Photo-responsive Diels–Alder-based azobenzene-functionalized main-chain liquid crystal networks

Light-responsive liquid crystal elastomer networks (LCNs) have received significant interest due to their potential application in soft robotics and shape-morphing devices. Here, we present a systematic examination of light-responsive LCNs prepared using a catalyst-free Diels–Alder cycloaddition and a new azobenzene functionalized monomer for main-chain incorporation. The networks have robust mechanical stiffness that can be reversibly modulated by 1 GPa by turning the UV light on and off. This study highlights the contribution of photothermal softening to reversibly control the rheological properties of the newly developed LCNs and demonstrates the ability to tune the modulus on demand. We believe this work will guide future developments of light-responsive LCNs based on the newly developed Diels–Alder cycloaddition.