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This Synthetic Iris Could Repair Damaged Eyes and Advance Microrobotics

The eye is among the most fragile body parts in the human body. Until the last few decades, there wasn't much that doctors could do to improve damaged eyes or lost vision. Recently, a team of scientists at Finland's Tampere University of Tech introduced a synthetic iris that automatically adjusts itself based on available light that can not only be used to repair human eyes, but could also lead the way to new microrobotic technologies.

Artificial iris responds to light like the human eye

An Iris by Any Other Name...

In the human eye, the iris is the thin circle surrounding the pupil that adjusts around the pupil to control the amount of light that gets through. It's also the part that can attract other humans due to its lovely "baby blue," "emerald green," or other hue along the color spectrum. Going from a darkened space such as a hallway to a bright, day-lit street, or vice versa, creates a need to wait a few seconds for the eyes to adjust accordingly. That's the iris in action! When there's a lot of light, the iris closes in around the pupil, shrinking it to the size of a pinhead if necessary, to protect the retina inside the eye. When it's dark, the iris widens the pupil so what little light available can help you guide yourself a little more easily and safely in the night.

Camera technology uses a similar mechanism (also known as an aperture) that controls the depth of perception as well as the amount of light in the photo. While a human eye is, of course, controlled by the brain, a camera's iris has traditionally required an external sensor to control its movement. That is, until now.

No Sensors Needed

At the Tampere University of Technology in Finland, a team lead by Arri Priimägi created a new, synthetic iris that is able to open and close autonomously without the need for an external sensor. Made with a rubbery-textured material called liquid crystal elastomer, the synthetic iris spans 14 millimeters across and is fashioned with 12 radial petals that are positioned to curl outward in the dark. While human eyes respond to light, the synthetic materials respond to heat, so to ensure their creation would be able to replicate the function of the real deal, they scientists added a type of red dye to the liquid crystal that heats up when it comes in contact with blue or green light, causing the petals to close the aperture.

Although Priimägi and his team say their invention is not yet ready to be implanted into a human eye, they believe it is the first step to making that a reality. In the meantime, the synthetic iris could also lead to new research in microbiotics, where it could be used as sensors on tiny, delicate machines.

Artificial Iris Works Like Your Eyes

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Written by Curiosity Staff August 1, 2017