MEMS Low Frequency Vector Hydrophone Imitating Bony Fish Ear

In the context of the present underwater sonar detection system, there is an urgent necessity to enhance the performance of the vector hydrophone in terms of ultralow frequency detection. This study proposes a MEMS low frequency vector hydrophone (BFVH) that imitates the bony fish ear is proposed. The auditory organ of the bony fish ear is used as the prototype of the sensitive structure, with the aim of increasing the surface area of the hydrophone to receive stress and improve the detection sensitivity of the hydrophone in the ultralow frequency band. The optimal size of the two stress-concentrated structures is obtained by finite element iterative analysis. The integration of the sensitive microstructure of the vector hydrophone with MEMS technology is based on the bionic principle and the piezoresistive principle, and the prototype is finally completed. The test results show that the operating frequency band of BFVH is 10–500 Hz, and the sensitivity at 315 Hz is −173.3 and −172.4 dB. The sensitivity of the low frequency band has been significantly enhanced, and the depth of the depression is greater than 30 dB, with good dipole directivity.