Science

New nanogenerator might set energy-generating car wheels in motion

New nanogenerator might set en...
Xudong Wang's team has developed a new way to harvest energy from rolling tires. The researchers used toy cars during the initial trials
Xudong Wang's team has developed a new way to harvest energy from rolling tires. The researchers used toy cars during the initial trials
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Xudong Wang's team has developed a new way to harvest energy from rolling tires. The researchers used toy cars during the initial trials
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Xudong Wang's team has developed a new way to harvest energy from rolling tires. The researchers used toy cars during the initial trials
Xudong Wang's team has developed a new way to harvest energy from rolling tires. The researchers used toy cars during the initial trials
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Xudong Wang's team has developed a new way to harvest energy from rolling tires. The researchers used toy cars during the initial trials
Associate professor of materials science and engineering at University of Wisconsin-Madison Xudong Wang has developed a new way to harvest energy from rolling tires
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Associate professor of materials science and engineering at University of Wisconsin-Madison Xudong Wang has developed a new way to harvest energy from rolling tires

Cars are one of mankind's most revolutionary creations. But just like with the iPhone, space travel or Wi-Fi, there's always room for improvement. In the eyes of a team of University of Wisconsin-Madison engineers, one of the more promising ways automotive technology might be improved upon lies in the energy wastage caused by friction as tires roll across the road. Armed with special nanogenerator and a toy Jeep, the researchers have demonstrated that this power can be captured and turned into electricity, a development that could bring about better fuel efficiency in the full-sized cars of the future.

According to Xudong Wang, associate professor of materials science and engineering at the University of Wisconsin, the friction created as a car's tires run over the ground accounts for approximately 10 percent of the vehicle's fuel usage. For him and PhD student Yanchao Mao, this presents a big opportunity to improve efficiency, so for the last year or so they have been building a device to tackle the problem.

Their work looks to harness the electrical charge that is created when certain materials come into contact with one another, much like what happens when you run a comb through your hair. This is known as the triboelectric effect and has been used in the early-stage development of promising technologies like electricity-generating touchscreens and clothing.

Not to be confused with the approach taken by Goodyear, which in March unveiled a concept tire that turns heat and motion into electricity using a fishnet pattern of thermo/piezoelectric material, Wang's solution sees an electrode built into a section of the tire. As the wheel spins and this part of the tire comes into contact with the ground, the charge created by the friction causes electrons to move, in turn generating electricity.

To bring this new source of electricity to life, the team equipped the toy Jeep with LED lights. As the car moved forward, enough power was created to cause the lights to flash on and off, suggesting that this hitherto wasted energy could actually be captured and put to use.

Interestingly, the researchers also found that the amount of energy the system was able to produce was proportionate to both the weight of the vehicle and the speed at which it was traveling. Wang estimates that the solution could offer approximately a 10 percent increase in the average vehicle's gas mileage.

The research was published in the journal Nano Energy.

Source: University of Wisconsin-Madison

8 comments
Roger Garrett
Dumb, dumb, dumb. It is utterly amazing, and very sad, that an actual associate professor of materials science and engineering at the University of Wisconsin can't figure out that the energy comes from whatever is powering the vehicle itself. It's not coming from the wheels, it's not coming from the friction. Its coming from the gasoline or whatever it is that's feeding into the engine. This is no different than putting a wind turbine on your car and thinking that you're getting energy from the wind caused by the movement of the vehicle. This professor needs to go back to college and take some introductory physics courses.
JeremyPepper
While I might agree with the idea that a wind turbine is an energy suck, I completely disagree with the idea that anything that harvests energy uses more energy than it generates. Think about the flywheels in hybrids. They dramatically increase the efficiency of a vehicle by turning kinetic energy into electric potential energy. If a car is putting off an electric field near the outer surface of the tire, then it may be possible to harvest that energy in a way that is beneficial. Whether or not this professor did that, I have no idea, but your hypothesis would be incredibly easy to test. Just do a range study and see what impact this technology has on the range of his small little test vehicle. It wouldn't take long to get that answer.
jumpjack
"This is no different than putting a wind turbine on your car and thinking that you're getting energy from the wind caused by the movement of the vehicle. no,he claims e can recovery the energy usually wasted as heat in tyres friction: "charge created by the friction causes electrons to move, in turn generating electricity."
equator180
This idea is about 25 years old. The first I heard was on a CBC radio interrupter with a mad hat inventor that wanted to use this technology for sidewalks in NYC. All the energy from all the sidewalks, wow! All those little machines going up and down under your feet...
Bob Stuart
I don't have any problem with the notion of harvesting some power from the tires. Most rubber is less bouncy than it could be, for some of the same reasons we use "shock absorbers" to waste motion as heat, usually. Traction is a complex compromise. Even if this technique increases rolling resistance, it could be applied to more resilient formulas and come out the same. What sets off my alarms is that the proposed savings is the same as the total estimated rolling resistance.
Jamurray
I don't know if the writer missed some critical detail but I cannot wrap my brain around the concept either. Anything on the vehicle that generates waste heat can be considered lost energy. So I can imagine the heat from rolling friction as having that potential.
tigerprincess
Roger, the professor did not claim that the energy he was trying to harness was not created by the fuel that powers the car. He just determined that energy was being thrown off by the tires and going to waste and he developed a way to recapture that energy and reuse it.
JebaQpt
but the researcher stated "the researchers estimate about a 10-percent increase in the average vehicle's gas mileage given 50-percent friction energy conversion efficiency." so there is some improvement over past.