Analysis and design of a novel piezoresistive accelerometer with axially stressed self-supporting sensing beams

A novel piezoresistive accelerometer was developed with high performance in sensitivity, resonant frequency and cross-axis sensitivity. The accelerometer chip with axially stressed self-supporting sensing beams has been designed, fabricated and tested in our study. We derived the expressions for the location of the sensing beams, stresses and resonant frequency, and then these results were verified by the finite element method (FEM) simulation. The fabricated accelerometer was characterized by the static and dynamic experiments. The results showed that the measuring sensitivity was 0.666 mV/g/3 V and the resonant frequency was 17.1 kHz. Meanwhile, the proposed accelerometer provided an available method for the low cross-axis sensitivity design. Compared with other accelerometers in the literatures, the developed accelerometer exhibited an excellent performance concerning a comprehensive figure of merit (FOM). The results demonstrated the feasibility of the novel structure to improve the accelerometer's performance.