Detailed Morphology of Rubbed Alignment Layers and Surface Anchoring of Liquid Crystals

Abstract

The authors have measured surface morphology with wavelength longer than about 150 Å, of rubbed alignment layers using atomic force microscopy. Using the elastic continuum theory, we have quantitatively evaluated the azimuthal surface anchoring strength from the distortion of the surface morphology. We have also measured the azimuthal surface anchoring strength experimentally and compared the experimental results with the calculated values. The azimuthal surface anchoring strength obtained experimentally is more than two orders of magnitude larger than that obtained from the theoretical calculation. From these results, we found that anisotropy of the surface morphology with wavelength longer than about 150 Å does not strongly influence the alignment of liquid crystals on a rubbed surface.