London, Feb 14 : You may soon not have to search for am electrical socket to charge your iPod or mobile phone, for your clothes may be doing the same for you by producing energy from body movements.
This clothing, which is being developed by nanotechnology researchers at the Georgia Institute of Technology, can be used by soldiers in the field, hikers and other users for powering small electronic devices that they usually carry along.
The Georgia Tech research team for fiber nanogenerators led by Zhong Lin Wang, Xudong Wang and Yong Qin, have explained how pairs of textile fibers covered with zinc oxide nanowires generate electricity in response to applied mechanical stress.
This effect is known as "the piezoelectric effect": the resulting current flow from many fibre pairs woven into a shirt or jacket may be used to power a range of portable electronic devices by using the wearer's body movement.
These fibres can also be used to make curtains, tents or other structures for capturing energy from wind motion, sound vibration or other mechanical energy.
"The two fibers scrub together just like two bottle brushes with their bristles touching, and the piezoelectric-semiconductor process converts the mechanical motion into electrical energy. Many of these devices could be put together to produce higher power output," Nature quoted Zhong Lin Wang, a Regents professor in the School of Materials Science and Engineering at the Georgia Institute of Technology, as saying.
The researchers have already made more than 200 of the fiber nanogenerators and all of them have been tested on an apparatus that uses a spring and wheel to move one fibre against the other. These fibres are then rubbed together for almost half hour in order to test their durability and power production.
Currently about four nanoamperes and the output voltage of about four millivolts have been measured from a nanogenerator that included two fibers that were each one centimeter long.
Wang has approximately calculated that with the help of a much improved design, a square meter of fabric made from the special fibers could supposedly generate as much as 80 milliwatts of power.
Boffins are now working on the only problem - how to wash such clothing.
As zinc oxide is sensitive to moisture, therefore shirts or jackets, the nanowires would have to be protected from the effects of the washing machine.
The study has been published in the recent issue of Nature.