Scientific Reports (Mar 2021)

Bilayer ventilated labyrinthine metasurfaces with high sound absorption and tunable bandwidth

  • Jiayuan Du,
  • Yuezhou Luo,
  • Xinyu Zhao,
  • Xiaodong Sun,
  • Yanan Song,
  • Xinhua Hu

DOI
https://doi.org/10.1038/s41598-021-84986-0
Journal volume & issue
Vol. 11, no. 1
pp. 1 – 8

Abstract

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Abstract The recent advent of acoustic metamaterials offers unprecedented opportunities for sound controlling in various occasions, whereas it remains a challenge to attain broadband high sound absorption and free air flow simultaneously. Here, we demonstrated, both theoretically and experimentally, that this problem can be overcome by using a bilayer ventilated labyrinthine metasurface. By altering the spacing between two constituent single-layer metasurfaces and adopting asymmetric losses in them, near-perfect (98.6%) absorption is achieved at resonant frequency for sound waves incident from the front. The relative bandwidth of absorption peak can be tuned in a wide range (from 12% to 80%) by adjusting the open area ratio of the structure. For sound waves from the back, the bilayer metasurface still serves as a sound barrier with low transmission. Our results present a strategy to realize high sound absorption and free air flow simultaneously, and could find applications in building acoustics and noise remediation.