In the future, people with certain vision disorders and even healthy eyed folks will have access to electronic contact lenses that can improve and augment native vision. There are already advancements in that direction, but the challenge of being able to embed tiny electronic components into such a small space may be the biggest hurdle. Now researchers at Princeton University have reported in journal Nano Letters the ability to use 3D printing to produce multi-color LEDs on contact lenses.
The LEDs are made out of quantum dot nanoparticle crystals, the size of which defines which color they will generate. These lenses still require an external power source to operate, but the proof of concept study effectively demonstrates that 3D printing is a viable technology to help miniaturize electronics for use in medical and other applications.
From the study abstract in Nano Letters:
Here, we show that diverse classes of materials can be 3D printed and fully integrated into device components with active properties. Specifically, we demonstrate the seamless interweaving of five different materials, including (1) emissive semiconducting inorganic nanoparticles, (2) an elastomeric matrix, (3) organic polymers as charge transport layers, (4) solid and liquid metal leads, and (5) a UV-adhesive transparent substrate layer. As a proof of concept for demonstrating the integrated functionality of these materials, we 3D printed quantum dot-based light-emitting diodes (QD-LEDs) that exhibit pure and tunable color emission properties. By further incorporating the 3D scanning of surface topologies, we demonstrate the ability to conformally print devices onto curvilinear surfaces, such as contact lenses. Finally, we show that novel architectures that are not easily accessed using standard microfabrication techniques can be constructed, by 3D printing a 2 × 2 × 2 cube of encapsulated LEDs, in which every component of the cube and electronics are 3D printed. Overall, these results suggest that 3D printing is more versatile than has been demonstrated to date and is capable of integrating many distinct classes of materials.
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