Optical response of a nematic liquid crystal cell at splay-bend transition: model and dynamic simulation

TL;DR

This paper models and simulates the dynamic optical response of a nematic liquid crystal cell during the splay-bend transition, considering flexoelectric effects and surface viscosity, to understand how various parameters influence response time.

Contribution

A simplified dynamical model incorporating flexoelectric coupling and surface viscosity for nematic liquid crystals during splay-bend transition is developed and numerically analyzed.

Findings

Response time depends on dielectric and elastic anisotropies.

Surface pretilt asymmetry affects transition dynamics.

Flexoelectricity influences the optical response behavior.

Abstract

We study dynamical optical response of a nematic liquid crystal cell that undergoes the splay-bend transition after applying the voltage across the cell. We formulate a simplified model that takes into account both the flexoelectric coupling and the surface rotational viscosity. The dynamic equations of the model were solved numerically to calculate temporal evolution of the director profile and the transmittance. We evaluate the response time as a function of a number of parameters characterising dielectric and elastic anisotropies, asymmetry of the surface pretilt angles, anchoring energy, surface rotational viscosity and flexoelectricity.