Within a time span of 15 years, acoustic metamaterials have emerged from academic
curiosity to become an active field driven by scientific discoveries and diverse application …

The recent advent of acoustic metamaterials has initiated a strong revival of interest on the
subject of sound absorption. The present review is based on the physics perspective as the …

The causal nature of the acoustic response dictates an inequality that relates the two most
important aspects of sound absorption: the absorption spectrum and the sample thickness …

An impedance-matched surface has the property that an incident wave generates no
reflection. Here we demonstrate that by using a simple construction, an acoustically …

We report the experimental realization of perfect sound absorption by sub-wavelength
monopole and dipole resonators that exhibit degenerate resonant frequencies. This is …

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 …

Conventional sound barriers impede airflow at the same time. Recent advances in acoustic
metasurfaces provide a solution for air-permeable barriers utilizing the Fano-like …

Acoustic metamaterials have been widely investigated over the past few decades and have
realized acoustic parameters that are not achievable using conventional materials. After …

Classical meta-absorber designs usually have a tradeoff between bandwidth, efficiency, and
thickness. Here, we introduce the concept of a nonlocal acoustic metasurface absorber by …

Willis fluids, or more generally Willis materials, are homogenized composites that exhibit
coupling between momentum and strain. This coupling is intrinsic to inhomogeneous media …