Silly putty pothole repair

Science magazine shores up our infrastructure with a report on how a kid’s toy can save our streets:

…[U]ndergraduates at Case Western Reserve University in Cleveland… devised the idea as part of an engineering contest sponsored by the French materials company Saint-Gobain — and took first prize last week. The objective was to use simple materials to create a novel product.

“So we were putzing around with different ideas and things we wanted to work with—and we were like, what’s a common, everyday problem all around the world that everybody hates?” explains 21-year-old team member Curtis Obert. “And we landed on potholes.” He and four other students decided on a non-Newtonian fluid as a solution because of its unusual physical properties. “When there’s no force being applied to it, it flows like a liquid does and fills in the holes,” says Obert, “but when it gets run over, it acts like a solid.”

There are plenty of familiar non-Newtonian fluids, says Michael Graham, a chemical engineer not involved in the project who studies non-Newtonian fluid behavior at the University of Wisconsin, Madison. Mayonnaise, ketchup, silly putty, and even blood are examples.

the fluid filled bags can be carried around in the trunks of police cruisers or vans and dropped into potholes on the spot by employees with little training or experience. They would then be covered with black adhesive fabric so that drivers don’t perceive them as a hazard. “We definitely don’t want people avoiding them,” says team member Mayank Saksena.

The students have road-tested their designs on a number of Cleveland’s potholes and found that the bags continue to perform well after more than a week of continuous use in high-traffic areas. Although the product has yet to be field tested in an actual Midwest winter, the students say the bags are intended to be sturdy enough that they can stand up to salt and freezing conditions for weeks at a time, until damaged roads can be permanently fixed.

We don’t know exactly what silly putty relative the students are using, because they’re patenting the invention.

But they do say the powder in it is biodegradable and safe enough to eat.