Broadband high sound absorption from labyrinthine metasurfaces
Huiting Chang,
Liu Liu,
Chi Zhang,
Xinhua Hu
Affiliations
Huiting Chang
Department of Materials Science, Key Laboratory of Micro- and Nano-Photonic Structures (Ministry of Education), and Laboratory of Advanced Materials, Fudan University, Shanghai 200433, China
Liu Liu
Department of Materials Science, Key Laboratory of Micro- and Nano-Photonic Structures (Ministry of Education), and Laboratory of Advanced Materials, Fudan University, Shanghai 200433, China
Chi Zhang
Department of Materials Science, Key Laboratory of Micro- and Nano-Photonic Structures (Ministry of Education), and Laboratory of Advanced Materials, Fudan University, Shanghai 200433, China
Xinhua Hu
Department of Materials Science, Key Laboratory of Micro- and Nano-Photonic Structures (Ministry of Education), and Laboratory of Advanced Materials, Fudan University, Shanghai 200433, China
Metamaterials are artificial structures which exhibit fascinating properties unreachable by traditional materials. Here, we report on the design, fabrication, and characterization of acoustic metasurfaces consisting of dead-end channels coiled in a 2D plane. It is found that when the area of the channel’s cross section is about 1/10 of the area (4.3 cm × 4.3 cm) of the upper surface of the building block, the sound loss in channels approaches to a critical value, resulting in near-perfect absorption (A > 99%) at resonant frequency. When the building block contains ten channels with specially designed lengths, sound waves can be highly absorbed above a cutoff frequency fc (A > 90% for fc < f < 3fc). The wavelength at the cutoff frequency can be 7.1 times of the thickness of the metasurface. Our results could find applications in noise reduction and sound detection.
