Design and implementation of a drumstick-shaped ciliated vector hydrophone

This paper aims to solve the problem of weak vector hydrophone detection ability and narrow working frequency band by developing a drumstick-shaped cilia MEME vector hydrophone (DSVH) through the optimization of the bionic cilia structure to improve the sensitivity of the vector channel, increase response to low-frequency signals and achieve underwater long-distance signal detection.

First, solid mechanics and dry and wet modal analysis are used to find the right size of the drumstick-shaped cilia. This shows that the design plan works in real life. The cilia are then finished being made using 3D printing technology. The secondary integration base is then used to connect the cilia to the cross beam. Finally, the detecting structure is put inside the hydrophone shell to finish making the vector hydrophone physically ready. Finally, the hydroacoustic experimental platform is used to measure the sensitivity and directivity to give technical support for the actual application of the vector hydrophone.

Simulation experiments show that the maximum stress of the drumstick-shaped cilia structure acting on the cantilever beam is 3.8 × 10⁵ Pa, and the maximum stress of the DSVH beam is 3.2 times larger than that on the beam of the conventional stress-centralized MEMS vector hydrophone (SCVH) in the steady-state simulation at 1 Pa. The results show that the structure has significant “8” directivity in the operating range of 20–1 kHz, with the depth of the notch reaching −35.2 dB @ 500 Hz. The sensitivity of the DSVH is 10.1 dB higher than that of the SCVH in the working range of 20–1 kHz and can hit −164.2 dB @ 1000 Hz.

The hollow construction of the top of the drumstick-shaped cilia considerably reduces the mass of the cilia itself, avoiding the problem of narrowing the operating bandwidth due to mass increase and adapting well to the characteristics of the ship’s radiated noise, which is normally less than 1 kHz. The sphere architecture can receive sound waves from all directions, considerably expanding the receiving area and sensitivity.