[tt] Contact lenses with circuits, lights a possible platform for superhuman vision

[Brian Atkins]

http://www.eurekalert.org/pub_releases/2008-01/uow-clw011708.php

Movie characters from the Terminator to the Bionic Woman use bionic eyes to zoom 
in on far-off scenes, have useful facts pop into their field of view, or create 
virtual crosshairs. Off the screen, virtual displays have been proposed for more 
practical purposes – visual aids to help vision-impaired people, holographic 
driving control panels and even as a way to surf the Web on the go.

The device to make this happen may be familiar. Engineers at the University of 
Washington have for the first time used manufacturing techniques at microscopic 
scales to combine a flexible, biologically safe contact lens with an imprinted 
electronic circuit and lights.

"Looking through a completed lens, you would see what the display is generating 
superimposed on the world outside," said Babak Parviz, a UW assistant professor 
of electrical engineering. "This is a very small step toward that goal, but I 
think it's extremely promising." The results were presented today 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 Sandia National Laboratories in Livermore, Calif. Other 
co-authors are Ehsan Saeedi and Samuel Kim in the 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. 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 multi-disciplinary UW group that 
is developing electronics for contact lenses.

The prototype device contains an electric circuit as well as red light-emitting 
diodes 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.

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. Researchers built the 
circuits from layers of metal only a few nanometers thick, about one thousandth 
the width of a human hair, and constructed light-emitting diodes 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," 
according to Parviz.

-- 
Brian Atkins
Singularity Institute for Artificial Intelligence
http://www.singinst.org/