased frequency stability are also ensured. In this study, an analytical modelization is used to determine the orientations of the vibrating membrane and the electric field that give satisfactory metrological performances. Electrical performances are discussed as a function of geometrical parameters. A simulation based on a Finite Element Modelization is performed in order to optimize the design of the resonant structure. The microfabrication process of the structure is presented. The choice of etchants is discussed in terms of etching rates and surface textures. Several steps of the fabrication of the sensing area structure are shown and characterized. Finally, the active area is fabricated according to the theoretical and experimental results of this study.

  7. Progress Towards Quantum Simulation Using Micro-fabricated Ion Traps

    NASA Astrophysics Data System (ADS)

    Wright, K.; Cao, C.; Ji, G.; Brennan, T.; Monroe, C.

    2014-05-01

    We report our current experimental progress towards using surface electrode traps for quantum simulation. Current progress is being made using a micro-fabricated Satellite trap from GTRI. This trap features two long storage arms which can be used to hold ions in reserve to mitigate the need to load ions via a heated oven in the event of ion loss. This should allow trapping of long ion chains with a substantial decrease in the time needed to recover an ion chain of a given length. The trap has 96 electrodes for fine control of the DC potential needed to create large anharmonic trapping wells. It also features two crossing linear regions for the ordering of mixed ion chains by selective shuttling between the arms of intersecting linear regions of the trap. This should allow us to trap multiple species and explore the advantages of having sympathetic coolant ions. Interspersing these ions through a chain of ions undergoing coherent operations potentially could increase the chain lifetime as well as mitigate certain heating effects. We hope to use these features as the next step in increasing the size of current quantum simulations being done at UMD, which are aimed at exploring quantum phenomena in spin systems. In collaboration with the GTRI QIS Group and supported by grants from the U.S. ARO with funding from the DARPA OLE program, IARPA, and the MURI program; and the NSF Physics Frontier Center at JQI.

  8. Intracellular delivery of molecules using microfabricated nanoneedle arrays.

    PubMed

    Park, Seonhee; Choi, Seong-O; Paik, Seung-joon; Choi, Seungkeun; Allen, Mark; Prausnitz, Mark

    2016-02-01

    Many bioactive molecules have intracellular targets, but have difficulty crossing the cell membrane to reach those targets. To address this difficulty, we fabricated arrays of nanoneedles to gently and simultaneously puncture 10(5) cells and thereby provide transient pathways for transport of molecules into the cells. The nanoneedles were microfabricated by etching silicon to create arrays of nanoneedles measuring 12 μm in height, tapering to a sharp tip less than 30 nm wide to facilitate puncture into cells and spaced 10 μm apart in order to have at least one nanoneedle puncture each cell in a confluent monolayer. These nanoneedles were used for intracellular delivery in two ways: puncture loading, in which nanoneedle arrays were pressed into cell monolayers, and centrifuge loading, in which cells in suspension were spun down onto nanoneedle arrays. The effects on intracellular uptake and cell viability were determined as a function of nanoneedle length and sharpness, puncture force and duration, and molecular weight of the molecule delivered. Under optimal conditions, intracellular uptake was seen in approximately 50 % of cells while maintaining high cell viability. Overall, this study provides a comparative analysis of intracellular delivery using nanoneedle arrays by two different loading methods over a range of operating parameters. PMID:26797026

  9. Microfabricated ratchet structures for concentrating and patterning motile bacterial cells

    NASA Astrophysics Data System (ADS)

    Yub Kim, Sang; Lee, Eun Se; Lee, Ho Jae; Lee, Se Yeon; Kuk Lee, Sung; Kim, Taesung

    2010-09-01

    We present a novel microfabricated concentrator for Escherichia coli that can be a stand-alone and self-contained microfluidic device because it utilizes the motility of cells. First of all, we characterize the motility of E. coli cells and various ratcheting structures that can guide cells to move in a desired direction in straight and circular channels. Then, we combine these ratcheting microstructures with the intrinsic tendency of cells to swim on the right side in microchannels to enhance the concentration rates up to 180 fold until the concentrators are fully filled with cells. Furthermore, we demonstrate that cells can be positioned and concentrated with a constant spacing distance on a surface, allowing spatial patterning of motile cells. These results can be applied to biosorption or biosensor devices that are powered by motile cells because they can be highly concentrated without any external mechanical and electrical energy sources. Hence, we believe that the concentrator design holds considerable potential to be applied for concentrating and patterning other motile microbes and providing a versatile structure for motility study of bacterial cells.

  10. Fractionation of Long DNA Molecules in Microfabricated Arrays

    NASA Astrophysics Data System (ADS)

    Bakajin, Olgica; Duke, T. A. J.; Chou, C. F.; Tegenfeldt, J.; Chan, S. S.; Austin, R. H.; Cox, E. C.

    2000-03-01

    Novel microfabricated devices promise to accomplish fractionation of megabase DNA quickly, accurately, at low cost, and by using small sample amounts. At the entrance to the device the DNA is concentrated in a thin band either at a barrier via entropic forces, or on a platinum wire via dielectric forces. The DNA is then electrophoretically driven into an array of posts arranged in a hexagonal lattice. The dependence of mobility on the length of the DNA molecule is induced by a periodically changing electric field. Under the field whose direction changes by 120 degrees, the DNA molecules move in a regular fashion: the longer DNA molecules backtrack more and move forward at lower speeds than the shorter ones. This technique allows electric fields as large as 1000 V/cm and, thus reduces separation times of long molecules compared to the presently used technique of pulsed-field gel electrophoresis. While in a gel it takes up to 48 hours of pulsing to resolve T4 (167 kbp) and lambda (48.5 kbp) molecules, in our device it takes less than 10 seconds. In 10 minutes we can separate these molecules by many millimeters. For video clips of DNA in hexagonal arrays go to http://suiling.princeton.edu

  11. Microfabricated alkali vapor cell with anti-relaxation wall coating

    SciTech Connect

    Straessle, R.; Pétremand, Y.; Briand, D.; Rooij, N. F. de; Pellaton, M.; Affolderbach, C.; Mileti, G.

    2014-07-28

    We present a microfabricated alkali vapor cell equipped with an anti-relaxation wall coating. The anti-relaxation coating used is octadecyltrichlorosilane and the cell was sealed by thin-film indium-bonding at a low temperature of 140 °C. The cell body is made of silicon and Pyrex and features a double-chamber design. Depolarizing properties due to liquid Rb droplets are avoided by confining the Rb droplets to one chamber only. Optical and microwave spectroscopy performed on this wall-coated cell are used to evaluate the cell's relaxation properties and a potential gas contamination. Double-resonance signals obtained from the cell show an intrinsic linewidth that is significantly lower than the linewidth that would be expected in case the cell had no wall coating but only contained a buffer-gas contamination on the level measured by optical spectroscopy. Combined with further experimental evidence this proves the presence of a working anti-relaxation wall coating in the cell. Such cells are of interest for applications in miniature atomic clocks, magnetometers, and other quantum sensors.

  12. Microfabrication-derived DDS: From batch to individual production.

    PubMed

    Takada, K

    2008-06-01

    As a result of recent advances in microfabrication technology (MFT), microparticles including microcapsules and microspheres can be prepared individually and the disadvantages of the conventional microparticles produced by batch production, i.e. (i) low loading efficiency, (ii) large size variation, and (iii) initial burst release, have been remedied. In addition, all conventional microparticles have the same structure, a spherical shape, so they have only one function, sustained release. Threelayer microcapsules (TLMCs) have been designed to address these issues. TLMCs consist of a surface layer, a drug carrying layer, and a basement layer. TLMCs have sustained release as well as adhesiveness and targeting functions. TLMCs are prepared using ink-jet printer nozzle technology. The obtained TLMCs are used for the oral delivery of peptide/protein drugs and long-term sustained-release injection preparation. In addition, self-dissolving micropiles (SDMPs) can be individually produced by MFT as a percutaneous preparation. MFT allows biopharmaceutical drugs like insulin, erythropoietin, and growth hormone to be absorbed through the skin. Thus, advances in MFT have accelerated the development of pharmaceutical technology. PMID:22504567

  13. Microfabricated silicon gas chromatographic micro-channels: fabrication and performance

    SciTech Connect

    Matzke, C.M.; Kottenstette, R.J.; Casalnuovo, S.A.; Frye-Mason, G.C.; Hudson, M.L.; Sasaki, D.Y.; Manginell, R.P.; Wong, C.C.

    1998-11-01

    Using both wet and plasma etching, we have fabricated micro-channels in silicon substrates suitable for use as gas chromatography (GC) columns. Micro-channel dimensions range from 10 to 80 {micro}m wide, 200 to 400 {micro}m deep, and 10 cm to 100 cm long. Micro-channels 100 cm long take up as little as 1 cm{sup 2} on the substrate when fabricated with a high aspect ratio silicon etch (HARSE) process. Channels are sealed by anodically bonding Pyrex lids to the Si substrates. We have studied micro-channel flow characteristics to establish model parameters for system optimization. We have also coated these micro-channels with stationary phases and demonstrated GC separations. We believe separation performance can be improved by increasing stationary phase coating uniformity through micro-channel surface treatment prior to stationary phase deposition. To this end, we have developed microfabrication techniques to etch through silicon wafers using the HARSE process. Etching completely through the Si substrate facilitates the treatment and characterization of the micro- channel sidewalls, which domminate the GC physico-chemical interaction. With this approach, we separately treat the Pyrex lid surfaces that form the top and bottom surfaces of the GC flow channel.

  14. Microfabricated silicon gas chromatographic microchannels: fabrication and performance

    NASA Astrophysics Data System (ADS)

    Matzke, Carolyn M.; Kottenstette, Richard J.; Casalnuovo, Stephen A.; Frye-Mason, Gregory C.; Hudson, Mary L.; Sasaki, Darryl Y.; Manginell, Ronald P.; Wong, C. Channy

    1998-08-01

    Using both wet and plasma etching, we have fabricated micro- channels in silicon substrates suitable for use as gas chromatography (GC) columns. Micro-channel dimensions range from 10 to 80 micrometer wide, 200 to 400 micrometer deep, and 10 cm to 100 cm long. Micro-channels 100 cm long take up as little as 1 cm2 on the substrate when fabricated with a high aspect ratio silicon etch (HARSE) process. Channels are sealed by anodically bonding Pyrex lids to the Si substrates. We have studied micro-channel flow characteristics to establish model parameters for system optimization. We have also coated these micro-channels with stationary phases and demonstrated GC separations. We believe separation performance can be improved by increasing stationary phase coating uniformity through micro-channel surface treatment prior to stationary phase deposition. To this end, we have developed microfabrication techniques to etch through silicon wafers using the HARSE process. Etching completely through the Si substrate facilitates the treatment and characterization of the micro-channel sidewalls, which dominate the GC physico- chemical interaction. With this approach, we separately treat the Pyrex lid surfaces that form the top and bottom surfaces of the GC flow channel.

  15. Optimization of dielectrophoretic DNA stretching in microfabricated devices

    PubMed Central

    Sung, Kyung Eun; Burns, Mark A.

    2008-01-01

    We have found that the surface and bulk solution properties in a microfabricated device affect the degree and probability of electrostretching of DNA molecules. Using lambda phage DNA, we found that significantly hydrophilic surfaces between the electrodes decreases the efficiency of stretching. Surfaces treated with higher silane (trimethyl chlorosilane) concentrations performed better presumably due to the decreased non-specific adsorption of DNA on these surfaces compared to their more hydrophilic counterparts. The shape and dimensions of the electrodes also affected the efficiency of stretching. Both lift-off and metal etching methods produced electrodes with random microscopic peaks along the electrode’s edge and were poorly suited for stretching. Annealing the electrodes (450°C for 10 min) removed most of these peaks and allowed for more controlled stretching to be obtained. We also found that thin electrodes (65nm) gave close to a 90% success rate of DNA stretching but stretching with thick electrodes (350nm) produced only a 20% success rate. PMID:16642979

  16. Microfabricated Thin Film Impedance Sensor & AC Impedance Measurements

    PubMed Central

    Yu, Jinsong; Liu, Chung-Chiun

    2010-01-01

    Thin film microfabrication technique was employed to fabricate a platinum based parallel-electrode structured impedance sensor. Electrochemical impedance spectroscopy (EIS) and equivalent circuit analysis of the small amplitude (±5 mV) AC impedance measurements (frequency range: 1 MHz to 0.1 Hz) at ambient temperature were carried out. Testing media include 0.001 M, 0.01 M, 0.1 M NaCl and KCl solutions, and alumina (∼3 μm) and sand (∼300 μm) particulate layers saturated with NaCl solutions with the thicknesses ranging from 0.6 mm to 8 mm in a testing cell, and the results were used to assess the effect of the thickness of the particulate layer on the conductivity of the testing solution. The calculated resistances were approximately around 20 MΩ, 4 MΩ, and 0.5 MΩ for 0.001 M, 0.01 M, and 0.1 M NaCl solutions, respectively. The presence of the sand particulates increased the impedance dramatically (6 times and 3 times for 0.001 M and 0.1 M NaCl solutions, respectively). A cell constant methodology was also developed to assess the measurement of the bulk conductivity of the electrolyte solution. The cell constant ranged from 1.2 to 0.8 and it decreased with the increase of the solution thickness. PMID:22219690

  17. Protocol for Identifying Fossil Biofilm Microfabrics in Archean and Martian Sedimentary Rocks

    NASA Astrophysics Data System (ADS)

    Bontognali, T. R. R.; McKenzie, J. A.; Vasconcelos, C.

    2014-12-01

    Microbial communities commonly live and grow in aggregates called biofilm. This slimy material is composed of exopolymeric substances (EPS) secreted from the microbial cell to the surrounding environment. Certain biofilms show internal microscopic fabrics, as for example, regularly shaped alveolar structures. These microfabrics are often considered as artifacts due to the dehydration steps required for scanning electron microscopy. However, recent studies have demonstrated that some microfabrics are not artifacts but actual structures, whose architecture is controlled by the microorganisms. These findings, mainly achieved for medical purposes, may have yet unconsidered implications for the search of early life on Earth and on Mars. Indeed, evidence exists that the microfabrics can be mineralized during early diagenesis, preserving fossil imprints of the original biofilm throughout the geological record. Here, we present the results of microscopic investigations of ancient sediments of various age, composition and metamorphic degree that contain microfabrics that we interpret as fossil biofilms. We compile a list of criteria that need to be evaluated before excluding that the putative fossil biofilms may be artifacts due to sample preparation or late stage contamination of the studied rocks. Additionally, we compare these microfabrics to those produced by pure cultures of microorganism grown in the laboratory, as well as microfabrics present in microbial mats that develop in modern evaporitic environments. Finally, we discuss the hypothesis - and the evidence that already exists in its support - that the micrometric size and the morphology of the EPS fabrics is specific to the organism and the genome concerned. By establishing a linkage between specific microbes and the architecture of the mineralized microfabrics, it may be possible to gain precise taxonomic information on early life, as well as to establish a new type of morphological biosignature to be searched

  18. Research of the new optical diffractive super-resolution element of the two-photon microfabrication

    NASA Astrophysics Data System (ADS)

    Wei, Peng; Zhu, Yu; Duan, Guanghong

    2006-11-01

    The new optical diffractive superresolution element (DSE) is being applied to improve the microfabrication radial superresolution in the two-photon three-dimension (3D) microfabrication system, which appeared only a few years ago and can provide the ability to confine photochemical and physical reactions to the order of laser wavelength in three dimensions. The design method of the DSE is that minimizing M if the lowest limit S l of the S and the highest limit G u of the G is set, where Liu [1] explained the definition of the S, M and G. Simulation test result proved that the microfabrication radial superresolution can be improved by the new optical DSE. The phenomenon can only be interpreted as the intensity of high-order and side of the zero-order diffraction peaks have been clapped under the twophoton absorption (TPA) polymerization threshold. In a word the polymerized volume can be chosen because the S l and the G u is correspondingly adjustable, even if the laser wavelength, objective lens and the photosensitive resin is fixed for a given two-photon microfabrication system. That means the radial superresolution of the two-photon microfabrication can be chosen.

  19. Microresonator Brillouin laser stabilization using a microfabricated rubidium cell.

    PubMed

    Loh, William; Hummon, Matthew T; Leopardi, Holly F; Fortier, Tara M; Quinlan, Frank; Kitching, John; Papp, Scott B; Diddams, Scott A

    2016-06-27

    We frequency stabilize the output of a miniature stimulated Brillouin scattering (SBS) laser to rubidium atoms in a microfabricated cell to realize a laser system with frequency stability at the 10-11 level over seven decades in averaging time. In addition, our system has the advantages of robustness, low cost and the potential for integration that would lead to still further miniaturization. The SBS laser operating at 1560 nm exhibits a spectral linewidth of 820 Hz, but its frequency drifts over a few MHz on the 1 hour timescale. By locking the second harmonic of the SBS laser to the Rb reference, we reduce this drift by a factor of 103 to the level of a few kHz over the course of an hour. For our combined SBS and Rb laser system, we measure a frequency noise of 4 × 104 Hz2/Hz at 10 Hz offset frequency which rapidly rolls off to a level of 0.2 Hz2/Hz at 100 kHz offset. The corresponding Allan deviation is ≤2 × 10-11 for averaging times spanning 10-4 to 103 s. By optically dividing the signal of the laser down to microwave frequencies, we generate an RF signal at 2 GHz with phase noise at the level of -76 dBc/Hz and -140 dBc/Hz at offset frequencies of 10 Hz and 10 kHz, respectively. PMID:27410604

  20. Microfabricated electrochemical detector for high-performance liquid chromatography.

    PubMed

    Ogburn, Evan T; Dziewatkoski, Michael; Moles, Don; Johnson, Jay M; Heineman, William R

    2011-09-15

    A microfabricated electrochemical cell has been developed as a disposable detector for flow injection analysis (FIA) and high-performance liquid chromatography (HPLC). The simplicity of the fabrication process allows this detector to be used as a low-cost, disposable device that can be replaced easily if its performance degrades rather than disassembling the detector and polishing the electrode surface, which is the usual procedure. The detector consists of thin film-metal electrodes-platinum working electrode, platinum auxiliary electrode, and silver/silver chloride coated on Pt reference electrode-deposited on a polyimide substrate with a locking layer of chromium in between. A microfluidic cover made of polyimide directs the solution flow across the electrodes. The detector was evaluated with FIA of ferrocyanide and HPLC of ascorbic acid and acetaminophen and a mixture of two pharmaceutical compounds-dextrorphan and levallorphan-with acetaminophen internal standard. The HPLC calibration curves showed good linearity (R(2) > 0.99). Limits of detection were 1 nM for acetaminophen, 1 nM for ascorbic acid, 50 nM for dextrorphan, and 80 nM for levallorphan. When detected with a commercial detector dextrorphan and levallorphan had lower limits of detection, 3 and 5 nM, respectively. Chromatograms of the mixture were comparable to those obtained with a commercial detector. The detector could be used continuously for about 48 h with FIA and about 10-20 h with HPLC after which performance gradually degraded as the AgCl on the reference electrode dissolved causing loss of potential control. PMID:21598939

  1. The maximum life expectancy for a micro-fabricated diaphragm

    NASA Astrophysics Data System (ADS)

    Cǎlimǎnescu, Ioan; Stan, Liviu-Constantin; Popa, Viorica

    2015-02-01

    Micro-fabricated diaphragms can be used to provide pumping action in microvalve and microfluidic applications. The functionality of the microdiaphragm in a wirelessly actuated micropump plays a major role in low-powered device actuation. In developing micropumps and their components, it is becoming an increasing trend to predict the performance before the prototype is fabricated. Because performance prediction allows for an accurate estimation of yield and lifetime, in addition to developing better understanding of the device while taking into account the details of the device structure and second order effects. Hence avoid potential pitfalls in the device operation in a practical environment. The goal of this research is to determine via FEA the life expectancy for a corrugated circular diaphragm made out of an aluminum alloy. The geometry of the diaphragm is given below being generated within SolidWorks 2010, all the calculations were made using Ansys 13TM . The sound design of a micropump is heavily depending on the lifetime expectancy of the working part of the device which is the diaphragm. This will be subjected on cyclic loading and the fatigue will limit the life of this part. Once the diaphragm is breaking, the micropump is no more able to fulfill its scope. Any micropump manufacturer will then be very concerned on the life expectancy from the fatigue point of view of the diaphragms. The diaphragm circular and corrugated and made of Al alloy, showed a very good behavior from the fatigue point of view, the maximum life expectancy being 1.9 years of continuous functioning with 100 cycles per second. This work showed an simple and forward application of FEA analysis methods in order to estimate the fatigue behavior of corrugated circular microdiaphragms.

  2. Microfabrication of hierarchical structures for engineered mechanical materials

    NASA Astrophysics Data System (ADS)

    Vera Canudas, Marc

    Materials found in nature present, in some cases, unique properties from their constituents that are of great interest in engineered materials for applications ranging from structural materials for the construction of bridges, canals and buildings to the fabrication of new lightweight composites for airplane and automotive bodies, to protective thin film coatings, amongst other fields. Research in the growing field of biomimetic materials indicates that the micro-architectures present in natural materials are critical to their macroscopic mechanical properties. A better understanding of the effect that structure and hierarchy across scales have on the material properties will enable engineered materials with enhanced properties. At the moment, very few theoretical models predict mechanical properties of simple materials based on their microstructures. Moreover these models are based on observations from complex biological systems. One way to overcome this challenge is through the use of microfabrication techniques to design and fabricate simple materials, more appropriate for the study of hierarchical organizations and microstructured materials. Arrays of structures with controlled geometry and dimension can be designed and fabricated at different length scales, ranging from a few hundred nanometers to centimeters, in order to mimic similar systems found in nature. In this thesis, materials have been fabricated in order to gain fundamental insight into the complex hierarchical materials found in nature and to engineer novel materials with enhanced mechanical properties. The materials fabricated here were mechanically characterized and compared to simple mechanics models to describe their behavior with the goal of applying the knowledge acquired to the design and synthesis of future engineered materials with novel properties.

  3. Microfabrication of Cell-Laden Hydrogels for Engineering Mineralized and Load Bearing Tissues.

    PubMed

    Li, Chia-Cheng; Kharaziha, Mahshid; Min, Christine; Maas, Richard; Nikkhah, Mehdi

    2015-01-01

    Microengineering technologies and advanced biomaterials have extensive applications in the field of regenerative medicine. In this chapter, we review the integration of microfabrication techniques and hydrogel-based biomaterials in the field of dental, bone, and cartilage tissue engineering. We primarily discuss the major features that make hydrogels attractive candidates to mimic extracellular matrix (ECM), and we consider the benefits of three-dimensional (3D) culture systems for tissue engineering applications. We then focus on the fundamental principles of microfabrication techniques including photolithography, soft lithography and bioprinting approaches. Lastly, we summarize recent research on microengineering cell-laden hydrogel constructs for dental, bone and cartilage regeneration, and discuss future applications of microfabrication techniques for load-bearing tissue engineering. PMID:26545742

  4. A unified scaling model for flow through a lattice of microfabricated posts.

    PubMed

    Srivastava, Nimisha; Din, Changsong; Judson, Andrew; MacDonald, Noel C; Meinhart, Carl D

    2010-05-01

    A scaling model is presented for low Reynolds number viscous flow within an array of microfabricated posts. Such posts are widely used in several lab-on-a-chip applications such as heat pipes, antibody arrays and biomolecule separation columns. Finite element simulations are used to develop a predictive model for pressure driven viscous flow through posts. The results indicate that the flow rate per unit width scales as approximately h1.17g1.33/d0.5 where h is the post height, d post diameter and g is the spacing between the posts. These results compare favorably to theoretical limits. The scaling is extended to capillary pressure driven viscous flows. This unified model is the first report of a scaling that incorporates both viscous and capillary forces in the microfabricated post geometry. The model is consistent with Washburn dynamics and was experimentally validated to within 8% using wetting on microfabricated silicon posts. PMID:20390133

  5. High-throughput three-dimensional (3D) lithographic microfabrication in biomedical applications

    NASA Astrophysics Data System (ADS)

    Kim, Daekeun; So, Peter T. C.

    2010-02-01

    Two-photon excitation microfabrication has been shown to be useful in the field of photonics and biomedicine. It generates 3D microstructures and provides sub-diffraction fabrication resolution. Nevertheless, laser direct writing, the most popular two-photon fabrication technique, has slow fabrication speed, and its applications are limited to prototyping. In this proceeding, we propose high-throughput 3D lithographic microfabrication system based on depthresolved wide-field illumination and build several 3D microstructures with SU-8. Through these fabrications, 3D lithographic microfabrication has scalable function and high-throughput capability. It also has the potential for fabricating 3D microstructure in biomedical applications, such as intertwining channels in 3D microfluidic devices for biomedical analysis and 3D cell patterning in the tissue scaffolds.

  6. Microfabric development in dunite during high stress deformation and subsequent recrystallization

    NASA Astrophysics Data System (ADS)

    Trepmann, Claudia; Druiventak, Anthony; Matysiak, Agnes; Renner, Jörg

    2010-05-01

    The microfabric development in dunite is analyzed in non-steady state deformation and annealing experiments, which are designed to simulate earthquake-driven episodic creep in the upper mantle of the oceanic lithosphere at the base of the seismogenic zone. The samples are deformed in a servohydraulically-controlled solid medium deformation apparatus at a temperature of 600°C, a constant strain rate of 10-4s-1 (kick) and a confining pressure of 1.0 GPa. In some experiments deformation is followed by annealing for 15 h to 70 h at zero nominal differential stress, temperatures of 800°C to 1000°C (kick & cook) and 2.0 GPa confining pressure. We use coarse-grained dunite from the Almklovdalen peridotite complex (Western Norway) as starting material. The dunite comprises ca. 90% olivine, <10% orthopyroxene and small amounts of spinel and chlorite. The kick experiments yield maximum differential stress of ca. 1 GPa and < 20% of permanent strain. The resulting microfabrics are analysed by optical and electron microscopic techniques. Intragranular microcracks and micro-shear zones in olivine, which can be crystallographically controlled, developed during deformation. After annealing at 1000°C, the microfabric is characterized by very fine-grained recrystallized olivine grains with an average diameter of ca. 5 µm. The recrystallized grains are arranged along micro-shear zones and occur in aggregates surrounding olivine porphyroclasts. The area fraction of recrystallized grains is varying but generally smaller than 20%. The microfabrics from our experiments compare well with microfabrics observed from naturally deformed peridotites of the Baldissero, Balmuccia and Finero complexes in the Western Alps. Similar olivine recrystallization aggregates in naturally deformed peridotites are frequently interpreted as indicative of deformation by dislocation or diffusion creep. The microfabrics of our kick & cook experiments indicate a development through an initial stage of high

  7. An Integrated Microfabricated Device for Dual Microdialysis and On-line ESI Ion Trap Mass Spectrometry for the Analysis of Complex Biological Samples

    SciTech Connect

    Xiang, Fan; Lin, Yuehe ); Wen, Jian Y.; Matson, Dean W. ); Smith, Richard D. )

    1999-05-01

    A microfabricated dual-microdialysis device in a single integrated microfabricated platform was constructed using laser micromachining techniques for the rapid fractionation and cleanup of complex biological samples. Results suggest the potential for integration of such microfabricated devices with other sample manipulations for the rapid ESI-MS analysis of complex biological samples.

  8. Development of Magnetic Microcalorimeters for Gamma-Ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    Le, L. N.; Hummatov, R.; Hall, J. A.; Cantor, R. C.; Boyd, S. T. P.

    2016-01-01

    Integrating the SQUIDs and sensing coils of magnetic microcalorimeters onto the same die is a promising approach for maximizing flux coupling and signal/noise. However, new challenges in microfabrication must be overcome, because the underlying SQUID devices are sensitive to chemical attack and elevated processing temperatures. In this report, we describe development and details of a microfabrication process for integrated SQUID/sensor gamma-ray magnetic microcalorimeters with electroformed gold absorbers, starting from a modified version of the STAR Cryoelectronics "Delta 1000" Josephson Junction process.

  9. Development of Magnetic Microcalorimeters for Gamma-Ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    Le, L. N.; Hummatov, R.; Hall, J. A.; Cantor, R. C.; Boyd, S. T. P.

    2016-07-01

    Integrating the SQUIDs and sensing coils of magnetic microcalorimeters onto the same die is a promising approach for maximizing flux coupling and signal/noise. However, new challenges in microfabrication must be overcome, because the underlying SQUID devices are sensitive to chemical attack and elevated processing temperatures. In this report, we describe development and details of a microfabrication process for integrated SQUID/sensor gamma-ray magnetic microcalorimeters with electroformed gold absorbers, starting from a modified version of the STAR Cryoelectronics "Delta 1000" Josephson Junction process.

  10. Functional integration of PCR amplification and capillary electrophoresis in a microfabricated DNA analysis device.

    PubMed

    Woolley, A T; Hadley, D; Landre, P; deMello, A J; Mathies, R A; Northrup, M A

    1996-12-01

    Microfabricated silicon PCR reactors and glass capillary electrophoresis (CE) chips have been successfully coupled to form an integrated DNA analysis system. This construct combines the rapid thermal cycling capabilities of microfabricated PCR devices (10 degrees C/s heating, 2.5 degrees C/s cooling) with the high-speed (< 120 s) DNA separations provided by microfabricated CE chips. The PCR chamber and the CE chip were directly linked through a photolithographically fabricated channel filled with hydroxyethylcellulose sieving matrix. Electrophoretic injection directly from the PCR chamber through the cross injection channel was used as an "electrophoretic valve" to couple the PCR and CE devices on-chip. To demonstrate the functionality of this system, a 15 min PCR amplification of a beta-globin target cloned in M13 was immediately followed by high-speed CE chip separation in under 120 s, providing a rapid PCR-CE analysis in under 20 min. A rapid assay for genomic Salmonella DNA was performed in under 45 min, demonstrating that challenging amplifications of diagnostically interesting targets can also be performed. Real-time monitoring of PCR target amplification in these integrated PCR-CE devices is also feasible. Amplification of the beta-globin target as a function of cycle number was directly monitored for two different reactions starting with 4 x 10(7) and 4 x 10(5) copies of DNA template. This work establishes the feasibility of performing high-speed DNA analyses in microfabricated integrated fluidic systems. PMID:8946790

  11. Development of a Web-Based System to Support Self-Directed Learning of Microfabrication Technologies

    ERIC Educational Resources Information Center

    Jou, Min; Wu, Yu-Shiang

    2012-01-01

    Having engineers in microfabrication technologies educated has become much more difficult than having engineers educated in the traditional technologies, and this may be because of the high cost for acquirement of equipment, materials, and infrastructural means (i.e., cleaning rooms), all in addition to the hands-on practices that are often times…

  12. MICROFABRICATED ELECTROCHEMICAL ANALYSIS SYSTEM FOR HEAVY METAL DETECTION. (R825511C047)

    EPA Science Inventory

    A low power, hand-held system has been developed for the measurement of heavy metal ions in aqueous solutions. The system consists of an electrode array sensor, a high performance single chip potentiostat and a microcontroller circuit. The sensor is a microfabricated array of ...

  13. Microfabricated capillary electrophoresis chip and method for simultaneously detecting multiple redox labels

    DOEpatents

    Mathies, Richard A.; Singhal, Pankaj; Xie, Jin; Glazer, Alexander N.

    2002-01-01

    This invention relates to a microfabricated capillary electrophoresis chip for detecting multiple redox-active labels simultaneously using a matrix coding scheme and to a method of selectively labeling analytes for simultaneous electrochemical detection of multiple label-analyte conjugates after electrophoretic or chromatographic separation.

  14. Miniature Trace Gas Detector Based on Microfabricated Optical Resonators

    NASA Technical Reports Server (NTRS)

    Aveline, David C.; Yu, Nan; Thompson, Robert J.; Strekalov, Dmitry V.

    2013-01-01

    While a variety of techniques exist to monitor trace gases, methods relying on absorption of laser light are the most commonly used in terrestrial applications. Cavity-enhanced absorption techniques typically use high-reflectivity mirrors to form a resonant cavity, inside of which a sample gas can be analyzed. The effective absorption length is augmented by the cavity's high quality factor, or Q, because the light reflects many times between the mirrors. The sensitivity of such mirror-based sensors scales with size, generally making them somewhat bulky in volume. Also, specialized coatings for the high-reflectivity mirrors have limited bandwidth (typically just a few nanometers), and the delicate mirror surfaces can easily be degraded by dust or chemical films. As a highly sensitive and compact alternative, JPL is developing a novel trace gas sensor based on a monolithic optical resonator structure that has been modified such that a gas sample can be directly injected into the cavity. This device concept combines ultra-high Q optical whispering gallery mode resonators (WGMR) with microfabrication technology used in the semiconductor industry. For direct access to the optical mode inside a resonator, material can be precisely milled from its perimeter, creating an open gap within the WGMR. Within this open notch, the full optical mode of the resonator can be accessed. While this modification may limit the obtainable Q, calculations show that the reduction is not significant enough to outweigh its utility for trace gas detection. The notch can be milled from the high- Q crystalline WGMR with a focused ion beam (FIB) instrument with resolution much finer than an optical wavelength, thereby minimizing scattering losses and preserving the optical quality. Initial experimental demonstrations have shown that these opened cavities still support high-Q whispering gallery modes. This technology could provide ultrasensitive detection of a variety of molecular species in an

  15. Microfabrication and Test of a Three-Dimensional Polymer Hydro-focusing Unit for Flow Cytometry Applications

    NASA Technical Reports Server (NTRS)

    Yang, Ren; Feeback, Daniel L.; Wang, Wan-Jun

    2005-01-01

    This paper details a novel three-dimensional (3D) hydro-focusing micro cell sorter for micro flow cytometry applications. The unit was microfabricated by means of SU-8 3D lithography. The 3D microstructure for coaxial sheathing was designed, microfabricated, and tested. Three-dimensional hydrofocusing capability was demonstrated with an experiment to sort labeled tanned sheep erythrocytes (red blood cells). This polymer hydro-focusing microstructure is easily microfabricated and integrated with other polymer microfluidic structures. Keywords: SU-8, three-dimensional hydro-focusing, microfluidic, microchannel, cytometer

  16. Microfabrication and Test of a Three-Dimensional Polymer Hydro-Focusing Unit for Flow Cytometry Applications

    NASA Technical Reports Server (NTRS)

    Yang, Ren; Feedback, Daniel L.; Wang, Wanjun

    2004-01-01

    This paper details a novel three-dimensional (3D) hydro-focusing micro cell sorter for micro flow cytometry applications. The unit was micro-fabricated by means of SU-8 3D lithography. The 3D microstructure for coaxial sheathing was designed, micro-fabricated, and tested. Three-dimensional hydrofocusing capability was demonstrated with an experiment to sort labeled tanned sheep erythrocytes (red blood cells). This polymer hydro-focusing microstructure is easily micro-fabricated and integrated with other polymer microfluidic structures.

  17. Magnetized Plasma for Reconfigurable Subdiffraction Imaging

    SciTech Connect

    Zhang Shuang; Xiong Yi; Bartal, Guy; Yin Xiaobo; Zhang Xiang

    2011-06-17

    We show that magnetized plasma with appropriately designed parameters supports nearly diffractionless propagation of electromagnetic waves along the direction of the applied magnetic field, arising from their unbounded equifrequency contour in the magnetized plasma. Such a unique feature can be utilized to construct subdiffraction imaging devices, which is confirmed by detailed numerical investigations. Subdiffraction imaging devices based on magnetic plasma do not require microfabrication normally entailed by construction of metamaterials; more importantly, they can be dynamically reconfigured by tuning the applied magnetic field or the plasma density, and therefore they represent a facile and powerful route for imaging applications.

  18. MAGNETS

    DOEpatents

    Hofacker, H.B.

    1958-09-23

    This patent relates to nmgnets used in a calutron and more particularly to means fur clamping an assembly of magnet coils and coil spacers into tightly assembled relation in a fluid-tight vessel. The magnet comprises windings made up of an assembly of alternate pan-cake type coils and spacers disposed in a fluid-tight vessel. At one end of the tank a plurality of clamping strips are held firmly against the assembly by adjustable bolts extending through the adjacent wall. The foregoing arrangement permits taking up any looseness which may develop in the assembly of coils and spacers.

  19. Utilization of a digital-versatile-disc pickup head for benchtop laser microfabrication.

    PubMed

    Hautefeuille, Mathieu; Jimenez-Zenteno, Alejandro K; Pérez-Alcázar, Pablo Roberto; Hess-Frieling, Kristopher M; Fernandez-Sanchez, Gerardo; Velazquez, Victor; Grether-Gonzalez, Marcela; Lopez-Moreno, Enrique

    2012-03-10

    Laser microfabrication is now offering interesting solutions to rapidly produce high-resolution photomasks or microstructures. However, most works require expensive commercial lasers and computer numerical control platforms, limiting its use by a large public. In this paper, we report the construction of a simple, custom-made, easily reproducible, automated laser system, based on a DVD optical pickup head. A user-friendly computer interface specifically designed to operate a motorized three-axis platform with micrometric precision controls focus distance and in-plane displacements. Writing performance characterization for both direct ablation and sintering of commercial black toner demonstrated flexibility in tridimensional microfabrication resolution and speed thanks to precise management of laser power and exposure time, with a minimal resolution of 3.1 μm. PMID:22410998

  20. Microfabrication of multi-layered electrodes for dielectrophoresis-based field flow fractionation

    NASA Astrophysics Data System (ADS)

    Mathew, Bobby; Alazzam, Anas; Khashan, Saud A.

    2015-06-01

    This article details the process layout required for realizing a three-dimensional arrangement of electrodes in a microfluidic device for field flow fractionation based on dielectrophoresis. The metal electrodes are placed horizontally, in a stair-case arrangement, and pass through the bulk of the fluid. Several standard microfabrication processes are employed, in realizing this microdevice, including multi-layer photolithography, casting and plasma bonding. Thus the process layout is repeatable and reproducible. The feasibility of this process layout is demonstrated using three electrodes arranged in aforementioned manner; nevertheless, this process can be extended to as many electrodes as desired in the horizontal direction. This process layout can will make applications possible that were not possible till date due to the inability in microfabricating three-dimensional horizontal metal electrodes that run through the entire width of the microchannel.

  1. Microfabricated chip-scale rubidium plasma light source for miniature atomic clocks.

    PubMed

    Venkatraman, Vinu; Pétremand, Yves; Affolderbach, Christoph; Mileti, Gaetano; de Rooij, Nico F; Shea, Herbert

    2012-03-01

    We present the microfabrication and characterization of a low-power, chip-scale Rb plasma light source, designed for optical pumping in miniature atomic clocks. A dielectric barrier discharge (DBD) configuration is used to ignite a Rb plasma in a micro-fabricated Rb vapor cell on which external indium electrodes were deposited. The device is electrically driven at frequencies between 1 and 36 MHz, and emits 140 μW of stable optical power while coupling less than 6 mW of electrical power to the discharge cell. Optical powers of up to 15 and 9 μW are emitted on the Rb D2 and D1 lines, respectively. Continuous operation of the light source for several weeks has been demonstrated, showing its capacity to maintain stable optical excitation of Rb atoms in chip-scale double-resonance atomic clocks. PMID:22481778

  2. Commercial importance of a unit cell: nanolithographic patenting trends for microsystems, microfabrication, and nanotechnology

    NASA Astrophysics Data System (ADS)

    Eijkel, Kees; Hruby, Jill M.; Kubiak, Glenn D.; Scott, Marion W.; Brokaw, J.; Saile, Volker; Walsh, Steven T.; White, Craig; Walsh, Daniel

    2006-01-01

    Microsystems and nanosystems hold the promise of new and much more effective approaches to both commercial and national security applications. The patenting rate in nanotechnology is exploding, underscoring its commercial and scientific potential. Yet how much of this effort is focused on nanopatterning or a top-down approach to nanofabrication? Nanopatterning in semiconductor microfabrication has already furthered Moore's law, facilitating the transistor as that medium's unit cell. Yet the search for a unit cell for the other two small technical markets (microsystems and the more broadbased nanotechnology) has proven much more elusive. Do nanopatterning advances hold the key to these technology bases finally obtaining a unit cell? We explore the intellectual property base of nanopatterning and how it pertains to semiconductor microfabrication, microsystems, and nanotechnology.

  3. NIST on a Chip: Realizing SI units with microfabricated alkali vapour cells

    NASA Astrophysics Data System (ADS)

    Kitching, J.; Donley, E. A.; Knappe, S.; Hummon, M.; Dellis, A. T.; Sherman, J.; Srinivasan, K.; Aksyuk, V. A.; Li, Q.; Westly, D.; Roxworthy, B.; Lal, A.

    2016-06-01

    We describe several ways in which microfabricated alkali atom vapour cells might potentially be used to accurately realize a variety of International System (SI) units, including the second, the meter, the kelvin, the ampere, and the volt, in a compact, low-cost “chip-scale” package. Such instruments may allow inexpensive in-situ calibrations at the user's location or widespread integration of accurate references into instrumentation and systems.

  4. Assembling a ring-shaped crystal in a microfabricated surface ion trap

    DOE PAGESBeta

    Stick, Daniel Lynn; Tabakov, Boyan; Benito, Francisco; Blain, Matthew; Clark, Craig R.; Clark, Susan; Haltli, Raymond A.; Maunz, Peter; Sterk, Jonathan D.; Tigges, Chris

    2015-09-01

    We report on experiments with a microfabricated surface trap designed for confining a chain of ions in a ring. Uniform ion separation over most of the ring is achieved with a rotationally symmetric design and by measuring and suppressing undesired electric fields. After reducing stray fields, the ions are confined primarily by a radio-frequency pseudopotential and their mutual Coulomb repulsion. As a result, approximately 400 40Ca+ ions with an average separation of 9 μm comprise the ion crystal.

  5. Selective Detection of Sulfur Derivatives Using Microfabricated Tuning Fork-Based Sensors

    PubMed Central

    Rai, Anant; Tsow, Francis; Nassirpour, Sanam; Bankers, Jeffrey; Spinatsch, Martina; He, M. Pete; Forzani, Erica; Tao, N. J.

    2009-01-01

    The paper describes an integtrated sensor system that can selectively and reversibly detect sulfur derivatives in the presence of interferent molecules. This is accomplished by integrating analyte-specific sensing materials with optimized filter materials. Microfabricated quartz tuning fork arrays are used to provide fast, accurate and low-cost transduction of the analyte binding events into electronic signals. The concept is demonstrated for detection of three sulfur derivatives – dimethyl disulfide, ethanethiol and methylsulfide. PMID:20160943

  6. Microfabricated phenol biosensors based on screen printing of tyrosinase containing carbon ink

    SciTech Connect

    Wang, J.; Chen, Q.

    1995-05-01

    Phenol biosensor strips were microfabricated by screen-printing of tyrosinase containing carbon inks. The ability of the enzyme to tolerate the 2-hour firing process (at 110{degrees}C) is attributed to its organic phase activity. The resulting strips offer unmediated detection of phenolic compounds down to the 1 x 10{sup {minus}7} M level. Direct assays of untreated drinking - and groundwater samples indicate great promise for field screening of phenolic compounds.

  7. A microfabricated electron-tunneling accelerometer as a directional underwater acoustic sensor

    SciTech Connect

    Rockstad, H.K.; Kenny, T.W.; Kelly, P.J.; Gabrielson, T.B.

    1996-04-01

    Microfabricated accelerometers have been developed for a wide variety of applications; however, the principal commercial focus has been on signal detection in the milli-g to tens or hundreds of g accelerations. The development of a microfabricated device to detect accelerations in the 10 to 100 nano-g range is a substantial technological challenge because of the conflict between the required increase in mass (and reduction in suspension stiffness) and the small volume. In an underwater sensor, designed to be nearly neutrally buoyant, there are additional restrictions on the packaging of the sensor with regard to overall density, resistance to hydrostatic pressure, and flexibility of power and signal leads. The design goal of this project is to demonstrate a two-axis sensor in an 8 cm{sup 3} (and 8 gram) package capable of immersion to 600 meters. The sensor must have a self noise below 100 nano-g per root hertz from 5 to 1000 Hz. Several of these requirements have been demonstrated with an accelerometer structure based on electron tunneling and microfabricated from single-crystal silicon. The electron-tunneling transduction mechanism provides an inherently large transduction constant (although at the expense of requiring closed-loop control) and is readily adapted to batch fabrication in silicon. {copyright} {ital 1996 American Institute of Physics.}

  8. Microfabrication of Super Absorbent Polymer Structure Using Nanoimprinting and Swelling Process

    NASA Astrophysics Data System (ADS)

    Inaba, Tomomi; Kano, Tomonori; Miki, Norihisa

    2013-06-01

    Micro-fabrication technologies have been extensively studied to achieve smaller sizes and higher aspect ratios. When the features have sizes of a couple of micrometers or below, nano-imprinting can be an effective method for micro-fabrication at low cost. However, it is difficult to achieve aspect ratio greater than 1. In this research, we propose micro fabrication of super absorbent polymer (SAP) as a new material for micro devices. SAP swells by adding deionized water, which can be used as a post patterning process to enhance the aspect ratio of micro structures. Micropatterning of SAP must be conducted under thoroughly dry conditions and we used nano-imprinting processes. We successfully augmented an aspect ratio of the nano-imprinted micro holes of SAP from 0.65 to 1.2 by the swelling process. The proposed patterning and swelling process of SAP can be applicable to micro-fabricate high-aspect-ratio structures at low cost for high performance lab-on-a-chip.

  9. Direct visualization of clay microfabric signatures driving organic matter preservation in fine-grained sediment

    NASA Astrophysics Data System (ADS)

    Curry, Kenneth J.; Bennett, Richard H.; Mayer, Lawrence M.; Curry, Ann; Abril, Maritza; Biesiot, Patricia M.; Hulbert, Matthew H.

    2007-04-01

    We employed direct visualization of organic matter (OM) sequestered by microfabric signatures in organo-clay systems to study mechanisms of OM protection. We studied polysaccharides, an abundant class of OM in marine sediments, associated with the nano- and microfabric of clay sediment using a novel application of transmission electron microscopy, histochemical staining (periodic acid-thiosemicarbazide-silver proteinate), and enzymatic digestion techniques. We used two experimental organo-clay sediment environments. First, laboratory-consolidated sediment with 10% chitin (w/w) added was probed for chitin before and after digestion with chitinase. Second, fecal pellets from the polychaete Heteromastus filiformis were used as a natural environment rich in clay and polysaccharides. Sections of this material were probed with silver proteinate for polysaccharides before and after digestion with a mixture of enzymes (amylase, cellulase, chitinase, dextranase, and pectinase). In both environments, chitin or other polysaccharides were found within pores, bridging clay domains, and attached to clay surfaces in undigested samples. Digested samples showed chitin or polysaccharides more closely associated with clay surfaces and in small pores. Our results imply protective roles for both sorption to clay surfaces and encapsulation within clay microfabric signatures.

  10. In situ mechanical characterization of square microfabricated elastomeric membranes using an improved microindentation

    NASA Astrophysics Data System (ADS)

    Liu, Kuo-Kang; Khoo, Hwa Seng; Tseng, Fan-Gang

    2004-02-01

    A testing method has been developed for in situ mechanical characterizations of square microfabricated elastomeric membranes, using a tailored microindentation instrument. Such a depth-sensing microindentation system, incorporated with a long-focal microscope for capturing the side view image, provides accurate load-displacement measurements and complete profiles of deformed membranes. The deformations of square silicon rubber membranes with various thicknesses were examined under different degrees of external central microindentation forces. These membranes were integrated and supported by SU-8 photoresist frames, with openings of 2 mm×2 mm. A theoretical model was applied to quantitatively correlate the membrane elasticity to the measured compliance under such indentation. Through comparing the simulated and experimental results, the average values of Young's modulus for these membranes were reasonably extracted and determined. Viscoelasticity of the membranes used was acknowledged; however, it showed no significant effect on the determination of the Young's modulus of the membranes in the current work. The good agreement between the experimental results and the theoretical analyses demonstrates the successful in situ mechanical characterizations of microfabricated elastomeric films, particularly for the square shape membrane, which is the most common structure or component for microfabricated devices.

  11. Micro-fabricated polydimethyl siloxane (PDMS) surfaces regulate the development of marine microbial biofilm communities.

    PubMed

    Ling, Gee Chong; Low, Min Hui; Erken, Martina; Longford, Sharon; Nielsen, Shaun; Poole, Andrew J; Steinberg, Peter; McDougald, Diane; Kjelleberg, Staffan

    2014-01-01

    This study explored an antifouling (AF) concept based on deployment of microfabricated polydimethyl siloxane (PDMS) surfaces with 1-10 μm periodicity corrugated topographies in temperate marine waters. The effect of the surfaces on the development of microbial biofilms over 28 days and during different seasons, including both summer and winter, was examined using confocal laser scanning microscopy (CLSM) as well as terminal restriction fragment (T-RF) analysis for phylogenetic fingerprinting. The microscale topography significantly impacted biofilm development by altering the attachment pattern and reducing microcolony formation on the 1, 2 and 4 μm PDMS surfaces. Also, field deployments over 28 days showed a significant reduction in biovolume on the 4 and 10 μm PDMS surfaces despite altered environmental conditions. The microfabricated PDMS surfaces further significantly impacted on the community composition of the biofilms, as revealed by changes in T-RF profiles, at different stages of development. Moreover, altered biofilm resistance was demonstrated by exposing pre-established biofilms on 10 μm micro-fabricated surfaces to enhanced flagellate predation by a heterotrophic protist, Rhynchomonas nasuta. Pronounced changes in the overall marine microbial biofilm development as well as community composition warrant exploring substratum modification for marine AF applications. PMID:24558964

  12. Permanent magnet microstructures using dry-pressed magnetic powders

    NASA Astrophysics Data System (ADS)

    Oniku, Ololade D.; Bowers, Benjamin J.; Shetye, Sheetal B.; Wang, Naigang; Arnold, David P.

    2013-07-01

    This paper presents microfabrication methods and performance analysis of bonded powder permanent magnets targeting dimensions ranging from 10 µm to greater than 1 mm. For the structural definition and pattern transfer, a doctor blade technique is used to dry press magnetic powders into pre-etched cavities in a silicon substrate. The powders are secured in the cavities by one of the three methods: capping with a polyimide layer, thermal reflow of intermixed wax-binder particles, or conformal coating with a vapor-deposited parylene-C film. A systematic study of micromagnets fabricated using these methods is conducted using three different types of magnetic powders: 50 µm Nd-Fe-B, 5 µm Nd-Fe-B and 1 µm barium ferrite powder. The isotropic magnets are shown to exhibit intrinsic coercivities (Hci) as high as 720 kA m-1, remanences (Br) up to 0.5 T and maximum energy products (BHmax) up to 30 kJ m-3, depending on the magnetic powder used. Process compatibility experiments demonstrate the potential for the magnets to withstand typical microfabrication chemical exposure and thermal cycles, thereby facilitating their integration into more complex process flows. The remanences are also characterized at elevated temperatures to determine thermal sensitivities and maximum operating temperature ranges.

  13. Micro-fabricated silicon spiral spring based electromagnetic energy harvester

    NASA Astrophysics Data System (ADS)

    Bang, Dong Hyun; Park, Jae Yeong

    2013-06-01

    In this study, an electromagnetic energy harvester using a bulk micromachined silicon spiral spring and a polydimethylsiloxane (PDMS) packaging technique was fabricated and characterized to generate electrical energy from ultra-low ambient vibrations under at vibration accelerations 0.3g. The proposed energy harvester was comprised of a highly-miniaturized neodymium-ironboron (NdFeB) magnet, a silicon spiral spring, a multi-turn copper coil, and a PDMS housing in order to improve its electrical output power and reduce its size/volume. When an external vibration directly moves the mounted magnet as a seismic mass at the center of the spiral spring, the mechanical energy of the moving mass was transformed into electrical energy through the 183 turns of the solenoid copper coil. Silicon spiral springs were used to generate a high electrical output power by maximizing the deflection of the movable mass in response to low-level vibrations. The fabricated energy harvester exhibited a resonant frequency of 36 Hz and an optimal load resistance of 99 Ω. It generated an output power of 29.02 µW and load voltage of 107.3 mV at a vibration acceleration of 0.3g. It also exhibited a power density and normalized power density of 48.37 µW·cm-3 and 537.41 µW·cm-3·g-2, respectively. The total volume of the fabricated energy harvester was 1 cm × 1 cm × 0.6 cm (height).

  14. Current driven dynamics of magnetic domain walls in permalloy nanowires

    NASA Astrophysics Data System (ADS)

    Hayashi, Masamitsu

    The significant advances in micro-fabrication techniques opened the door to access interesting properties in solid state physics. With regard to magnetic materials, geometrical confinement of magnetic structures alters the defining parameters that govern magnetism. For example, development of single domain nano-pillars made from magnetic multilayers led to the discovery of electrical current controlled magnetization switching, which revealed the existence of spin transfer torque. Magnetic domain walls (DWs) are boundaries in magnetic materials that divide regions with distinct magnetization directions. DWs play an important role in the magnetization reversal processes of both bulk and thin film magnetic materials. The motion of DW is conventionally controlled by magnetic fields. Recently, it has been proposed that spin polarized current passed across the DW can also control the motion of DWs. Current in most magnetic materials is spin-polarized, due to spin-dependent scattering of the electrons, and thus can deliver spin angular momentum to the DW, providing a "spin transfer" torque on the DW which leads to DW motion. In addition, owing to the development of micro-fabrication techniques, geometrical confinement of magnetic materials enables creation and manipulation of a "single" DW in magnetic nanostructures. New paradigms for DW-based devices are made possible by the direct manipulation of DWs using spin polarized electrical current via spin transfer torque. This dissertation covers research on current induced DW motion in magnetic nanowires. Fascinating effects arising from the interplay between DWs with spin polarized current will be revealed.

  15. Microfabricated modules for sample handling, sample concentration and flow mixing: application to protein analysis by tandem mass spectrometry.

    PubMed

    Figeys, D; Aebersold, R

    1999-02-01

    The comprehensive analysis of biological systems requires a combination of genomic and proteomic efforts. The large-scale application of current genomic technologies provides complete genomic DNA sequences, sequence tags for expressed genes (EST's), and quantitative profiles of expressed genes at the mRNA level. In contrast, protein analytical technology lacks the sensitivity and the sample throughput for the systematic analysis of all the proteins expressed by a tissue or cell. The sensitivity of protein analysis technology is primarily limited by the loss of analytes, due to adsorption to surfaces, and sample contamination during handling. Here we summarize our work on the development and use of microfabricated fluidic systems for the manipulation of minute amounts of peptides and delivery to an electrospray ionization tandem mass spectrometer. New data are also presented that further demonstrate the potential of these novel approaches. Specifically, we describe the use of microfabricated devices as modules to deliver femtomole amounts of protein digests to the mass spectrometer for protein identification. We also describe the use of a microfabricated module for the generation of solvent gradients at nl/min flow rates for gradient chromatography-tandem mass spectrometry. The use of microfabricated fluidic systems reduces the risk of sample contamination and sample loss due to adsorption to wetted surfaces. The ability to assemble dedicated modular systems and to operate them automatically makes the use of microfabricated systems attractive for the sensitive and large-scale analysis of proteins. PMID:10080083

  16. Magnetic

    NASA Astrophysics Data System (ADS)

    Aboud, Essam; El-Masry, Nabil; Qaddah, Atef; Alqahtani, Faisal; Moufti, Mohammed R. H.

    2015-06-01

    The Rahat volcanic field represents one of the widely distributed Cenozoic volcanic fields across the western regions of the Arabian Peninsula. Its human significance stems from the fact that its northern fringes, where the historical eruption of 1256 A.D. took place, are very close to the holy city of Al-Madinah Al-Monawarah. In the present work, we analyzed aeromagnetic data from the northern part of Rahat volcanic field as well as carried out a ground gravity survey. A joint interpretation and inversion of gravity and magnetic data were used to estimate the thickness of the lava flows, delineate the subsurface structures of the study area, and estimate the depth to basement using various geophysical methods, such as Tilt Derivative, Euler Deconvolution and 2D modeling inversion. Results indicated that the thickness of the lava flows in the study area ranges between 100 m (above Sea Level) at the eastern and western boundaries of Rahat Volcanic field and getting deeper at the middle as 300-500 m. It also showed that, major structural trend is in the NW direction (Red Sea trend) with some minor trends in EW direction.

  17. Microfabricated electrospray emitter arrays with integrated extractor and accelerator electrodes for the propulsion of small spacecraft

    NASA Astrophysics Data System (ADS)

    Dandavino, S.; Ataman, C.; Ryan, C. N.; Chakraborty, S.; Courtney, D.; Stark, J. P. W.; Shea, H.

    2014-07-01

    Microfabricated electrospray thrusters could revolutionize the spacecraft industry by providing efficient propulsion capabilities to micro and nano satellites (1-100 kg). We present the modeling, design, fabrication and characterization of a new generation of devices, for the first time integrating in the fabrication process individual accelerator electrodes capable of focusing and accelerating the emitted sprays. Integrating these electrodes is a key milestone in the development of this technology; in addition to increasing the critical performance metrics of thrust, specific impulse and propulsive efficiency, the accelerators enable a number of new system features such as power tuning and thrust vectoring and balancing. Through microfabrication, we produced high density arrays (213 emitters cm-2) of capillary emitters, assembling them at wafer-level with an extractor/accelerator electrode pair separated by micro-sandblasted glass. Through IV measurements, we could confirm that acceleration could be decoupled from the extraction of the spray—an important element towards the flexibility of this technology. We present the largest reported internally fed microfabricated arrays operation, with 127 emitters spraying in parallel, for a total beam of 10-30 µA composed by 95% of ions. Effective beam focusing was also demonstrated, with plume half-angles being reduced from approximately 30° to 15° with 2000 V acceleration. Based on these results, we predict, with 3000 V acceleration, thrust per emitter of 38.4 nN, specific impulse of 1103 s and a propulsive efficiency of 22% with <1 mW/emitter power consumption.

  18. Microfabricated Modular Scale-Down Device for Regenerative Medicine Process Development

    PubMed Central

    Reichen, Marcel; Macown, Rhys J.; Jaccard, Nicolas; Super, Alexandre; Ruban, Ludmila; Griffin, Lewis D.; Veraitch, Farlan S.; Szita, Nicolas

    2012-01-01

    The capacity of milli and micro litre bioreactors to accelerate process development has been successfully demonstrated in traditional biotechnology. However, for regenerative medicine present smaller scale culture methods cannot cope with the wide range of processing variables that need to be evaluated. Existing microfabricated culture devices, which could test different culture variables with a minimum amount of resources (e.g. expensive culture medium), are typically not designed with process development in mind. We present a novel, autoclavable, and microfabricated scale-down device designed for regenerative medicine process development. The microfabricated device contains a re-sealable culture chamber that facilitates use of standard culture protocols, creating a link with traditional small-scale culture devices for validation and scale-up studies. Further, the modular design can easily accommodate investigation of different culture substrate/extra-cellular matrix combinations. Inactivated mouse embryonic fibroblasts (iMEF) and human embryonic stem cell (hESC) colonies were successfully seeded on gelatine-coated tissue culture polystyrene (TC-PS) using standard static seeding protocols. The microfluidic chip included in the device offers precise and accurate control over the culture medium flow rate and resulting shear stresses in the device. Cells were cultured for two days with media perfused at 300 µl.h−1 resulting in a modelled shear stress of 1.1×10−4 Pa. Following perfusion, hESC colonies stained positively for different pluripotency markers and retained an undifferentiated morphology. An image processing algorithm was developed which permits quantification of co-cultured colony-forming cells from phase contrast microscope images. hESC colony sizes were quantified against the background of the feeder cells (iMEF) in less than 45 seconds for high-resolution images, which will permit real-time monitoring of culture progress in future experiments. The

  19. Real-Time Ozone Detection Based on a Microfabricated Quartz Crystal Tuning Fork Sensor

    PubMed Central

    Wang, Rui; Tsow, Francis; Zhang, Xuezhi; Peng, Jhih-Hong; Forzani, Erica S.; Chen, Yongsheng; Crittenden, John C.; Destaillats, Hugo; Tao, Nongjian

    2009-01-01

    A chemical sensor for ozone based on an array of microfabricated tuning forks is described. The tuning forks are highly sensitive and stable, with low power consumption and cost. The selective detection is based on the specific reaction of the polymer with ozone. With a mass detection limit of ∼2 pg/mm2 and response time of 1 second, the sensor coated with a polymer sensing material can detect ppb-level ozone in air. The sensor is integrated into a miniaturized wearable device containing a detection circuit, filtration, battery and wireless communication chip, which is ideal for personal and microenvironmental chemical exposure monitoring. PMID:22346720

  20. Microfabrication of an Implantable silicone Microelectrode array for an epiretinal prosthesis

    SciTech Connect

    Maghribi, M

    2003-06-10

    Millions of people suffering from diseases such as retinitis pigmentosa and macular degeneration are legally blind due to the loss of photoreceptor function. Fortunately a large percentage of the neural cells connected to the photoreceptors remain viable, and electrical stimulation of these cells has been shown to result in visual perception. These findings have generated worldwide efforts to develop a retinal prosthesis device, with the hope of restoring vision. Advances in microfabrication, integrated circuits, and wireless technologies provide the means to reach this challenging goal. This dissertation describes the development of innovative silicone-based microfabrication techniques for producing an implantable microelectrode array. The microelectrode array is a component of an epiretinal prosthesis being developed by a multi-laboratory consortium. This array will serve as the interface between an electronic imaging system and the human eye, directly stimulating retinal neurons via thin film conducting traces. Because the array is intended as a long-term implant, vital biological and physical design requirements must be met. A retinal implant poses difficult engineering challenges due to the size of the intraocular cavity and the delicate retina. Not only does it have to be biocompatible in terms of cytotoxicity and degradation, but it also has to be structurally biocompatible, with regard to smooth edges and high conformability; basically mimicking the biological tissue. This is vital to minimize stress and prevent physical damage to the retina. Also, the device must be robust to withstand the forces imposed on it during fabrication and implantation. In order to meet these biocompatibility needs, the use of non-conventional microfabrication materials such as silicone is required. This mandates the enhancement of currently available polymer-based fabrication techniques and the development of new microfabrication methods. Through an iterative process, devices

  1. Tight focusing of plane waves from micro-fabricated spherical mirrors.

    PubMed

    Goldwin, J; Hinds, E A

    2008-10-27

    We derive a formula for the light field of a monochromatic plane wave that is truncated and reflected by a spherical mirror. Within the scalar field approximation, our formula is valid even for deep mirrors, where the aperture radius approaches the radius of curvature. We apply this result to micro-fabricated mirrors whose size scales are in the range of tens to hundreds of wavelengths, and show that sub-wavelength focusing (full-width at half-maximum intensity) can be achieved. This opens up the possibility of scalable arrays of tightly focused optical dipole traps without the need for high-performance optical systems. PMID:18958062

  2. Manipulating cell shape by placing cells into micro-fabricated chambers.

    PubMed

    Chang, Fred; Atilgan, Erdinc; Burgess, David; Minc, Nicolas

    2014-01-01

    Cell shape is an important cellular parameter that influences the spatial organization and function of cells. However, it has often been challenging to study the effects of cell shape because of difficulties in experimentally controlling cell shape in a defined way. We describe here a method of physically manipulating sea urchin cells into specified shapes by inserting them into micro-fabricated chambers of different shapes. This method allows for generation of large systematic and quantitative data sets and may be adaptable for different cell types and contexts. PMID:24633802

  3. Quantum information experiments with a micro-fabricated, cryogenic, surface-electrode ion trap

    NASA Astrophysics Data System (ADS)

    Wilson, A. C.; Brown, K. R.; Ospelkaus, C.; Colombe, Y.; Leibfried, D.; Wineland, D. J.

    2011-05-01

    Although the basic components of a quantum information processor using trapped ions have been demonstrated, scaling to large numbers of qubits and operations so that algorithms and simulations of practical importance can be implemented remains a major challenge. This is technically challenging because it requires significant improvements in the precision with which quantum states of ions are prepared, manipulated and measured. Solutions are multi-disciplinary - involving micro-fabrication, cryogenics, integrated photonic devices, as wells as materials and surface science. Here we report progress from experiments that address a range of these issues. We use a micro-fabricated, cryogenic, surface-electrode ion trap, with two closely-spaced independently controlled potential wells. In the first experiment with this new apparatus, we implement a scheme for coupling two ions trapped in separate wells, and demonstrate tunable energy exchange at approximately the single quantum level. A second experiment investigates errors in single qubit gates (rotations) with the use of randomized bench-marking. Although the basic components of a quantum information processor using trapped ions have been demonstrated, scaling to large numbers of qubits and operations so that algorithms and simulations of practical importance can be implemented remains a major challenge. This is technically challenging because it requires significant improvements in the precision with which quantum states of ions are prepared, manipulated and measured. Solutions are multi-disciplinary - involving micro-fabrication, cryogenics, integrated photonic devices, as wells as materials and surface science. Here we report progress from experiments that address a range of these issues. We use a micro-fabricated, cryogenic, surface-electrode ion trap, with two closely-spaced independently controlled potential wells. In the first experiment with this new apparatus, we implement a scheme for coupling two ions trapped

  4. Assembling a ring-shaped crystal in a microfabricated surface ion trap

    SciTech Connect

    Stick, Daniel Lynn; Tabakov, Boyan; Benito, Francisco; Blain, Matthew; Clark, Craig R.; Clark, Susan; Haltli, Raymond A.; Maunz, Peter; Sterk, Jonathan D.; Tigges, Chris

    2015-09-01

    We report on experiments with a microfabricated surface trap designed for confining a chain of ions in a ring. Uniform ion separation over most of the ring is achieved with a rotationally symmetric design and by measuring and suppressing undesired electric fields. After reducing stray fields, the ions are confined primarily by a radio-frequency pseudopotential and their mutual Coulomb repulsion. As a result, approximately 400 40Ca+ ions with an average separation of 9 μm comprise the ion crystal.

  5. Microfabricated nanotopological surfaces for study of adhesion-dependent cell mechanosensitivity.

    PubMed

    Chen, Weiqiang; Sun, Yubing; Fu, Jianping

    2013-01-14

    Cells exhibit high sensitivity and diverse responses to the intrinsic nanotopography of the extracellular matrix through their nanoscale cellular sensing machinery. A simple microfabrication method for precise control and spatial patterning of the local nanoroughness on glass surfaces by using photolithography and reactive ion etching is reported. It is demonstrated that local nanoroughness as a biophysical cue could regulate a diverse array of NIH/3T3 fibroblast behaviors, including cell morphology, adhesion, proliferation, migration, and cytoskeleton contractility. The capability to control and further predict cellular responses to nanoroughness might suggest novel methods for developing biomaterials mimicking nanotopographic structures in vivo for functional tissue engineering. PMID:22887768

  6. Characterizing and reducing microfabrication-induced loss in superconducting devices, Part I: Resonators

    NASA Astrophysics Data System (ADS)

    Dunsworth, Andrew; Megrant, A.; Chen, Z.; Quintana, C.; Burkett, B.; Kelly, J.; Barends, R.; Fowler, A.; Jeffrey, E.; White, T.; Sank, D.; Mutus, J.; Campbell, B.; Chen, Y.; Chiaro, B.; Neill, C.; O'Malley, P. J. J.; Roushan, P.; Vainsencher, A.; Wenner, J.; Martinis, J. M.

    Planar and 3D superconducting qubits have previously been shown to be limited by microfabrication induced loss. Using finite element simulations, we have identified a major source of this decoherence in superconducting qubits. Furthermore, we experimentally verified this dominant loss channel using a novel resonator based approach, which we call 'Hydra' resonators. We fully characterized and then substantially reduced this loss channel using these Hydra resonators. I will report on these measurements and their implications on improving the coherence of superconducting qubits. This work is supported by Google inc.

  7. Insights into foraminiferal influences on microfabrics of microbialites at Highborne Cay, Bahamas

    PubMed Central

    Bernhard, Joan M.; Edgcomb, Virginia P.; Visscher, Pieter T.; McIntyre-Wressnig, Anna; Summons, Roger E.; Bouxsein, Mary L.; Louis, Leeann; Jeglinski, Marleen

    2013-01-01

    Microbialites, which are organosedimentary structures formed by microbial communities through binding and trapping and/or in situ precipitation, have a wide array of distinctive morphologies and long geologic record. The origin of morphological variability is hotly debated; elucidating the cause or causes of microfabric differences could provide insights into ecosystem functioning and biogeochemistry during much of Earth’s history. Although rare today, morphologically distinct, co-occurring extant microbialites provide the opportunity to examine and compare microbial communities that may be responsible for establishing and modifying microbialite microfabrics. Highborne Cay, Bahamas, has extant laminated (i.e., stromatolites) and clotted (i.e., thrombolites) marine microbialites in close proximity, allowing focused questions about how community composition relates to physical attributes. Considerable knowledge exists about prokaryotic composition of microbialite mats (i.e., stromatolitic and thrombolitic mats), but little is known about their eukaryotic communities, especially regarding heterotrophic taxa. Thus, the heterotrophic eukaryotic communities of Highborne stromatolites and thrombolites were studied. Here, we show that diverse foraminiferal communities inhabit microbialite mat surfaces and subsurfaces; thecate foraminifera are relatively abundant in all microbialite types, especially thrombolitic mats; foraminifera stabilize grains in mats; and thecate reticulopod activities can impact stromatolitic mat lamination. Accordingly, and in light of foraminiferal impacts on modern microbialites, our results indicate that the microbialite fossil record may reflect the impact of the radiation of these protists. PMID:23716649

  8. Microfabrication of a High-Throughput Nanochannel Delivery/Filtration System

    NASA Technical Reports Server (NTRS)

    Ferrari, Mauro; Liu, Xuewu; Grattoni, Alessandro; Fine, Daniel; Hosali, Sharath; Goodall, Randi; Medema, Ryan; Hudson, Lee

    2011-01-01

    A microfabrication process is proposed to produce a nanopore membrane for continuous passive drug release to maintain constant drug concentrations in the patient s blood throughout the delivery period. Based on silicon microfabrication technology, the dimensions of the nanochannel area, as well as microchannel area, can be precisely controlled, thus providing a steady, constant drug release rate within an extended time period. The multilayered nanochannel structures extend the limit of release rate range of a single-layer nanochannel system, and allow a wide range of pre-defined porosity to achieve any arbitrary drug release rate using any preferred nanochannel size. This membrane system could also be applied to molecular filtration or isolation. In this case, the nanochannel length can be reduced to the nanofabrication limit, i.e., 10s of nm. The nanochannel delivery system membrane is composed of a sandwich of a thin top layer, the horizontal nanochannels, and a thicker bottom wafer. The thin top layer houses an array of microchannels that offers the inlet port for diffusing molecules. It also works as a lid for the nanochannels by providing the channels a top surface. The nanochannels are fabricated by a sacrificial layer technique that obtains smooth surfaces and precisely controlled dimensions. The structure of this nanopore membrane is optimized to yield high mechanical strength and high throughput.

  9. Microfabricated Electrochemical Cell-Based Biosensors for Analysis of Living Cells In Vitro

    PubMed Central

    Wang, Jun; Wu, Chengxiong; Hu, Ning; Zhou, Jie; Du, Liping; Wang, Ping

    2012-01-01

    Cellular biochemical parameters can be used to reveal the physiological and functional information of various cells. Due to demonstrated high accuracy and non-invasiveness, electrochemical detection methods have been used for cell-based investigation. When combined with improved biosensor design and advanced measurement systems, the on-line biochemical analysis of living cells in vitro has been applied for biological mechanism study, drug screening and even environmental monitoring. In recent decades, new types of miniaturized electrochemical biosensor are emerging with the development of microfabrication technology. This review aims to give an overview of the microfabricated electrochemical cell-based biosensors, such as microelectrode arrays (MEA), the electric cell-substrate impedance sensing (ECIS) technique, and the light addressable potentiometric sensor (LAPS). The details in their working principles, measurement systems, and applications in cell monitoring are covered. Driven by the need for high throughput and multi-parameter detection proposed by biomedicine, the development trends of electrochemical cell-based biosensors are also introduced, including newly developed integrated biosensors, and the application of nanotechnology and microfluidic technology. PMID:25585708

  10. In situ collagen assembly for integrating microfabricated three-dimensional cell-seeded matrices

    NASA Astrophysics Data System (ADS)

    Gillette, Brian M.; Jensen, Jacob A.; Tang, Beixian; Yang, Genevieve J.; Bazargan-Lari, Ardalan; Zhong, Ming; Sia, Samuel K.

    2008-08-01

    Microscale fabrication of three-dimensional (3D) extracellular matrices (ECMs) can be used to mimic the often inhomogeneous and anisotropic properties of native tissues and to construct in vitro cellular microenvironments. Cellular contraction of fibrous natural ECMs (such as fibrin and collagen I) can detach matrices from their surroundings and destroy intended geometry. Here, we demonstrate in situ collagen fibre assembly (the nucleation and growth of new collagen fibres from preformed collagen fibres at an interface) to anchor together multiple phases of cell-seeded 3D hydrogel-based matrices against cellular contractile forces. We apply this technique to stably interface multiple microfabricated 3D natural matrices (containing collagen I, Matrigel, fibrin or alginate); each phase can be seeded with cells and designed to permit cell spreading. With collagen-fibre-mediated interfacing, microfabricated 3D matrices maintain stable interfaces (the individual phases do not separate from each other) over long-term culture (at least 3weeks) and support spatially restricted development of multicellular structures within designed patterns. The technique enables construction of well-defined and stable patterns of a variety of 3D ECMs formed by diverse mechanisms (including temperature-, ion- and enzyme-mediated crosslinking), and presents a simple approach to interface multiple 3D matrices for biological studies and tissue engineering.