A5057626532- Advanced MEMS and NEMS Technologies
- Photonic and Optical Devices
- Mechanical and Optical Resonators
- Acoustic Wave Resonator Technologies
- Electrowetting and Microfluidic Technologies
- Semiconductor Lasers and Optical Devices
- Semiconductor materials and devices
- Modular Robots and Swarm Intelligence
- Nanowire Synthesis and Applications
- Force Microscopy Techniques and Applications
- Advanced Surface Polishing Techniques
- Adaptive optics and wavefront sensing
- Advanced Sensor and Energy Harvesting Materials
- 3D IC and TSV technologies
- Biosensors and Analytical Detection
- Carbon Nanotubes in Composites
- Cold Atom Physics and Bose-Einstein Condensates
- Heat Transfer and Optimization
- Adhesion, Friction, and Surface Interactions
- Semiconductor Quantum Structures and Devices
- Advanced optical system design
- Advanced Fluorescence Microscopy Techniques
- Metal and Thin Film Mechanics
- Laser Material Processing Techniques
- GaN-based semiconductor devices and materials
University of Colorado Boulder
2015-2024
University of Colorado System
1998-2024
Sandia National Laboratories
2020
Defense Advanced Research Projects Agency
2008-2011
Max Planck Institute for Solid State Research
2006
ETH Zurich
2006
Georgia Institute of Technology
1989-2003
Digital Wave (United States)
2003
U.S. Air Force Institute of Technology
1993-2002
Wright-Patterson Air Force Base
1995-2002
An atom Michelson interferometer is implemented on an ``atom chip.'' The chip uses lithographically patterned conductors and external magnetic fields to produce guide a Bose-Einstein condensate. Splitting, reflecting, recombining of condensate atoms are achieved by standing-wave light field having wave vector aligned along the waveguide. A differential phase shift between two arms introduced either magnetic-field gradient or with initial velocity. Interference contrast still observable at...
We report on the fabrication and characterization of bulk micromachined pressure sensors based individual single-walled carbon nanotubes (SWNTs) as active electromechanical transducer elements. The sensor device consists an electrically connected SWNT adsorbed top a 100-nm-thick atomic layer deposited (ALD) circular alumina (Al2O3) membrane with radius in range 50−100 μm. A white light interferometer (WLI) was used to measure deflection due differential pressure, mechanical properties were...
Because of the low dimensional power its force scaling law, surface tension is appropriate for carrying out reshaping and assembly in microstructure size domain. This paper reviews work on powered self-assembly microstructures. The existing theoretical approaches rotational are unified. demonstrated fabrication processes compared. Mechanisms accurately determining assembled shape discussed, limits accuracy structural distortion considered. Applications optics, electronics mechanics...
We present a miniature head mounted two-photon fiber-coupled microscope (2P-FCM) for neuronal imaging with active axial focusing enabled using electrowetting lens. show three-dimensional of structure and record activity from GCaMP6s fluorescence multiple focal planes in freely-moving mouse. Two-color simultaneous GFP tdTomato is also demonstrated. Additionally, dynamic control the scanning lens allows tilting plane enabling neurons depths to be imaged single plane. Two-photon increased...
Flat, flexible, lightweight, polymer heat pipes (FPHP) were fabricated. The overall geometry of the pipe was 130 mm × 70 1.31 mm. A commercially available low-cost film composed laminated sheets low-density polyethylene terephthalate, aluminum and layers used as casing. triple-layer sintered copper woven mesh served a liquid wicking structure, water working fluid. coarse nylon provided space for vapor transport mechanical rigidity. Thermal power ranging from 5 to 30 W supplied evaporator...
In this paper, polymer-based flat heat pipes (PFHPs) with a thickness on the order of 1 mm have been successfully developed and tested. Liquid-crystal polymer (LCP) films copper-filled thermal vias are employed as case material. A copper micropillar/woven mesh hybrid wicking structure was designed fabricated to promote evaporation/condensation transfer liquid supply evaporator PFHP. Water selected working fluid because its superior thermophysical properties. An experimental study conducted...
In this Letter we report on the fabrication, device characteristics, and optical coupling of a two-nanowire comprising GaN nanowires with light-emitting photoconductive capabilities. Axial p-n junction were grown by molecular beam epitaxy, transferred to non-native substrate, selectively contacted form discrete source or detector nanowire components. The demonstrated for may provide new opportunities integration interconnects between on-chip electrical subsystems.
Low-temperature AlN buffer layers grown via plasma-assisted molecular beam epitaxy on Si (111) were found to significantly affect the subsequent growth morphology of GaN nanowires. The exhibited nanowire-like columnar protrusions, with their size, shape, and tilt determined by V/III flux ratio. nanowires frequently observed adopt structural characteristics underlying columns, including size degree tilt. Piezoresponse force microscopy polarity-sensitive etching indicate that films protruding...
We present a high-resolution miniature, light-weight fluorescence microscope with electrowetting lens and onboard CMOS for high resolution volumetric imaging structured illumination rejection of out-of-focus scattered light. The miniature (SIMscope3D) delivers light using coherent fiber bundle to obtain optical sectioning an axial 18 µm. Volumetric eGFP labeled cells in fixed mouse brain tissue at depths up 260 µm is demonstrated. functionality SIMscope3D provide background free 3D shown by...
A $^{87}\mathrm{Rb}$ Bose-Einstein condensate (BEC) is produced in a portable atom-chip system less than $30\ifmmode\times\else\texttimes\fi{}30\ifmmode\times\else\texttimes\fi{}15\phantom{\rule{0.3em}{0ex}}\mathrm{cm}$, where the ultrahigh vacuum maintained by small, $8\phantom{\rule{0.3em}{0ex}}\mathrm{L}∕\mathrm{s}$, ion pump and nonevaporable getter. An aluminum nitride chip with lithographically patterned copper used to seal system, provide electrical feedthroughs, create magnetic trap...
This paper presents the fabrication and application of a micro-scale hybrid wicking structure in flat polymer-based heat pipe spreader, which improves transfer performance under high adverse acceleration. The enhances evaporation condensation acceleration consists 100 µm high, 200 wide square electroplated copper micro-pillars with 31 grooves for liquid flow woven mesh 51 diameter wires 76 spacing. interior vapor chamber spreader was 30×30×1.0 mm3. casing is thick crystal polymer contains...
Large arrays of 3-terminal nanoelectromechanical graphene switches are fabricated. The switch is designed with a novel geometry that leads to low actuation voltages and improved mechanical integrity, while reducing adhesion forces, which improves the reliability switch. A finite element model including non-linear electromechanics used simulate switching behavior deduce scaling relation between voltage device dimensions.
An adaptive electrowetting-based element with focusing and steering capability has been demonstrated in a monolithic design. Curvature tip-tilt variation have using low voltages. A range of up to 4.3° lens tuning 18 diopters measured at 30 V DC 21 DC, respectively.
We report a miniature, lightweight fiber-coupled confocal fluorescence microscope that incorporates an electrowetting variable focus lens to provide axial scanning for full three-dimensional (3D) imaging. Lateral is accomplished by coupling our device laser-scanning through coherent imaging fiber-bundle. The optical components of the are combined in custom 3D-printed adapter with assembled weight <2 g can be mounted onto head mouse. Confocal sectioning provides resolution ∼12 μm and scan...
A light detection and ranging (lidar) system with ±90 • of steering based on an adaptive electrowetting-based prism for nonmechanical beam has been demonstrated.Electrowetting-based prisms provide a transmissive, low power, compact alternative to conventional optics as scanner.The electrowetting range ±7.8 .We demonstrate method amplify the scan angle perform one-dimensional in lidar system.
Abstract We demonstrate a microLED light source for optical sectioning structured illumination microscopy (OS‐SIM). A bottom‐emitting design is employed to improve the uniformity and intensity of emission by removing anode contact from path. This facilitates addition potential equalizing light‐reflecting layer top surface source. The irradiance, emission, contrast ratio are characterized. system demonstration performed with integrated into fluorescence microscope used OS‐SIM imaging.
Microelectromechanical systems must include large-deflection actuators to create devices which can interact mechanically with their surroundings. Electrostatic large nonresonant motion require high voltages and surface areas produce useful forces. Large-deflection thermal have been fabricated in electroplated metal processes, but the choice of materials is limited, conductivity means these need a current generate required heat. Thus, there for low voltage actuator deflection be integrated...