Optimizing Sensitivity and Bandwidth in Ciliary MEMS Vector Hydrophones Using a Dandelion-Like Composite Ciliary Structure

To address the mutual constraints between sensitivity and operational bandwidth in the cilia MEMS vector hydrophone, this study proposes a dandelion-like composite materials ciliary structure to optimize the hydrophone's sensitive element. Using COMSOL 6.0 simulations, the impact of materials on sensitivity and bandwidth was evaluated. Dandelion-shaped ciliary structure increases the hydrophone's sensitivity by enlarging the reception area, and using composite materials ensures an operational bandwidth of 20-1000 Hz. Experimental results show that the composite-material dandelion-shaped cilia MEMS vector hydrophone [QCVH(2)] exhibits significant "8" directivity, with a depth greater than 35 dB at 315 Hz. Additionally, QCVH(2) achieves a sensitivity of -186.3 dB at 1000 Hz, which is an improvement of 11.4 dB over the conventional cilia MEMS vector hydrophone (CVH). Compared to the single-material (red wax) dandelion-shaped cilia MEMS vector hydrophone [QCVH(1)], QCVH(2) maintains the same sensitivity while extending the operational bandwidth from 20-400 Hz to 20-1000 Hz.