Engineers from the University of Delaware have developed a smart glass prototype that costs a fraction of the price of existing smart glass structures and can be 3D-printed.
Keith Goossen, an associate professor of electrical and computer engineering, and Daniel Wolfe, who earned a doctoral degree at the university last year, unveiled their prototype at the SPIE Smart Materials and Nondestructive Evaluation for Energy Systems IV conference in Denver.
“It performed better than we thought it would based on our theoretical understanding,” said Goossen. “There is a lot of interest in the capability this might represent.”
The prototype consists of a pair of plastic sheets separated by a thin cavity; the plastic contains structures that make the material retroreflective, enabling it to bounce light back to its source. The cavity is filled with methyl salicylate, a fluid often found in over-the-counter pain relief creams, with optical properties that match those of the plastic. When the two substances are combined, light can pass through and both plastic and filling become transparent, a process known as index matching.
The glass can switch from transparent to reflective a thousand times without degrading, and is estimated to cost one-tenth the price of competing smart glass structures to produce. The researchers are continuing to test the prototype, particularly between 3oF and 16oF, temperatures that can cause the fluid filling to freeze.
The prototype is 3D-printed, but Goossen is already considering scaling up the technology for commercial processes. He is an author of 82 patents, and works as a co-teacher of High Technology Entrepreneurship, a course teaching students how to overcome financial, legal, scientific and engineering issues faced by tech startups.
With smart glass being used in the Knaus Travelino campervan, a vehicle selling for US$22,800, the technology may prove lucrative in the future.