Electrically assisted light-induced azimuthal gliding of the nematic liquid crystal easy axis on photoaligned substrates

TL;DR

This study investigates how combined UV light and electric fields induce azimuthal reorientation of nematic liquid crystal easy axes on photoaligned substrates, revealing faster reorientation with polarized light and dependence on initial irradiation dose.

Contribution

It introduces a combined optical and electrical method to control liquid crystal alignment, supported by a phenomenological model matching experimental observations.

Findings

Polarized light accelerates easy axis reorientation.

Reorientation slows with higher initial irradiation dose.

Theoretical model aligns well with experimental data.

Abstract

We study azimuthal gliding of the easy axis that occurs in nematic liquid crystals brought in contact with the photoaligned azo-dye film under the action of reorienting UV light combined with an in-plane electric field. For irradiation with the linearly polarized light, dynamics of easy axis reorientation is found to be faster as compared to the case of non-polarized light. In addition, it slows down with the initial irradiation dose used to prepare the azo-dye film. This effect is interpreted by using the previously suggested phenomenological model. We present the theoretical results computed by solving the torque balance equations of the model that agree very well with the experimental data.