Low-magnetic-threshold acoustic switching utilizing magnetoelastic FeNi/brass phononic crystal plate

Acoustic switches (ASs) can control the wave propagation in media for acoustic wave applications including smart acoustic structures and materials [1]. Especially, contactless magnetic-controlled AS based on magnetoelastic Terfenol-D/epoxy phononic crystals has been developed by exploiting external static magnetic fields [2]. However, the magnetic-controlled AS exhibits an ultra-high threshold of the magnetic field due to the small change in the wave coupling between phononic crystal elements under the external stimuli.