Imagine popping in your contact lens then finding yourself inside your favourite video game or on a virtual vacation. Think of what it would be like if you could blink your eyes and surf the web without a computer or even a handheld device. Or, how cool would it be if you could look up obscure IMDB movie trivia (that no one else could see) in the middle of an argument by simply rolling your eyes in exasperation?
These super-human abilities may soon be a reality thanks to a new technology which is equipping contact lenses with bionic power!
Did you know? By age 13, even as early as age 11, most eyes are developed enough for contact lenses.
Engineers in the lab of Babak Parviz, at the University of Washington in Missouri are able to imprint tiny electronic circuits capable of generating visual displays onto flexible, safe contact lenses. When you look through the lens, you can see an electronically generated image superimposed on the real world. The applications are as many as you can dream up even though the research is still in preliminary stages.
The challenge in constructing these devices is to combine the delicate flexible polymers of contact lenses, typically made out of silicone hydrogels, with electrical circuits and light-emitting diodes (LEDs). The circuits are made from very thin metal layers, a few nanometres (millionths of a millimetre) thick, and diodes that are one third of a millimetre cross. That's less than the thickness of a human hair!
Did you know? Nanotechnology is a broad field which theme is the control of matter at the nano scale(generally 100 nanometres or smaller), and the creation of devices with dimensions that lie within that size range.
These tiny pieces, which appear like a powder, have a very precise geometry that allows them to slide into exact position when pulled together by capillary action — the force that draws water into a plant or paper towel. This"self assembly", as it is called, means that the heat and caustic chemicals involved in traditional soldering of circuitry can be avoided.
Did you know? The new bionic lenses are not designed to correct vision. Instead, they allow users to zoom in on objects and display data.
Since in normal vision, the transparent part of the eye (i.e. the cornea) is needed to bend light to focus an image, much of the electronics have been developed to be placed outside this region so that the person's view wouldn't be obstructed — that is, placed in the eye's natural blind spots.
To date, researchers have only been able to really demonstrate that the electric circuits can be assembled on the lens and that they appear safe when tested on rabbits so there's lots more work to be done. One issue which researchers are still working on is actually seeing the image or data — as it will be difficult to see an image that is formulated directly on the lens, members of the research team are trying to manipulate the light so that the image appears further away. The other is powering the lenses up and seeing if they actually work!
And how exactly would you go about powering a circuit if it's in your eye? One idea has been to power the circuits by solar cells on the lens itself. Another idea is to use radio-frequency energy in which an electric current would be generated in wire coils within the lens in response to an electromagnetic field.
So what does the future potentially hold for bionic lenses other than fun and games? Eventually, researchers hope to add wireless communication to and from the lens making possible internet access or to create"smart" displays that interact with the environment to, for example, enhance visual details of distant objects.
Another intriguing possible use for the lens would be to sample the biochemical environment, i.e. the surface of the eye, and relay health information such as glucose for a diabetic or potassium for a patient who takes potassium-wasting diuretic medication...all while allowing the patient to win that movie argument!!!
Article first published June 2, 2008
The research was presented in January 2008 at the Institute of Electrical and Electronics Engineers' International conference on Micro Electromechanical Systems and was funded by the National Science Foundation and the Technology Gap Innovation Fund from the University of Washington.
Dr. Hasini Reddy is a Rhodes Scholar whose PhD research focused on brain imaging techniques (University of Oxford, England). She completed her medical degree at Memorial University (St. John’s, ND), and is now a medical resident at the University of Western Ontario specializing in neurology and pathology. She enjoys reading, traveling and horseback riding.