A single-layered elastic metasurface for switching wide-angle asymmetric transmission of flexural waves

A limitation of present elastic metasurfaces remains in their modest flexibility to meet convertible functions on demand. Here, a feasible single-layered lossless metasurface is theoretically proposed and experimentally demonstrated for adjusting the asymmetric transmission of flexural waves. The easily reconstructed unit is derived from multiple pillared resonators; then, the number of units per period can be changed depending on the desired integer parity. In addition, the asymmetric transmission is physically realized by the uneven diffraction of the +/- 1st orders in opposite fields of the designed metasurface. Requiring neither active modules nor passively multilayer or loss-induced strategies, our design using only a layer of lossless metasurface allows the elastic-wave behavior to switch between efficient symmetric and asymmetric transmissions. Furthermore, a high contrast ratio of transmitted energy is verified in experiments and simulations within a wide-angle range. The present work is connected with the pragmatic applications of metasurfaces in timely directional vibration control and compactly elastodynamic rectifications.

Automated summary

This study proposes a single-layer lossless metasurface for adjusting the asymmetric transmission of flexural waves. The design allows for efficient symmetric and asymmetric transmissions without the need for additional active modules or passively multilayered designs, and demonstrates a high contrast ratio of transmitted energy within a wide-angle range.