Static and dynamic behavior of the vortex–electrohydrodynamic instability in freely suspended layers of nematic liquid crystals

Publisher Website
Google Scholar
Abstract
The vortex–electrohydrodynamic instability occurring in thin freely suspended layers of some nematic liquid crystals is investigated. The vortex pattern is observed both in the anisotropic and in the isotropic phase of the nematic liquid crystal. In this paper, we study the behavior of the vortex pattern when dc and ac electric fields are applied parallel to the free surfaces. The threshold electric field of the instability is measured as a function of the temperature, the thickness and the electric conductivity of the sample. In order to explain the main features of the vortex regime, we develop a new isotropic electrohydrodynamic model based on surface electric forces, which shows a satisfactory agreement with the experimental results.