Researchers develop better instant color-change lenses
A team of researchers from University of Connecticut (UConn) perfected a method for creating quick-changing, variable colors in films and displays. They managed to make them less expensive and less wasteful to manufacture compared to any previous method. The technology could be used for displays, solar cells, OLEDs, transistors, vanity glasses, or glasses used by soldiers.
Typical material behind a transition lens is called a photochromic film – a sheet of polymers that change color when light hits them. Led by Greg Sotzing, professor of chemistry in the UConn’s College of Liberal Arts and Sciences, the team developed a technology which does things slightly differently. Their electrochromic lenses are controlled by an electric current passing through them when triggered by a stimulus.
The researchers inject a mixture of polymers in between the layers, which create the lens as it hardens. The novel approach of assembling polymer electrochromic devices avoids the tedious cleaning process of the substrates and produces almost no waste, making it more cost effective to produce than previous mixtures. It also offers simplicity in device construction and it is easily adapted to patterned systems.
By inkjetting insulating materials to mask the substrates, letters and high-resolution images could be achieved inside the converted polymer devices. Since the material can change colors as quickly as electricity passes through it, it could be very useful in situations where you need a fast adaptation to light variation.
For example, if a person emerges from a dark passageway and into the bright sunlight of the desert, a lens that would alter its color instantly to complement the surroundings could mean life or death in some situations. Sotzing will begin a one-year sabbatical at the Air Force Academy in August, where he hopes to develop some of the ideas for potential military applications.
In November 2010, Sotzing and colleague Michael Invernale, now a post-doctoral researcher at MIT, founded an UConn R&D Corp. company called Alphachromics. Aside searching for partners among sunglasses manufacturers, Alphachromics is testing applications of these polymer systems for energy-saving windows and custom fabrics.
For more information, you can read the article published in the Journal of Materials Chemistry named: “A simple, low waste and versatile procedure to make polymer electrochromic devices”.