Challenges and opportunities by fluid-structure-interaction in natural and metamaterials

Fluid-filled materials exhibit various modes of dynamic signals that depend on frequency and stimulation. While this can pose challenges for band-gap design and modeling, it also provides opportunities for characterization and control. This talk first illustrates classical solid-bound and fluid-bound waves in geomaterials, which are effectively described by Biot's theory. However, in softer materials, the roles of the solid and fluid change. Numerical and experimental findings highlight these reversed roles, showcasing a slow solid wave traveling through a polymer frame alongside a faster airborne wave propagating through its channels. Finally, the so-called squirt-flow effect is used to design a metamaterial capable of achieving high attenuation by buckling pores that locally exchange fluid.