Micro Manipulation with Optical Responsive Cholesteric and Compensated Nematic Liquid Crystal

Abstract We have developed photoresponsive liquid crystalline films (cholesteric liquid crystal and compensated nematic liquid crystal) having azobenzene compound to manipulate micro particles on the surface by light irradiation. When few solid particles (polystyrene bead) were placed on the surface of the film, movement of the solid particles was observed upon irradiation of UV (365 nm) or visible light (>420 nm). Only rotational motion of the particles was observed on the cholesteric liquid crystal film. Both translation and rotation was observed on the compensated nematic liquid crystal film. So the mode of motion (either rotation or both translation and rotation) was changed by changing the film from cholesteric film to compensated liquid crystal film. The rotational direction of the solid was controlled by using chiral azobenzene compound with right or left handed twisting ability. Keywords: chirality of azobenzene compoundliquid crystalline filmmicro manipulationphoto responsivetransfer of particles