|
Lenses of "smart" sunglasses can
change color on demand.
Image: Courtesy of University of
Washington and Chunye Xu |
“Through polymer chemistry, we’ve developed
lenses that aren’t like anything else on the market. This could be the
fashion statement of the future,” says Chunye Xu, Sc.D., a chemical
engineer at the University of Washington and associate director of the
University’s Center for Intelligent Materials and Systems (C.I.M.S.).
The lenses of the ‘smart’ sunglasses feature a
unique type of electrochromic polymer that has the ability to change
levels of darkness and color in the presence of an electric current.
Researchers have been developing electrochromic polymers for decades,
but Xu’s lab is one of just a few using the technology to develop
improved eyewear.
Xu has developed a prototype of the eyewear that
demonstrates the feasibility of these color-changing sunglasses.
Powered by a tiny battery, the prototype shades currently resemble a
pair of laboratory goggles with a button attached to the frame.
Turning the button activates the battery and dials up the desired
color, the researcher says. Ultimately, the sunglasses can be
manufactured to resemble the size and shape of regular sunglasses and
should cost about the same, according to Xu.
In laboratory demonstrations, Xu has shown the
lenses can switch from transparent to blue, plus various shades in
between, at the flip of a switch. “We are working on a multicolored
device as well, but no prototype is available yet,” she says.
As the glasses require power only during switching,
the device saves energy and prolongs battery life. Like regular
sunglasses, they also can be coated with a protective layer to block
ultraviolet light.
Fashion-conscience shoppers will have to wait a
little while for this latest thing in eyewear: A practical version of
the ‘smart’ sunglasses won’t be available to consumers for another one
to two years, says Xu, whose lab has filed several patents related to
the color-changing glasses. More testing is needed, she notes.
So far, Xu and her associates have produced the
electrochromic polymers in red, blue and green. By combining the
polymers of different colors into multiple layers and supplying
different levels of current from the batteries in the sunglasses, a
wide variety of different colors can be produced in the lenses, Xu
says. Funding for the study was provided by the University of
Washington. |
