Study and Analysis of Materials for Design of MEMS Capacitive Accelerometer

This research work presents the analysis of a capacitive surface micromachined Microelectro mechanical System (MEMS) based accelerometer. A 3D model of the inertial sensor with mathematical model of accelerometer has been explained. This is followed by parametric analysis of the sensor for three different materials chosen as Germanium, Polysilicon and Lead Zirconate Titanate (PZT). The displacement sensitivity of the accelerometer is studied and quantitative analysis of results has been presented for three electrical parameters which are acceleration, electric field and customized frequency response. All investigations are done for two constant values of acceleration i.e. 25 g and 50 g. Apart from this Eigen frequency analysis of structure is also carried out and found to be maximum for Ge at 6 kHz for displacement of proof mass. Thus overall Ge is found to show the best response for displacement, electric field response and frequency and presented in this paper. The characterization of the accelerometer is carried out and analyzed for chosen design using COMSOL tool.