An electrometric method to measure the mechanical parameters of MEMS devices

It is difficult to acquire the actual mechanical parameters of comb-finger MEMS devices, for its sensing element has special structure. In order to derive the parameters, such as the proof mass m, the equivalent distance d₀ between fingers, and the mechanical stiffness k_m, a static electrometric method is investigated. The method includes two experiments, the electrostatic force experiment and the open loop frequency response experiment, and the values of d₀, d₀, and k_m can be calculated with the electrical variables in the experiments. The experimental results show that the actual mechanical parameters of the sensing element can be estimated with a high accuracy. It is a convenient and useful method to be used in the fieldwork without the special requirement of environment and costly facilities.