Research on the influence of hydrostatic pressure on the sensitivity of bionic cilia MEMS vector hydrophone

Abstract

Hydrophones are one of the main sensors for underwater acoustic signal detection, and their positioning accuracy is closely related to their sensitivity. However, in practice, hydrophones need to work in different depths of water environment. The ciliated MEMS vector hydrophone has a four-beam structure and has a certain anti-interference ability against hydrostatic pressure. However, due to the manufacturing process and other reasons, there may be certain errors in the production of varistors, which leads to the hydrophone's resistance to hydrostatic pressure. The resistance to the impact is reduced. Therefore, studying the influence of hydrostatic pressure environment on the sensitivity of MEMS vector hydrophones is of great significance to the application of MEMS vector hydrophones. According to the application environment of MEMS vector hydrophone, the sensitivity of MEMS vector hydrophone is studied in this paper within the range of hydrostatic pressure 1 atm ∼ 12 MPa. In this paper, the influence of hydrostatic pressure on the sound transmission loss and piezoresistor are studied to theoretically verify that the hydrostatic pressure has little effect on the sensitivity of MEMS vector hydrophone. It is verified by COMSOL5.6 software simulation that the sensitivity changes within the pressure range of 1 dB. In order to facilitate the experiment of the MEMS vector hydrophone in the hydrostatic environment, this paper proposed a method of combining an external sound source with a marine environment simulation test machine. It is concluded that within the test pressure range, the sensitivity change of the MEMS vector hydrophone fluctuates within ±1 dB.