Extremely Large‐Stroke Hair Artificial Muscles with Fast Recovery Prepared by a Facile and Green Method

Twisted artificial muscles based on natural fibers are of special interest in diverse fields. However, current research is limited either by the material itself, or by the preparation methods requiring complex processing or specialized equipment. In this study, a facile and green method is introduced to prepare hair artificial muscles with extremely large tensile stroke and fast recovery. The maximum tensile stroke for the hair artificial muscles upon water actuation is as large as 10 000% and the large‐stroke muscles can recover fast in ethanol. In addition, these hair artificial muscles maintain their excellent performance after either 100 water–ethanol stimulation cycles or staying in open air for 5 months. Moreover, the hair artificial muscle is able to contract by 59% when lifting 10 times its own weight, pull a wheel model or climb a long distance under water, and work as a smart water‐sensitive switch. This work provides new insights into the development of simpler and more environmentally friendly methods for preparing advanced natural fiber‐based artificial muscles that have broad applications in soft robotics and biomedical engineering. An interactive preprint version of the article can be found here: https://doi.org/10.22541/au.167385630.01748766/v1 .