David A. Horsley

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— Angular electrostatic microactuators suitable for use in a two-stage servo system for magnetic disk drives have been fabricated from molded chemical-vapor-deposited (CVD) polysilicon using the HexSil process. A 2.6-mm-diameter device has been shown to be capable of positioning the read/write elements of a 30% picoslider over a 6 6 61-m range, with a(More)
This paper examines the performance of rotating microdevices incorporating a liquid bearing to couple a rotating element to a fixed substrate. Liquid bearing technology promises to significantly improve the durability and lifetime of micromechanical motors. Here, the fluid is confined between the rotor and stator using surface patterning of a hydrophobic(More)
We have developed a microelectromechanical system (MEMS) optical phased array incorporating a high-index-contrast subwavelength grating (HCG) for beamforming and beamsteering in a range of ± 1.26° × 1.26°. Our approach needs only a thin single-layer HCG made of silicon, considerably improving its speed thanks to the low mass, and is suitable for high(More)
We report a high speed 8x8 optical phased array using tunable 1550 nm all-pass filters with ultrathin high contrast gratings (HCGs) as the microelectromechanical-actuated top reflectors. The all-pass filter design enables a highly efficient phase tuning (1.7 π) with a small actuation voltage (10 V) and actuation displacement of the HCG (50 nm). The(More)
We present a high-speed optical beamsteering system based on an 8x8 MEMS phased array. The system incorporates an in situ interferometer that provides a real-time, dynamic measure of the phase of each mirror in the array during beamsteering. A closed-loop phase-control algorithm results in <π/100 mirror phase accuracy and far field beam steering is shown.(More)
We present a free-space optical interconnect system capable of dynamic closed-loop optical alignment using a microlens scanner with a proportional integral and derivative controller. Electrostatic microlens scanners based on combdrive actuators are designed and characterized with vertical cavity surface emitting lasers (VCSELs) for adap-tive optical beam(More)
We present an electrothermally actuated, rotating microlens array for the application of aligning free-space optical interconnects. A bistable mechanical brake holds the rotating stage after alignment so it does not consume any power in steady state. A 4×4 double-sided microlens array is fabricated via micro-inkjet printing and is precisely mounted on the(More)
For the recent production of The Incredible Hulk, Rhythm and Hues Studios has developed a set of tools to simulate crushing and crumpling of metalic objects (such as car smashed by a hero character). Metal Deformation To simulate crumpling of metals, we revised our in-house cloth sim-ulator in many ways. In reality, stiffness of metal is orders of magnitude(More)
Parametric amplification, resulting from intentionally varying a parameter in a resonator at twice its resonant frequency, has been successfully employed to increase the sensitivity of many micro- and nano-scale sensors. Here, we introduce the concept of self-induced parametric amplification, which arises naturally from nonlinear elastic coupling between(More)