Numerical characterization of nematic liquid crystal microstructures under applied electric fields

In the current work we propose an efficient and accurate numerical approach to the problem of electrical characterization of Nematic Liquid Crystal (N-LC) microstructures under the influence of low-frequency AC electric fields. N-LCs are anisotropic and their electrical properties are determined by the directors' tilt angles which in turn depend on the applied electric field. Therefore, the problem is governed by a coupled system of two-dimensional PDEs: A Poisson equation with variable coefficients for the electric potential and a highly nonlinear second-order equation for the tilt angle of the directors. Both equations are solved using finite-difference schemes with relaxation and the results are found to be in good agreement with the literature. Various 2-D geometries are considered and it is shown that a low DC voltage is sufficient to tune the average refractive index of the N-LC structures under consideration.