A high Q factor MEMS accelerometer with quasi-zero effective stiffness

Abstract This paper presents a high-performance MEMS accelerometer with ultralow noise and wide bandwidth based on a force control of a mechanical system with high quality-factor (Q factor) and quasi-zero effective stiffness. Both dynamic model and noise model of the proposed accelerometer were developed. Based on the dynamic model, a new damping controller and a phase compensation controller are proposed to improve the bandwidth for the high Q factor accelerometers. The noise model is verified experimentally, indicating that the readout circuit noise and mechanical thermal noise are greatly reduced by the decrease of the effective stiffness and air damping, respectively. The accelerometer with phase compensation controller exhibits a linear relationship between the noise power and the bandwidth, which can be tuned by adjusting the controller parameters. Finally, the bandwidth of ranging from 130 to 381 Hz and the base noise of ranging from 140 ng √Hz −1 to 860 ng √Hz −1 are achieved for the proposed accelerometer.