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This paper investigates dielectric charge in oxide-coated composite-beam silicon electrostatic resonators. The effects of charge in the oxide layers on resonant frequency are theoretically modeled. Evidence for the presence of both fixed and mobile charge is presented through experimental studies. It is shown that the motion of charge is controllable through the bias voltage applied to the resonator. These studies are relevant for improving the reliability of non-contacting MEMS where dielectrics may be present such as timing references, inertial sensors, and optical actuators.

This paper demonstrates using charge-biased vacuum encapsulated single-anchored double-ended tuning fork (DETF) resonators for humidity sensing. We charge-bias the DETF resonators and measure the change in the stored charge by observing the resonant frequency. Environmental humidity modifies the discharge characteristic of the resonator by varying the resistance between the bias bondpad and the surface silicon dioxide. Using this variation, we demonstrate a sensor that can determine relative humidity from <1 % to 60% with an absolute measurement uncertainty of less than ±0.8% RH.

This paper describes the fabrication and testing of a one-axis polymer-based capacitive accelerometer made using a reel-to-reel/roll-to-roll compatible, printing-based process. The accelerometer is a suspended parallel-plate sense capacitor made from a laser-printed polystyrene composite material on a flexible plastic substrate. With a simple analog voltage readout circuit, device sensitivity is 58mV/g with +/-1.5g range. This device demonstrates fabrication of ultra-low-cost MEMS sensors on flexible polymer substrates.

This paper demonstrates the effect o humidity measurements using a charge-b encapsulated single-anchored double-en resonator (DETF). The resonator is electr to a metal bond pad on the external dioxide. Changes in the ambient humidity decay characteristics of the resonator b surface resistance of the oxide. This chan by measuring the shift in resonant fr electrostatic spring softening. Varying from 12°C to 32°C and the relative humid to 60%, the temperature dependence of tim from -0.05/°C to -0.03/°C and the re dependence of time decay ranged from 0