Manipulate Elastic Wave Modes by an Ultrathin Three-component Elastic Metasurface

TL;DR

This paper introduces an ultra-thin elastic metasurface capable of efficiently converting elastic wave modes, with potential applications in elastic devices, by controlling energy exchange between longitudinal and transverse waves.

Contribution

The study presents a novel ultra-thin elastic metasurface design that achieves high conversion rates of elastic wave modes through a simple, general mechanism based on dipolar resonance.

Findings

Achieves over 95% mode conversion efficiency.

Controls elastic wave mode exchange via rubber inclination angle.

Applicable to various solid backgrounds.

Abstract

We design a two-dimensional ultra-thin elastic metasurface consisting of steel cores coated with elliptical rubbers embedded in epoxy matrix, capable of manipulating bulk elastic wave modes for reflected waves. The energy exchanges between the longitudinal and transverse modes are completely controlled by the inclined angle of rubber. One elastic mode can totally convert into another by the ultra-thin elastic metasurface. The conversion mechanism based on the non-degenerate dipolar resonance is a general method and easily extended to three-dimensional or mechanical systems. A mass-spring model is proposed and well describe the conversion properties. We further demonstrate that high conversion rates (more than 95%) can be achieved steadily for one elastic metasurface working on almost all different solid backgrounds. It will bring wide potential applications in elastic devices.