Polar anchoring energy measurement of vertically aligned liquid-crystal cells

An electric-field method is developed for measuring the polar anchoring energy of vertically aligned nematic liquid-crystal cells. Both theoretical analyses and confirming experimental results are presented. Vertically aligned liquid-crystal cells with buffed polyimide alignment layers are used to investigate the measurement techniques. Based on the voltage-dependent transmittance of the liquid-crystal cells, a linear fitting can be obtained, leading to a precise determination of the anchoring energy. If some specific liquid-crystal material parameters are known, measuring of the cell capacitance is not necessary.