Contacts for Bionic Vision
SEATTLE, Wash., Jan. 18, 2008 -- For the first time, engineers have used microfabrication techniques to combine a flexible, biologically safe contact lens with an imprinted electronic circuit and lights. The lens could serve as a platform for the kind of superhuman vision -- the ability to zoom in on far-off scenes, have useful facts pop up in the field of view and create virtual crosshairs -- demonstrated in science fiction by characters such as the Bionic Man and the Terminator.
"Looking through a completed lens, you would see what the display is generating superimposed on the world outside," said Babak Parviz, a University of Washington (UW) assistant professor of electrical engineering. "This is a very small step toward that goal, but I think it's extremely promising."
A researcher holds one of the completed lenses that contain an imprinted electronic circuit and lights. The lens, created by engineers at the University of Washington, could serve as a platform for achieving superhuman vision seen now only in science fiction. (Images courtest University of Washington)
The results were presented yesterday at the Institute of Electrical and Electronics Engineers' international conference on Micro Electro Mechanical Systems by Harvey Ho, a former graduate student of Parviz's now working at the Sandia National Laboratories in Livermore, Calif. Other co-authors are Ehsan Saeedi and Samuel Kim in UW's electrical engineering department and Tueng Shen in the UW Medical Center's ophthalmology department.
There are many possible uses for virtual displays. Drivers or pilots could see a vehicle's speed projected onto the windshield. Video-game companies could use the contact lenses to completely immerse players in a virtual world without restricting their range of motion. People with sight problems could be provided with visual aids. And for communications, people on the go could surf the Internet on a midair virtual display screen that only they would be able to see.
"People may find all sorts of applications for it that we have not thought about. Our goal is to demonstrate the basic technology and make sure it works and that it's safe," said Parviz, who heads a multidisciplinary UW group that is developing electronics for contact lenses.
The prototype device contains an electric circuit as well as red LEDs for a display, though it does not yet light up. The lenses were tested on rabbits for up to 20 minutes and the animals showed no adverse effects, the researchers said.
Ideally, installing or removing the bionic eye would be as easy as popping a contact lens in or out, and once installed the wearer would barely know the gadget was there, Parviz said.
Building the lenses was a challenge because materials that are safe for use in the body, such as the flexible organic materials used in contact lenses, are delicate. Manufacturing electrical circuits, however, involves inorganic materials, scorching temperatures and toxic chemicals.
Contact lenses with metal connectors for electronic circuits were safely worn by rabbits in lab tests.
Researchers built the circuits from layers of metal only a few nanometers thick, about one thousandth the width of a human hair, and constructed LEDs one third of a millimeter across. They then sprinkled the grayish powder of electrical components onto a sheet of flexible plastic. The shape of each tiny component dictates which piece it can attach to, a microfabrication technique known as self-assembly. Capillary forces -- the same type of forces that make water move up a plant's roots, and that cause the edge of a glass of water to curve upward -- pull the pieces into position.
The prototype contact lens does not correct the wearer's vision, but the technique could be used on a corrective lens, Parviz said. And all the gadgetry won't obstruct a person's view.
"There is a large area outside of the transparent part of the eye that we can use for placing instrumentation," Parviz said. Future improvements will add wireless communication to and from the lens. The researchers hope to power the whole system using a combination of radio-frequency power and solar cells placed on the lens, Parviz said.
A full-fledged display won't be available for a while, but a version that has a basic display with just a few pixels could be operational "fairly quickly," said Parviz.
The research was funded by the National Science Foundation and a Technology Gap Innovation Fund from the University of Washington.
For more information, visit: www.uwnews.org
- A transparent optical component consisting of one or more pieces of optical glass with surfaces so curved (usually spherical) that they serve to converge or diverge the transmitted rays from an object, thus forming a real or virtual image of that object.
- The technology of generating and harnessing light and other forms of radiant energy whose quantum unit is the photon. The science includes light emission, transmission, deflection, amplification and detection by optical components and instruments, lasers and other light sources, fiber optics, electro-optical instrumentation, related hardware and electronics, and sophisticated systems. The range of applications of photonics extends from energy generation to detection to communications and...
- The processes in which luminous energy incident on the eye is perceived and evaluated.
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