Chapter 3: Molecular Alignment Patterning Enabled by Novel Photopolymerization with Structured Light and its Optical Applications
Precise patterning of two-dimensional (2D) alignment of liquid crystals (LCs) has attracted great attention with a view to enhancing their optical and mechanical functionalities. However, current photoalignment methods still require doping of photo-responsive dyes and polarized light or multi-step process to induce molecular alignment. Our group has developed a novel photoalignment method based on the concept of scanning wave photopolymerization (SWaP). This method can generate 2D alignment patterning of LCs over large areas in a single step. The key to alignment is molecular diffusion induced by spatiotemporal photopolymerization, with the great advantages of requiring no polarized light, photo-responsive dyes, or specific surface treatment. Furthermore, various types of polymerization reactions can be applied to SWaP. We believe that SWaP has great potential to realize advanced optical devices and mechanical soft actuators based on 2D alignment patterning.