Enabling Ultra-High Work Capacity and Scalable Processability of Liquid Crystal Actuators through Densely Entangled...

Liquid crystal elastomers (LCEs) are important soft actuators that show strong promise in many fields where traditional rigid actuators or robotics are impractical. However, their real-world applications are lacking primarily due to inadequate actuation performance and complicated fabrication processes. Here, a novel design is reported that significantly enhances actuation performance while simplifying the fabrication process. The design involves constructing densely entangled structures by synthesizing high-molecular-weight linear LCEs (>180 kDa) with a moderate number of side groups in a single step. These entangled structures greatly enhance mechanical strength while maintaining toughness, resulting in an ultra-high actuation work capacity (1427 kJ m^{- 3}). By applying melt shearing or solvent treatment, these entanglements can be temporarily disrupted, providing thermoplastic-like processability. With these properties, lightweight wearable devices (<10 g) capable of generating over 30 N of contractile force are developed, which is sufficient to reversibly lift an adult male's arm. This work employs a single fabrication step to develop densely entangled LCEs with exceptional actuation performance and thermoplastic-like processability, signaling a bright future for their applications in rehabilitation devices, wearables, and beyond.