A metamaterial structure capable of wave attenuation and concurrent energy harvesting

In this study, the capability of wave attenuation as well as energy harvesting in a metamaterial beam with built-in resonators is presented. Each resonator consists of a pretensioned elastic membrane and split-ring masses. The flexural wave band characteristics, eigenmodes, and frequency response are predicted by finite element method. Experiments are conducted to verify the finite element results. The results show that, with proper resonators, vibration caused by disturbances can be conspicuously attenuated at certain frequencies. The attenuation region can be manipulated by adjusting the properties of the membrane-split-ring system. Besides, by adding piezoelectric patches to the membrane, the stored energy in the local resonator can be converted into electric power. The generated voltage output reaches a maximum at the frequency where wave is greatly attenuated. Finally, it is shown that double-layer resonators with parallel connection can generate twice as much voltage as the single-layer resonator.