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HomemistoryMaking Magic: The Smart Contact Lens

Making Magic: The Smart Contact Lens

Sometimes in a research lab, magic happens. And so it was when Associate Professor Drew Evans, from the University South Australia’s Future Industries Institute (UniSA FII), was exploring potential coatings for a contact lens… he discovered how to grow electrically conductive polymers on a lens. This polymer could be used to communicate valuable information in real time about the wearer’s health.

Associate Professor Drew Evans and his team at University South Australia’s Future Industries Institute (UniSA FII) have been collaborating with Contamac, a UK based manufacturer of materials for contact lens production, to develop a more wettable and therefore comfortable solution for contact lens wearers.
However, the contact lens they have developed as a coincidence of this research will offer wearers much more than that.

A/Professor Evans believes the smart contact lens currently being tested for robustness will determine valuable information – such as a patient’s blood glucose levels – and communicate them to the wearer in real time so that action can be taken.

A/Professor Evans said the ability to apply the polymer technology to a silicone hydrogel contact lens came as a surprise.

“It was one of those excellent examples of how research happens – the concept came completely out of left field while we were trying to do something else,” said A/Professor Evans. “One of the ambitions of a contact lens is to stay wet and this is one of the things that all manufacturers are trying to achieve. So in partnership with Contamac we were looking at a way to do that, exploring different materials to use as a coating. That indirectly led us to apply our materials research expertise in conducting polymer technology, in the initial phases of the research, to keep the lens wet. But then through that process we realised that by putting that material onto the lens we’d given it new function – the ability to have electrical circuits… It was a serendipitous outcome.”

This is not a first of its kind.A/Professor Evans is up against the likes of Verily (a spin-off of Google) and Samsung, who have their own devices well underway and could be hitting the market within the next two years.

However, there are three important differences between UniSA FII’s smart contact lens and those developed by Verily and Samsung: it does not require a smartphone or other external device to make it operate, it does not need to be powered up, and it is made from a polymer that is soft, flexible and biocompatible, and therefore safer for human use.

How Does It Work?

A/Professor Evans’ smart contact lens has a polymer thin-film coating that conducts electricity and has the potential for miniature electrical circuits to be ‘grown’ on the lens in different patterns according to the function required. Indeed, the technology being used to develop the smart contact lens was pioneered by FII for the development of the precursor product to the world’s first fully plastic car mirror which has been commercialised by its partner SMR Automotive.
In what has been described as a ‘simple procedure’, the conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) is deposited from the vapour phase onto hydrated hydrogel substrates and blended with biocompatibilising coconstituents incorporating polyethylene glycol (PEG) and polydimethyl siloxane. Get that?

Verily& Samsung

“In the last 12 months both Verily and Samsung have demonstrated the ability to affix traditional circuits, using metals and copper on contact lenses. Samsung put a CCD camera on a contact lens – so there are all those opportunities. What’s different about our lens, is that our electronic materials are polymers not metals. The polymers themselves are also biocompatible, as well as being inherently soft and flexible. So they are more comfortable and in terms of interaction with conductive material with cells on the body, there is less risk of infection or rejection. So it could, in the future, be used as an IOL as opposed to worn on the surface – that is our vision.”

While Samsung is working on a contact lens with augmented reality for entertainment purposes, Novartis and Verily have been working together on two smart intraocular contact lenses that will provide health benefits. One lens will help diabetic patients measure their blood glucose levels and one will correct vision impaired by presbyopia. The device, which is battery powered, may also have the capacity to correct for myopia, hyperopia and astigmatism.

In 2015, Novartis told a Swiss newspaper it was on track for human trials of its intraocular lens for presbyopia patients in 2016. As well as helping the eye focus light onto the retina, it would also include components for external communication and data storage.

Interestingly, the very near future could see FII’s innovative polymer technology applied to military equipment and uniforms throughout the world

A Passive Device

In Adelaide, A/Professor Evans and his team hope to make an immediate difference to the eye health of patients by developing a passive lens that doesn’t require power or an external interface device to receive and transmit vital information.

“This technology has huge potential for impact – but in terms of the technology development it’s a shorter timeframe because we don’t have to invent batteries and transmitters to make it work.”

Sensimed Triggerfish

One smart contact lens that is already out in the market is the Sensimed Triggerfish, a contact lens developed with the aim of helping to cure glaucoma. This soft disposable silicone contact lens, with an embedded micro-sensor, captures continuous and natural changes of the eye at the corneoscleral area system.

The lens is installed on the eye by an eye professional and an adhesive Sensimed Triggerfish antenna is placed around the eye to wirelessly receive information from the contact lens over a 24-hour period while the patient participates in daily activities including sleep. Data is transmitted through a thin flexible cable from the antenna to the portable recorder.

At the end of the recording period, the data is transferred via Bluetooth from the recorder to software.
As Sydney optometrist Jim Kokkinakis points out, until the cumbersome design of the Triggerfish is overcome, this lens will have limited appeal, particularly for wearers. “I suspect it will have a limited use similar to sleeping with a blood pressure monitor for 24-hours,” said Mr. Kokkinakis.

“Invaluable clinical information will be available for the first time for glaucoma management. Being able to routinely measure eye pressure while a patient sleeps and all through the day will give us an insight into a minority of glaucoma patients (around 10 per cent of them) that are very difficult to manage. Maybe having 24 hour pressure readings will allow us to be more aggressive with this small cohort.

“However, I do not see this device at this stage being able to be worn as an extended wear lenses for a month at a time. Why?

We struggle with extended wear contact lenses now. This will not be any better until we can overcome the extended wear hurdle.”

Looks like we need Associate Professor Drew Evans and his team to bring on their very smart contact lens asap.

Preparing for Market

However, before the smart lens heads into the market, there is still plenty to be done.

“To date, we have been able to demonstrate that we can coat the conducting polymer on the lens material. This is a big step forward towards a new range of personal health monitoring devices. However, before we can start to test these in medical applications we are testing the robustness of the coatings, particularly to ensure the polymer ‘sticks’ to the lens under a range of different conditions. When making new devices, it is imperative to test robustness before getting excited about the potential end device.

That may sound like a simple test, however there’s more to it than meets the eye (so to speak). “There is a lot of science behind this lens, in terms of nano-engineering to try to get the coating to stick, so we need to make sure it doesn’t come off. We grow the polymer on the lens and then the first test is mimicking what people do with a normal contact lens – so we do the ‘rub test’ that people do every day before they put the lens in their eye – ie we take our coated lens, put it in saline, rub it in the palm of our hands, and then inspect it to see any damage – this has to be done over time because of course these lenses won’t be daily disposables,” said A/Prof. Evans.

“Once we have the robustness sorted, we will be working with Contamac’s end customers as well as ophthalmologists to understand more about the diseases they want this type of device for. Our immediate thoughts are related to passive sensors, which do not require a power source or some form of remote readout (i.e. no battery or wireless connection to your smartphone). The sensor would respond to specific chemicals in a wearer’s tears, causing the polymers’ optical properties to change. This change will be obvious to the wearer who can then take the appropriate course of action to fix their body’s chemistry. Once the body recovers, the chemistry of the tear will return to normal, and the lens will go back to being transparent.

“If all goes well, we are aiming to be at the device stage within the next few years.”

Looking Further Afield

A/Professor Evans is also looking further afield – perhaps for another of those serendipitous discoveries. “Because the contact lens is soft, flexible, and compatible with the body, we are exploring other places in the body that it can be applied to. We are looking at developing a technology that can be connected by a battery and have a wireless transfer of information – so wearable electronics that monitor the health of a person and relay that information to display technologies. Another concept we’re looking into is virtual reality, similar to Google Glass but on a contact lens. But that’s very pie in the sky – and it will require a lot of different technologies to come together. We have colleagues working in this space at the University right now, showing how you can use visual aids – cameras and computers – to improve safety and efficiency in industries that use manual equipment.”

Other Applications

Interestingly, the very near future couldsee FII’s innovative polymer technology applied to military equipment and uniforms throughout the world.

A/Professor Evans’s team is currently in stage three of the development of a military application for camouflage with Australia’s Defence Science and Technology Group (DSTG).

This application uses electricity as a trigger to modify the polymer so it can go from brown to green and back. Being highly flexible, the polymer can be used on fabrics or metals.

“Right now large panels made by FII are being tested in field with DSTG, but again it comes back to ensuring robustness and durability – for any product you make, people want to know it’s going to last – particularly on the battlefield,” said A/Professor Evans.

“Like the contact lens, we are still a few years away – one of the biggest things people don’t understand is the time it takes to scale up manufacturing so while we can create an innovative technology on a small scale, being able to make hundreds of thousands or millions of units takes time,” he said.

Novartis Verily Contact Lens

The patent application for a smart contact lens under development by Verily (an off-shoot of Google) and Novartis, describes the insertion process as injecting a fluid into the lens capsule of the eye, after, or at the same time as the natural lens of the eye is removed from the lens capsule. The intra-ocular device would be inserted within the fluid in the lens capsule which would then solidify, to form a coupling between the lens capsule and the intra-ocular device, in response to light or an alternative method.

According to a patient application filed in the US, this smart electronic intraocular lens device will adjust its focus in response to the accommodation forces applied on the lens capsule by the ciliary muscles, either directly or indirectly.

It would wirelessly communicate with an external interface device. The exposed regions of the intraocular device are made of a polymeric material formed to be in intimate contact with the inside surface of the lens capsule of an eye. An active device is embedded in the polymeric material and contains a power supply, a controller, bio-interactive components, and a communication antenna. The bio-interactive components
are operated by the controller