Researchers claim T-shirts with built-in nanotechnology may soon be enough to power your MP3 player.

The researchers, from the Georgia Institute of Technology, have shown how pairs of textile fibres covered with zinc oxide nanowires generate electricity in response to applied mechanical stress.

Scientifically referred to as the piezoelectric effect, "the resulting current flow from many fibre pairs woven into a shirt or jacket could allow the wearer's body movement to power a range of portable electronic devices", said the National Science Foundation (NSF), which funded the project.

Typical real-world scenarios would be military personnel in service, hikers and other outdoor users.

However, it isn't limited to shirts. The fibres could also be woven into curtains, tents or any other fabric subject to movement.

"The two fibres scrub together just like two bottle brushes with their bristles touching, and the piezoelectric-semiconductor process converts the mechanical motion into electrical energy," explained Zhong Lin Wang, a Regents professor in the School of Materials Science and Engineering at the Institute. "Many of these devices could be put together to produce higher power output."

The researchers have measured current of about four nanoamperes and output voltage of about four millivolts. Wang estimates that a square metre of fabric made from the fibres could theoretically generate as much as 80 milliwatts of power.

The only set back to the research: zinc oxide is sensitive in water. So washing your clothes may pose a problem.