News | November 22, 2011

Terminator-Style Info-Vision Takes Step Towards Reality

The streaming of real-time information across your field of vision is a step closer to reality with the development of a prototype contact lens that could potentially provide the wearer with hands-free information updates.

In a study published recently, 22 November, in IOP Publishing's Journal of Micromechanics and Microengineering, researchers constructed a computerised contact lens and demonstrated its safety by testing it on live eyes. There were no signs of adverse side effects.

At the moment, the contact lens device contains only a single pixel but the researchers see this as a "proof-of-concept" for producing lenses with multiple pixels which, in their hundreds, could be used to display short emails and text messages right before your eyes.

The device could overlay computer-generated visual information on to the real world and be of use in gaming devices and navigation systems. It could also be linked to biosensors in the user's body to provide up-to-date information on glucose or lactate levels.

The contact lens, created by researchers at the University of Washington and Aalto University, Finland, consisted of an antenna to harvest power sent out by an external source, as well as an integrated circuit to store this energy and transfer it to a transparent sapphire chip containing a single blue LED.

One major problem the researchers had to overcome was the fact that the human eye, with its minimum focal distance of several centimetres, cannot resolve objects on a contact lens. Any information projected on to the lens would probably appear blurry.

To combat this, the researchers incorporated a set of Fresnel lenses into the device; these are much thinner and flatter than conventional bulky lenses, and were used here to focus the projected image on to the retina.

After testing the contact lens in free space, it was fitted to the eye of a rabbit, under the strict guidelines for animal use in the laboratory, to evaluate the effect of wearing the contact lens on the cornea and the body in general. In addition to visualising techniques, a fluorescent dye was added to the eye of the rabbit to test for any abrasion or thermal burning.

After demonstrating the operation and safety of the contact, the researchers state that significant improvements are necessary to produce fully functional, remotely powered, high-resolution displays. For instance, the device could be wirelessly powered in free space from approximately one metre away, but this was reduced to about two centimetres when placed on the rabbit's eye.

Co-author of the study, Professor Babak Praviz, said "We need to improve the antenna design and the associated matching network and optimize the transmission frequency to achieve an overall improvement in the range of wireless power transmission.

"Our next goal, however, is to incorporate some predetermined text in the contact lens."

From Tuesday 22 November, this paper can be downloaded from http://iopscience.iop.org/0960-1317/21/12/125014.

A single-pixel wireless contact lens display
The published version of the paper ‘A single-pixel wireless contact lens display' (Lingley A R et al 2011 J. Micromech. Microeng. 21 125014) will be freely available online from 22 November at http://iopscience.iop.org/0960-1317/21/12/125014.

Journal of Micromechanics and Microengineering
Journal of Micromechanics and Microengineering is a leading journal in its field, covering all aspects of microelectromechanical systems, devices and structures as well as micromechanics, microengineering and microfabrication. The journal publishes key research from around the world and is essential reading for all MEMS researchers.

About IOP Publishing
IOP Publishing provides publications through which leading-edge scientific research is distributed worldwide. IOP Publishing is central to the Institute of Physics (IOP), a not-for-profit society. Any financial surplus earned by IOP Publishing goes to support science through the activities of IOP. Beyond our traditional journals programme, we make high-value scientific information easily accessible through an ever-evolving portfolio of community websites, magazines, conference proceedings and a multitude of electronic services. Focused on making the most of new technologies, we're continually improving our electronic interfaces to make it easier for researchers to find exactly what they need, when they need it, in the format that suits them best. For more information, visit http://publishing.iop.org.

About The Institute of Physics
The Institute of Physics is a leading scientific society promoting physics and bringing physicists together for the benefit of all.

It has a worldwide membership of around 40 000, comprising physicists from all sectors, as well as those with an interest in physics. It works to advance physics research, application and education; and engages with policymakers and the public to develop awareness and understanding of physics. Its publishing company, IOP Publishing, is a world leader in professional scientific communications. For more information, visit www.iop.org.

SOURCE: The Institute of Physics