Design and realization of cap-shaped cilia MEMS vector hydrophone

Abstract

Ciliary MEMS vector hydrophone (CVH) has excellent performance in low-frequency detection, however, there is still the problem of poor sensitivity in some applications. A cap-shaped ciliary vector hydrophone (CCVH) is proposed in this paper. The microstructure not only ensures the working bandwidth of the hydrophone, but also increases the sensitivity. A single integration process is adopted to complete the pasting of the cap-shaped cilia and the cantilever beam, requiring no complicated secondary cilia integration process. Firstly, a mathematical model is established for theoretical derivation, and then the principle is verified via COMSOL simulation. Finally, test results show that the sensitivity of CCVH can reach −182.7 dB at 1 kHz (1 kHz, 0 dB@1 V/µPa). Compared with the CVH, the sensitivity has increased by 14.4 dB. Concave point depth of 8-shaped directivity is beyond 30 dB, which indicates that CCVH has an excellent ability to detect underwater ship noise.