Conditions for the formation of a uniformly lying helix structure induced by the electrohydrodynamic effect

Abstract

The uniform lying helix (ULH) structure in a cholesteric liquid crystal (CLC) cell has been widely discussed in the literature. Based on the electrohydrodynamic (EHD) effect, we have suggested that the voltage-induction of a well-aligned ULH state can be fine-tuned in a CLC cell by optimizing both the amplitude and the frequency of the applied voltage. However, since the EHD effect is correlated with the migration of mobile ions within the bulk of the cell, the ionic conditions for such an EHD-induced ULH state have not been clarified. In this research, we focus on studying the influence of ion density and the diffusivity on the formation of the EHD-induced ULH structure in a CLC cell, followed by finding out some key conditions for the generation of well-aligned ULH states.