Acoustic One-way Manipulation by Metamaterials

date March 28, 2014
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Friday, March 28, 2014 4:00 p.m. ETC 4.150

Professor Bin Liang
Institute of Acoustics
Department of Physics
Nanjing University
Nanjing, China
http://acoustics.nju.edu.cn/

Acoustic waves have long been thought to propagate as easily along two opposite directions in a given path. It can therefore be expected that the one-way propagation of acoustic waves, if could it be realized successfully, would have deep implications for acoustic devices, acoustic applications and the field of acoustics in general. Here a series of theoretical and experimental works will be reported on how to realize acoustic one-way manipulations by designing various kinds of acoustic metamaterials. The first theoretical model of an “acoustic diode” that enables the rectification of acoustic energy flux was proposed by coupling a nonlinear medium with a superlattice, and the prototype was fabricated experimentally. By introducing a nonlinear resonance cavity, the efficiency of the nonlinear acoustic diode was dramatically enhanced. On the other hand, different schemes of one-way acoustic manipulations have been developed in linear systems, resulting in significant improvements in aspects of transmission efficiency, bandwidth and waveform preservation, etc.