South Korean researchers developed graphene-coated contact lenses that can protect wearers from electromagnetic (EM) radiation and dehydration.

Chemical vapor deposition was used to synthesize a graphene layer on copper foil. The carbon sheet was then transferred onto the surface of a contact lens with the help of a polymer layer after etching the copper.

The smart graphene-coated lens. Courtesy: BH Hong/Seoul National UniversityThe smart graphene-coated lens. Courtesy: BH Hong/Seoul National UniversityThe EM wave-shielding properties of the coated lens were evaluated by placing it on egg whites exposed to strong EM waves inside a microwave oven. The EM energy was absorbed by the graphene layer and dissipated as heat, minimizing damage to the egg whites.

Thermal infrared images were obtained after applying EM radiation (of 120 W) to the samples for 20 seconds. The temperature of the graphene-coated contact lens rapidly increased to more than 45 °C, while a conventional lens barely registered a temperature increase.

The graphene layer also guards against dehydration: 30% less water evaporated from vials capped with the graphene-coated lens compared with vials covered with a non-coated one.

For diabetes diagnosis, the researchers from Seoul National University, Graphene Square Inc., and Interojo Inc. plan to integrate an active circuit with graphene-based sensors and electrodes for real-time wireless monitoring of glucose concentration in tears.

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