Smartphones could soon be charged using 'friction and static'
Researchers have developed a two-layered material that generates power from static electricity and flexing.
Sihong Wang and Long Lin, graduate students in Georgia Tech's materials science department, used a thin film made of a layer of polymer and another of aluminium.
Both layers have tiny structures etched on them at the nanometer scale. When the plastic and the metal come in contact with each other, they accumulate a static electric charge. Flexing them generates a current.
The etched nanostructures increase the surface area, which gives electrons a lot more room to gather and boosts the charge accumulated, Discovery news reported.
According to the paper, the efficiency with which the material turns the mechanical motion of flexing into electricity can go as high as 40 percent.
Wang has done similar work in 2009, when he demonstrated that a hamster could wear a jacket that generated power in a similar way.
Wang and his team say they have hit 230 volts, at 15.5 microamperes per square centimetre, with a power output of 128 milliwatts per cubic centimetre.
This means that a sheet the size of the latest iPod Nano, which is about three inches by 1.6 inches, would generate just enough to charge the iPod as it is being flexed.
If it were used in the real world, odds are this wouldn't replace a battery, but it could extend the time between charges.
The study has been published in the journal Nano Letters.