MEMS仿生矢量水听器是一种新型水声传感器,其工作性能决定于内部MEMS声电换能微结构的几何、材料及流体环境参数。为深入探讨该水听器的工作机理并提高其工作性能,针对其内部微结构通过合理的简化建立了相应的单自由度等效力学模型,并推导出理想流体环境下该微结构一阶固有频率与其几何、材料及流体环境参数间的解析表达式。在此基础上,推导出现有水听器微结构的一阶固有频率,并搭建实验平台进行验证,实验结果表明理论值与实验值间的相对误差低于5%,从而验证了该力学模型的有效性,为水听器的设计及优化提供了理论基础和参考依据,同时也为具有类似结构的传感器的性能分析奠定了基础。

The MEMS bionic vector hydrophone is a new type of underwater acoustic sensor, whose working performance is determined by the geometrical, material and environmental parameters of the internal MEMS acoustic-electric transduction microstructure. In order to have an insight of this kind of hydrophone and improve its working performance, the single degree of a freedom equivalent mechanical model of the microstructure is established through reasonable simplification. On this basis, the first order natural frequency of the micro structure of the hydrophone currently used is calculated, and an experimental platform is built to verify the calculated result. The results show that the error between the theoretical value and the experimental value is less than 5%, which verifies the validity of the mechanical model. This mechanical model provides a theoretical basis and reference for the design and optimization of the hydrophone and it is also a foundation for the performance analysis of sensors with similar structure.