Searching for a charging point for a mobile phone or tablet could soon be a thing of the past.
Researchers have developed a small metal tab that when attached to the body can generate electricity from bending a finger and other simple movements.
The 1.5cm tab is made up of two sheets of gold with a layer of silicon in between.
When bent the motion leads to friction between the gold layers.
This causes electrons to flow back and forth between the gold layers, which produces power.
In trials the tab delivered a maximum voltage of 124 volts and lit 48 red LED lights simultaneously.
Lead researcher Qiaoqiang Gan, of the University of Buffalo in New York, said: "No one likes being tethered to a power outlet or lugging around a portable charger.
"The human body is an abundant source of energy. We thought why not harness it to produce our own power?”
Researchers are also developing a portable battery to store energy produced by the tab.
They forecast the system acting as a power source for various wearable and self-powered electronic devices.
The findings appear in the science journal Nano Energy.