Fabrication and Performance Evaluation of the Helmholtz Resonator Inspired Acoustic Absorber Using Various Materials
Department of Mechanical Engineering, Kyungpook National University, Daegu 41566, Korea
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Author to whom correspondence should be addressed.
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These authors contributed equally to this work.
Micromachines 2020, 11(11), 983; https://doi.org/10.3390/mi11110983
Received: 9 October 2020
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Revised: 24 October 2020
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Accepted: 30 October 2020
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Published: 31 October 2020
A soundwave is transmitted by adjacent molecules in the medium, and depending on the type of sound, it exhibits various characteristics such as frequency, sound pressure, etc. If the acoustic wavelength of the soundwave is sufficiently long compared with the size of an acoustic element, physical analysis within the sound element could be simplified regardless of the shape of the acoustic element: this is called “long wavelength approximation”. A Helmholtz resonator, a representative acoustic element which satisfies the “long wavelength theory”, consists of a neck part and a cavity part. The Helmholtz resonators can absorb certain frequencies of sound through resonance. To exhibit attenuation properties at ultrasound range, the Helmholtz resonator should be made into a microscale since Helmholtz resonators should satisfy the “long wavelength approximation”. In this study, Helmholtz resonator inspired acoustic elements were fabricated using MEMS technology, and acoustic attenuation experiments in a water bath were conducted using various shapes and materials. As a result, the fabricated samples showed admirable attenuation properties up to ~13 dB mm−1 at 1 MHz. The results were analyzed to derive the necessary conditions for the fabrication of acoustic elements with acoustic attenuation properties in ultrasound range.
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MDPI and ACS Style
Lee, S.H.; Kang, B.S.; Kim, G.M.; Roh, Y.R.; Kwak, M.K. Fabrication and Performance Evaluation of the Helmholtz Resonator Inspired Acoustic Absorber Using Various Materials. Micromachines 2020, 11, 983. https://doi.org/10.3390/mi11110983
AMA Style
Lee SH, Kang BS, Kim GM, Roh YR, Kwak MK. Fabrication and Performance Evaluation of the Helmholtz Resonator Inspired Acoustic Absorber Using Various Materials. Micromachines. 2020; 11(11):983. https://doi.org/10.3390/mi11110983
Chicago/Turabian StyleLee, Sung H., Bong S. Kang, Gyu M. Kim, Yong R. Roh, and Moon K. Kwak. 2020. "Fabrication and Performance Evaluation of the Helmholtz Resonator Inspired Acoustic Absorber Using Various Materials" Micromachines 11, no. 11: 983. https://doi.org/10.3390/mi11110983
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