An associate professor at the University of Minnesota, Michael McAlpine, has designed the latest prototype for a rudimentary bionic eye, and it could actually lead to versions capable of replacing the real thing.
The team began to build the prototype with a hemispherical glass dome, similar in size and shape to the back of a human eye. Using a custom-built 3D printer, they then added stripes of an ink containing silver particles; the ink successfully dried in place, as opposed to running down the inside of the dime and pooling at the bottom. Over the top of that ink base, a printed layer of semiconducting polymer was added.
The result was an array of 3D-printed photodiodes, which are capable of converting light into an electrical current with an efficiency of 25 per cent. McAlpine's team is now planning on boosting that efficiency, and incorporating many more of the photodiodes into a single dome. Ultimately, it is hoped that the technology could be used to create a fully-functioning bionic eye, which would restore a blind recipient's vision by stimulating their optic nerve in response to perceived light.
Additionally, the scientists are looking at ways of printing the photodiodes onto a soft hemispherical material, which could be the next prototype, that could be surgically implanted into the back of a patient's existing eye, where it would replace the retina.
A paper on the research can be found in the journal Advanced Materials, while the 3D-printing process can be seen in the video below. McAlpine has brought us 3D-printed items such as skin-mounted electronics, guides for nerve regeneration, spinal-cord-injury "bridges," and model internal organs upon which surgeons could practice.