介质损耗对声学超材料性质影响的理论研究

项目名称： 介质损耗对声学超材料性质影响的理论研究

项目编号： No.11274121

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 侯志林

作者单位： 华南理工大学

项目金额： 78万元

中文摘要： 声学超材料(acoustical metamaterial) 是将一种或几种结构单元按规则排列于基体材料中所构成的复合结构。这种结构在特定频率声波下的行为需要用负的有效质量密度或/和负的弹性模量来描述，因而具有常规材料所不具有的特殊性质。研究表明，介质的损耗作用对这种材料的性质有重要的影响，过大的损耗会使其功能，如超透镜、隐形斗篷等效应，无法实现。由于结构单元的存在所导致的波场分布非均匀性，使超材料中的波损耗必然不同于其构成组元的介质损耗，而与其构成单元的结构及晶格排列存在关系。本项目将研究介质损耗与超材料构成的关系，明确损耗对超材料性质的影响。这一研究包括两主方面: 其一，研究单元结构及晶格排列对超材料有效波损耗的影响，以达到调节超材料性质的目的；其二，基于超材料界面行为对其性质的重要影响，而界面场分布又与内部场分布存在显著差异，我们将研究损耗对界面模式的传播及耦合性质的影响。

中文关键词： 声学超材料；负折射；等效媒质理论；双负材料；压电体

英文摘要： Acoustical metamterial is the artifical composite medium construted by one or several kinds of microstructural unit embedded into the uniform matrix. Compared to the convensional wave medium, the wave behavior of this kind of material need to be described by the nagative effective mass density and/or nagtive elastic modulus. As a result, they have some special wave properties beyond the conventional medium. It has been shown that, wave disipation can affect drastically the property of this kind of materials, a large enough wave dissipation can destroy the phenomenons,such as the supperlens effect and cloaking,etc.. Because of the existing of the microstructure, the wave distribution in the composite is usually inhomogeneous, as a result, the effective wave dissipation of metamaterials, which should be different from its constructing component, relys strongly on the detail of the microstructure unit and the lattice struture. In this project, we will study the general relationship between the wave dissipation and the structures of the unit and the whole lattice. The study includes two aspects. Firstly, we will study how the wave behavior can be influenced by the structure of the unit and the lattice. Secondly, we will study how the dissipation of the medium can change the propagating and coupling of the surface mo

英文关键词： acoustic metamaterial；negative refraction；effective medium theory；double-negative material；piezoelectric material