Wednesday, February 26, 2014

Artificial Muscles from Fishing Line and Sewing Thread

Muscles With a Twist 
ScienceVol. 343 no. 6173 pp. 845-846 
DOI: 10.1126/science.1250471



Fibers Do the Twist

  1. Philippe Poulin
+Author Affiliations
  1. Centre de Recherche Paul Pascal, CNRS, Université de Bordeaux, 115 Avenue Schweitzer, 33600 Pessac, France.
  1. E-mail:
In a rubber band–powered airplane, a pretwisted band untwists when the hook used to initially balance its torque is released (see the figure). Such an actuation is based on the elastic recovery of the stretched polymer chains. The material has to be mechanically retwisted to operate but the method is simple and efficient, because the rubber band delivers almost as much energy as needed to twist it. Unfortunately, soft rubber cannot easily provide large stress and cannot be used in modern applications such as robotics, artificial muscles, smart textiles, and new medical devices. But as Haines et al. show on page 868 of this issue (1), the concept of twisted fibers can nevertheless be useful in demanding actuator applications.

Vol. 343 no. 6173 pp. 868-872 
DOI: 10.1126/science.1246906


Artificial Muscles from Fishing Line and Sewing Thread

  1. Ray H. Baughman1,*
+Author Affiliations
  1. 1The Alan G. MacDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, TX 75083, USA.
  2. 2Intelligent Polymer Research Institute, ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, New South Wales 2522, Australia.
  3. 3Department of Electrical and Computer Engineering and Advanced Material and Process Engineering Laboratory, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
  4. 4Center for Bio-Artificial Muscle and Department of Biomedical Engineering, Hanyang University, Seoul 133-791, South Korea.
  5. 5Department of Textile Engineering, Çorlu Engineering Faculty, Namık Kemal University, Çorlu-Tekirdağ, Turkey.
  6. 6Alan G. MacDiarmid Institute, Jilin University, Changchun 130012, China.
  1. *Corresponding author. E-mail:
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.

No comments:

Post a Comment