掺钒氧化锌厚膜MEMS矢量水听器研究

The MEMS vector hydrophone is an important direction for the development of underwater transducer, and has an important application prospect in the field of national defense and civil. The MEMS piezoelectric vector hydrophone has the advantages of passive and low noise, but its sensitivity can not meet the requirements of practical application at present. To improve the sensitivity, the project put forwards a piezoelectric cantilever beam with U-grooves structure MEMS vector hydrophone. The piezoelectric cantilever beam is divided into several independent cantilever beams by U-grooves, and the several independent cantilever beams share a mass block. In order to further improve the sensitivity, the transducers on independent cantilever beams are electrically connected in series. The vibration process of piezoelectric cantilever beam with U-grooves is analyzed using the finite element and analytical method, and the theoretical model including the equivalent circuit is established, the optimization of the key structural parameters is carried out. The growth mechanism of vanadium doped ZnO thick film prepared by a novel method is studied, and the process parameters are optimized; Based on the study of key preparation techniques, the MEMS piezoelectric vector hydrophone is developed. The performances including sensitivity and bandwidth are tested. Through the study of this project, the sensitivity of the MEMS piezoelectric vector hydrophone is significantly improved, and a solid physical and technical basis for its practical use is laid.

MEMS矢量水听器是矢量水听器发展的一个重要方向，在国防和民用领域有着重要的应用前景。MEMS压电矢量水听器具有无源、低噪音等优点，但其灵敏度目前还不能达到实用化的要求。为了提高灵敏度，本项目提出一种具有U形槽压电复合悬臂梁结构的MEMS矢量水听器，通过悬臂梁上刻蚀U形槽，使原来单个的压电复合悬臂梁变成多个独立的、共用一个质量块的压电复合悬臂梁，并且独立悬臂梁上的压电换能器被串联起来。利用有限元和解析方法对其振动过程进行分析，建立等效电路等理论分析模型，优化关键结构参数；提出一种掺钒ZnO厚膜的制备方法，研究厚膜生长机理，并优化工艺参数；对关键制备技术进行研究，研制出MEMS压电矢量水听器实验性器件，并对其进行测试分析。通过本项目的研究显著提高MEMS压电矢量水听器灵敏度，为其实用化打下坚实的物理和技术基础。

MEMS矢量水听器是矢量水听器发展的一个重要方向，在国防和民用领域有着重要的应用前景。本项目以提高MEMS矢量水听器的灵敏度为目的，研制了一种基于ZnO材料的新型MEMS压电矢量水听器。对新型MEMS压电矢量水听器的结构、高性能压电材料和制备工艺等进行了研究与优化，提高了矢量水听器的灵敏度。提出了具有U形槽和基底刻槽的悬臂梁结构，采用有限元分析和解析分析对不同结构进行了研究与优化，使理论灵敏度提高了11dB。进一步地，提出了理论灵敏度和能量综合分析的方法，分析了杂散电容对水听器实际灵敏度的影响，对器件的实际灵敏度进行了更加准确的优化。另一方面，通过对高性能掺钒ZnO膜生长机理的分析，优化了多个制备工艺参数，研制出了高性能的掺钒ZnO压电膜，使压电系数d33达到了280pm/V，比纯ZnO提高了一个数量级以上。最后对设计的新型MEMS压电式矢量水听器进行了研制与测试，在1kHz处的等效声压灵敏度为-186.8dB（放大34dB），并且具有良好的指向性。本项目的开展，不仅促进了MEMS矢量水听器的应用，同时，高性能掺钒ZnO压电膜的成功制备，也将推动其他MEMS压电式器件，如射频（RF）滤波器、超声换能器、声表面波器件、水听器、惯性传感器、MEMS扬声器和麦克风以及能量收集器，在不同领域的应用。