Membrane-based acoustic metamaterial with near-zero refractive index  

作　　者：Yi-Feng Li Jun Lan Hui-Yang Yu Xiao-Zhou Liu Jia-Shu Zhang 李义丰;蓝君;余辉洋;刘晓宙;张嘉澍(Department of Computer Science and Technology, Nanjing Technology University, Nanjing 211800 China;Key Laboratory of Modem Acoustics, Ministry of Education, Nanjing University, Nanjing 210093, China;Key Laboratory of Modem Acoustics, Ministry of Education, Institute of Acoustics and School of Physics, Nanjing University, Nanjing 210093, China;Department of Electronic and Electrical Engineering, The University of Sheffield, Sheffield S102TN, UK)

机构地区：[1]Department of Computer Science and Technology, Nanjing Technology University, Nanjing 211800, China [2]Key Laboratory of Modern Acoustics, Ministry of Education, Nanjing University, Nanjing 210093, China [3]Key Laboratory of Modem Acoustics, Ministry of Education, Institute of Acoustics and School of Physics, Nanjing University, Nanjing 210093, China [4]Department of Electronic and Electrical Engineering, The University of Sheffield, Sheffield S102TN, UK

出　　处：《Chinese Physics B》2017年第1期237-242,共6页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.61571222,11104142,and 11474160);the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20161009);the Qing Lan Project of Jiangsu Province,China;the Six Talent Peaks Project of Jiangsu Province,China

摘　　要：We investigate a one-dimensional acoustic metamaterial with a refractive index of near zero（RINZ） using an array of very thin elastic membranes located along a narrow waveguide pipe. The characteristics of the effective density, refractive index, and phase velocity of the metamaterial indicate that, at the resonant frequency fm, the metamaterial has zero mass density and a phase transmission that is nearly uniform. We present a mechanism for dramatic acoustic energy squeezing and anomalous acoustic transmission by connecting the metamaterial to a normal waveguide with a larger cross-section. It is shown that at a specific frequency f1, transmission enhancement and energy squeezing are achieved despite the strong geometrical mismatch between the metamaterial and the normal waveguide. Moreover, to confirm the energy transfer properties, the acoustic pressure distribution, acoustic wave reflection coefficient, and energy transmission coefficient are also calculated. These results prove that the RINZ metamaterial provides a new design method for acoustic energy squeezing,super coupling, wave front transformation, and acoustic wave filtering.We investigate a one-dimensional acoustic metamaterial with a refractive index of near zero（RINZ） using an array of very thin elastic membranes located along a narrow waveguide pipe. The characteristics of the effective density, refractive index, and phase velocity of the metamaterial indicate that, at the resonant frequency fm, the metamaterial has zero mass density and a phase transmission that is nearly uniform. We present a mechanism for dramatic acoustic energy squeezing and anomalous acoustic transmission by connecting the metamaterial to a normal waveguide with a larger cross-section. It is shown that at a specific frequency f1, transmission enhancement and energy squeezing are achieved despite the strong geometrical mismatch between the metamaterial and the normal waveguide. Moreover, to confirm the energy transfer properties, the acoustic pressure distribution, acoustic wave reflection coefficient, and energy transmission coefficient are also calculated. These results prove that the RINZ metamaterial provides a new design method for acoustic energy squeezing,super coupling, wave front transformation, and acoustic wave filtering.

关 键 词：acoustic metamaterial refractive index of near zero（RINZ） energy squeezing transmission enhancement 

分 类 号：TB33[一般工业技术—材料科学与工程]