Phononic crystals (PCs) and metamaterials (MMs) can exhibit abnormal properties, even far
beyond those found in nature, through artificial design of the topology or ordered structure of …

The imaging resolution of conventional lenses is limited by diffraction. Artificially engineered
metamaterials now offer the possibility of building a superlens that overcomes this limit. We …

The attenuation of low-frequency sound has been a challenging task because the intrinsic
dissipation of materials is inherently weak in this regime. Here we present a thin-film …

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 …

Phononic crystals have been proposed about two decades ago and some important
characteristics such as acoustic band structure and negative refraction have stimulated …

We show experimentally that thin membrane-type acoustic metamaterials can serve as a
total reflection nodal surface at certain frequencies. The small decay length of the …

Similar to their optic counterparts, acoustic components are anticipated to flexibly tailor the
propagation of sound. However, the practical applications, eg for audible sound with large …

Nonreciprocal wave propagation typically requires strong nonlinear materials to break time
reversal symmetry. Here, we utilized a sonic-crystal-based acoustic diode that had broken …

Acoustics is a classical field of study that has witnessed tremendous developments over the
past 25 years. Driven by the novel acoustic effects underpinned by phononic crystals with …

The engineering of optical and acoustic material functionalities via construction of ordered
local and global architectures on various length scales commensurate with and well below …