Back to Departmental Colloquium: Fall 2015
Departmental Colloquium
Date: Thursday, Nov 19, 2015
Time: 4:00PM
Location: LCB 219
Ping Sheng
HKUST
Title |
Hybrid resonances and the perfect absorption of low frequency sound |
Abstract |
An impedance-match surface has the property that an incident wave generates no reflection. Here we demonstrate that by using simple construct, an acoustically reflecting surface can acquire hybrid resonances and becomes impedance-matched to airborne sound at tunable frequencies, so that no reflection is generated. Each resonant cell of the metasurface is deep-subwavelength in all its spatial dimensions, with its thickness less than the peak absorption wavelength by two orders of magnitude. As there can be no transmission, the impedance-matched acoustic wave is hence either completely absorbed at one or multiple frequencies, or converted into other form(s) of energy such as electrical current. A high acoustic-electrical energy conversion efficiency of 23% is achieved. We use the geometric perspective to derive the hybrid resonance condition, and show that the hybrid resonance is a by-product of the anti-resonance condition for the membrane-type acoustic metamaterials. This is work in collaboration with Guancong MA, Min YANG, Songwen XIAO, and Zhiyu YANG. Spring 2016 |
Mathematical Biology
Data Science and Machine Learning