Enhanced Underwater Sound Absorption in Composites via Mechanically Responsive BCZT@SiO2 Core–Shell Resonators

Low-frequency sound waves in marine environments present a substantial challenge to underwater equipment due to their high penetration capability. To address this issue, a novel energy dissipation and sound absorption mechanism based on resonant-driven piezoelectric core–shell structures is proposed, and fabricate corresponding underwater acoustic absorption components. The design integrates mechanically responsive piezoelectric core–shell materials into an energy dissipation network, enabling efficient conversion of mechanical energy into electrical energy, followed dissipated as heat. Structural and morphological analyses confirm that the piezoelectric particles are encapsulated within a silicon-based shell featuring an internal cavity. This sophisticated architecture facilitates multiple energy dissipation pathways, significantly enhancing the acoustic performance of the composite. The optimized components exhibit a remarkable loss factor of 1.76 and achieve a sound absorption coefficient of 0.8 at 1 kHz, representing a 135% improvement over pure resin. Furthermore, the composite demonstrates exceptional structural stability under high pressure, with minimal deformation (1.47%) at 5 MPa, equivalent to depths of 500 meters. This study establishes a viable strategy for designing high-performance underwater sound-absorbing materials, offering promising potential for practical applications in marine noise mitigation.