The engineering-adaptive design and optimization of MEMS hydrophones for complex deep-sea environments

Abstract To address the challenges of acoustic detection in complex deep-sea environments, this study presents a novel engineering-adaptive MEMS piezoelectric hydrophone. By leveraging a high-performance scandium-doped aluminum nitride (Sc0.2Al0.8 N) thin film featuring an optimized hexagonal diaphragm structure, the design achieves a superior balance between sensitivity and structural stability compared to traditional PZT-based devices. Through comprehensive fluid-structure coupled multi-physics simulations, the hydrophone’s pressure resistance, acoustic transmission, and noise suppression capabilities were rigorously evaluated for operation at depths up to 5000 m. Experimental characterization of the fabricated prototype validated the simulation predictions, exhibiting a high and uniform sensitivity across the broad operating bandwidth (20–20 000 Hz). Notably, the device maintains excellent signal fidelity with a linearity error of less than 5% under high hydrostatic pressure exceeding 10 MPa. These results validate the efficacy of the proposed design strategy, providing a reliable and high-precision solution for broadband deep-sea acoustic exploration.