声学超表面及其声波调控特性研究

Research on Acoustic Metasurface and Its Acoustic Wave Control Characteristics

声学超材料作为近年来研究的一个新兴领域,极大地拓宽了声学材料在各个领域的应用,声学超表面作为声学超材料的一个分支,近几年也受到了国内外研究者的广泛关注。声学超表面是一种由超材料结构单元阵列构成的基于亚波长尺寸的新型声学超材料,能够利用广义Snell定理实现对反射声波或透射声波的定向调控,具有利用亚波长厚度调控声波的独特优势。由于其具有结构简单、物理特性丰富独特、对声波灵活有效调控等特点,成为了超材料研究中的热点课题。从超表面的概念出发,以折叠空间型超表面、五模式超表面、非结构化超表面为基础,详细介绍了几种常见结构单元的设计方法,及其对声波调控的物理机制,实现诸如负折射、声聚焦及声非对称传输等功能。此外,简略探讨了声学超表面有待解决的问题,以期为后续研究提供参考。

Acoustic metamaterials as an emerging field of research in recent years,have greatly expanded the application of acoustic materials in various fields.Acoustic metasurfaces,a branch of acoustic metamaterials,have also received extensive attention from both domestic and foreign researchers.Acoustic metasurface composed of an array of metamaterial structural units based on sub-wavelength dimension is a new type of acoustic metamaterial.It can use the generalized Snell’s law to achieve certain directional control of reflected or transmitted sound wave,and it has the unique advantage of using sub-wavelength thickness to control sound wave.Due to its simple structure,rich and unique physical characteristics,and flexible,effective control of acoustic wave,it has become a hot topic in the research of metamaterials.This article first introduced the concept of metasurface,then the design method of common structural units and the physical controlling mechanism of acoustic wave to realize negative refraction,sound focusing and asymmetric sound transmission based on folded space metasurface,pentamode metasurface and unstructured metasurface were elaborated in detail.Finally,the future problems related to the acoustic metasurface were discussed briefly,hoping to provide valuable information for the future study.