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The surface-friction characteristics of the post-bake temperature were compared to that of the rubbing condition on VA-mode alignment films (AFs) using frictional force microscopy (FFM). The surface roughness and the surface frictional force increased when the temperature was elevated. However, the frictional asymmetry could not be detected by the frictional loop due to the instability of the side-chain molecular arrangement. For the inter-influences of the total friction and surface roughness, the density of the side chain was changed and it was intentionally rubbed for evaluation. The results showed that the total friction was higher when the rubbing was stronger and side-chain density lower, and the surface roughness also increased in the same manner. This can be explained by the potential interaction due to the curved structure of the side-chain surface that establishes the probe that is scanned and the top surface layer. In order to confirm the influence of the pre-tilt angle on the tilt of the side chain, a test cell was produced under the same conditions and evaluated. The results showed that the pre-tilt-angle decreased according to the difference in density of the side chain and strength of rubbing after injecting liquid-crystal (LC). FIGURE 1 -(a) The principle of AFM/FFM. (b), (c) The density of side chain molecular on PI layer surface. Sample 2 has half density of side chain compared with sample 1. The samples of this experiment were artificially applied rubbing condition and the probe scanned along the rubbing direction.