Usually the only alcohol-powered muscles are the ones in barroom brawls, but one scientist is adding alcohol to artificial muscles to power robots and more.
Scientists at the University of Texas at Dallas have developed "artificial muscles"—science's best attempt at mimicking natural muscles. But they're not made with the hydraulics or gears that power most of today's big, strong machines. These muscles are made of an elastic metal called "shape memory wire."
"These artificial muscles are able to do over a hundred times more work per cycle than a natural muscle," head researcher Ray Baughman says, "They're a hundred times stronger than an actual muscle."
Most robotic muscles are powered by an electrical current. But as he reported in the journal Science, Baughman's artificial muscles are powered by chemical energy, just as human muscles are.
In one experiment, Baughman used alcohol to fuel the movement of these artificial muscles. His team coated the shape memory wire with a chemical called a catalyst. When alcohol was added, it reacted with the oxygen in the air, burning up and releasing heat. The catalyst on the surface of the wire made the combustion of the alcohol proceed at a faster rate. All of that burning fuel causes the artificial muscle to heat up. "And as the shape memory wire is heated it actually contracts. Normally you think that a material heated would expand, but these shape memory materials contract," says Baughman.
According to Baughman, they contract by a large amount, "This contraction is like the contraction of arm muscles in our body." The muscles then expand when the alcohol is shut off.
Baughman says they hope to one day power these muscles with environmentally friendly fuel sources such bio-diesel or bio-alcohol.
Baughman, who works with funding from the military, says these artificial muscles could serve multiple uses. "Artificial muscles are needed for a variety of applications that are extremely important for our society, for example for prosthetic limbs for those that are handicapped," he says. He adds that they could also power everything from artificial hearts, to super-muscles for astronauts or soldiers, and maybe even self-sufficient robotic androids.
"On the more humorous side," he says, "perhaps in a very distant future the humanoid robot who is sitting next to you in a bar might be drinking alcohol in order to work the next day."