ОптоЕлектроника

‘Smart’ lenses with chameleon’s powers are driven by electrochromic polymer.

The so-called “smart” eyewear relies on an electrochromic polymer in the lens that can modify the level of shading or that can change color when prompted by an electrical current. The glasses are powered by a tiny commercial cell battery with a standard electric capacity of ∼100 coulombs. Turning a button mounted on the frame of the glasses activates the battery and allows the user to control the tint and opacity. The researchers said that the lens can be tuned to a colored state in one second and back to a completely transparent state in two seconds.

After more than 100,000 cycles of switching the lens between a transparent and colored state, the researchers found that the device had a less than 6 percent change in transmission on the colored state and almost no change on the transparent state. They also found that the device could stay in a colored or transparent state without any charge for 30 days. A single battery powered thousands of transitions.

Organic molecules allowed the researchers to create colored lenses.

"In organic materials, the elements are simple but the structure is much more complicated," Xu said. "We can add more branches to this structure and tune in colors."

The prototype glasses change from dark blue to light blue. Xu and her colleagues have developed other adjustable lenses in red and yellow. In the future, they will layer sheets to create a range of colors in a single pair of shades.