In the work, the authors Roshan Nasare, Hongshuang Guo and Arri Priimägi present a multi-mode, supramolecular liquid crystal elastomer actuator that integrates shape memory programming, humidity sensitivity, and photochemical actuation, depending on the pre-activation conditions. Switching between different states is enabled using carboxylic-acid-containing chain extenders, which can form dynamic supramolecular crosslinks or act as handles for saltification via base treatment. In the former state, the LCE is humidity-insensitive, yet exhibits shape memory properties. The shape memory properties are lost in the latter state, but humidity changes can drive the LCE actuation due to anisotropic swelling. Due to the presence of azobenzene, both states are photochemically active, and they enable distinct soft actuator demonstrations both in the air and underwater. You can find more details in the original publication “Hydrogen-bonded multi-mode liquid crystal elastomer actuators“
Light-controllable gripper under water based on the shape memory effect