Google Glass may soon get a competitor, according to Technology Review. An electronic contact lens that will give users a display directly on their cornea is being researched. In the past, it was not possible to develop electronic contact lenses because of the kind of material that was available. Using the expertise of researchers from several institutions, along with two research wings of Samsung, research into new forms of nanomaterials have taken steps to address that.
Using a transparent and conductive combination of graphene and silver nanowires, researcher Jang-Ung Park, along with a group of researchers, was able to put a light-emitting diode on a custom-made soft contact lens. Researchers were able to test these lenses on rabbits, which share a similar eye structure with humans, and found that there were no side-effects after 5 hours of use. While the electronics kept working, the animals did not show any sign of irritation.
In the past, a few companies and researchers have been working on electronic contact lenses. While Switzerland’s Sensimed makes lenses for 24-hour monitoring of eye pressure in glaucoma patients, other researchers, including University of Washington and Google Glass project founder Babak Parviz, have built contact-lens displays. The drawback here is that these devices use rigid or nontransparent materials.
Researchers are looking at constructing electronic contact lenses using new nanomaterial..
Park wants to make contact lenses that will be able to work like a wearable computer using transparent and soft material. “Our goal is to make a wearable contact-lens display that can do all the things Google Glass can do,” Park said in a conversation with Technology Review. The only thing that was holding researchers back was the lack of a transparent, highly conductive material that was also flexible.
The choices in conventional rigid electronics proved problematic. The use of indium tin oxide was out of the question because of its brittle structure as well as the need for high temperatures to fix it onto the lens. Other organic conductors like graphene and nanowires, while being flexible and transparent enough, were not as conductive as needed.
Researchers worked on this to come up with an elegant solution. While working with Sung-Woo Nam of the University of Illinois at Urbana-Champaign, Park found that putting silver nanowires between sheets of graphene gave a material that had a much lower electrical resistance than either material showed when tested alone. While the industry standard for the resistance a transparent conductor should have stands at 50 ohms per square or less, the new material has a resistance of about 33 ohms per square, according to Nam.
Researchers were able to create these computers using liquid solutions of the nanomaterials which are put on a spinning surface, like the contact lens, at low temperatures. While the contact lens cannot yet be called a display, the material being used may be a necessary component in the construction of future contact-lens displays, according to Herbert De Smet, who works on electronic contact lenses at Ghent University in Belgium but was not involved with the work.
The applications of electronic contact lenses seem far-reaching. Nam is currently working on using the conductors to construct biosensors that can monitor health conditions by sampling the chemistry of the eye’s tear film. Another application being looked at is actively filtered light to compensate for vision problems.
Publish date: June 12, 2013 12:50 pm| Modified date: December 19, 2013 12:01 pm