In the future we will wear computers. The Google Glasses, true PCs “disguised” as eyeglasses, will soon land on the market and allow to browse the web and watch real-life images supported by information collected from the web – as well as to make phone calls, take photos , and shoot videos – using voice recognition software and touch surfaces.
While this sounds like futuristic innovation, some researchers are already trying to reach beyond it. A team of the Uslan National Institute of Science and Technology (Korea), headed by engineer Jang-Ung Park, is working to create contact lenses that may reproduce the same features as the Google Glasses without the bulk of the frame.
Soft and clear, these lenses would have a built-in LED display capable to convey information, correct visual defects, and monitor the eyes’ health. In order to achieve this ambitious objective, flexible, transparent, and conductive nanoelectrodes need to be inserted into the lens, but these are not easy to find.
According to the MIT Technology Review, in the last 5 years some companies developed electronic contact lenses, for example for non-stop eye pressure monitoring in patients with glaucoma. However these are stiff or non-transparent devices. Indium tin oxide is generally used as a conductor in these cases, however with some drawbacks: it is brittle and needs to be deposited at high temperatures, which may damage the lens. Other organic conductors, such as graphene or nanothreads (metal “wires” with a nanometric section), are flexible and transparent, but not enough conductive.
However Park, in co-operation with his peer Sung-Woo Nam of the Illinois University at Urbana-Champaign and with researchers at Samsung, found that sheets of graphene can be overlapped to layers of silver nanothreads to obtain a compound with a much lower electric resistance compared to the individual materials. Moreover, this nanostructure can convey 94% of visible light, and can be extended and integrated with other surfaces at low temperature. Thus, it is ideal for the intended purpose.
A soft contact lens was therefore coated with a liquid solution of the new elastic conductor, and a LED was applied to its end. While this cannot be defined as a display, being a single pixel, this discovery, published in the prestigious scientific review Nanoletters, lays the foundations to develop future computerized contact lenses.
Someday, such devices could be used in medicine as biosensors to analyze the chemical composition of tears and monitor the patient’s health conditions, as well as filters to correct visual defects.
: MIT Technology Review
The Editorial Staff
Published on Monday, June 10, 2013