Photo-induced dynamics of micro-particles in nematic liquid crystal

Abstract

A small amount of azo-dendrimer molecules dissolved in a liquid crystal enables dynamic motions of defects around microspheres and even translational and rotational motions of microrods in a liquid crystal matrix under unpolarized UV light irradiation. These motions are intitiated by a light-induced trans-to-cis conformational change of the dendrimer adsorbed at the surface of microparticles and the associated director reorientation. The bending direction of the cis conformers is not random but is selectively chosen due to the curved local director field in the vicinity of the dendrimer-coated surface. Different types of director distortions occur around the particles, leading to different types of motions.