LED lenses make eyes light upContact lenses with imprinted LEDs could benefit drivers, pilots, or patients with impaired vision.
A researcher holds one of the completed lenses.
Credit: University of Washington
The prototype lenses developed at the University of Washingtoninclude red light-emitting diodes and an electronic circuit, althoughtrials to date have focused on wearability studies and have notincluded turning on the LEDs. The lenses were tested on rabbits for upto 20 minutes and the animals were said to show no adverse effects.
"Looking through a completed lens, you would see what the display isgenerating superimposed on the world outside," said Babak Parviz of theUniversity of Washington. "This is a very small step toward that goal,but I think it's extremely promising."
Researchers built the circuits from layers of metal a few nanometersthick and LEDs one third of a millimeter across using microscopic-scalemanufacturing techniques. The shape of each tiny component dictatedwhich piece it could attach to, and a self-assembly process driven bycapillary action pulled the pieces into position on a sheet of flexibleplastic.
The trial lenses did not provide vision correction, but thetechnique could be used on a corrective lens and does not obstruct thewearer's vision. "There is a large area outside of the transparent partof the eye that we can use for placing instrumentation," said Parviz.
Contact lenses with metal connectors for electronic circuits were safely worn by rabbits in lab tests.
Credit: University of Washington
A full-fledged display will not be available for a while, but aversion with a basic display of just a few pixels could be operational"fairly quickly", according to Parviz. Other improvements in the futurecould include adding wireless communication to and from the lens. Theresearchers hope to power the whole system using a combination of radiofrequency power and solar cells placed on the lens.
Drivers or pilots wearing functioning lenses could see theirvehicle's speed projected ahead of them, while video-game players couldfeel themselves immersed in a virtual world without restrictions ontheir range of motion. Web surfers could see the internet on a virtualscreen visible only to them. "People may find all sorts of applicationswhich we have not thought about," said Parviz. "Our goal is todemonstrate the basic technology, and make sure that it works and thatit's safe."
