Hierarchical Structures of Self-assembled Liquid Crystals and Their Applications

Liquid crystals, featured by self-assembly property and stimuli responsiveness, have attracted intensive attention not only in fundamental material sciences, but also in advanced functional applications. At different phases, liquid crystals exhibit distinguished structures, such as layered focal conic domains and oil streaks in smectics, lying or standing helical structures in cholesterics, and cubic lattices stacked by double-twisted structures in blue phases. These hierarchical structures present novel optical, mechanical and electromagnetic characteristics, which can be further modulated by external stimuli. In recent years, high-quality liquid crystal hierarchical structures have been realized in large scales via optimizing material components and introducing external confinements. Multi-dimensional manipulations of these hierarchical structures have been achieved by adopting various external stimuli. A series of remarkable applications of such liquid crystal hierarchical structures in particle manipulation, surface modification and optical devices have been demonstrated. This paper reviews the latest research progress in above fields and aims to extend the understanding of soft matter architectures.