Non-resonant metasurface for broadband elastic wave mode splitting

Mingye Zheng,Rui Zhu,Yoon Young Kim,Chung Il Park,Xiaoning Liu,Gengkai Hu

doi:10.1063/5.0005408

Mingye Zheng, Rui Zhu + Show 4 more

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https://doi.org/10.1063/5.0005408

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Abstract

Complex polarizations of elastic waves allow mode conversions between two solids, making wave mode separation extremely difficult even for a narrow frequency range with resonant metamaterials. In this Letter, a non-resonant elastic metasurface design is proposed to achieve a perfect splitting of longitudinal and shear waves in space. The key to this broadband design is a singly polarized solid with engineered static elastic tensor, which provides a tool to tune the polarization through non-resonant microstructure design. Both full-wave simulations and experiments are conducted to validate the mode splitting function of the designed metasurface. Potential applications such as elastic wave shifting and selective wave mode focusing are also demonstrated. This research provides an alternative route to design broadband and compact metasurfaces for elastic wave communications, biomedical diagnosis, and wave-based damage evaluations.

Highlights

S (EMMs) provides a very efficient way to achieve peculiar wave trajectory manipulations15–18 and elastic wave mode separation/ conversion19–23 in a certain frequency range
In this Letter, a non-resonant elastic metasurface design is proposed to achieve a perfect splitting of longitudinal and shear waves in space. The key to this broadband design is a singly polarized solid with engineered static elastic tensor, which provides a tool to tune the polarization through non-resonant microstructure design
Cao et al.26 introduced the concept of disorder effects into the elastic metasurface and realized anomalous deflection and focusing effects of flexural waves, which expanded the category of elastic metasurfaces

Summary

Introduction

S (EMMs) provides a very efficient way to achieve peculiar wave trajectory manipulations15–18 and elastic wave mode separation/ conversion19–23 in a certain frequency range. In this Letter, a non-resonant elastic metasurface design is proposed to achieve a perfect splitting of longitudinal and shear waves in space.

Results

Conclusion