Studies of Frictional Properties on TN mode Alignment Film Surfaces with AFM/FFM

The surface characteristics of hybrid type twisted nematic (TN) mode alignment film (AF) were studied with atomic force microscopy (AFM) and frictional force microscopy (FFM). As a result, the contrast of friction on FFM image had changed when the probe was scanned in rubbing directions. In the friction loop, the frictional asymmetry was detected differently according to the drying temperature conditions. The difference was explained by pretilt uniformity of side chain molecules arrangement on polyimide (PI) layer surface. The measured data of surface energy and pretilt angle after liquid crystal (LC) injection couldn't represent realistic layer frictional characteristics of AF surface.