Manipulation of reflected acoustic wavefront by a comb-like metasurface

Abstract

This work proposes a design strategy for an acoustic metasurface with the goal of flexibly modulating reflected waveforms. The metasurface unit is composed of a rigid base and a column of rectangular partitions arranged in a comb-like configuration. A full 2π phase shift of the reflected waves can be achieved by adjusting the height of these rectangular partitions. The utilization of a particle swarm optimization algorithm determines the specific phase shift of the units along the metasurface. As a pragmatic example, it is shown that the comb-like metasurface offers a superior ability to direct the propagation of reflected sound waves in the desired directions, and experiments are performed to verify this anomalous reflection phenomenon. Furthermore, numerical calculations effectively demonstrate the application of the acoustic ground illusion. This work presents an effective and feasible design scheme for acoustic wave manipulation.