Tunable guided waves in a soft phononic crystal with a line defect

Defects in phononic crystals may induce localized states and therefore can serve as microcavities, waveguides, or perfect mirrors. In this article, we numerically and experimentally investigate the deformation behavior and wave propagation characteristics of a defected phononic crystal, which consists of a soft porous matrix and hard inclusions along with a line defect that is introduced designedly. Static and dynamic localized states appear due to the presence of the line defect. The results show that the soft phononic crystal with the line defect can control the guided waves by harnessing the uniaxial compression, which paves a new way to design tunable elastic waveguides.