Transparent coupled membrane metamaterials with simultaneous microwave absorption and sound reduction

Metamaterials offer a novel strategy to control wave propagation in different physical fields ranging from acoustic, electromagnetic, and optical waves to static electric and thermal fields. However, fundamental and practical challenges still need to be overcome for multi-physical manipulation, especially for independent control of acoustic and electromagnetic waves simultaneously. In this paper, we propose and experimentally demonstrate a transparent bifunctional metamaterial in which acoustic and electromagnetic waves could be engineered jointly and individually. Specifically, a transparent composite coupled membrane metamaterial is introduced with indium tin oxide (ITO) patterns coated on the top and bottom membranes, giving rise to simultaneous electromagnetic wave dissipation and sound reduction. Our results could help broaden the current research scope for multiple disciplines and pave the way for the development of multi-functional devices in new applications.