3D printing of multimaterial objects is an emerging field
with
promising applications. The layer-by-layer material addition technique
used in 3D printing enables incorporation of distinct functionalized
materials into the specialized devices. However, very few studies
have been performed on the usage of multimaterial 3D printing for
printable photonic and wearable devices. Here, we employ vat photopolymerization-based
3D printing to produce multimaterial contact lenses, offering enhanced
multiband optical filtration, which can be valuable for tackling ocular
conditions such as color blindness. A combination of hydroxyethyl
methacrylate (HEMA) and polyethylene glycol diacrylate (PEGDA) was
used as the base hydrogel for 3D printing. Atto565 and Atto488 dyes
were added to the hydrogel for wavelength filtering, each dye suitable
for a different type of color blindness. Multimaterial disks and contact
lenses, with separate sections containing distinct dyes, were 3D-printed,
and their optical properties were studied. The characteristics of
multimaterial printing were analyzed, focusing on the formation of
a uniform multimaterial interface. In addition, a novel technique
was developed for printing multiple dyed materials in complex lateral
geometrical patterns, by employing suitable variations in CAD models
and the UV curing time. It was observed that the multimaterial printing
process does not negatively affect the optical properties of the contact
lenses. The printed multimaterial contact lenses offered a combined
multi-band color blindness correction due to the two dyes used. The
resulting optical spectrum was a close match to the commercially available
color blindness correction glasses.