for National Geographic News
A new self-healing coating could erase unsightly scratches on your cell phone or music player upon exposure to sunlight.
The coating is made by fusing microscopic polyurethane rings with a protein derived from shrimp and crab shells that is sensitive to ultraviolet light.
When the coating gets scratched, the polyurethane rings break open, creating two reactive ends. Exposure to ultraviolet rays in sunlight activates the protein, called chitosan, which binds with the broken rings to repair the scratch.
The coating can repair itself in about an hour and, unlike other self-healing systems, it can function at room temperature.
"It can work any place that is exposed to ultraviolet light," said study team member Marek Urban at the University of Southern Mississippi. The coating doesn't even need to be in the sun—a UV lamp would work, too.
In addition to electronics, the coating could be applied to cars, clothing, even furniture, Urban added.
There's a catch, however: The coating can heal only once at a particular spot.
This limitation could prevent the technology from being widely used in consumer electronics, said Brian Lam, editorial director of the gadget blog Gizmodo.
"That is defiantly a deal breaker," Lam said.
It's also not clear that consumers are overly concerned about scratching their gadgets.
"A lot of this stuff is almost designed to be disposable," Lam said. "If you look at things like iPods, they're redesigned every year and people pick them up every year."
A simpler and less exotic solution to scratches would be to use more durable plastics or choose a color that makes scratches less visible, Lam added.
Findings detailed in the March 13 issue of the journal Science.
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