How do you like the idea of scanning data and taking pictures with your contact lenses? It may sound like something out of a sci-fi book or film but such lenses already exist thanks to the hybrid electrode developed by Korean scientists from the Ulsan National Institute of Science and Technology (UNIST).
As with every new invention, it may take a while to commercialise, but the leader of the research team, Professor Jang-Ung Park, believes that the hybrid structure has great potential in the area of flexible, wearable electronics and implantable bio-sensors.
Park and his team showed inorganic light-emitting diode (ILDED) devices attached to a soft contact lens through the transparent, stretchable interconnects of the hybrid electrodes. The demonstration involved a rabbit wearing the contact lens for five hours. There were no signs of any discomfort in the rabbit after the experiment, for example a bloodshot eye or eye rubbing.
The UNIST team has combined graphene with silver nanowires to create a thin, transparent and stretchable electrode. This combination has allowed the researchers to eliminate weaknesses associated with the individual materials. Transparent electrodes have actually been around for a while and are extensively used in touch screens, flat-screen TV sets, solar cells and light-emitting devices. However, the transparent electrodes produced at present are typically made from indium tin oxide (ITO). The material does its job adequately but is brittle, cracks easily and loses its functionality when flexed. In addition, ITO degrades over time and sparse supplies of indium make it somewhat expensive.