Design and simulation of a MEMS flexible vector hydrophone based on piezoelectric effect

Purpose This study aims to design a small and flexible vector hydrophone that does not require external power supply to meet the miniaturization requirements of unmanned underwater vehicles. Design/methodology/approach This design uses a flexible substrate, including four beams, mushroom-shaped composite cilia mounted on a central micro mass block, four Polyvinylidene fluoride piezoelectric films integrated on the beams and eight electrodes. The cilia receive sound pressure to drive the deformation of the beam, which in turn drives the deformation of the piezoelectric film on the beam. According to the positive piezoelectric effect, there will be voltage output. Findings A hydrophone model in seawater was established using COMSOL Multiphysics 6.2 software. By optimizing structural data, a working bandwidth of 20–868 Hz has been achieved. At 868 Hz, the sensitivity of the X channel can reach −173.4 dB, and the sensitivity of the Y channel can reach −171.7 dB. It has good “8” directionality at 100, 300, 500 and 868 Hz. Originality/value This study innovatively proposes a microelectromechanical system flexible vector hydrophone based on piezoelectric effect. It does not require external power supply, achieves curved surface attachment and improves the detection sensitivity of the hydrophone.