Ultra-Soft Organogel Artificial Muscles Exhibiting High Power Density, Large Stroke, Fast Response and Long-Term Durability in Air

AbstractPolymeric gel‐based artificial muscles exhibiting tissue‐matched Young's modulus (10 Pa–1 MPa) promise to be core components in future soft machines with inherently safe human–machine interactions. However, the ability to simultaneously generate fast, large, high‐power, and long‐lasting actuation in the open‐air environment, has yet been demonstrated in this class of ultra‐soft materials. Herein, to overcome this hurdle, the design and synthesis of a twisted and coiled liquid crystalline glycerol‐organogel (TCLCG) is reported. Such material with a low Young's modulus of 133 kPa can surpass the actuation performance of skeletal muscles in a variety of aspects, including actuation strain (66%), actuation rate (275% s−1), power density (438 kW m−3), and work capacity (105 kJ m−3). Notably, its power density is 14 times higher than the record of state‐of‐the‐art polymeric gels. No actuation performance degradation is detected in the TCLCG even after air exposure for 7 days, owing to the excellent water retention ability enabled by glycerol as co‐solvent with water. Using TCLCG, mobile soft robots with extraordinary maneuverability in unstructured environments are successfully demonstrated, including a crawler showing fast bidirectional locomotion (0.50 mm s−1) in a small‐confined space, and a roller that can escape after deep burying in sand.