Metallic surfaces as alignment layers for nondisplay applications of liquid crystals

Nearly all liquid crystal devices use a rubbed organic layer as a method of orienting the liquid crystals. This letter studies the alignment of nematic liquid crystals by rubbed and nonrubbed metallic surfaces. For rubbed metallic films, a homogeneous planar alignment of liquid crystals is found. Nonrubbed metallic surfaces align liquid crystals nonuniformly and randomly. The alignment produced by a single rubbed metallic surface extends from 10 to 50 μm and is stable in time. These results are important because they show that the organic layer may be eliminated for some applications, including tunable microwave and infrared signal processing elements.