Experimentally validated reconfigurable piezoelectric metamaterial plate for sound directivity control

This work presents an experimentally validated investigation of a reconfigurable piezoelectric metamaterial plate designed for sound directivity control. The metastructure consists of an aluminum plate with an array of piezoelectric patches, each connected to a tunable resonant shunt circuit. By selectively adjusting the spatial distribution of tuned and open-circuit elements, it becomes possible to modify vibration modes and steer the radiated acoustic energy without physically modifying the structure. The study presents transverse velocity and near-field acoustic measurements of the metastructure, which also validate the finite element simulations of the vibroacoustic system. Results demonstrate that different tuning patterns can confine vibrations to specific regions of the plate, producing far-field radiation patterns that range from omnidirectional to highly directional lobes. These findings emphasize the potential of reconfigurable piezoelectric metamaterials as a versatile solution for adaptive noise and vibration control in engineering applications.