These examples show the contrast in colors that can be achieved using Sotzing’s new electrochromic method. |
Ever
looked thoughtfully at those PhotoGray sunglasses and wished they would
turn some other fun color? Like, say yellow? Or UConn blue?
Okay,
maybe you haven’t. But if you did, the technology is here, thanks to
Greg Sotzing, professor of chemistry in the College of Liberal Arts and
Sciences and member of UConn’s Polymer Program.
Not
only have he and his colleagues perfected a method for creating
quick-changing, variable colors in films and displays, such as
sunglasses, they’ve made them less expensive and less wasteful to
manufacture than any previous method. And aside from creating vanity
glasses, the technology is in high demand from the U.S. military.
“This is the next big thing for transition lenses,” Sotzing says.
The
typical material behind a transition lens is what’s called a
photochromic film, or a sheet of polymers that change color when light
hits them. Sotzing’s new technology does things slightly differently –
his electrochromic lenses are controlled by an electric current passing
through them when triggered by a stimulus, such as light.
“They’re
like double pane windows with a gap between them,” explains Sotzing. He
and his colleagues squirt a mixture of polymers – or as he calls it,
“goop” – in between the layers, creating the lens as it hardens. The
mixture of polymers used in this lens, says Sotzing, creates less waste
and is less expensive to produce than previous mixtures.
“The
lifetime of sunglasses is usually very short,” says Sotzing, who points
out that people often misplace them. So by making the manufacturing
less expensive, he says, commercial retailers will be able to produce
more of them.
Another
benefit of this material is that it can change colors as quickly as
electricity passes through it – which is virtually instantaneously. This
process could be very useful for the military, Sotzing says. For
example, if a person emerges from a dark passageway and into the desert,
a lens that would alter its color instantly to complement the
surroundings could mean life or death for some soldiers.
“Right
now, soldiers have to physically change the lenses in their goggles,”
Sotzing says. “This will eliminate that need.” Sotzing will begin a
one-year sabbatical at the Air Force Academy in August, where he hopes
to develop some of these ideas.
In
November 2010, partially based on work supported by the Center for
Science and Technology Commercialization’s Prototype Fund, the UConn
R&D Corporation started a company, called Alphachromics Inc., with
Sotzing and colleague Michael Invernale, now a post-doctoral researcher
at MIT, as founders. The university has a patent pending for this new
technology, which is currently under option to the company.
Alphachromics is also testing applications of these polymer systems for
energy-saving windows and custom fabrics.
Sotzing
and Alphachromics are currently in talks with sunglass manufacturers,
and Sotzing says that the world of Hollywood could be a market for this
technology. He describes applications he calls “freaky,” including
colors that move back and forth across the glasses, evoking styles like
those sported by Lady Gaga.
But
Sotzing stresses that the best thing about this technology is the
creation of business in Connecticut. Although the glasses may not be
made here, because the technology will be licensed to out of state
manufacturers, he hopes Alphachromics will continue to expand in
Connecticut.
“We don’t make the sunglasses,” he says. “We make the formulation of what goes inside.”
The
findings were published July 7 in the Journal of Materials Chemistry.
Sotzing’s collaborators on the paper are Invernale and Ph.D. students
Yujie Ding, Donna Mamangun and Amrita Kumar.
