Modeling and Analysis of a SiC Microstructure-Based Capacitive Micro-Accelerometer

In this study, a comb-type capacitive accelerometer based on a silicon carbide (SiC) microstructure is presented and investigated by the finite element method (FEM). It has the advantages of low weight, small volume, and low cross-coupling. Compared with silicon(111) accelerometers with the same structure, it has a higher natural frequency. When the accelerometer vibrates, its resistive force consists of two main components: a viscous damping and an elastic damping force. It was found that viscous damping dominates at low frequency, and elastic damping dominates at high frequency. The second-order linear system of the accelerometer was analyzed in the time-frequency domain, and its dynamic characteristics were best when the gap between the capacitive plates was 1.23 mu m. The range of this accelerometer was 0-100 g, which is 1.64 times that of a silicon(111) accelerometer with the same structure. In addition, the accelerometer could work normally at temperatures of up to 1200 degrees C, which is much higher than the working temperatures of silicon devices. Therefore, the proposed accelerometer showed superior performance compared to conventional silicon-based sensors for inertial measurements.

Automated summary

A comb-type capacitive accelerometer based on silicon carbide microstructure was investigated in this study, showing superior performance compared to conventional silicon-based sensors. It has the advantages of low weight, small volume, and low cross-coupling, with a higher natural frequency than silicon(111) accelerometers. The accelerometer's resistive force consists of viscous damping and elastic damping components, with viscous damping dominating at low frequency and elastic damping dominating at high frequency.