Ultra-sparse metasurface for high reflection of low-frequency sound based on artificial Mie resonances
Ultra-sparse metasurface for high reflection of low-frequency sound based on artificial Mie resonances
复制标题
基于人工米氏共振的超稀疏超表面，用于低频声音的高反射
DOI：
10.1038/nmat4393
复制
发表时间：
2015-10-01
期刊：
影响因子：
41.2
通讯作者：
Liu, X. J.
中科院分区：
文献类型：
--
作者：
Cheng, Y.;Zhou, C.;Liu, X. J.
声学超材料为操纵声波提供了极大的灵活性，并承诺前所未有的功能，从变换声学，超分辨率成像到声学隐身。然而，具有激励功能的声学超材料的设计仍然具有挑战性，传统的方法使用经典的声学元件，如亥姆霍兹谐振器和膜。在这里，我们展示了一个超低流体状颗粒与强烈的人工米氏共振低频空气中的声音。本征态分析和有效的参数检索显示两个单独的负带在单一尺寸的晶胞，其中之一表现出负的体积模量的单极米氏共振支持，而另一个表现出负的质量密度诱导的偶极米氏共振。独特的单负性质用于开发对低频声音具有高反射率的超稀疏亚波长超颖表面。我们展示了一个0.15毫米厚，15%填充率超颖表面的插入损耗超过93.4%。所设计的米氏谐振器提供了不同的路线，以构建具有多功能应用的新型声学器件。
Acoustic metamaterials offer great flexibility for manipulating sound waves and promise unprecedented functionality, ranging from transformation acoustics, super-resolution imaging to acoustic cloaking. However, the design of acoustic metamaterials with exciting functionality remains challenging with traditional approaches using classic acoustic elements such as Helmholtz resonators and membranes. Here we demonstrate an ultraslow-fluid-like particle with intense artificial Mie resonances for low-frequency airborne sound. Eigenstate analysis and effective parameter retrieval show two individual negative bands in the single-size unit cell, one of which exhibits a negative bulk modulus supported by the monopolar Mie resonance, whereas the other exhibits a negative mass density induced by the dipolar Mie resonance. The unique single-negative nature is used to develop an ultra-sparse subwavelength metasurface with high reflectance for low-frequency sound. We demonstrate a 0.15 lambda-thick, 15%-filling ratio metasurface with an insertion loss over 93.4%. The designed Mie resonators provide diverse routes to construct novel acoustic devices with versatile applications.