A catalyst-contacting carbon nanotube electrode is used as fuel-cell electrode to convert chemical energy to electrical energy as a super-capacitor electrode to store the electrical energy. It is also used as a muscle electrode to transform the electrical energy to mechanical energy. Then, a fuel-powered charge injection in a carbon nanotube electrode produces the changes that are needed for it to function. This is possible due to a combination of quantum mechanical and electrostatic effects present on the nanoscale, Baughman said.
Baughman told Jorge Salazar with EarthSky that a carbon nanotube is a little cylinder of carbon that can be one-thousandth the diameter for a human hair. Further, the individual carbon nanotubes are twisted together until it reminisce some sort of a yarn.
The project was initially inspired by a visit from Dr. John Main from the Defense Advanced Projects Agency (DARPA). Main described his vision of a future that could include advancements such as artificial muscles for autonomous humanoid robots that can protect people from danger, artificial limbs that can act like natural limbs and exoskeletons that can provide super-human strength to firefighters, astronauts and soldiers.
Another version of the artificial muscles, currently the most powerful one, converts the chemical fuel to heat by a catalytic reaction of a mixture of fuel and oxygen in the air. The increase in temperature causes a contraction of a shape memory muscle wire that supports the catalyst.
The patent applications for the muscle is still pending, but there is a diverse application opportunity, Baughman said. They range from robots and morphing air vehicles to dynamic Braille displays and muscles powered by the fuel/air mixture delivered to an engine that are able to regulate this mixture.
The fuel-powered muscle can easily be downsized into micro- and nano-scales, and arrays of micro-muscles could be used in “smart skins” that improve the performance of marine and aerospace vehicles. By replacing metal catalyst with tethered enzymes, it might eventually be possible to use artificial muscles powered by food-derived fuels that can function in the human body—potentially even human hearts.
The research leading to the discoveries was funded by DARPA, an agency of the U.S. Department of Defense, the Robert A. Welch Foundation and the coordinated support efforts of the Strategic Partnership for Research in Nanotechnology and the U.S. Air Force.
To read the interview Jorge Salazar did with Ray H. Baughman, go to EarthSky
Image courtesy: EarthSky