Molecular Crystals and Liquid Crystals, Vol.526, 46-57, 2010
Light Controlled Capillarity of Liquid Crystals on Photo Anisotropic Surfaces
We report the observation and experimental study of an anisotropic photo controlled capillarity effect in liquid crystal cells. The photo sensitive substrates of the cell are composed of reactive mesogen host that is doped by guest azobenzene dye. We first describe the study of photo induced phenomena in those substrates, then the capillary propagation of the liquid crystal that is blocked in the areas exposed to circularly polarized light. We believe that the wetting of the surface is changed by the photo induced molecular reorientation of the surface. In addition, this reorientation forces a corresponding reorientation of the liquid crystal during its penetration. The corresponding orientational deformation energy then changes the balance of forces and the corresponding capillary action.