Researchers at the University of Wisconsin-Madison, in collaboration with a scientist in China, have developed a nanogenerator that can harvest energy from a tire rolling against the pavement.
In research published in the journal Nano Energy, the international team created a single-electrode nanogenerator that could be incorporated into a tire. When the part of the tire that contains the electrode comes into contact with the pavement, the friction between the rubber and the road creates an electrical charge, which is known as the tribolectric principle. The researchers believe that capturing the energy that is typically lost in the friction between a tire and the road surface could be a new avenue for greater energy efficiency in automobiles.
The researchers also determined that the amount of energy that the nanogenerator produces is proportional to the weight of the car and the speed at which it’s traveling.
“The friction between the tire and the ground consumes about 10 percent of a vehicle’s fuel,” said Xudong Wang, associate professor at Wisconsin-Madison, in a press release. “That energy is wasted. So if we can convert [some of it to electricity], it could give us very good improvement in fuel efficiency.”
To test their device, the researchers used a toy car with LED lights. When the electrode in the tires of the toy car ran over the surface, the energy harnessed by the generator would turn the LED lights on.
While the release doesn’t speculate where the energy might be used in a full-scale vehicle, it’s conceivable that the energy could be stored in the batteries of hybrid electric vehicles or full EVs.
“Regardless of the energy being wasted, we can reclaim it, and this makes things more efficient,” Wang said in the release. “I think that’s the most exciting part of this, and is something I’m always looking for: how to save the energy from consumption.”
Dexter Johnson is a contributing editor at IEEE Spectrum, with a focus on nanotechnology.