A new contact lens embedded with electronic circuits could be the seed for “bionic eyes” that can see displays overlaid on a person’s field of view, researchers say. The minute circuitry could aid the vision-impaired or could be used to create tiny but discernible readouts offering data such as driving directions or on-the-go Web surfing. Researchers at the University of Washington created the flexible, biologically safe lens—the first of its kind—using nano-scale manufacturing techniques. The results were presented January 17 at a meeting of the Institute of Electrical and Electronics Engineers in Tucson, Arizona.
“If it works, it would be fabulous,” said Blair MacIntyre, who heads the Georgia Institute of Technology’s Augmented Environments Lab.
MacIntyre, who was not involved in the new research, works on so-called augmented reality—techniques to overlay visual data using external devices such as headsets but a contact lens, he said, could eliminate the need for these bulkier viewing techniques.
Until recently, display circuitry couldn’t be made small and light enough to be placed on a contact lens without a noticeable increase in the lens’s weight.
“The nice thing about nanotechnology is that we can make all these parts really tiny,” said project leader Babak Parviz, an assistant professor of electrical engineering at the University of Washington. The first challenge was designing the surface of the lens so the electronics didn’t block regular vision.
The trick, Parviz said, was to place most of the minute components in the areas over the eye’s natural blind spots.
Perhaps the more pressing problem was how to attach the electronic components—each thinner than a human hair—to the delicate polymer of a contact lens. Direct placement would probably damage the lens and be too time consuming. Instead the team built separate, nano-size metal components and mixed them together so that they appeared like a fine powder.
This powder was then placed in a vial of fluid and poured over a pitted lens surface.
Each pit corresponded to a particular component, so as the mixture washed over the lens, the components found their positions.
A molecular adhesive force known as capillary action—the same property that allows plants to “suck up” water—locked the pieces into place.
The lenses were then put into the eyes of lab rabbits, which showed no signs of adverse effects after at least 20 minutes of wear.