Locally Resonant Metagrating by Elastic Impedance Modulation

Abstract

The optical and acoustic metagratings have addressed the limitations of low-efficiency wave manipulation and high-complexity fabrication of metamaterials and metasurfaces. In this research, we introduce the concept of elastic metagrating and present the theoretical and experimental demonstration of locally resonant elastic metagrating (LREM). Remarkably, the LREM, with dimensions two orders of magnitude smaller than the relevant wavelength, overcomes the size limitations of conventional metagratings and offers a unique design paradigm for highly efficient wave manipulation with an extremely compact structure in elastic wave systems. Based on a distinctive elastic impedance engineering with hybridization of intrinsic evanescent waves, the proposed LREM achieves wide-angle perfect absorption. This tackles a fundamental challenge faced by all elastic metastructures designed for wave manipulation, which consists in the unavoidable vibration modes in finite structures hindering their implementations in real-world applications.

References in corpus (14)

• Meta-Gratings: Beyond the Limits of Graded Metasurfaces for Wavefront Control
• A Metalens with Near-Unity Numerical Aperture
• Quantum control of surface acoustic wave phonons
• Elastic metamaterials with simultaneously negative effective shear modulus and mass density
• Phonon-mediated quantum state transfer and remote qubit entanglement
• Experimental realization of on-chip topological nanoelectromechanical metamaterials
• Source illusion devices for flexural Lamb waves using elastic metasurfaces
• Topology optimization of anisotropic elastic metamaterial with broadband double-negative index
• Achromatic metasurfaces with inversely customized dispersion for ultra-broadband acoustic beam engineering
• Highly efficient acoustic refractive metasurfaces by harnessing near field coupling
• Perfect anomalous splitter by acoustic meta-grating
• Time Driven Subwavelength Focusing with Negative Refraction
• The Inverse Grating Problem: Efficient Design of Anomalous Flexural Wave Reflectors and Refractors
• Smart patterning for topological pumping of elastic surface waves