Researchers from the University of Minnesota have made an important breakthrough in the development of a bionic eye. We’re not exactly talking about a Terminator-like bionic eye, but it does skew into the realm of science fiction, as the bionic eye could one day enable people with visual impairments to see better.
The breakthrough I mention consisted of 3D printing an array of light receptors onto a hemispherical surface. The achievement, which marks a first, was recently published in the journal Advanced Materials.
In developing the bionic eye, the research team started with a hemispherical glass dome on which they planned to 3D print electronics. Up until now, printing electronics onto a curved surface has remained a challenge. Thanks to a custom multi-material 3D printer, the team was able to achieve some success.
As a release about the project explains, the researchers started with a base ink made up of silver particles, which was deposited by the 3D printer. The specialized ink was designed to stay in place once dispensed and dry uniformly to prevent it from succumbing to gravity and running down the sides of the glass base.
Next, the team printed photodiodes onto the substrate using semiconducting polymer materials which function to convert light into electricity. Impressively, the team says it only takes about an hour to complete this printing process.
“Bionic eyes are usually thought of as science fiction, but now we are closer than ever using a multi-material 3D printer,” said Michael McAlpine, a co-author of the study and University of Minnesota Benjamin Mayhugh Associate Professor of Mechanical Engineering. He added that the 3D printed semiconductors have demonstrated a 25% efficiency when converting light into electricity, which he says surpassed the researchers expectations.
“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,” McAlpine elaborated. “Plus, we can easily print a semiconducting device on a curved surface, and they can’t.”
This is not the first time that McAlpine and the University of Minnesota have worked with bionic bodyparts, as the team gained attention a few years back for 3D printing a bionic ear. Leveraging their combined expertise in 3D printing, electronics and biology, the team has also printed artificial organs for pre-surgical practice, scaffolds, “bionic skin” made from an electronic fabric, and they have even printed electronics onto a moving hand.
According to McAlpine, whose mother is blind in one eye, the 3D printed bionic eye project is one of his most personal ventures yet. “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?'” he said.
Though the recent breakthrough in the bionic eye development is exciting, there is still a lot of work to be done. The next phase of the research will be to create a prototype with more efficient and sophisticated light receptors. Down the line, the team also hopes to 3D print a soft and implantable hemispherical material.
Assisting McAlpine in the bionic eye research are researchers Ruitao Su, Sung Hyun Park, Shuang-Zhuang Guo, Kaiyan Qiu, Daeha Joung, Fanben Meng and undergraduate student Jaewoo Jeong. The project is being funded by the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health, The Boeing Company and the Minnesota Discovery, Research, and InnoVation Economy (MnDRIVE) Initiative.