Design and fabrication of a novel MEMS piezoelectric hydrophone

• DOI: 10.1016/j.sna.2020.112203
• Publication Date: 2020-07-09T22:49:06Z
• Authors: Shuzheng Shi; Wenping Geng; Kaixi Bi; Jian He; Xiaojuan Hou; Jiliang Mu; Fen Li; Xiujian Chou
• Keywords: 01 natural sciences; 7. Clean energy; 0104 chemical sciences

Abstract Hydrophone, serving as a part of sonar, has a significant effect on the performance of acoustic sensors such as frequency characteristics and sensitivity, however, some limitation such as high cost and complexity in SOI manufacturing technique hinder the industrial application of hydrophones. Therefore, a novel Micro-Electro-Mechanical Systems (MEMS) piezoelectric vector hydrophone based on PZT (lead zirconate titanate) film has been adopted in obtaining vector information of underwater sound field. The piezoelectric hydrophone sensor was analyzed, designed and fabricated with PZT-on-Si substrate, and the structure consists of a four-cantilevers and an acoustics columnar cilium fixed on the center micro mass. According to the simulation results, the piezoelectric films are optimally distributed at the tip of the four beams, where the maximum strain locates. Finally, the piezoelectric vector hydrophone was characterized by comparative calibration experiments in a standing wave bucket. This passive MEMS piezoelectric hydrophone has the characteristics of receiving sensitivity with −189.3 dB at 920 Hz (0dB = 1 V/μPa) and a typical directional pattern of "8" shape, low noise output and high dynamic test range, which is suitable for high precision passive underwater detection.