Asymmetric transmission of acoustic waves in a waveguide via gradient index metamaterials

Wen-Kang Cao; Li-Ting Wu; Cheng Zhang; Jun-Chen Ke; Qiang Cheng; Tie-Jun Cui; Yun Jing

doi:10.1016/j.scib.2019.01.002

Asymmetric transmission of acoustic waves in a waveguide via gradient index metamaterials

Sci Bull (Beijing). 2019 Jun 30;64(12):808-813. doi: 10.1016/j.scib.2019.01.002. Epub 2019 Jan 6.

Authors

Wen-Kang Cao¹, Li-Ting Wu¹, Cheng Zhang¹, Jun-Chen Ke¹, Qiang Cheng², Tie-Jun Cui³, Yun Jing⁴

Affiliations

¹ State Key Laboratory of Millimeter Waves, Department of Radio Engineering, Southeast University, Nanjing 210096, China.
² State Key Laboratory of Millimeter Waves, Department of Radio Engineering, Southeast University, Nanjing 210096, China. Electronic address: qiangcheng@seu.edu.cn.
³ State Key Laboratory of Millimeter Waves, Department of Radio Engineering, Southeast University, Nanjing 210096, China. Electronic address: tjcui@seu.edu.cn.
⁴ Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA. Electronic address: yjing2@ncsu.edu.

PMID: 36659670
DOI: 10.1016/j.scib.2019.01.002

Abstract

We demonstrate that asymmetric acoustic wave transmission in a waveguide can be achieved via gradient index metamaterials (GIMs). We theoretically prove that the acoustic wave can be efficiently converted to surface waves (SWs) via GIMs. The GIMs in a waveguide can allow the transmission of acoustic waves in one direction but block them in the other direction. This theory is validated by experiments. Our findings may provide new applications in various scenarios such as high-efficiency acoustic couplers and noise control.

Keywords: Asymmetric transmission; Gradient index metamaterials; Surface waves; Waveguide.