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‘The idea of a bionic eye was something the entire scientific and medical community wanted to develop’

Samantha Lichterhas a vision for a bionic eye that is fully encased in diamond.

 

‘The idea of a bionic eye was something the entire scientific and medical community wanted to develop. In Australia, and around the world, everyone was trying to make one.

The bionic ear was a success story born out of Melbourne in the 1970s. When I read an article on the possibility of working together with the Cochlear team to use their expertise, I knew I wanted to be involved. 

So how does the bionic eye work? Some diseases cause the death of light-sensitive cells in the retina of the eye. That means a lot of other nerve cells in the eye don’t receive the information they need to work. 

 ‘The ironic crux of my project was that diamond – the very material that provided such ingenious properties we so desperately needed – was chemically inert and the hardest natural material known to man.’

Bionic eye technology means we can implant a small chip onto these cells to give them the information they crave in the form of electrical pulses. 

The problem is that the chip needs to exist to be insulated and physically isolated to protect it from degradation in the wet and hostile environment of the eye. At the same time, the chip needs to be conducting and able to deliver the electric pulses necessary to stimulate the nerves. 

This was an engineering dilemma and one of the biggest challenges facing the industry. 

Developing a waterproof packaging for the implant that essentially acted as an umbrella to water and a shower hose for electricity became the focus of my PhD. 

Previous models relied on small titanium cans to encase the chip, preventing water getting in and anything that was toxic from getting out. 

Tiny holes were needed so electric currents could escape, wires threaded through, and holes plugged back up again with ceramic. 

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But we wanted more electrodes to deliver more pulses that would give an even higher and superior resolution. 

We would need thousands of wires for thousands of electric currents all integrated into complex wiring circuitry in an incredibly tiny space.

The risk of a leak and contamination in the body using this previous method was too high. 

That’s how I started thinking about diamond. It’s biocompatible and totally resistant to degradation by the body. It’s durable and can be cut into very tiny but very complex structures. It’s also electrically insulating and by adding nitrogen we could make some sections electrically conducting to enable nerve cell stimulation. 

That would mean that instead of drilling and plugging thousands of tiny holes into a titanium can, we could simply make the entire protective case out of diamond. 

The diamond itself would provide the conducting electrode array. It would make complicated and inefficient individual electrode wiring redundant. 

Better yet, what if we could  actually grow diamond ourselves and grow it around the chip? It would be cost effective and could be produced in bulk.

I took pre-grown blocks of synthetic diamond grown in a huge microwave reactor in the lab and laser-cut it into small squares with a hollow in the middle, fit the chip inside, and found the right materials and techniques to seal it up leak-tight. The ironic crux of my project was that diamond – the very material that provided such ingenious properties we so desperately needed – was chemically inert and the hardest natural material known to man.

It is incredibly resistant to chemical reactions and difficult to join together in a leak-proof way. We were working on a project that most people thought would never work. To make it harder, we also wanted superior vision and resolution.

‘Better yet, what if we could actually grow diamond ourselves and grow it around the chip? It would be cost effective and could be produced in bulk.’

The old “titanium can” model could offer only coarse wide-angle vision giving patients a vague outline of an image. I was also working on an incredibly tiny (on Nano) scale. 

We wanted to give vision over a smaller area within the central vision with a higher number of pixels. We needed to increase the electrode count from less than 100 to potentially more than 1000. 

This would give patients the ability to read someone’s body language, recognise faces and facial expressions and read large print. This was a world entirely shut out by existing visual aids. 

The project was the first in the world to use diamond for stimulation and only one of a few that focused on high resolution. 

We had a design unlike anything else and we made it in an amazingly short amount of time. Medical devices are usually made over a period of 30 years.

We went from virtually nothing to pre-clinical trials in five years. Unfortunately, much of our funding on the project has been cut.

This is an enormous shame considering the bionic ear was an invention that came directly from Melbourne and currently has 70 per cent of the world market share.

The bionic eye could have the same potential. Scientific literacy is therefore more important than ever.

We need a less short-sighted vision of scientific development. We have the technology, we have the ideas and we have an educated workforce.

This is a real opportunity to build in Australia a new and exciting industry. 

Perhaps we need a different approach to science itself as something not to be feared but to be excited and curious about. We have a generation of potential scientists who can make this world a better place. ’

Samantha Lichter’s  thesis is titled: “An all-diamond hermetic encapsulation for a high–acuity retinal prosthesis.”

My PhD is an irregular series in which The Citizen speaks with recent Melbourne University PhD graduates. 

About The Citizen

THE CITIZEN is a publication of the Centre for Advancing Journalism. It has several aims. Foremost, it is a teaching tool that showcases the work of the students in the University of Melbourne’s Master of Journalism and Master of International Journalism programs, giving them real-world experience in working for publication and to deadline. Find out more →

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