Study of the influence of fringe edge on MEMS capacitive accelerometers self-calibration

This paper is the follow-up of the research we conduct to improve the self-calibration precision of high-precision MEMS capacitive accelerometers. In the previous published study, we have analyzed the influence of DRIE fabrication error on the dynamic self-calibration. In this paper, the influence of fringe effect on the self-calibration is discussed in order to improve the self-calibration precision further more, and the results has proved the feasibility of this self-calibration technique. Aimed at the capacitive accelerometer in this paper, the self-calibration error is only 0.18 % in closed-loop circuit, which is approach to the absolute calibration error of laser interferometer (0.5–1 %), which can satisfy the demand of high-precision sensors. In open-loop circuit, the fringe effect influences the self-calibration obviously and the error reaches 24.2 %, but it can be reduced to 1.49 % by correcting the actuation voltage. The method proposed in this paper may be used to develop full-automatic self-calibration system integrated on circuit board in the future.