Locking Alignment of Liquid Crystal Actuators Using Hydrogen Bonds to Enable Room‐Temperature Shape Programmability and Enhanced Work Capacity

Abstract Soft actuators that mimic the softness and deformability of living organisms have great potential for use in various fields. For most soft actuators, achieving both reprogrammable shape and high work capacity is crucial but challenging. These properties are mutually exclusive for liquid crystal elastomers (LCEs), an important type of soft actuators. Herein, a room‐temperature shape‐programmable LCE capable of high‐energy actuation is developed. Our approach utilizes hydrogen bonds to stabilize the aligned liquid crystal phases. The slow recovery of H‐bonds at room temperature provides a specific processing window, during which the sample shape can be programmed after the thermal treatment. The temperature‐dependent rearrangement of hydrogen bonds allows for fabrication of actuators with customized shapes in a facile do‐it‐yourself manner. Additionally, the integration of strong covalent cross‐links is vital for holding structural integrity. The combination of non‐covalent and covalent cross‐linking significantly improves the mechanical properties, enabling the actuators to perform reversible actuation with a work capacity (440 kJ m −3 ) higher than that of traditional LCEs (<100 kJ m −3 ). This study provides a turnkey strategy to address the conflict between shape reprogrammability and work capacity, advancing the development of soft actuators.