The human eye is one of the fascinating pieces of engineering in the human body. Various researches have been conducted all over the world to understand the working of the eye and its reaction to external stimuli. In the past, humans were limited by the technological resources, however, now we are at a level where the technology is progressing at a breakneck speed. The latest achievement earned by the research team at the University of Minnesota, which is the development of a bionic eye, is clearly showing the pace with which the development is progressing. The team has printed 3D light receptors into a hemispherical surface. In case of an actual human eye, the light receptors are lined at the back of an eye while accommodating corneal fluids.
In an artificial eye, no fluid medium is needed to facilitate the vision by the light receptors. The complete research was summed up by the co-author of the study Michael McAlpine, Mechanical Engineer at the University of Minnesota. He said, “Bionic eyes are usually thought of as science fiction, but now we are closer than ever using a multi-material 3D printer.” The inspiration to develop the bionic eye came when the mother of the lead scientist lost her sight in a surgery. Micheal Alpine has been testing methods ever since to create a bionic eye which can give light to people who have spent a lot of their time in darkness. McAlpine said, “My mother is blind in one eye, and whenever I talk about my work, she says, ‘When are you going to print me a bionic eye?”
This is the first time that McAlpine worked in bionics since he has a portfolio of products which combine electronics, bionic and 3D printing. His team McAlpine & Co. has developed the artificial organs, bionic ears, bionic skin, etc. He also put up a patent for 3D printing semiconductors, but 3D printing on a curved surface is a difficult task as the ink will flow on the bent areas rather than sticking to the surface. To overcome this challenge, the researchers used a base ink of silver particles on the hemispherical dome. The ink managed to stay at the place and dried equally. After this, the researchers further used semiconducting polymer materials for printing photodiodes on the surface of the dome which is covering light into electrical signals which can be processed and turned into actual images.
When the research team tested the systems, it worked with nearly 25% efficiency and converted light signals into electrical signals, McAlpine said, “We have a long way to go to routinely print active electronics reliably, but our 3D-printed semiconductors are now starting to show that they could potentially rival the efficiency of semiconducting devices fabricated in microfabrication facilities. Plus, we can easily print a semiconducting device on a curved surface, and they can’t.” The team achieved their goal using a 3D printer which was built at home.