Scientists at the University of Wisconsin-Madison have developed an innovative car tire that harvests energy from friction. The tire is embedded with a new nanogenerator and electrodes, and when it rubs against the road it produces a small electric current. This occurrence is known as the triboelectric effect, and it reclaims energy that is otherwise lost during transit. The development has obvious applications for electric cars, and it could also improve the fuel efficiency of petrol-sucking vehicles.
The UW-M team led by Xudong Wang sought a way to harvest energy typically lost in the operation of a car. In a release, Wang notes, “The friction between the tire and the ground consumes about 10 percent of a vehicle’s fuel. That energy is wasted. So if we can convert that energy, it could give us very good improvement in fuel efficiency.”
To test the nanogenerator, Wang and his team implanted electrodes into segments of a tire on a toy car, and wired it up to small LEDs on the vehicle. As the car traversed, the lights flickered on and off, a sign it was successfully harvesting and reusing energy from friction. The team hopes to adapt this technology on a larger scale.
When deployed on a real-world scale, the amount of energy harvested will be directly related to the weight of the vehicle, but Wang estimates that with a 50 percent friction to energy rate, the efficiency of a given vehicle could be improved by 10 percent. And that is no small feat.