High-Efficiency Sound Absorber with Hybrid Metamaterial Structure at Low Frequency

A new hybrid metamaterial (HMM) comprises a circular split ring of tungsten covered by a circular split ring of silicon carbide in a layer of polydimethylsiloxane (PDMS) polymer, epoxy, steel, rubber, fiberglass, or carbon fiber, respectively, to develop a low-frequency sound absorber. We carried out finite element simulations with COMSOL Multiphysics software to take theoretical measurements for acoustic hybrid metamaterial and demonstrate the influence of structural parameters. The results demonstrate that material type, geometric characteristics, and change in diameter for circular split rings of tungsten with visco-thermal losses can control the dissipative loss effect. This enables the construction of highly efficient absorber (99%) at low frequencies across a broad low-frequency spectrum. The present study paves the way for a novel approach to advancing the design of acoustic hybrid metamaterial and controlling underwater acoustic waves.