Modelling of nematic liquid crystal display devices

TL;DR

This paper introduces a comprehensive lattice Boltzmann method for simulating nematic liquid crystal displays, capable of modeling complex physical effects and device behaviors with high accuracy.

Contribution

It presents a novel lattice Boltzmann scheme that solves the Qian-Sheng equations, incorporating multiple physical effects for realistic LCD device simulation.

Findings

Accurately reproduces analytical solutions for validation cases.

Successfully simulates defect motion in bistable liquid crystal devices.

Provides a full device-level simulation integrating electric field effects.

Abstract

A lattice Boltzmann scheme is presented which recovers the dynamics of nematic and chiral liquid crystals; the method essentially gives solutions to the Qian-Sheng equations for the evolution of the velocity and tensor order-parameter fields. The resulting algorithm is able to include five independent Leslie viscosities, a Landau-deGennes free energy which introduces three or more elastic constants, a temperature dependent order parameter, surface anchoring and viscosity coefficients, flexo-electric and order electricity and chirality. When combined with a solver for the Maxwell equations associated with the electric field, the algorithm is able to provide a full 'device solver' for a liquid crystal display. Coupled lattice Boltzmann schemes are used to capture the evolution of the fast momentum and slow director motions in a computationally efficient way. The method is shown to give results in close agreement with analytical results for a number of validating examples. The use of the method is illustrated through the simulation of the motion of defects in a zenithal bistable liquid crystal device.