The effect of rubbing strength on the on-substrate distribution of pretilt angle

To determine the relation between on-substrate distribution of liquid crystal (LC) pretilt angle and rubbing parameters, we measured different test cells which were fabricated with given specific sets of rubbing parameters. By analyzing the influence of rubbing density and pile impression on the distribution of pretilt angle, we can find an optimum set of rubbing parameters to produce higher uniformity of pretilt angle. In our experiment, higher rubbing density and smaller pile impression were shown to improve the uniformity of on-substrate distribution of pretilt angle.