Clothes With A Spark
It may not be too long before that new blazer or blouse recharges your BlackBerry.
A team of scientists at Georgia Tech has developed proof-of-concept fibers that generate small amounts of electricity when individual strands rub together – the way fibers might as a person walks. If the technology can be scaled up, the team envisions using it to power tiny sensors or surveillance devices for the military. Variations might also appear in clothing, curtains, or other fabric-based products.
For its experiments, the team formed fibers out of Kevlar, then grew tiny nanowires of zinc oxide on the fibers, giving them the look of a microscopic roller-style brush. They coated the nanowires on one strand with gold, to ensure that electric current would flow in only one direction, as it does in a battery. Then they rubbed the two strands back and forth against each other with an 80-r.p.m. motor. As the bristles brushed past each other, they bent back and forth, generating a small amount of electricity though a process called the piezoelectric effect.
For wash-n-wear, however, zinc oxide won't do. It doesn't get along well with water. The results appear in today's issue of the journal Nature.