Small- and nano-scale soft phononics

1993, twelve years after the discovery of photonics, was the birth of phononic materials for the controlled propagation of mechanical/acoustic waves. The first experimental realization followed in soon after at sonic and later at hypersonic frequencies using macromachinery and soft matter self-assembly. Two examples, artificial and natural hierarchical structures, will highlight the new emerging field of high frequency phononics aiming at tunable strong, deaf, cool and interactive materials.