Orientation Control of Smectic Liquid Crystals via a Combination Method of Topographic Patterning and In-Plane Electric Field Application for a Linearly Polarized Illuminator.

We dynamically controlled the configuration of layering structures built by smectic A liquid crystal molecules using the combination method of the microchannel confinement and the in-plane electric field to realize the linearly polarized illuminator and bistable structures. Once a mild in-plane electric field (∼30 V) is applied between polymeric walls, the layer configuration was changed from the toric focal conic domains to periodic zigzag patterns of alternatively packed focal conic domains. The transformed zigzag patterns maintained their structures even after turning off the applied electric fields, revealing the ability for use in a bistable memory device. Indeed, a strong electric field (∼100 V) can make unidirectionally aligned LC molecules along with the applied electric field via zigzag patterns, and electro-optical performance of resultant textures when the sample is mixed with fluorescent dyes was characterized to show a linearly polarized light illuminator. Our electric field in and on the confined geometries will be used in the fabrication of functional structures built by polar soft materials which can broaden applications in patterning platforms and efficient electro-optical devices in the near future.