Artificial Muscles from Fishing Line and Sewing Thread

The high cost of powerful, large-stroke, high-stress artificial muscles has combined with performance limitations such as low cycle life, hysteresis, and low efficiency to restrict applications. We demonstrated that inexpensive high-strength polymer fibers used for fishing line and sewing thread can be easily transformed by twist insertion to provide fast, scalable, nonhysteretic, long-life tensile and torsional muscles. Extreme twisting produces coiled muscles that can contract by 49%, lift loads over 100 times heavier than can human muscle of the same length and weight, and generate 5.3 kilowatts of mechanical work per kilogram of muscle weight, similar to that produced by a jet engine. Woven textiles that change porosity in response to temperature and actuating window shutters that could help conserve energy were also demonstrated. Large-stroke tensile actuation was theoretically and experimentally shown to result from torsional actuation.Air Force Office of Scientific ResearchUnited States Department of DefenseAir Force Office of Scientific Research (AFOSR) [FA9550-12-1-0211]; Air Force [AOARD-10-4067, AOARD-13-4119]; Office of Naval Research MURIMURIOffice of Naval Research [N00014-08-1-0654]; Robert A. Welch FoundationThe Welch Foundation [AT-0029]; Creative Research Initiative Center for Bio-Artificial Muscle; Korea-U.S. Air Force Cooperation Program [2012-00074]; Australian Research CouncilAustralian Research Council; Australian National Fabrication Facility, China National 973 Project [2007CB936203, S2009061009]; NSF ChinaNational Natural Science Foundation of China (NSFC) [51003036]; Natural Sciences and Engineering Research Council of CanadaNatural Sciences and Engineering Research Council of Canada (NSERC)CGIARWe thank C. Mozayan, D. B. Hagenasr, Y. Zhang, D. A. Tolly, D. E. Wait, and P. E. Javidnia for assistance with sample preparation and measurements. Support is largely from Air Force Office of Scientific Research grant FA9550-12-1-0211, with additional support from Air Force grants AOARD-10-4067 and AOARD-13-4119, Office of Naval Research MURI grant N00014-08-1-0654, Robert A. Welch Foundation grant AT-0029, the Creative Research Initiative Center for Bio-Artificial Muscle, the Korea-U.S. Air Force Cooperation Program grant 2012-00074 (Korea), Centre of Excellence funding from the Australian Research Council and the Australian National Fabrication Facility, China National 973 Project (nos. 2007CB936203 and S2009061009), NSF China (no. 51003036), and a Natural Sciences and Engineering Research Council of Canada Discovery grant. Correspondence and requests for materials should be addressed to ray.baughman@utdallas.edu. A provisional patent application (61784247) and an international patent application (PCT/US2013/053227) have been filed by N. Li et al. on Coiled and non-coiled twisted nanofiber yarn and polymer fiber torsional and tensile muscles