A Two-Axis MEMS Piezoresistive In-Plane Accelerometer with Pure Axially Deformed Microbeams

Abstract

Novelty-A novel high performance two-axis piezoresistive accelerometer is developed with high sensitivity and high resonant frequency. The accelerometer with pure axially deformed sensitive micro beams has been designed. The biggest advantage of the sensor structure is that the motion of the sensitive beam always satisfies the direct - stretch - compress condition, that can greatly improve the sensor performance. Meanwhile, the sensitive element separated from the support element, which greatly weakening the direct coupling between the resonant frequency and sensitivity. Then we carry out the finite element method (FEM) simulation, according to the simulation results the sensor structure parameters were optimized and it proved that the stress on the sensitive beam is pure axial stress. The theoretical sensitivity of the sensor with the range of 0-100g is more than 0.9mV/g/3V, and its theoretical resonant frequency is 25kHz. Compared with the sensor performance of existing literatures, the accelerometer has excellent performance.