Automated +1 Topological Defects Driven Locomotions of Light-Responsive Liquid Crystalline Networks

Liquid crystalline polymer networks (LCNs) with various topological defects have drawn great interest owing to their significant deformation at the defect sites for designed performances. Liquid crystalline molecules could be aligned by various methods including mechanical rubbing, an electric field, magnetic field and photo-induced alignment. In contrast to the mechanical shear method, which is advantageous for synthesizing monodomains due to the application of only unidirectional shear, the photo-induced alignment for complex topological defects typically involves using polarized blue light to induce molecular alignment. However, photoalignment systems require photo-reactive chemicals and high-cost optical equipment, including lasers, polarizers, and optical tables. Moreover, photo-induced alignment systems can be especially demanding in terms of time and cost when applied to large-area patterning. Notably, inducing complex topological defects through mechanical rubbing is particularly significant challenging. In this study, we present a simple and low-cost mechanical alignment technique to rapidly produce macroscopic +1 topological defects in LCNs using a custom-built rotational rubbing machine. Light-responsive-LCNs with +1 topological defects were shaped into various forms to create different locomotion modes for intelligent systems. Additionally, swimming motions were demonstrated in various liquid environments under irradiating UV light conditions. This rotational machine offers the potential for low-cost, rapid, and centimeter-scale manufacturing of light-responsive-LCNs with +1 topological defects for further intelligent systems.