Abstract
Polyimide thin films were produced by spin-coating a fluoride polyimide on glass substrates, followed by a mechanical rubbing. The application of mechanical rubbing to the polyimide thin films breaks the symmetry on the polymer surface and promotes the formation of a template for liquid crystal alignment. The surface tension of the rubbed polyimide is studied and found to decrease with an increase in rubbing strength. The polar part of the surface tension of the polyimide decreases significantly after the polymer surface is rubbed. The rubbed polyimide thin films exhibit anisotropic surface tension. The surface tension measured along the direction antiparallel to the rubbing direction is higher than that measured along the rubbing direction. The azimuthal variation in surface tension is direction-dependent on the rubbed polymer surfaces.