Acoustic metamaterials by bending layered structures

Abstract

In this talk, basic concepts of metamaterials for acoustic imaging and wave manipulation using layered structures will be introduced. Starting from periodically layered structures, we can easily construct metamaterials with large anisotropy which is very useful to obtain sub-wavelength resolution in acoustic imaging. By geometric scaling the layered structure in a fixed direction, an acoustic hyperlens can be obtained so that the image with subwavelength details can be progressively magnified and exit the lens as far-fields. We have now further developed different geometric transformations by bending the layered structures to achieve a variety of wave manipulations including negative refraction in the effective medium regime, acoustic cloaking, and tunneling with a density-near-zero material.