Electrospun Liquid Crystal Elastomers as Stress-Free Thermo- and Photoresponsive Actuators

Actuators based on liquid crystalline elastomers (LCEs) can realize reversible and complex shape changes exploitable in soft robotics, actuators, surface haptics, photocontrolled microfluidic, and artificial muscles. A key prerequisite for the actuation of LCEs lies in predetermined alignment of mesogenic units. Here, we describe a single-step fabrication process for manufacturing LCE actuators using electrospinning coupled with simultaneous photo-cross-linking. Branched oligomers were designed and synthesized to address the trade-off between electrospinnability and cross-linking density. Moreover, optimizing the photoinitiator system and electrospinning setup allowed us to achieve long-range alignment of liquid crystalline domains. These fibrous materials display impressive stress-free thermal actuation without the need for external loads, reaching reversible deformations of over 30%. Additionally, we explored photoresponsive behavior by integrating photothermal dyes, enabling movement triggered by either UV or blue light. These results provide a scalable framework for developing smart materials suitable for applications in soft robotics and artificial muscles.