Electronic Contact Lens promises bionic capabilities for everyone

January 22, 2008 It's not often in this era of rampant technological innovation that a fundamentally new concept surfaces – with almost no limitations to what can be achieved with the myriad new technologies coming to market over the last few years, fundamentally new ideas of this magnitude are becoming increasingly rare, much less technologies with groundbreaking societal implications. Such a technology emerged this week when it was announced that engineers at the University of Washington have used microscopic scale manufacturing techniques to combine a flexible contact lens with an imprinted electronic circuit and lights.

Though in its infancy, the combination of a wearable contact lens with embedded optoelectronic and electronic devices promises many things, most notably this could well be the beginning of the Computer Human Interface of the future.

The trend towards miniaturization of computers has now reached a roadblock due to our inability to adequately display the information they provide on smaller screens – the main limiting factor in relation to the ever-shrinking size of computers and telephones has become the size of the display – if it gets any smaller, we can't read it.

Currently, the most obvious solutions for further reduction in size of wearable computer-based devices are miniature projectors and externally worn heads up displays.

The amount of investment in miniaturized projector technologies bears testimony to the prospects for this market and we have seen numerous prototypes showcased recently by the likes of Microvision, 3M, Texas Instruments, Explay, Neochroma, Digislide, Light Blue Optics and from research labs such as the Fraunhofer Institute for Photonic Microsystems . Though the microprojection area promises the ability to project a large screen on any flat surface, we have yet to see commercially available products and the technology won't suit everyone, partially because they're still not quite small enough, and partially because of privacy issues – projecting delicate company information onto an airport terminal wall, for example, might not be a good idea.

Similarly, those heads up displays that have come to market are either prohibitively expensive or do not yet offer high resolution screens of sufficient clarity and stability to avoid the attendant migraine headaches. The promise is there for the near future, but one of the major drawbacks to mass adoption of these products is that not everybody wishes to look like a cyborg.

Accordingly, the University of Washington's contact lens offers the promise of a viable large screen display alternative for connecting users with their mobile devices. Project head and Assistant Professor of Electrical Engineering Babak Parviz envisages that his team's electronic contact lens will offer the ability to superimpose a transparent high resolution display over the field of vision of one, maybe both eyes of the wearer .

"Looking through a completed lens, you would see what the display is generating superimposed on the world outside," says Parviz.

Apart from the expectation of eventually offering a large screen display for our wearable and micro computers, PDAs and phones, the heads-up aspect of the contact lens leaves the way open for a democratization of Augmented Reality.

Unlike Virtual Reality, where the user's field of view is completely replaced with an artificial visual environment, Augmented Reality uses head tracking in conjunction with augmented vision to overlay complimentary information on the user's view.

The system can tell which direction the user is looking and adjusts the displayed image accordingly, displaying new and appropriate information for the scene being viewed. For example, when viewing a map, it may be beneficial to orient the map to the user's field of view so that the user can identify landmarks in the real world by their proximity to landmarks on the map.

Augmented Reality is already in use in a wide range of industrial applications due to the work of companies such as Arkiva which is used by technicians doing extremely complex work, enabling them to overlay instructions, circuit diagrams, mechanical drawings and the like over real-world tangles to ensure they get it right.

If the tools were readily available and in mass usage, a plethora of new applications for augmented reality would almost certainly come to light.

In tourism, for example, Augmented Reality would offer the ability to see the ancient ruins in Rome, overlayed with what the buildings originally looked like and for buildings to be labeled in a real/virtual mixed tour.

At a sporting event, players might be labeled, the ball/puck tracked, distances marked, and for certain professions, such as a surgeon, vital organs, veins and arteries could be delineated. Obviously, such capabilities would require additional technologies to come into play, but with wireless networking becoming ubiquitous, it's a possibility for the mid-term future.

Another aspect of AR is displaying vital information to someone who is actively involved in doing something where the need to refocus on a dashboard or set of instruments would impair that person's ability to perform their task. The heads up display was pioneered and significantly evolved in jet fighters, and has been trailed in Formula One and there are now commercially available systems on the market for racing drivers, motorcyclists and bicycle riders.

The Parviz team's contact lens would enable pervasive heads up displays in automobiles, which would significantly reduce accidents, even if it only helped people tune their radio or find the album they wanted on their iPod whilst driving.

Taking wireless technologies and the evolution of the UW Contact Lens even further, there's significant promise of using the contact lens displays in coordinating groups of people to work more effectively in teams, the most likely first up usage for this being for military personnel on the battlefield and for disaster response teams in a crisis where saving time and doing things efficiently means saving lives.

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.

Bionic Zoom Vision

One of the aspects of the UW Contact Lens most likely to capture the imagination of the public is its promise of bionic vision, popularized in mass market science fiction such as the Terminator movie series where Arnold Schwarzenegger's cyborg character and his cyborg combatants demonstrated the ability to zoom in on distant objects, as did Lee Majors' character Steve Austin in the Six Million Dollar Man television series.

"Using nanotechnology you can extend the sophistication of the contact lens as far as you like," says Parviz. "There is interest in including cameras on the contact lens and incorporating other lenses so that, for example, if you were looking at something very small, you would be able to zoom in to get a closer look. Similarly, if something is far away, you would be able to zoom in."

With an array of lenses wirelessly connected to a wearable computer, there's obviously the capability of "recording images" says Parviz. We prompt him on the possibility of recording in real time what we see, and he adds that there are many uses for the technology they are developing that have not yet been explored, and indeed, that there are uses they almost certainly haven't even thought of.

Once again, the military and law enforcement domains are the most likely to pony up the dollars for real-time recording of critical encounters, but the possibilities are almost endless once someone is wearing such a contact lens – could it be that at some point in the future, those "this conversation could be recorded for training purposes" on-hold telephone announcements (warnings) might be applicable to every conversation with a customer service representative?

With the ability to record everything we see, which the UW Contact lens will ultimately enable, the concept of privacy, instant recall and a whole host of new capabilities come into play – remember that reliable, solid state data storage is becoming more cost effective by the day. A decade from now, recording everything we say and do is now a distinct possibility.

Bio-sensing and a wearable health monitoring system

Perhaps the most left-field aspect to the UW study is the promise of a wearable health monitoring system. "The second big area that we are looking at is bio-sensing, because on the surface of the contact lens there are a lot of biomarkers already present that are important for monitoring health care," explains Parviz.

"We recognized that if we could have a contact lens that incorporated biosensors that could sample the biology of the eye we could constantly report it outside, and hence have a non-invasive way of putting people on continuous health monitoring."

Whatsmore, the system also has the capability of displaying the key indicators in real time to the wearer or a relevant third party as a personal dashboard via their heads up display.

How the project began

"The way this whole thing started," says Assistant Professor Babak Parviz, "was that we were looking at conventional contact lenses and we noticed that they were straightforward polymer structures. They do something useful in vision correction, but the structure of the system is simple – it's just one material."

"The expertise we have in our group surrounds nanotechnology and microfabrication which enables us to make a lot of very small, very useful devices, so we thought that if we could migrate all these devices onto a contact lens, we could get a lot more functionality out of this simple object that's used by millions of people. The contact lens is safe to use and people are quite comfortable with using them."

"We had a few things in mind. The first was that we could display some information – the level of the sophistication of the display would obviously be dependent on the sophistication of the technology we used. At its simplest, it might just be a single pixel that switched on and off and indicated something that's important to the user. Going several levels beyond that, it might be a high resolution display."

"There are a variety of applications in that domain once you have a reasonable degree of resolution in a display, such as augmented reality and computer generated images that you could superimpose over the outside world."

"Going beyond that, we could incorporate all sorts of optical devices on a contact lens. Obviously it needs to be remotely powered and it would communicate with outside devices via a wireless link."

"A fully functional high resolution display is still some way off," he says, explaining that the existing prototype lens contains an electric circuit as well as red light-emitting diodes for a display, and have been tested on rabbits with no adverse effects.

"Our immediate goal is to have a display that has only a few pixels to demonstrate the viability of the concept and after that we will work upwards towards increasing the resolution of the display but it will be some time yet before we have a fully functional hires display."

"This is a very small step toward that goal, but I think it's extremely promising."

"So those are all doable things that are on our agenda", says Parviz, referring to the array of technological possibilities mentioned elsewhere in this article, "but they're not easy to implement so they're all in the future still."

"What's interesting and encouraging is that a lot of these things have already been demonstrated independently so there are lots of different micro-lens designs already."

"These are lens that are exactly the right size, but they have never been incorporated into a contact lens so what's really encouraging is that a lot of these things exists and one of our hopes is that we have opened the venue of the contact lens to microelectronics – people thinking about contact lenses as a place where we can put elecronics and optoelectronics."

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. 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.

"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.

The results of the project to date were presented last week 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 were Ehsan Saeedi and Samuel Kim in the UW's electrical engineering department and Tueng Shen in the UW Medical Center's ophthalmology department.