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

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.