At the very start of her PhD, Samantha Lichter could see just how much of a positive impact her work could have on the lives of others.
A research student in the Melbourne Materials Institute and the Department of Chemical and Biomolecular Engineering, Samantha has been working as part of Bionic Vision Australia’s bionic eye project team, which last year performed its first successful patient implant.
During the first year of her PhD, Samantha would attend regular Bionic Eye project meetings at The Bionic Ear Institute (now The Bionics Institute). Samantha said she would regularly see the patients coming in and out of the institute.
“When I was walking up one day, I saw a young dad pushing a pram with a little girl in it. She must’ve been about 3 or 4 – a happy little girl. I saw a little purple device stuck to the back of her head.”
“I thought, wow, that little girl’s life has been totally changed by the implant she has that has allowed her to hear; an implant that was designed right here in Melbourne and has changed the lives of so many people.”
“Now I have the privilege to be working on a project that is in exactly the same vein – designing a prosthesis for the blind. It just gave me such a jolt to be coming in at the grassroots level of the project, when it’s at its most exciting development phase.”
Samantha has been working on a particularly revolutionary aspect of the bionic eye, which will potentially help deliver a vastly improved resolution in vision quality for patients with the device.
The bionic eye currently works by delivering pulses of electrical current into the retina. Each pulse is able to create the perception of a dot. If more dots are created, a higher the resolution is delivered, allowing for the formation of a better image.
Samantha said that at this stage the bionic eye design has 256 electrodes, and the design goal for the future was to create a bionic eye with over 1000 electrodes to deliver these pulses A key challenge in the implant design, however, is keeping the microchip isolated from the moisture inside the body, while allowing for the many connections required for each of the electrodes. Samantha said that researchers at Bionic Vision Australia were initially looking for a materials engineer to address this problem and she thought it was something she could do.
A Department of Physics team led by Dr Kumar Ganesan devised an electrode array made of synthetic diamonds that are able to conduct electricity, and therefore do not have the problem of requiring many wires to and from the device. Samantha then devised a box shaped entirely from diamond that creates a leak-proof capsule with the electrode array on one wall. The capsule would then house the microchip that drives the bionic eye.
“It’s an amazing achievement because no one has been able to make an electrode array that finely that is also leak-proof.”
She said that the leak-proofing was important, not just in terms of keeping the electronics dry so they don’t fail, but to also shield the body from those electronics. She said that as a material, diamond was biocompatible, so would not be rejected by the human body. It is also an extremely durable material and, perhaps surprisingly, very cost-effective.
“When we make diamonds synthetically, it’s very different to the costs associated with digging them out of the ground. The reactor we use is very expensive but the raw materials that we use are very cheap; methane which is a waste gas, and hydrogen which is the most abundant element in the universe.”
“Over time when we make more diamonds they become cheaper and cheaper.”
The next phase of the project would see the diamond capsule being tested to determine its lifespan.
“We expect that to be very favourable based on the materials we have chosen.”
In coming years the device will then move towards human clinical trials.
Samantha said that it was absolutely thrilling to be working on such an iconic project, and to have been part of the research team through the project’s early stages leading to the first patient transplant.
The Bionic Vision Australia team she is working with includes researchers from the University of Melbourne as well as the University of NSW, NICTA, the Centre for Eye Research Australia, the Bionics Institute the Royal Victorian Eye and Ear Hospital, and the National Vision Research Institute and the University of Western Sydney.
“I find the whole concept and the ambition of the project to be extremely motivating,” Samantha said.
“It’s a really exciting time to be part of this team.”
Visit Bionic Vision Australia for more information about the project.