A novel squeezed-film damping model for MEMS comb structures

Abstract

We present the implementation and validation of a novel model for simulating comb squeezed-film damping. The model is computationally efficient regardless of finger count and optionally includes top and bottom encapsulation surfaces surrounding the fingers. Comparison with standard numerical simulation shows a difference in damping coefficient of less than 1%. One application is to predict the Q factors of resonant MEMS such as gyroscopes for which a high Q-factor ensures stable oscillations and certain magnetometers for which it amplifies the sensitivity. The model is validated against experimental Q factors of a magnetometer, predicted values are within 10% of measurement from 0.01MPa to 100Pa.