- [Narrator] About one out of every 10 people in the United States will lose their eyesight as they age.

The retina, the light sensing bit at the back of your eye just sort of wears out.

And at this point, there's really nothing we can do about it.

But imagine if we could implant a light sensor and with a little inspiration from nature, coax our brain into reading the signal.

And that's "All Science, No Fiction".

(upbeat music) (door whirring) Working in a clean room may feel like a job from our shiny sci-fi futures but the reality of it is not quite so glamorous.

- And it's not comfortable wearing that gear.

It's hot, it gets hot.

- [Narrator] But Saba Moslehi is here because these silicone wafers are the foundation of a new design of eye implant.

The technology could eventually restore sight to millions of people.

- So vision is our primary sense.

It's fantastic.

It works beautifully until it stops working beautifully.

And there are a number of diseases that can attack the retina.

And then you know what happens then is that gradually you start to lose your vision.

- [Narrator] The clean room is vital to their work.

(liquid sprays) - [Saba Moslehi] I can fabricate silicon wafers without any dust or contamination.

- [Narrator] She doesn't want anything to come between the implants and the living cells from the eye.

To understand how eye diseases like macular degeneration work, it helps to know a little anatomy.

- Can I use my hands?

- [Narrator] Yes, please, please do.

Please do.

- So.

If you think about your eyeball, you have a lens at the front and that focuses light onto a screen at the back.

That's called the retina.

(gentle music) (camera shutter clicks) - [Narrator] In the retina, there are photo receptors that convert light into electricity and the neurons that carry that electrical message to the brain.

(camera shutter clicks) Retinal diseases often attack and destroy the light receptors.

- The idea is that long term, we will drop this implant in which will have an array of artificial photo receptors.

So same thing, light will come in, generate electricity, and then that will pass to the natural neurons that have not been affected by the diseases.

- [Narrator] Retinal implants are already being tested in people but so far none have succeeded in significantly restoring vision.

- We thought if the the implants are not working there must be a reason for that.

- [Narrator] Their answer, brain and machine just aren't fully communicating.

So these Oregon researchers are making a new kind of interface, which starts by adding a special chemical called "Photo Resist" to the top of the silicone wafer.

Moslehi then exposes the wafer to light with a laser writer.

- [Saba Moslehi] It changes its molecular structures so that later, I can wash those parts away and create a mold.

- [Narrator] The mold will shape the layout of the electrodes on the implant.

The scientists believe the electrode pattern and texture are the key.

- A lot of the artificial electronics tends to have smooth surfaces and smooth surfaces don't exist in your body.

- [Narrator] Smooth surfaces, right angles, clean lines.

These are all the realm of Euclidean Geometry.

- Lines, triangles, squares, circles, the things that we all learn in the classroom.

But nature uses this very different geometry a much more complicated geometry.

- [Narrator] Nature's geometry is fractal.

- [Richard Taylor] When you look at the tree, you can see the big pattern traced out by the trunk and the large branches.

But if you zoom in and look at the twigs, you'll see that the same pattern is actually repeated and it keeps on repeating and repeating at finer and finer scales.

- [Narrator] Clouds are fractals, so are rivers, and the rugged terrain of the Oregon coastline.

Broccoli?

It's a fractal.

- But even when you look inside you, your, you know, your blood system, your veins are fractal, the wiring, your neurons are fractal.

So really it is the fingerprint of nature.

- [Saba Moslehi] So we thought, okay, what if we build an electrode that has a fractal shape, that mimics the shape of the neurons?

Would that eventually end up increasing the resolution of the potential future implants?

That's our goal.

- [Narrator] The better the resolution, the better the visual result.

The design they focused on is a fractal called an H tree, for obvious reasons.

And what they found in experiments so far has been extremely promising.

(gentle music) Neurons are nerve cells that transport electric and chemical signals to our brains.

They're kind of a big deal, so big that they have groupies that cater to their every need.

These groupies are called glia and they need to be close by to do their jobs.

When glia detect an unfamiliar object like say a smooth implant in your retina, they tend to wall it off and prevent your neurons from making good connections.

This is where the H tree is so successful.

In in-vitro tests, the pattern and texture of the Hs attracted the neurons and the glia were funneled into the gaps in between.

- So the glial cells aren't getting in the way of the interaction between the neurons and the implant but the glial cells are close enough still to supply their life support.

- [Narrator] Their hope is that by combining that life support with better connectivity between the neurons and the artificial electrode, what the brain sees with the implant will be much clearer.

- The very first time that we imaged these samples under the microscope, and I saw a big cluster of glial cells within the gaps, it was like, oh my God, we did it.

It happened.

- [Narrator] Now that they have a pattern that works- - [Saba Moslehi] Okay, I'm gonna close the door.

- [Narrator] They're starting to refine the texture of the H tree material.

It's made of microscopic structures called carbon nanotubes.

- Let me focus on it.

So right now I'm at 20,000 X magnification and this is the top surface of the nanotubes.

The roughness of the top surface of the carbon nanotubes that we grew sort of gives the neurons this ability to adhere to the surface and then grow their dendrites.

- [Narrator] And if you look at the profile of the nanotubes on the chip, the shape you see- - That mountain range like structure.

- [Narrator] Is also a fractal, a more chaotic version called a statistical fractal.

Moslehi will test different versions of this fractal pattern to see which works best.

Ultimately, their goal is to insert a little chaos into the H tree design to even better match the patterns in our eyes.

- [Richard Taylor] That is one of the wonders of science, that you can, just by pushing those frontiers can actually do something very useful as well.

If we get this right, we could actually restore vision to somebody.

- [Narrator] If we can crack the interface between mind and machine, who knows where our bionic futures will lead.

- Behind the scenes, smile.

- [Narrator] OPB members are vital to the work we do.

You help us bring the world into focus.

Thanks and don't miss out on any of OPB's science, environment, and arts programs.

- Oh, you're in it.

- That's funny, okay.

- [Narrator] By subscribing to OPB Insider at opb.org/allscience.

(gentle music)