Engineers in the US have developed a nanogenerator that can harvest the energy produced by the friction of a tyre rolling along the ground.

They say the system could be used to gather power for a vehicle while it is moving, extending its efficiency by reclaiming lost energy.

The charge comes from the ‘triboelectric effect’, where contact between two dissimilar objects creates powerful friction. In this case, it comes from the ground’s surface rubbing against the vehicle's wheels.

The changing electric potential from the two surfaces is harvested by an electrode embedded in the tyre, and transmitted to the nanogenerator on board the vehicle where it is stored.

“Regardless of the energy being wasted, we can reclaim it, and this makes things more efficient,” said Xudong Wang, lead author of the research.

“I think that's the most exciting part of this, and [it’s] something I'm always looking for: how to save the energy from consumption.

“The friction between the tire and the ground consumes about 10 per cent 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,” he said.

During trials, Wang and his colleagues used a toy car with LED lights to demonstrate the concept.

They attached an electrode a segment of the wheels of the car, and as it rolled across the ground, the LED lights flashed on and off.

The researchers also determined that the amount of energy harnessed is directly related to the weight of a car, as well as its speed.

Therefore the amount of energy saved can vary depending on the vehicle, but Wang estimates about a 10 per cent increase in the average vehicle's gas mileage given 50 per cent friction energy conversion efficiency.

More details are available in a paper published in the journal Nano Energy.