Design and fabrication of a multipurpose cilia cluster MEMS vector hydrophone

[Display omitted] •A novel MEMS vector hydrophone was designed for applying based on piezoresistive effect and fish bionics in the range of 20 Hz–1628 Hz.•Compared with previous studies, fabrication of this micro-structure can be made more simple and efficient.•By using Design Exploration function of ANSYS19.0 software, the optimum solution of the highest sensitivity was obtained with the restrictions of bandwidth.•The MEMS vector hydrophone have a good performance for engineering application, such as the high sensitivity and 8-shape directivity, the wider working bandwidth could realizes the dual use of military and civilian. The previous cilia MEMS vector hydrophone were mainly aimed at monitoring the noises of remote ships due to the limitation of frequency band. Moreover, the methods of adding appendants to cilia were usually used to improve the sensitivity, which increased the difficulty of fabrication, secondary integration and the consistency of production. In this paper, based on the bionic principle of multiple cilia on fishes’ sense cells, a cilia cluster MEMS vector hydrophone(CCVH) is designed. This micro-structure not only improves the sensitivity of hydrophone without adding appendants to cilia, but also designs a suitable frequency band to monitor ships and some valuable marine species. Firstly, a mathematical model is established for theoretical analysis. Then, simulation analysis is carried out to verify the correctness of theoretical analysis, and the optimal size of cilia is found simultaneously. Secondly, the fabrication of cilia cluster MEMS vector hydrophone is more simpler because the cilia have the same properties and integrated process. Finally, test results show that the sensitivity of hydrophone has been increased by 9.6 dB, which can reach up to -183.3 dB@1600 Hz(0 dB ref.1 V/uPa) with the frequency band in the range of 20 Hz-1 kHz. Besides, the sensitivity is increased by 6 dB per octave. Concave point depth of 8-shaped directivity is beyond 30 dB, which indicates that CCVH is promising in underwater application.