Bioinspired acoustic metamaterials: mimicking the cuttlebone for advanced noise control applications

Cuttlebones—the internal shells of cuttlefish—are lightweight and buoyant while exhibiting sufficient stiffness and strength to protect the animal from predators and withstand deep-sea pressures up to 2 MPa. Studies indicate that these multifunctional properties stem from their unique porous architecture. Here, we draw inspiration from cuttlebones to design cuttlebone-mimicking porous acoustic metamaterials for passive noise control applications. Using a MATLAB routine, we systematically control pore architecture parameters, including the length, height, and curvature of labyrinthine internal walls, the depth of individual cavities, and the thickness and porosity of the septa. The designed geometries are fabricated via fused filament fabrication, and their sound absorption properties are evaluated using the normal incidence impedance tube test method. Preliminary results suggest that the acoustic performance of these cuttlebone-mimicking materials can be tuned to achieve broadband noise reduction while maintaining their multifunctional characteristics.