Ultra Thin Acoustic Metamaterial Panels Based on Resonant Bricks for Perfect Absorption

Abstract

Perfect absorption by an ultra thin acoustic metamaterial panel working in reflection is theoretically and experimentally reported in this work. The system is made by a rigid panel with a periodic distribution of thin closed slits, the upper wall of which are loaded by Helmholtz Resonators (HRs). The propagation in the slit is highly dispersive due to the presence of the resonators, producing a slow sound propagation before the HRs resonance, and down shifting the resonance frequency to low values. By controlling the geometry of the HRs, the visco-thermal losses can be tuned in order to compensate the leakage of the system and fulfill the critical coupling condition so activating the perfect absorption of sound. Theoretical predictions and experimental results show the possibility to design simple structures with deep sub-wavelengths dimensions (lambda/88).

@inproceedings{Jimenez2016METAb,
 author = {Noé Jiménez and W. Huang and Jean Philippe Groby and Vincent Pagneux and Vicent Romero-García},
 booktitle = {METAMATERIALS 2016: 10th International Congress on Advanced Electromagnetic Materials in Microwaves and Optics. Crete, Greece. 17-22 September},
 doi = {http://congress2016.metamorphose-vi.org/files/Metamaterials_2016_Program_2.pdf},
 editor = {Conference proceedings},
 month = {9},
 organization = {Metamaterials Conferences},
 pages = {1-3},
 publisher = {IEEE},
 series = {Oral},
 title = {Ultra Thin Acoustic Metamaterial Panels Based on Resonant Bricks for Perfect Absorption},
 url = {http://congress2016.metamorphose-vi.org/},
 year = {2016}
}