A smart contact lens is a product attached to the human eye like a normal lens and provides various information. Research on the lens is being conducted mainly on diagnosing and treating health. Recently, Google and others are developing smart contact lenses for displays that can implement AR. Still, many obstacles to commercialization exist due to severe technical challenges. In implementing AR with smart contact lenses, electrochromic[1] displays that can be driven with low power are suitable, and “Pure Prussian Blue” color, with high price competitiveness and quick contrast and transition between colors, is attracting attention as the lens’ material. However, in the past, the color was coated on the substrate in the form of a film using the electric plating method[2], which limited the production of advanced displays that can express various information (letters, numbers, images).” The achievement of KERI-UNIST lies in the fact that it is a technology that can realize AR by printing micro-patterns on a lens display using a 3D printer without applying voltage. The key is the Meniscus of used ink. The Meniscus is a phenomenon in which a curved surface is formed on the outer wall without water droplets bursting due to capillary action when water droplets are gently pressed or pulled with a certain pressure.
Through the precise movement of the nozzle, the crystallization of Prussian blue is continuously performed, thereby forming micro-patterns. Patterns can be formed not only on flat surfaces but also on curved surfaces. The research team’s micro-pattern technology is very fine (7.2 micrometers) that can be applied to smart contact lens displays for AR, and the color is continuous and uniform. The main expected application area is navigation. Simply by wearing a lens, navigation unfolds in front of a person’s eyes through AR. Games such as the popular ‘Pokemon Go’ can also be enjoyed with smart contact lenses, not smartphones. Dr. Seol Seung-Kwon’s of KERI said, “Our achievement is a development of 3D printing technology that can print functional micro-patterns on non-planner substrate that can commercialize advanced smart contact lenses to implement AR.” He added, “It will greatly contribute to the miniaturization and versatility of AR devices.” The related research results were recently published as a cover article in Advanced Science (IF 17.521/JCR 4.71%), a world-renowned academic journal in the field of materials science, in recognition of its excellence. The research team believes that this achievement will attract a lot of attention from companies related to batteries and biosensors that require micro-patterning of Prussian blue as well as the AR field, and plans to find related demand companies and promote technology transfer. Meanwhile, KERI is a government-funded research institute under the Ministry of Science and ICT’s National Research Council for Science and Technology. Dr. Seol Seung-Kwon is also a professor at the KERI campus of the University of Science and Technology (UST). Notes Reference: “Meniscus-Guided Micro-Printing of Prussian Blue for Smart Electrochromic Display” by Je Hyeong Kim, Seobin Park, Jinhyuck Ahn, Jaeyeon Pyo, Hayeol Kim, Namhun Kim, Im Doo Jung and Seung Kwon Seol, 28 November 2022, Advanced Science.DOI: 10.1002/advs.202205588
