All-Solid-State Electrochemical Artificial Muscles Enabled by Magnetically Aligned Ionic Liquid Crystal Elastomers

Liquid crystal elastomers (LCE) with high actuation stroke, dynamically reprogrammability, and multiple molecular designabilities receive increasing attention in artificial muscles. However, the mechanical strength of LCE suffers a remarkable decrease at high temperatures. Herein, an ionic LCE with high ionic conductivity is designed by grafting ionic chain extenders into the LCE network. The mesophase of ionic LCE is oriented by a magnetic field, and the oriented mesophase provides a rapid ion transport channel with the ionic conductivity of 47.5 mS m^-1, which is over 200% increase compared to that of polydomain ionic LCE. LCE-based all-solid-state electrochemically actuated artificial muscles are investigated by introducing carbon nanotube (CNT) coiled fibers as the actuating host materials in ionic LCE. The CNT/monodomain ionic LCE artificial muscles exhibit excellent driving performance with a maximum contraction stroke of 20.5% and a maximum contraction rate of 18.0%/min, which surpass those of the CNT/polydomain ionic LCE artificial muscle by 1.9 and 2.1 times, respectively. Furthermore, the artificial muscles show negligible attenuation of actuation performance in a vacuum and are demonstrated to rotate solar panels for powering vehicles. This work provides promising application scenarios for all-solid-state electrochemical artificial muscles in vacuum deformable structures and wearable smart textiles.