2020/07/19 by Yao‐Ting Wang, Richard V. Craster, Wang, Yao-Ting +1
Engineering · Materials Science · #Acoustic Wave Phenomena Research #Aerodynamics and Acoustics in Jet Flows #Applied Physics (physics.app-ph) #FOS: Physical sciences #Metamaterials and Metasurfaces Applications
paper · pdf · doi:10.48550/arxiv.2007.09759
openalex publication_date 2020/07/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We design extremely-thin acoustic metasurfaces, providing a versatile platform for the manipulation of reflected pressure fields, that are constructed from mass loads and stretched membranes fixed to a periodic rigid framework. These metasurfaces demonstrate deeply subwavelength control and can have thicknesses an order of magnitude less than those based around Helmholtz resonators. Each sub-unit of the metasurface is resonant at a frequency tuned geometrically, this tunability provides phase control and using a set of finely tuned membrane resonators we create a phase-grating metasurface. This surface is designed to exhibit all-angle negative reflections with the ratio of wavelength, λ, to thickness, h, of λ/h≈ 23.1, and to create a flat mirror using the phase profile of an elliptic reflecting mirror. A further important acoustic application is to sound diffusers and we proceed to design a deeply subwavelength membrane-based meta-diffuser that can be two orders of magnitude thinner than the operating wavelength, i.e. thickness ≈λ/102. This paves the way for developing advanced acoustic metasurfaces with applicability to functional acoustic devices in sound-related industries.