Acoustic metamaterials II

11:35 : A Lightweight yet Sound-proofing Honeycomb Acoustic Metamaterial

N. Sui (1),X. Yan (1),T. Y. Huang (1),J. Xu (2),F. G. Yuan (1),Yun Jing (1)

(1)North Carolina State University (USA) , (2)Massachusetts Institute of Technology (USA)

A class of honeycomb acoustic metamaterial possessing lightweight and yet sound-proofing properties is designed and experimentally verified. This metamaterial having a remarkably small area density can achieve low frequency (< 500 Hz) sound transmission loss (STL) >45 dB. The high STL is attributed to the large acoustic impedance and the broad-band negative effective density introduced by no-mass-attached membranes. The proposed metamaterial can also be used as the core in sandwich structures that could exhibit strong, lightweight, and sound-proofing properties.
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11:50 : Coriolis Force Induced Topological Order for Classical Vibration

Yao-Ting Wang (1),Pi-Gang Luan (2),Shuang Zhang (1)

(1)University of Birmingham (United Kingdom) , (2)National Central University (Taiwan)

A two-dimensional mass-spring system with Honeycomb lattice for topologically protected vibrational edge modes is proposed. Interestingly, as the system is placed on a constantly rotational coordinate system, the Coriolis force resulted from the non-inertial reference frame provides a possibility to break the time-reversal symmetry. Thus, caused from topologically non-trivial band gaps, phononic edge modes are present between bands, which are verified by the calculation of Chern numbers for corresponding bands.
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12:05 : Multiplexed Acoustic Sensing with Metamaterial-based Physical Layer Encoding

Yangbo Xie, Tsung-Han Tsai, David J. Brady, Steven Cummer

Duke University (USA)

We present an acoustic sensing system that combines acoustic metamaterials and multiplexed computational sensing. Acoustic signals are directly encoded on the physical layer by the tailored resonant modulations of metamaterials in the measurement stage, and the object information is computed with L1-norm regularization algorithms in the reconstruction stage. The experimental results of two sensing tasks are demonstrated. The presented design method may be useful for sound source localization, robust speech recognition and other acoustic imaging modalities.
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