Switchable phononic wave filtering, guiding, harvesting, and actuating in polarization-patterned piezoelectric solids

We demonstrate the ability to manipulate the propagation of phononic (elastic, acoustic) waves in two-dimensional piezoelectric solids by spatially patterning the polarization distribution. We simulate the wave fields by the finite element method and demonstrate the ability to dynamically alter the wave propagation by switching (on/off) the piezoelectric behavior by operating the electrodes in a closed or open circuit configuration. The piezoelectric polarization patterns are nonintuitive and are determined by topology optimization. We illustrate the interesting response of optimally patterned phononic devices with four examples: a filter, a waveguide, an energy harvester, and a wave actuator.