3D Printing of Multimaterial Contact Lenses

3D printing of multimaterial objects is an emerging fieldwithpromising applications. The layer-by-layer material addition techniqueused in 3D printing enables incorporation of distinct functionalizedmaterials into the specialized devices. However, very few studieshave been performed on the usage of multimaterial 3D printing forprintable photonic and wearable devices. Here, we employ vat photopolymerization-based3D printing to produce multimaterial contact lenses, offering enhancedmultiband optical filtration, which can be valuable for tackling ocularconditions such as color blindness. A combination of hydroxyethylmethacrylate (HEMA) and polyethylene glycol diacrylate (PEGDA) wasused as the base hydrogel for 3D printing. Atto565 and Atto488 dyeswere added to the hydrogel for wavelength filtering, each dye suitablefor a different type of color blindness. Multimaterial disks and contactlenses, with separate sections containing distinct dyes, were 3D-printed,and their optical properties were studied. The characteristics ofmultimaterial printing were analyzed, focusing on the formation ofa uniform multimaterial interface. In addition, a novel techniquewas developed for printing multiple dyed materials in complex lateralgeometrical patterns, by employing suitable variations in CAD modelsand the UV curing time. It was observed that the multimaterial printingprocess does not negatively affect the optical properties of the contactlenses. The printed multimaterial contact lenses offered a combinedmulti-band color blindness correction due to the two dyes used. Theresulting optical spectrum was a close match to the commercially availablecolor blindness correction glasses.