Design of flexural wave bessel metasurface with resonant pillar-type metamaterials

In this paper, we design a flexural wave Bessel metasurface with resonant pillars, which converts the flexural wave produced by a point into a Bessel beam. The refractive index is determined through the application of the generalized Snell’s law, subsequently discretized into pixel blocks. These blocks facilitate implementation via the use of metamaterial unit cells. The metasurface is realized by resonant pillar-type metamaterials, and composed of 41 different independent unit cells obtained by retrieving the energy bands. Simulation results demonstrate that the designed metasurface exhibits effective focusing for flexural wave. Additionally, the self-reconstruction effect of the Bessel metasurface is verified through the introduction of obstacles. This research provides a new perspective for the application of Bessel beam in the domain of flexural wave.