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Freestanding micrometer-scale Ag membranes were laser printed via the laser decal transfer process without the use of sacrificial layers. Cross-sectional focused ion beam milling revealed uniform membrane thickness. Material and structural properties, including Young's modulus E \approx 40\ \GPa, residual stress \sigma0 \approx 61\ \MPa, and yield stress \sigma^y \approx 110\ \MPa , were extracted via a coupled nanoindentation/finite-element simulation approach. Dynamic characterization of membranes via laser vibrometry confirmed resonant frequencies in the megahertz regime with quality factors comparable to fully dense structures fabricated via traditional lithography. \hfill[2010-0199] [ABSTRACT FROM AUTHOR]

We present a design approach that enables monolithic integration of high-quality-factor (Q) radio-frequency (RF) microelectromechanical systems (MEMS) resonators with CMOS electronics. Commercially available CMOS processes that feature two polysilicon layers and field oxide isolation can be used to implement this approach. By using a nonplanar resonator geometry in conjunction with mechanical stress in polycrystalline silicon (poly) gate layers, we create rigid and robust mechanical structures with efficient electromechanical transduction. We demonstrate polysilicon domes with capacitive pickup and arch-bridge resonators with piezoresistive readout. The small footprint of our MEMS structures enables on-chip integration of large arrays of resonators for RF signal processing or sensing applications. Their large surface-to-volume ratio in combination with high rigidity (that alleviates stiction associated with wet chemistry processing) can make these resonators particularly useful for sensors that require surface functionalization. [ABSTRACT FROM AUTHOR]

The dominant damping mode for micromachined resonators operating at low pressures, typically 1000 Pa or less, is collisions with gas particles. This paper presents simple models for determining the damping and the quality factor of micro- cantilever, bridge, and paddle resonators in vertical, horizontal, and torsional motion, using a consistent model of gas-surface interaction, operating in the free-molecular-flow regime. These models incorporate effects such as wall temperature, accommodation coefficients, and high aspect ratios. Finally, the limiting case of vibrational velocities approaching the thermal velocity of the gas particles is considered, with analysis showing that these models are valid until the peak velocity of the vibration reaches 0.2c, where c is the thermal velocity of the gas. [2007-0120] [ABSTRACT FROM AUTHOR]