Anisotropic Metamaterials for Transformation Acoustics and Imaging

MetamaterialsAnisotropic are becomingAcoustics a prominentImaging class of artificial materials that allow us to have very precise and specific optical properties. Its associated engineering flexibility opens up a wide range of applications and provides an effective route in molding the flow of energy. By drawing analogies between electromagneticElectromagnetics and acousticAcoustics waveWaves frameworks, many concepts like invisibility cloakingCloaking and subwavelengthSubwavelength imagingImaging can be transplanted from electromagnetic to acousticAcoustics wavesWaves easily. However, we need quite different ways of constructing the artificial materials and devices for acousticsAcoustics. Here, we show how anisotropicAnisotropic metamaterials can be constructed to control the constitutive parameters of the effective medium through positioning hard platesPlate in different preferred directions. We will then use them to construct an acoustic carpet cloakAcoustic carpet cloak, an acoustic hyperlensAcoustic hyperlens and a superlens as examples.