Study on the sensitivity mechanism of low-coupled heat flow biaxial MEMS accelerometers

A new sensitive structure of a low-coupling heat flow biaxial MEMS accelerometer is proposed and its sensitivity mechanism is investigated. A three-dimensional model of the sensitive structure was created by COMSOL, and the temperature field of the sensitive structure was calculated using the finite element method. The results show that the accelerometer has a temperature sensitivity of 1.71 K·g-1in the X-axis, 1.69 K·g-1in the Y-axis, 0.7% cross-coupling, and the sensitivity of both X-axis and Y-axes was 1.5 mV·g-1with a heater power of 5mW and an acceleration of [-1~1] g. The accelerometer is characterized by a high sensitivity and a low cross-coupling, which lays a theoretical basis for the optimization of the structure in the following years.