A H-Shaped Piezoelectric MEMS Dual-axis Accelerometer

This paper focuses on the study of a piezoelectric dual-axis accelerometer using AlN/ScAlN double-layer piezoelectric films. The proposed accelerometer adopts SOI wafer as the substrate and constructs the AlN/ScAlN/Mo stack as the sensing layer. Through the establishment of theoretical model and finite element simulation, the relationship between the deformation of the structure and the output voltage of the port was analyzed and obtained. The first-order resonant frequencies of the designed accelerometer in the X and Y directions are 157.48 kHz and 83.28 kHz respectively. In addition, the experimental test results indicate that under the acceleration excitation at 500 Hz, the voltage sensitivities of the accelerometer in the X and Y directions are 1.19 mV/g and 1.81 mV/g respectively, and the minimum detectable signals in the X and Y directions are 7 mg and 6 mg respectively. The manufactured accelerometer has good linearity (0.9984) within the acceleration range of 0.2-2.4 g. The innovative structure proposed in this paper provides a new design idea for the research of piezoelectric accelerometers and is expected to promote the further development of this field.