DESIGN AND ANALYSIS OF A NOVEL MEMS PIEZOELECTRIC ACCELEROMETER FOR VECTOR HYDROPHONE

A novel ZnO film accelerometer based composite beam with double U grooves was proposed for MEMS vector hydrophone to increase the sensitivity. The sensitivity analysis and structure optimization were carried out by finite element method (FEM). The optimized thickness of ZnO film is around 67% of the thickness of silicon layer. The length of the U groove has little effect on the average stress of ZnO film, while the width of U groove has obvious effect on the average stress. The average stress in ZnO film of the new structure is 1.5 times of that with regular piezoelectric composite cantilever structure, and three times output voltage can be further obtained by the electrode series connection. Based on the above-mentioned factors, the sensitivity of accelerometer with double U grooves is 4.5 times of that with regular cantilever, and the acoustic sensitivity of the vector hydrophone can be increased by 13dB.