Extreme Acoustic Metamaterial by Coiling Up Space

Abstract

We show that by coiling up space using curled perforations, a two-dimensional acoustic metamaterial can be constructed to give a frequency dispersive spectrum of extreme constitutive parameters, including double negativity, a density near zero, and a large refractive index. Such an approach has band foldings at the effective medium regime without using local resonating subwavelength structures, while the principle can be easily generalized to three dimensions. Negative refraction with a double negative prism and tunneling with a density-near-zero metamaterial are numerically demonstrated.

Elastic metamaterials and dynamic homogenization: a review

“…The combination of these two structures was shown to exhibit LHM properties [34,35] Since then, researchers have proposed more complicated acoustic/elastic LHM architectures. These include multiply resonant microstructures that lead to density and some components of the modulus tensor simultaneously becoming negative [36], periodic array of curled perforations [37,38], tunable piezoelectric resonator arrays [39], anisotropic LHMs by arranging layers of perforated plates [40], etc. It is clear that the materials which would satisfy the requirements for LHM properties will need to be dispersive since there does not exist any material with quasistatic LHM properties.…”

Wavefront modulation and subwavelength diffractive acoustics with an acoustic metasurface

“…Our metasurface is essentially a metamaterial/ phononic crystal hybrid structure 10 and both the local and non-local responses can be leveraged for the purpose of shaping the wavefront with a much larger degree of control than traditional acoustic wave manipulation methods. Such thin planar acoustic metasurfaces, along with existing bulk metamaterials [11][12][13][14][15][16][17][18][19][20] , provide a new design methodology for acoustic wave modulation, sensing and imaging applications.…”

Design of double negativity elastic metamaterial

“…Although a number of double negativity (DN) acoustic metamaterials have been investigated [7][8][9][10][11][12][13][14][15], there are few reports in literature on DN elastic metamaterials. Among the elastic metamaterials that have been published, Wang theoretically investigated the mechanism of negative mass and/or negative modulus of lumped mass models [16].…”