Researchers at the University of Minnesota have created for the first time through 3D printing a sensory light arrangement on a hemispherical surface – an achievement that is an important step toward creating a bionic eye that can allow blind people to see or visually impaired people to see better.
“Biodiversity is usually seen as a science fiction, but we are now closer than ever before, using a 3D multi-media printer,” said Michael McCallin, one of the researchers in the Advanced Materials and Associate Professor at the University.
The researchers began with a hemispherical glass dome to show how they were able to print electronically on a convex surface. Using their dedicated 3D printer, they began with a basic silver oxide ink. The ink remained in place and dried uniformly instead of sliding on the convex surface. The researchers then used semiconductor polymeric materials to print photodiodes that convert light into electricity. The whole process takes about an hour.
McAlpain noted that the most astonishing feature of the process is the 25% efficiency of light conversion to electricity, which was achieved with fully 3D printed semiconductors.
“We still have a long way to go until we can reliably print electronically, but our 3D print semiconductors are starting to show that they could potentially compete with the performance of semiconductor devices produced in microfabrication facilities,” he said. “We can also easily print a semiconductor device on a convex surface while they do not,” he added.
Mcalpin and his team are known for combining 3D printing, electronics and biology on a single platform: A few years ago they were internationally known for creating a “bionic ear”. Since then, they have made extremely realistic artificial instruments for surgeon training, an electronic cloth that could be used as a “bionic skin”, have printed electronically directly in hand on the move, and more.
However, for Makalpain the bionic eye was more personal, as his mother is blind from one eye. “My mother is blind to one eye, and when I tell her about my job, she tells me” when will you print me a bionic eye? “He said. The next steps of the researchers include creating a more efficient prototype with more light sensing, as well as finding a way of printing on soft, hemispherical material that can be implanted in real eyes.