Piezoelectric elastic metasurface for tunable guided waves control in plate

In this work, an electromechanical metasurface is designed for wave controlling of multi-mode guided waves in plate, including shear horizontal wave, symmetrical mode and anti-symmetrical mode of Lamb waves. The metasurface is constructed by staggered arrangement of in-plane polarized and out-of-plane polarized piezoelectric patches, which are connected with shunting circuits. The transmitted phase of different guided wave modes can be changed individually in 0~2π range by adjusting the negative capacitances of the shunting circuits without changing the structure geometry. By coding transmitted phase along the metasurface, multi-function including tunable focusing and tunable anomalous refraction of guided waves can be achieved by wave front control. Furthermore, by modulating each mode wave simultaneously, the incident mixed guided wave can be separated after transmitting through the metasurface and specific wave mode can be further extracted.