2C03 Nematic Liquid Crystal Alignment Using Extended Porous Polymer Films

Abstract

We studied a new method controlling spatially liquid crystal alignment using a molecule-aligned porous polymer film. The polymer film (thickness : 6μm, porosity : 92%) was formed by stretching a porous polymer film extremely. The polymer extended in one direction was sandwiched by transparent electrodes of glass substrates without conventional alignment layers after nematic liquid crystal was filled in the porous polymer. From the optical anisotropy of composite film of polymer and liquid crystal, it was confirmed that the liquid crystal molecules are aligned in parallel to the extending direction, and the fabricated device had a light modulation function based on the electrically controlled birefringence effect. Although the light modulation is obtained by using applied voltage of 10V, and it needs high saturation voltage of more than 50V for alignment change. This means that the molecular-aligned polymer surface exhibits a large anchoring effect for liquid crystal alignment. The rise and decay response times of the device were 3ms and 13ms, respectively.