Observation of a photo wetting effect on anisotropic liquid-solid interfaces.

This paper reports on the experimental observation of an anisotropic photo controlled wetting effect. We discuss how capillary propagation of nematic liquid crystals in a "sandwich" cell is blocked in areas exposed to light. We postulate that the underlying mechanism is related to the optical reorientation of molecules on the surface of the surrounding solid, which in turn, forces a corresponding reorientation of the liquid crystal molecules. The corresponding orientation deformation energy of the liquid then changes the balance of forces and the corresponding capillary action.