Optimal design of high-g MEMS piezoresistive accelerometer based on Timoshenko beam theory

The high-g micro-electro-mechanical systems (MEMS) piezoresistive accelerometers are designed based on silicon-on-insulator (SOI) to be used in explosion and penetration circumstance whose range is 2000,000 g. However, the classical Bernoulli–Euler theory is inadequate for the short and thick beams subject to high-frequency excitation, this paper presents theoretical model of the high-g accelerometer as a crossed clamped–clamped Timoshenko beams with a lumped moment of inertia at the free end which can optimize the two conflicting indicators eigenfrequency and sensitivity. In order to obtain the bigger sensitivity when the anti-overload is 200,000 g, considering the dynamic performances comprehensively, the dimensions of the accelerometer are determined. It can be found that the theoretical analyses are in good consistent with simulation results. The micro-machined accelerometers were tested by the Machete hammer and Hopkinson, the experimental calibration results show that the sensitivity of accelerometer has been improved to 0.4 μv/g. Consequently, the optimal design method proposed in this paper can improve the sensitivity under the anti-overload ability of 200,000 g.