Fundamentals of Acoustic Metamaterials

This chapterAcoustic metamaterial introduces the field of acousticAcoustics metamaterials in lightLight of correspondences with related phenomena in electromagneticsElectromagnetics. The semantic frontier between phononic/photonic crystals (PCs) and metamaterials is underpinned by low-frequency high-contrast and high-frequency homogenizationHomogenization models for periodic structuresPeriodic structures, the former being well suited for metamaterials, while the latter unveils the band structure and associated anomalous dispersionDispersion of PCs. We find it therefore worthwhile to outline the corresponding asymptotic models for wavesWaves propagating in such structured media. The mathematics behind the physical scene are illustrated by numerical simulations including cloakingCloaking, absorption, lensingLensing and confinement effects via artificial anisotropyAnisotropy (motivated by transformational opticsOptics and acousticsAcoustics), negative refractionNegative refraction and slow wavesWaves.