A Model for the Pull-In Parameters of Magnetostatic Actuators with Fringing Effect

Abstract

Predicting Pull-In parameters is crucial in the design of MEMS actuators. In the past, the Pull-In parameters of magnetostatic actuators with the fringing field effect are often estimated using finite element method (FEM). However, FEM is cumbersome, time consuming and non-transparent, which is not convenient for the design optimization. Usually, there are a simple analytical model without leakage reluctance and a detailed analytical model with leakage reluctance respectively. This paper used the two models to derive the Pull-In model of magnetostatic actuators respectively. The accuracy of the two Pull-In models is examined by comparing their results with the FEM results. Simulation results show that the Pull-In model without leakage reluctance is unsuitable to predict Pull-In parameters. The Pull-In model with leakage reluctance has shown a good agreement with the FEM results for a wide range of gap spacing.