Analysis and experimental verification of multiple scattering of acoustoelastic waves in thin plates for enhanced energy harvesting

Acoustoelastic wave energy harvesting in thin plates and other structures has recently gained attention from the energy harvesting research community. Metamaterial-inspired concepts for enhancing wave power generation have been investigated, including metamaterial funnels, mirrors, and defect-based resonators. In support of such concepts, this paper presents an electromechanically coupled, multiple scattering formulation for accurately modeling, exploring, and optimizing metamaterial-based harvesting systems incorporating scatterers (e.g., cylindrical inclusions and voids). Following development, the formulation is applied to determining optimal arrangements of scatterers, nominally in a semi-elliptical path, which maximize electrical power harvested, This is done, in part, by diminishing side lobes resulting from ellipse truncation. Optimization results exhibit minimized side lobes and harvester power nearly ten times that of the non-optimized case. Finally, an experimental study is presented which confirms many of the model predictions.