MEMS仿生矢量水听器微结构的有限元分析

结合压电原理和仿生学理论，利用MEMS工艺制作的仿生矢量水听器，具有高灵敏度、宽频带、矢量性及高信噪比等特点。为了进一步提高水听器预测水下环境中声学特性的准确性并提高其固有频率，利用有限元方法对MEMS水听器仿生微结构进行优化分析。首先，对仿生微结构固有频率和灵敏度与其结构尺寸关系作了理论分析并画出不同微结构尺寸下的固有频率和最大应力曲线。其次，运用ANSYS软件对仿生微结构进行有限元仿真并画出固有频率和最大应力响应曲线。对比分析理论与仿真结果，得出当悬臂梁长、宽、厚及仿生纤毛的高度和半径分别为400, 80, 50, 1000和80 m 时，MEMS矢量水听器的性能得到最优化，同时对理论与仿真结果的差异进行了分析。

Analysis for microstructure of MEMS bionic vector hydrophone

The MEMS bionic vector hydrophone, which has advantages of high sensitivity, broad frequency band, vector and high Signal to Noise Ratio(SNR), is one kind of underwater acoustic signal detection device integrating piezoelectricity and MEMS technology. However, to make a further step in improving the predictive accuracy and the resonant frequency of underwater acoustic signal, optimization design of the MEMS hydrophone bionic microstructure is performed with finite element method in this paper. Firstly, it can be learned from theoretical formulas of natural frequency and stress that the natural frequency of bionic microstructure is inversely-proportional to the height of bionic cilia and the beam length, at the same time, is proportional to the beam width and thickness; Instead, the sensitivity is proportional to the bionic cilia height and beam length, and is inversely-proportional to the beam width and thickness. Based on the theoretical analysis, maximum stress curves and resonance frequency curves of sensor under different structural parameters are drawn. Secondly, a static analysis was done with ANSYS software and a response curve of natural frequency and stress was drawn. Finally, the simulation results show that a better performance of high sensitivity and broad frequency band for MEMS hydrophones can be obtained by designing beam length, width, thickness and bionic cilia height and radius as 400, 80, 50, 1000 and 80 m respectively. The simulation results and the theoretical analysis are compared, and the differences between them are analyzed.