Precise and Omnidirectional Opto‐Thermo‐Elastic Actuation in Van Der Waals Contacting Systems

Abstract

Actuation of micro‐objects along unconstrained trajectories in van der Waals contacting systems—in the same capacity as optical tweezers to manipulate particles in fluidic environments—remains a formidable challenge due to the lack of effective methods to overcome and exploit surface friction. Herein, a technique that aims to resolve this difficulty is proposed. This study shows that, by utilizing a moderate power beam of light, micro‐objects adhered on planar solid substrates can be precisely guided to move in arbitrary directions, realizing sub‐nanometer resolution across extended surfaces. The underlying mechanism is the interplay between surface friction and pulsed opto‐thermo‐elastic deformations, and to render a biased motion with off‐centroid light illumination. This technique enables high‐precision assembly, separation control of nanogaps, regulation of rotation angles in various material‐substrate systems, whose capability is further tested in reconfigurable construction of optoelectronic devices. With simple set‐up and theoretical generality, opto‐thermo‐elastic actuation opens up an avenue for versatile optical manipulation in the solid domain.