An analysis of electrostatically actuated micro vibrating structures incorporating squeezed film damping effect using an electrical equivalent circuit

Abstract

This paper investigates the response of microcantilever and microbridge actuators, under alternating current (AC) and direct current (DC) excitations. The analysis is carried out by simulating the electrical equivalent circuit of the actuators. An analogous circuit model for evaluation of velocity and acceleration in the microstructure is incorporated to the basic circuit model. The influence of squeeze film on the vibrating structure is also investigated. The effect of DC bias voltage on displacement, capacitance and electrostatic force are investigated. The transient response predicts a minimal change due to the pressure variation in the damping medium owing to the geometrical dimensions of the elements in the actuator. The frequency dependence of velocity and acceleration are also evaluated in this study.