Membrane-based acoustic metamaterial with near-zero refractive index
Li Yi-Feng1, 2, †, Lan Jun1, Yu Hui-Yang1, Liu Xiao-Zhou3, Zhang Jia-Shu4
       

(a) Model of a one-dimension (1D) membrane-based RINZ acoustic metamaterial. (b) The picture and dimensions of a single unit cell. (c) The equivalent mechanic prototype of a unit cell.