Wednesday, February 20, 2008

LED Contact Lense

Researchers at the University of Washington in Seattle have developed a prototype contact lens that incorporates an imprinted electronic circuit and lights. The prototype is a step toward creating a form of bionic vision, the researchers say.

The researchers say the flexible lens is biologically safe and was worn by rabbits for up to 20 minutes with no adverse effects. Along with a circuit, the prototype contains red LEDs for a display, though it does not yet light up. The display could potentially create a surface for Web surfing in midair, flash a vehicle's speed to a driver, or immerse someone in a virtual world, the university said.

The prototype lens does not correct vision, but the researchers say that it could someday offer "visual aids" to help people with vision problems.

Don't expect to get one of these from your optometrist anytime soon, though. Babak Parviz, a professor of electrical engineering who is leading the research, called the prototype a "very small step" toward a completed lens. Still, Parviz is optimistic that creating a version with a basic display just a few pixels wide should happen "fairly quickly."

Despite the display being on the cornea of the eye, the image it shows would appear to be on an exterior object such as the windshield of a car, or might even seem to be in midair for people browsing the Internet or immersing themselves in a virtual world.

"Looking through a completed lens, you would see what the display is generating superimposed on the world outside," Parviz said in a statement when the research was made public last week. The images wouldn't obstruct a wearer's view, researchers added. "There is a large area outside of the transparent part of the eye that we can use for placing instrumentation," Parviz said.

The circuits in the lens are just a few nanometers thick, and the light-emitting diodes are one-third of a millimeter across. Working on this tiny scale, the researchers used a microfabrication technique known as self-assembly, in which a component's shape dictates how and where it attaches on top of a flexible plastic sheet.

As the team continues to work on the basic technology, it hopes to add wireless communication capabilities and to provide power to the system using both radio-frequency techniques and solar cells placed on the lens.

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