Flexural Mie Resonances: Localized Surface Platonic Modes

TL;DR

This paper introduces localized surface platonic modes on elastic surfaces with subwavelength corrugations, enabling plasmonic-like phenomena in elastic media with potential applications in sensing and cloaking.

Contribution

It presents the concept of surface platonic modes on elastic cylinders, expanding plasmonics to elastic waves and demonstrating their generation on corrugated surfaces.

Findings

Corrugated rigid surfaces act as elastic scatterers with negative, dispersive flexural rigidity.

Localized surface platonic modes can be excited by incident flexural waves.

Potential applications include earthquake sensing, elastic imaging, and cloaking.

Abstract

Surface plasmons polaritons were thought to exist only in metals near their plasma frequencies. The concept of spoof plasmons extended the realms of plasmonics to domains such as radio frequencies, magnetism, or even acoustic waves. Here, we introduce the concept of localized surface platonic modes (SPMs). We demonstrate that they can be generated on a two-dimensional clamped (or stress-free) cylindrical surface, in a thin elastic plate, with subwavelength corrugations under excitation by an incident flexural plane wave. Our results show that the corrugated rigid surface is elastically equivalent to a cylindrical scatterer with negatively uniform and dispersive flexural rigidity. This, indeed, suggests that plasmonic-like platonic materials can be engineered with potential applications in various areas including earthquake sensing, or elastic imaging and cloaking.