DEVELOPMENT OF A FLAGELLUM-INSPIRED MEMS HYDROPHONE WITH BIOMIMETIC STRUCTURES FOR ENHANCED LOW-FREQUENCY ACOUSTIC SENSING

Abstract

This study presents a novel MEMS vector hydrophone utilizing a flagellum-inspired structure for enhanced underwater acoustic sensitivity. The hydrophone employs piezoresistive technology with a biomimetic design that integrates cilia-like structures, a four-beam linkage, and Wheatstone bridge connections. Simulations conducted in COMSOL Multiphysics revealed significant improvements in sensitivity and frequency response due to optimized structural parameters and materials. A parametric sweep demonstrated that cilia height and pole thickness were critical factors affecting natural frequency and stress distribution, with cilia heights of 2000 µm and pole thicknesses of 10 µm achieving optimal performance. The hydrophone demonstrated a linear frequency response in the 20–500 Hz range, with an eigenfrequency peak at 652 Hz, confirming operational stability outside resonance. Stress analysis showed a maximum value of 60 kPa on poles under 1 Pa acoustic pressure, with higher stress concentration achieved by increasing cilia width and height. The electrical output from the Wheatstone bridge circuit yielded a sensitivity of -211 dB (re: 1 V/µPa), substantially improving over conventional designs. The proposed hydrophone achieves a broader bandwidth and higher sensitivity than existing models, making it suitable for applications requiring precise directional and low-frequency acoustic sensing. This work highlights the effectiveness of biomimetic principles and MEMS technology in developing compact, cost-efficient hydrophones, advancing capabilities in underwater acoustic research and marine biology.