" Xue-Feng Li and colleagues at Nanjing University and California Institute of Technology report on a new acoustic diode design that manipulates the sonic crystal itself to achieve nonreciprocal propagation of sound. The device consists of a two-dimensional sonic crystal arranged in a mesh of square steel rods. By rotating the steel rods, Li et al.are able to manipulate the unit cell of the sonic crystal element to turn the diode on (sound waves only propagate one way) and off (sound waves can move back and forth). Li et al. make their device entirely from linear acoustic materials, which allows them to control sound propagation with a simpler and more efficient process". – Daniel Ucko, One-way sound
