关键词: acoustic metasurface, source illusion, piezoelectric materials, adjustable control

Abstract: Source illusion is an important issue in acoustic fields that has significant applications in various practical scenarios. Recent progress in acoustic metasurfaces has broken the limitation of manipulating large-scale waves at subwavelength scales and enables a better illusion capability, while there is still a problem that most previous studies are hampered by a lack of tuning capability. Here we propose a reconfigurable source illusion device capable of providing azimuthally-dependent phase delay in real-time via changing the static voltage distribution. The resulting device is implemented by employing an adjustable piezoelectric metasurface with a subwavelength thickness that can achieve a full 2π -phase shift while maintaining efficient transmittance. The effectiveness of our mechanism is demonstrated via two distinctive source illusion phenomena of shifting and transforming a simple point source without changing the device geometry. We anticipate that our methodology, which does not require a large device size or a complicated phased array, will open up new avenues for the miniaturization and integration of source illusion devices and may promote their on-chip applications in a variety of fields, such as acoustic camouflage and manipulation precision.

Key words: acoustic metasurface, source illusion, piezoelectric materials, adjustable control