for National Geographic News
Next-generation threads may soon give a whole new meaning to the phrase "change your clothes"advanced new fibers that can change color with a flip of a switch.
The threads may one day be used to make clothing that suits the wearer's mood or to allow a person to blend in with the environment.
The concept is similar to the way light-sensitive eyeglass lenses darken when exposed to sunlight.
The threads, created from materials known as electrochromic polymers, change color in response to an electric current, said Gregory Sotzing, a professor of polymer and organic chemistry at the University of Connecticut in Storrs.
"The part we're getting into is the wearable display, a flexible fabric display," Sotzing said.
An article on the research appears in the April 9 issue of New Scientist magazine.
The threads work because the polymer absorbs light across a range of visible wavelengths (related photos: the power of light).
When voltage is applied, the polymer's electrons are raised to a higher energy level. In this state the fibers absorb light of different wavelengths, and the color changes.
"You can tune color by tuning the chemistry," Sotzing said.
Electrochromic polymers have been made before, Sotzing said. But the polymers are very rigid and can't be spun into fibers using conventional means.
"In order to spin a fiber, what you need is high viscosity [of the polymer]," he said.
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