Reconfigurable Structural Audio Based on an Anisotropic Stretchable Metasurface

Audio recording, synthesis, reconfiguring and playing technologies have revolutionized our auditory sense to the world. Increasing storage density, improving switching efficiency, and enhancing diversified encryption are significant in audio information processing. However, they are generally achieved through active digital processing methods. Inspired by the structural color materials in optics, we propose a physical audio processing method, termed as structural audio, which flexibly reconfigures acoustic response to structure deformation. Various dynamic reconfigurations of audio record are realized based on the overall physical deformation of the stretchable metasurface, including the tonal variation, open/closed states switching, and multi-channel conversion. The originally stored tones can be steadily kept, linearly fallen or nonlinearly modified by stretching the metasurface in different directions. The audio record can also be selectively open (allow access) or closed (deny access). In addition, it supports the stable storage and rapid conversion of multiple customized audio records through the elaborate arrangements of component unit cells. Both the structure deformation and audio conversion are reversible and reusable. This work provides a strategy to increase audio storage density, reconfigure and process audio information in an analog way, which would find broad applications in advanced audio technology and selective acoustic communication.