An Annular Slots Back Island Mems Hydrophone With Ultra-High Sensitivity At Low Frequency

This paper reports a piezoelectric MEMS hydrophone based on the annular slots back island (ASBI) structure. The stress concentration areas of the annular slots increase the sensitivity of underwater sound wave reception, and the back island improves the low-frequency performance of the hydrophone. The sensitivity of the ASBI hydrophone is higher than -170 dB at low frequency (below 10 Hz) without amplification circuit, and the highest sensitivity can reach -155.7 dB@5 Hz (reference 1Vrms/μPa). The ABSI hydrophone can withstand at least 10 MPa water pressure due to the annular slots structure. The high sensitivity at low frequency and high pressure resistance show that the ASBI hydrophone has great potential in deep sea long-range detection.