This Robotic Eyeball Might Outperform Human Eyes Soon

Mimicking the eye's shape is a dream come true for many optical engineers.
Derya Ozdemir

Well, it's for sure that you won't see anything that's "alive" when you look into these eyes. Researchers from the Hong Kong University of Science and Technology built an artificial eye that could provide vision for humanoid robots, and more so, it has the potential to function as a bionic eye for visually impaired people in the future. ElectroChemical Eye, in other words, EC-Eye, resembles a biological eye, but it couldn't be more different.

It goes like this: The eye mimics the human iris and retina using a lens to focus light onto a dense array of light-sensitive nanowires. Wires, which act like the brain's visual cortex, pass through information to a computer for processing.

As you'd imagine, engineering the human eye is not an easy feat. Many scientists have tried to develop such devices, yet fabricating the spherical shape of the human eye, the hemispherical retina, in particular, is a big challenge that many researchers try to tackle.


Tackling the hemispherical shape problem

In order to tackle this problem and many more, the research was built on the fact that perovskite, which is a conductive and light-sensitive material used in solar cells. This material can be used to create thin nanowires that mimic the structure of the eye's photoreceptor cells. 

However, the main problem was to fabricate an array of nanowires in a hemispherical substrate to form a hemispherical retina. In order to solve it, the researchers deformed soft aluminum foil into the desired hemispherical shape.

This Robotic Eyeball Might Outperform Human Eyes Soon
Source: Hongrui Jiang/Nature

The next step was to treat the metal with an electrochemical process to transform it into an insulator called aluminum oxide. Since this process also left the material with nanoscale pores, the researchers were able to get a curved hemisphere that had densely clustered holes in which they could "grow" perovskite nanowires

Most Popular

Apparently, the density of the nanowires was even higher than the photoreceptors in human eyes.

Using nanowires to detect light and send it to external devices

With the curved "retina" in their pocket, the researchers combined it with an artificial eye that had a curved lens on its front. By filling it with an ionic liquid where charged particles can move, they were able to get perovskite nanowires to perform the electromechanical function of detecting light and sending the signal to external electronics that process images.

When testing the ability of this artificial eyeball the researchers found it was capable of detecting on average of 86 photons per second -- a rate on par with that of a human eye. These artificial eyes were also able to recover from light detection even faster than human eyeballs, taking only 40 seconds to recover while a human eye would take closer to two-and-a-half minutes. The robotic eye was also able to accurately capture, or "see", the letters "E," "Y," "E."

Superior to the human eye in some areas

During tests, the researchers saw that the artificial eyeball was capable of detecting on average of 86 photons per second which is a rate on par with the human eye. Moreover, they were able to recover superiorly from light detection, the artificial eyeball took only 40 seconds to recover while a human eye would most probably take two-and-a-half minutes.  

The computer was able to recognize the letters "E," "I" and "Y," and let's just say that, in some ways, the robotic eye was better than the real deal since it could pick up a wider change of wavelengths and didn't have a blind spot.

This is such exciting news since, with medical researchers, there could be prosthetic devices built in the future.

message circleSHOW COMMENT (1)chevron