Circuit Shirt

Scientists have developed a way to generate electricity by jostling fabric with unbelievably tiny wires woven inside. Now your bad taste in clothes can power your iPod so you can enjoy your bad taste in music.

The research combines the precision of ultra-small nanotechnology with the principle known as the piezoelectric effect, in which electricity is generated when pressure is applied to certain materials. For example, a Japanese railway has experimented with mats, placed under turnstiles, that translate the pressure from thousands of commuters' footfalls into usable power. And French scientists have proposed capturing energy from raindrops hitting a structure with piezoelectric properties. Wow, don't those ideas just seem to fit their creators?.

In the study, individual fibers of fabric were coated with nanowires made of zinc oxide. These wires are only 50 nanometers in diameter — 1,800 times thinner than a human hair. Alternating fibers are coated with gold, and as one strand of the fabric is stretched against another, the nanowires on one fiber rub against the gold-coated ones on the other. The resulting tension and pressure generates a piezoelectric charge that is captured by the gold and can be fed into a circuit.

The allure of the idea is that it doesn't take unusual movement to generate usable electricity. Pretty much anything someone does while wearing a piezoelectric shirt would be productive. Estimates are that one square meter of nanowire-infused fabric would produce around 80 milliwatts of electricity, enough to recharge portable music players.

So far, the one big hurdle to the advent of power shirts is keeping the material infused with the zinc oxide. A nice sunscreen, yes, but zinc oxide is not really waterproof. Without a protective coat a one trip through the washing machine or one rainy day would rob the nanowires of their potency. Or make clothing manufacturers billions on replaceable garments.