Dynamic Behaviour and Piezoresistive Analysis of a Single Mass 3-Axis Polymer MEMS Accelerometer

In this work, for the first-time dynamic behavior of an SU-8 polymer based single proof mass, 3-axis MEMS piezoresistive accelerometer is presented. The beams dimensions were optimized to induce the maximum stress with an applied acceleration of 100g. Polysilicon is used as a piezoresistive material to understand the sensitivity and deduce the gauge factor of the device. Finite Element Modeling analysis is used to simulate the dynamic behavior, frequency response and effects of squeeze-film damping. Frequency response and dynamic analysis are then validated. The Eigen frequencies for the first three modes were found to be 1.0847 kHz, 1.5067 kHz and 1.5073 kHz, respectively. The quality factor deduced from the frequency response is approximately 15. The maximum gauge factor is found to be 11.2.