The law of reciprocity in acoustics and elastodynamics codifies a relation of symmetry
between action and reaction in fluids and solids. In its simplest form, it states that the …

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 …

This broad review summarizes recent advances and “hot” research topics in nanophononics
and elastic, acoustic, and mechanical metamaterials based on results presented by the …

In solid state physics, a bandgap (BG) refers to a range of energies where no electronic
states can exist. This concept was extended to classical waves, spawning the entire fields of …

We report on the experimental observation of topologically protected edge waves in a two-
dimensional elastic hexagonal lattice. The lattice is designed to feature K-point Dirac cones …

By employing periodic electrical boundary conditions, an innovative method to generate
actively tunable topologically protected interface mode in a “homogeneous” piezoelectric …

Elastic waveguides with time-modulated stiffness feature a frequency-periodic dispersion
spectrum, where branches merge at multiple integers of half the modulation frequency and …

Mechanical metamaterials, also known as architected materials, are rationally designed
composites, aiming at elastic behaviors and effective mechanical properties beyond ('meta') …

A moving medium drags light along with it as measured by Fizeau and explained by
Einstein's theory of special relativity. Here we show that the same effect can be obtained in a …

Acoustic waves in a linear time-invariant medium are generally reciprocal; however,
reciprocity can break down in a time-variant system. In this Letter, we report on an …