US university develops tread wear sensors

Durham, North Carolina – An American private research university has developed a printed sensor that can monitor the tread of car tires in real time.

Electrical engineers at Duke University, based in Durham, North Carolina, said the “inexpensive” sensor will warn drivers when the rubber meeting the road has grown “dangerously thin”.

According to Aaron Franklin, associate professor of electrical and computer engineering at Duke, there are two patents pending for the product, which uses mechanics of how electric fields interact with metallic conductors.

A sensor is placed on the inside of the tire, where the tire wall and tread interferes with an electric field that arcs between two electrodes.

“That interference can be measured to determine the thickness of the rubber with millimetre accuracy,” the university paper explained.

"When we pitch this idea to industry experts, they say to each other, 'why haven't we tried that before?'" said Franklin. "It seems so obvious once you see it, but that's the way it is with most good inventions."

The sensors can be printed on almost anything using an aerosol jet printer – even on the inside of the tires themselves.

According to Franklin, whatever approach is ultimately used, the sensors should cost “far less than a penny apiece once they're being made in quantity.”

Franklin's group also wants to explore other automotive applications for the printed sensors, such as keeping tabs on the thickness of brake pads or the air pressure within tires.

This is consistent with a key trend in the automotive sector toward using embedded nanosensors.