Advanced materials used to create artificial muscle

Artificial muscles that can lift more than 100,000 times their own weight and generate 85 times more mechanical power than natural muscle of the same size have been unveiled at the University of Texas at Dallas.

The muscle was constructed from yarns made out of carbon nanotubes - seamless, hollow cylinders made from the same type of graphite layers found in the core of ordinary pencils. The yarns were infiltrated with paraffin wax and twisted until coils formed along their length. Heating the wax-filled yarn, either electrically or using a flash of light, caused the wax to expand, the yarn volume to increase, and the yarn length to contract. Team leader Ray Baughman said: "Because of their simplicity and high performance, these yarn muscles could be used for such diverse applications as robots, catheters for minimally invasive surgery, micromotors, mixers for microfluidic circuits, tuneable optical systems, microvalves, positioners and even toys." Baughman added that because the yarn muscles can be twisted together and are able to be woven, sewn, braided and knotted, they might eventually be deployed in a variety of self powered intelligent materials and textiles. While the new technology has many applications, it is not expected to be used in the human body, for now at least. The team is currently working to upscale the single yarn muscles to larger and more complex systems which implement thousands of yarn muscles in parallel.