Nanogenerator harvests energy from the friction of rolling tires

While we are all hoping that electric vehicles become the standard personal transportation mode over gasoline cars in the near future, for now, the majority of cars being made require gas and most of us that own cars, own one with an internal combustion engine.

Automakers have made great gains over the past decade or so when it comes to fuel efficiency, but there's room for more improvement. Researchers at University of Wisconsin - Madison have developed a technology that will help boost gas mileage now and improve EV range in the future.

The team has designed a nanogenerator that harnesses energy from rolling tires, basically reusing the energy that is generally lost through friction.

"The friction between the tire and the ground consumes about 10 percent of a vehicle's fuel," said Xudong Wang, an associate professor of materials science and engineering at UW-Madison. "That energy is wasted. So if we can convert that energy, it could give us very good improvement in fuel efficiency."

© University of Wisconsin - Madison, College of Engineering

The nanogenerator works through the triboelectric effect in order to harness energy from the changing electric potential between the pavement and a vehicle's wheels. The nanogenerator uses an electrode placed in a piece of the tire. As the tire rolls, that part of the tire will strike the ground, creating an electrical charge through the friction between the two surfaces.

The technology was tested using a toy remote car outfitted with LED lights. The electrodes were applied to the cars' tires and as they struck the ground, the energy captured would turn the LEDs on, proving that the energy lost through friction could be collected and reused.

They found that the amount of energy that can be harnessed is directly related to the weight of the car and its speed, meaning that the energy captured will vary between cars and how they're driven, but each vehicle should see an average of a 10 percent increase in gas mileage.

"There's big potential with this type of energy," Wang says. "I think the impact could be huge."

As the technology is further developed and improved, it could make current car models far more efficient and also help add range to electric vehicle batteries in the future.

Tags: Electric Vehicles | Renewable Energy | Technology


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