Relationship Between Temperature Drift and Thermal Expansion of Sensing Structure in Sandwich Micro-Accelerometer

Abstract

To cope with the temperature drift of capacitive sandwich type micro-accelerometer, based on mechanics and thermal principle, mechanics equilibrium of sensing structure after thermal expansion is obtained. Then, in light of the accelerometer’s closed loop operation mode, the electrical equilibrium is obtained. On the basis of two equilibriums, the output drift induced by thermal expansion of sensing structure is attained, which implies that the drift is less than 0.002 gn per 10oC. Meanwhile, an experiment is conducted which indicates that the drift due to the temperature is from 0.1 gn to 0.2 gn per 10oC. The comparison implies that the thermal expansion of sensing structure is not a dominant reason for temperature drift of the accelerometer. Keywords: Sandwich micro-accelerometer, sensing structure, temperature drift, thermal expansion.