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A novel microelectromechanical systems (MEMS) actuation technique is developed for retinal scanning display and imaging applications allowing effective drive of a two-axes scanning mirror to wide angles at high frequency. Modeling of the device in mechanical and electrical domains, as well as the experimental characterization is described. Full optical scan angles of 65[degrees] and 53[degrees] are achieved for slow (60 Hz sawtooth) and fast (21.3 kHz sinusoid) scan directions, respectively. In combination with a mirror size of 1.5 mm, a resulting [[theta].sub.opt]D product of 79.5 deg *mm for fast axis is obtained. This two-dimensional (2-D) magnetic actuation technique delivers sufficient torque to allow non-resonant operation as low as dc in the slow-scan axis while at the same time allowing one-atmosphere operation even at fast-scan axis frequencies large enough to support SXGA (1280 x 1024) resolution scanned beam displays. [1653]

This paper presents a CMOS power supply unit for electrically isolated microscale applications, where the provision of electrical power is not appropriate through wiring. A miniature fiberoptic platform consisting of an inclined silicon mirror fabricated using bulk micromachining is coupled to the monolithically integrated photodiode/dc–dc converter system, to yield a stand-alone optical power supply. In this approach, the dc/dc converter steps up the voltage of a single CMOS-integrated photodiode to a higher level. A test chip is fabricated using UMC 0.18-μm triple-well CMOS technology to demonstrate the power supply unit. Two different types of photodiodes, namely, a triple-well photodiode and an n-well photodiode are compared. It is found that on-chip triple-well photodiode results in a projected responsivity of 26 mA/W. The dc/dc converter had a maximum efficiency of 56% and is able to boost an input voltage level of 0.5-to-1.2 V. Silicon mirrors coated with 25-nm-thick aluminum are measured to have a reflectivity of 80% for a laser beam at a wavelength of 650 nm. Capability of the overall packaged optoelectronic system, consisting of the optical fiber, silicon mirror, CMOS photodiode, and the dc/dc converter, is demonstrated by generation of an electrical power of 60 μW. [ABSTRACT FROM PUBLISHER]

Si nanowire (NW) stacks are fabricated by utilizing the scalloping effect of inductively coupled plasma deep reactive ion etching. When two etch windows are brought close enough, scallops from both sides will ideally meet along the dividing centerline of the windows turning the separating material column into an array of vertically stacked strings. Upon further thinning of these NW precursors by oxidation followed by oxide etching, Si NWs with diameters ranging from 50 nm to above 100 nm are obtained. The pattern of NWs is determined solely by photolithography. Various geometries ranging from T-junctions to circular coils are demonstrated in addition to straight NWs along specific crystallographic orientations. The number of NWs in a stack is determined by the number of etch cycles utilized. Due to the precise lithographic definition of NW location and orientation, the technique provides a convenient batch-compatible tool for the integration of NWs with MEMS. This aspect is demonstrated with a microgripper, where an electrostatic actuation mechanism is simultaneously fabricated with the accompanying NW end- effectors. Mechanical integrity of the NW-MEMS bond and the manipulation capability of the gripper are demonstrated. Overall, the proposed technique exhibits a batch-compatible approach to the issue of micronanointegration [ABSTRACT FROM AUTHOR]