BOSTON — Someday, your shirt might be able to power your iPod — just by doing the normal stuff expected of a shirt.
Scientists have developed a way to generate electricity by jostling fabric with unbelievably tiny wires woven inside, raising the prospect of textiles that produce power simply by being stretched, rustled or ruffled by a breeze.
The research, described in today’s edition of the journal Nature, combines the precision of ultra-small nanotechnology with the elegant principle known as the piezoelectric effect, in which electricity is generated when pressure is applied to certain materials.
While the piezoelectric effect has been understood at least as far back as the 19th century, it is getting creative new looks now, as concerns about energy supplies are inspiring quests for alternative power sources.
For example, a Japanese railway has experimented with mats, placed under turnstiles, that translate the pressure from thousands of commuters’ footfalls into usable power. French scientists have proposed capturing energy from raindrops hitting a structure with piezoelectric properties.
For the research described in Nature, Zhong Lin Wang and colleagues at the Georgia Institute of Technology covered individual fibers of fabric with nanowires made of zinc oxide.
These wires are only 50 nanometers in diameter — a human hair is 1,800 times thicker.
Alternating fibers are coated with gold. As one strand of the fabric is stretched against another, the nanowires on one fiber rub against the gold-coated ones on the other, like the teeth of two bottle brushes. 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.
“The beauty of this work is that if you have wind or you have sonic waves or you have vibrations, that works for you,” Wang said. “You do not need a very large force for that.”
