Metamaterial 'Gecko Toe': Optically-Controlled Adhesion to Any Surface

TL;DR

This paper demonstrates a plasmonic metamaterial that, when illuminated with light, can generate a strong near-field force capable of controlling adhesion to surfaces, mimicking gecko toes, with potential applications in optically-controlled adhesion systems.

Contribution

The study introduces a novel optically-controlled adhesion mechanism using a plasmonic metamaterial that surpasses traditional forces like radiation pressure and Casimir effects.

Findings

Near-field force exceeds radiation pressure and Casimir forces.

Light intensity of tens of nW/μm^2 can overcome gravity.

Metamaterial adhesion mimics gecko toe mechanism.

Abstract

On the mesoscopic scale, electromagnetic forces are of fundamental importance to an enormously diverse range of systems, from optical tweezers to the adhesion of gecko toes. Here we show that a strong light-driven force may be generated when a plasmonic metamaterial is illuminated in close proximity to a dielectric or metal surface. This near-field force can exceed radiation pressure and Casimir forces to provide an optically controlled adhesion mechanism mimicking the gecko toe: at illumination intensities of just a few tens of nW/um^2 it is sufficient to overcome the Earth's gravitational pull.