What if you could power your car by bolting an energy-storing, flapping device to your roof?
That's not likely to happen any time soon. But researchers in South Korea have demonstrated a prototype that might be capable of recharging your smartphone or tablet. They explain how it works in a report published Tuesday in the journal Nature Communications.
The researchers dubbed their contraption a "flutter-driven triboelectric generator," or FTEG for short. It consists of a flexible woven "flag" coated in a thin layer of gold and a stiff plate covered with a Teflon-like material. When the flag flutters in the wind and hits the plate, "the two structures become oppositely charged," according to the study. Then, when the flag and plate separate, the resulting "electronic potential difference" can send electrons to an external circuit.
This "simple mechanism" converts the kinetic energy of the wind into potential energy in the form of electricity, according to the Korean team.
After a series of lab tests to optimize their design, the engineers stacked several of these FTEG contraptions and mounted them to the roof of a sedan. With the car cruising along at 70 kilometers per hour (about 45 miles per hour), the apparatus was able to charge a 1,000-microfarad capacity to 30 volts in 25 minutes, the researchers reported. (You can see a demonstration in the video at the top of this story.)
As more people find themselves using more wireless devices, demand for electricity on the go is sure to grow, the researchers wrote. FTEGs could be a "promising solution" to this impending power crunch, they added.