One of the problems with the artificial muscles commonly used in robots is their poor performance compared to biological muscles. This is an important reason why they generally have not found favor as a replacement for conventional motors. A new artificial muscle developed at the University of Texas at Dallas Nanotech Institute may change that. Researchers there, led by Ray Baughman, are working on muscles made from carbon nanotubes, twisted into yarn and filled with paraffin wax. The resulting muscles can lift 100,000 times their own weight and generate 85 time the mechanical power of natural, biological muscles. According to Baughman,
"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, tunable optical systems, microvalves, positioners and even toys."
The coiled nature of the yarn provides two additional applications. First it can twist and untwist at up to 11,500 RPM, allowing it be used in much the same way as the rubber band that powers a model airplane. Second, the yarn can be sewn into fabrics which then have macro-level properties that can change in the presence of certain chemicals, lighting conditions, or temperature levels. A paper on the latest development appeared in the 16 Nov issue of Science. Unfortunately Science is a pay-walled journal so it's not generally available yet. You can, however, read other related papers on the Nanotech Institute's publications page. You can also get a little more info from the recent UTD news release. Read on to see video of the super-muscles lifting weights and doing other cool things.