Artificial Retina Technology

Researchers at Lawrence Livermore National Laboratory are developing an implantable system for a third-generation artificial retina as part of a U.S. Department of Energy project to produce an 'retinal prosthesis' that could restore vision to millions of people suffering from eye diseases.

Transcript

00:00:00 [Music] some people call this the bionic eye an artificial retina that may eventually help the estimated 6 million Americans and 25 million people worldwide who have become blind or who have severe visual impairments from diseases that destroy the photo receptors in the eye such as age related macular degeneration and retinitis Pigmentosa in collaboration

00:00:27 with four other National Laboratories four universities and and one industrial partner Lawrence lmore National Laboratory has developed the first long-term retinol proceses that can function for years inside the harsh biological environment of the eye this is what it's all about a thin metallic electrode array that will ultimately be implanted on the surface

00:00:48 of the patient's retina here at Lawrence Livermore National Laboratory we play a key role in the department of energies artificial retina program in conjunction with our other do team members we design and build the compl implantable artificial retina system that includes a thin film electrode array that interfaces with the delicate neural tissue that thin film electrod array is

00:01:10 fabricated much in the same way that the computer chips are fabricated in your home computer we fabricate all those components here at the center for micro and nanotechnology at Lawrence limore National Laboratory I'd like you to show you a few of the processes we use to fabricate those chips so let's go inside and take a look the process starts in a clean room after we've coated a silicon

00:01:29 wafer with an extremely thin layer of plastic-like substance we then insert it into this machine which deposits a thin layer of platinum which can then be patterned to form the electrical wiring in neural electrodes timing is key here it's the machine works too quickly the plastic will burn if it takes too long the process bogs down we can actually

00:01:53 process 25 Wafers at a time which means we can reduce the overall cost of the device it is crucial that the Platinum is coated evenly on the wafer creating a mirrorlike finish some of that shiny Platinum will be removed later to form the electrical Pathways for the artificial retina but first we need to spray a photosensitive material onto the wafer in another section of our clean

00:02:16 room it is important that we don't expose the photosensitive material too early so this section of the clean room is lit with special orange lighting so in order to make the artificial retinal device we actually need to deposit a pattern or photo Define the pattern of of the device onto a polymer we do that with this station here so we actually place the Wafers with the thin film

00:02:40 polymers in the entry cassette it actually then takes the Wafers over deposits a chemical that allows us to spin on this photosensitive polymer it then comes into this this uh station here where the Wafers actually come down onto a cassette it lowers it into to a a vacuum system that deposits the thin fill material in the center of the wafer the

00:03:06 wafer then spins to uniformally coat this material to a thickness of 1 Micron which is roughly 100th of the thickness of a human hair after that procedure is complete which usually takes about a minute the Wafers come back up and go over to a hot plate where we bake the the solvents out of this material and then the material then or the wafer then can use on over to the exit station and

00:03:33 that that process is repeated for each wafer so every single wafer that we want to deposit a pattern onto goes through this complete system so once we have the thin fill material onto our wafers in order to actually transfer the pattern to that thin film we need to expose it with ultraviolet radiation and in order to expose it we actually need to mask that light through some kind of photo

00:03:57 reflective film in this case it's a Pro mask and so we actually place the Wafers into our lithography system load the wafer and The Mask into the chamber if we have previous features that we've defined on the Wafers we actually align the new mask to those features using an optical microscope once the alignment is complete we can then expose the whole wafer at one shot with a UV Source an

00:04:26 ultrai radiation Source that's in this system and when once that's complete we actually have transferred the pattern onto the thin film on the wafer the next step is similar to how photographic film used to be developed in a dark room it takes only a few minutes for a chemical solution to develop the photos sensitive material on the wafer you can see how the little squares are showing up the

00:04:49 wafer is then washed to remove the chemical solution the wafer's photos sensive material now has the desired pattern imprinted on it which will soon be transferred to the platinum in order to accomplish this we need to remove the excess Platinum first so that all that's left on the wafer is the desired network of platinum wires each only about 150th the width of a human hair it's a

00:05:14 delicate process and we constantly need to check the wafer under a microscope once we leave the dark room section of the clean room it's easy to see the transformation that's taking place on the surface of the wafer each of the Dozen arrays is visually inspected under a computerized microscope at a magnification of up to 1500 times any defect no matter how

00:05:37 small means that that array must be rejected luckily about 90% of the arrays pass inspection here then there's another inspection in the Next Room this one is electronic the tip on the end of the computer controlled arm physically checks the Integrity of the circuitry on the array to make sure that the thin Platinum wiring is intact it takes about an hour to check the 12 arrays on each

00:06:03 wafer the array by itself is just one part of the assembly that eventually be implanted into the patient there also needs to be a package of miniaturized electronics only about the size of a hearing aid battery the device's two sets of integrated circuits are now connected to one another in this machine which functions much like a sewing machine it meticulously attaches a thin

00:06:26 gold wire from one set of electronics to the other it Tak takes the machine only about 5 minutes to complete just over 100 separate connections using a wire that's only about 1 qu of the thickness of a human hair next the completed Electronics package is assembled onto a thin film array this machine uses sensitive cameras to align both components they are carefully brought

00:06:51 together and bonded using a unique glue using pressure and heat the curing process takes about 5 minutes at this point the implantable device is complete what you see here is an incredible engineering success previous attempts to provide artificial retinas relied on handcrafted electrod arrays and were limited to just 16 pixels we've move far beyond that now with our

00:07:17 current technology and we are now working on increasing the number of pixels to more than 1,000 we are incredibly proud of what we've accomplished knowing that this thin film has already restored at least partial sight to dozens of patients at multiple medical facilities around the world