Optical response of a nematic liquid crystal cell at splay-bend   transition: model and dynamic simulation
  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. 
Peizhi Xu, Vladimir Chigrinov, Alexei D. Kiselev