
A brand new sensible contact lens has been developed that may present navigation info by way of augmented actuality. The lens is hooked up to the human eye like a standard contact lens and makes use of a 3D printing course of for its core know-how.
Core 3D printing course of know-how for sensible contact lenses that may implement augmented actuality (AR)-based navigation has been developed by Dr. Seol Seung-Kwon’s Sensible 3D Printing Analysis Workforce on the Korea Electrotechnology Analysis Institute (KERI) and Professor Lim-Doo Jeong’s group at Ulsan Nationwide Institute of Science and Know-how (UNIST).
A sensible contact lens is a product hooked up to the human eye like a standard lens and gives numerous info. Analysis on the lens is being carried out primarily on diagnosing and treating well being. Lately, Google and others are creating sensible contact lenses for shows that may implement AR. Nonetheless, many obstacles to commercialization exist on account of extreme technical challenges.

Picture displaying meniscus phenomenon. Credit score: Korea Electrotechnology Analysis Institute
In implementing AR with sensible contact lenses, electrochromic[1] shows that may be pushed with low energy are appropriate, and “Pure Prussian Blue” colour, with excessive value competitiveness and fast distinction and transition between colours, is attracting consideration because the lens’ materials. Nonetheless, previously, the colour was coated on the substrate within the type of a movie utilizing the electrical plating technique[2], which restricted the manufacturing of superior shows that may categorical numerous info (letters, numbers, photographs).”
The achievement of KERI-UNIST lies in the truth that it’s a know-how that may understand AR by printing micro-patterns on a lens show utilizing a 3D printer with out making use of voltage. The bottom line is the Meniscus of used ink. The Meniscus is a phenomenon by which a curved floor is fashioned on the outer wall with out water droplets bursting on account of capillary motion when water droplets are gently pressed or pulled with a sure stress.

Crystallization of FeFe(CN)6 happens on the substrate in a area confined by the meniscus, forming the uniform sample. FeFe(CN)6 sample is transformed to the PB (Fe4[Fe(CN)6]3) by way of thermal discount. Credit score: Korea Electrotechnology Analysis Institute
Prussian blue is crystallized by way of solvent evaporation within the Meniscus fashioned between the micronozzle and the substrate. The meniscus of the acidic-ferric-ferricyanide ink is fashioned on the substrate when the ink-filled micronozzle and substrate are available in contact. Heterogeneous crystallization of FeFe(CN)6 happens on the substrate throughout the meniscus by way of spontaneous reactions of the precursor ions (Fe3+ and Fe(CN)3-) at room temperature. Concurrently, the solvent evaporation occurrs on the meniscus floor. When water evaporates from the meniscus, the water molecules and precursor ions transfer towards the meniscus floor by convective circulation, producing a preferential accumulation of the precursor ions within the outer a part of the meniscus. This phenomenon induces the edge-enhanced crystallization of FeFe(CN)6; that is essential for controlling the elements that affect the crystallization of FeFe(CN)6 within the printing step to acquire uniformly printed PB patterns on a substrate. As with typical electroplating, the substrate used to must be a conductor when voltage was utilized, however an amazing benefit of utilizing the meniscus phenomenon is that there isn’t any restriction on the substrate that can be utilized as a result of crystallization happens by pure evaporation of the solvent.

Picture presents a schematic of the PB-based EC show with a navigation operate in an AR sensible contact lens that exhibits instructions to the vacation spot to a person on the EC show by receiving GPS coordinates in actual time. Credit score: Korea Electrotechnology Analysis Institute
By the exact motion of the nozzle, the crystallization of Prussian blue is constantly carried out, thereby forming micro-patterns. Patterns may be fashioned not solely on flat surfaces but additionally on curved surfaces. The analysis group’s micro-pattern know-how may be very nice (7.2 micrometers) that may be utilized to sensible contact lens shows for AR, and the colour is steady and uniform.
The principle anticipated software space is navigation. Just by carrying a lens, navigation unfolds in entrance of an individual’s eyes by way of AR. Video games equivalent to the favored ‘Pokemon Go’ may also be loved with sensible contact lenses, not smartphones.
Dr. Seol Seung-Kwon’s of KERI mentioned, “Our achievement is a growth of 3D printing know-how that may print purposeful micro-patterns on non-planner substrate that may commercialize superior sensible contact lenses to implement AR.” He added, “It should tremendously contribute to the miniaturization and flexibility of AR units.”

Cowl picture of Superior Science Meniscus-guided micro-printing of Prussian Blue is realized by the localized crystallization of FeFe(CN)6 on the substrate confined by the ink meniscus and thermal discount of the crystallized FeFe(CN)6. This technique is able to getting used as an electrochromic show to provide real-time instructions on an augmented actuality (AR) sensible contact lens system. Credit score: Korea Electrotechnology Analysis Institute
The associated analysis outcomes had been lately printed as a canopy article in Superior Science (IF 17.521/JCR 4.71%), a world-renowned tutorial journal within the discipline of supplies science, in recognition of its excellence.
The analysis group believes that this achievement will entice lots of consideration from firms associated to batteries and biosensors that require micro-patterning of Prussian blue in addition to the AR discipline, and plans to search out associated demand firms and promote know-how switch.
In the meantime, KERI is a government-funded analysis institute beneath the Ministry of Science and ICT’s Nationwide Analysis Council for Science and Know-how. Dr. Seol Seung-Kwon can be a professor on the KERI campus of the College of Science and Know-how (UST).
Notes
- Electrochromism: a phenomenon the place the colour of a substance modifications reversibly on account of an electrochemical response.
- Plating is the method of making use of a skinny layer of one other steel to enhance the floor situation of an object. On this course of, if electrical vitality is used, it’s known as ‘electroplating,’ and if chemical reactions are utilized with out electrical energy, it’s known as ‘electroless plating.’ Significantly electroplating is principally used within the manufacturing of bijou equivalent to rings.
Reference: “Meniscus-Guided Micro-Printing of Prussian Blue for Sensible Electrochromic Show” by Je Hyeong Kim, Seobin Park, Jinhyuck Ahn, Jaeyeon Pyo, Hayeol Kim, Namhun Kim, Im Doo Jung and Seung Kwon Seol, 28 November 2022, Superior Science.
DOI: 10.1002/advs.202205588