Nanoparticles-Induced Alignment of Nematic Liquid Crystals for Tunable Electro-Optical Devices

Nematic Liquid Crystals (NLCs), long-range orientationally ordered fluids, have always been the best choice for the development of various display and non-display devices due to their simplest phase structure, good thermal stability, and easier alignment. The extreme sensitivity of NLCs to the external stimuli such as electric, magnetic, light, and surface forces, etc. has been the key feature for their broad range of applications. For tunable electro-optical device fabrication, the response of NLC molecules to the external stimuli must be coherent. Such coherent stimuli response of NLC molecules could be achieved by using various alignment techniques. For instance, rubbing of polyimides, coating of surfactants, magnetic field, oblique evaporation of SiOx, photoalignment, etc. are being utilized for the uniform and stable alignment of NLCs. Besides these alignment techniques, the use of nanoparticles to align NLCs has also recently been considered as one of the novel techniques to align NLCs without using any alignment layer. In this chapter, we have greatly reviewed the recent progress made in the field of nanoparticle-controlled alignment of NLCs useful for the tunable electro-optical devices and discussed the future perspectives.