GEL LAYERS FOR INDUCING ADJUSTABLE PRETILT ANGLES IN LIQUID-CRYSTAL SYSTEMS

A novel system for inducing pretilt angles in liquid crystals (LC) was devised. For this purpose thin layers of a LC mixture containing diacrylate molecules were spun on glass plates covered with rubbed polyimide films. The layers were then photopolymerized to form a gel by UV radiation. In this way the orientation within the pregel layer was frozen. In a cell construction when another LC system was brought in between such gel layers, it was found that a pretilt angle within the LC system was induced. The induced pretilt angle was found to be easily controllable by varying the thickness of the gel layer and a wide range of pretilt angles could be induced.