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Abstract
Suitably deposited thin films of poly (tetrafluoroethylene) (PTFE) will induce alignment in a liquid crystal [1]. These films are deposited in a one step dry process which offers advantages over polyimide or SiO2 alignment layer application [2]. Previous studies of such films [3, 4] have shown the quality of liquid crystal alignment to be good and to exhibit an induced surface pretilt of the order of 1°. The relationship between the conditions under which the films are deposited, the uniformity of the deposited film and the induced surface pretilt induced by these surfaces has been investigated further. The uniformity has been studied by observation of the surface tension and the pretilt studied using a modified version of the crystal rotation method. There would appear to be a relationship between the observed uniformity of the surface, the alignment quality and the induced pretilt observed. The data are consistent with the hypothesis that the induced surface pretilt observed is due to irregularities in the structure of the surface.