Every part of the human body is a wonder of evolution, but eyeballs are particularly amazing. A human eye can see a huge range of color with spectacular clarity, refocus between objects over huge distances, and quickly adapt to large changes in lighting. Building a bionic replacement is, therefore, an extremely complicated undertaking. It’s just one step towards that goal, but University of Minnesota researchers have now 3D-printed an array of light receptors onto a hemispherical surface.
The goal is to eventually achieve the ability to fabricate complete bionic eyes and restore the vision of some blind people. Blindness can be caused by either damage to the eyes themselves, or by neurological issues. So, a bionic eye would only help the former, but that would still be a major breakthrough that could help a lot of people. Actually interfacing a bionic eye with the brain will be the biggest challenge, but this is important progress on the road to making it happen.
That progress is in the fabrication of light receptors, and for that the researchers turned to 3D printing. They started with a glass hemisphere that would make up half of a complete bionic eyeball. They then 3D-printed a structure of silver particles onto the curved surface of the glass. With that structure in place, they printed semiconducting polymer in order to create photodiodes. Those act as the synthetic equivalent of the rods and cones in your eye. Eventually, the process could be refined to fabricate the basic components needed to create a functioning artificial eye.