Tunable metagrating for flexural wave based on knob elastic metasurfaces

In the study, a tunable metagrating of flexural waves by using knob elastic metasurface is presented. By precisely designing the angles of the rotary knobs, the gradient of the upper and lower half regions of the metasurface can be made symmetric to realize the beam splitting of the flexural wave and the phenomenon of the acoustic bottle beam. The numerical results confirm the broadband and robustness of the metasurface in terms of the flexural wave manipulation capability, which provides a basis for the design of the beam splitter device. More importantly, the switching of these functions can be done by a simple rotation of the knob angle without the need to redesign the new metarsurface.