According to a study published in Advanced Materials, a research team at the University of Minnesota attempted, for the first time, to fully 3D print a set of light receptors on a hemispherical surface. The 3D product can advance the field of optometry and ophthalmology by making a significant contribution towards the creation of a "bionic eye", which can bring sight to individuals who are blind or help sighted people improve their vision. "Bionic eyes are usually thought of as science fiction, but now we are closer than ever using a multi-material 3D printer," says Michael McAlpine, an author of the study and Associate Professor of Mechanical Engineering at the University of Minnesota.
The researchers began with a hemispherical glass dome that present’s a way of overcoming challenges associated with printing electronics on a curved surface. Utilizing a custom-built 3D printer, they used a base ink of silver particles which stayed put while drying uniformly instead of running down a curved surface. Following this procedure, the researchers began using semiconducting polymer materials for printing photodiodes that transform light into electricity; the process took about an hour.
Using the full 3D-printed semiconductors, McAlpine and research team were surprised to convert light into electricity by only using 25 percent efficiency. "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 explains. "Plus, we can easily print a semiconducting device on a curved surface, and they can't."
McAlpine and research team were famous in the scientific community for their attempts on pure interdisciplinary research that combines biology, 3D printing, and electronics, on one platform. In fact, they have been preconized internationally for their efforts in producing a "bionic ear”, 3D printing life-like artificial organs for surgery, making electronic fabrics known as "bionic skin," applying electronics on a moving hand, and cells and scaffolds that assist people surviving with spinal cord injuries to gain some function. However, the need to create a bionic eye was driven by McAlpine’s personal interests, he states: "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?'".
Now, researchers are looking forward to creating a prototype with more efficient light receptors. Additionally, they seek to find a way to implant soft hemispherical material that can be printed.
Watch this video below about 3D-printed prototype for a bionic eye:
Source: University of Minnesota