A new artificial eye mimics and may outperform human eyes – Science News

Scientistscant yet rebuild someone with bionic body parts. They dont have thetechnology. But a new artificial eye brings cyborgs one step closer to reality.

Thisdevice, which mimics the human eyes structure, is about as sensitive to lightand has a faster reaction time than a real eyeball. It may not come with the telescopicor night vision capabilities that Steve Austin had in The Six MillionDollar Man television show,but this electronic eyepiece does have the potential for sharper vision thanhuman eyes, researchers report in the May 21 Nature.

Inthe future, we can use this for better vision prostheses and humanoidrobotics, says engineer and materials scientist Zhiyong Fan of the Hong KongUniversity of Science and Technology.

Thehuman eye owes its wide field of view and high-resolution eyesight to the dome-shapedretina an area at the back of the eyeball covered in light-detecting cells.Fan and colleagues used a curved aluminum oxide membrane, studded with nanosizesensors made of a light-sensitive material called a perovskite (SN: 7/26/17), to mimicthat architecture in their synthetic eyeball. Wires attached to the artificialretina send readouts from those sensors to external circuitry for processing,just as nerve fibers relay signals from a real eyeball to the brain.

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Theartificial eyeball registers changes in lighting faster than human eyes can within about 30 to 40 milliseconds, rather than 40 to 150 milliseconds. Thedevice can also see dim light about as well as the human eye. Although its100-degree field of view isnt as broad as the 150 degrees a human eye can takein, its better than the 70 degrees visible to ordinary flat imaging sensors.

Intheory, this synthetic eye could perceive a much higher resolution than thehuman eye, because the artificial retina contains about 460 million lightsensors per square centimeter. A real retina has about 10 millionlight-detecting cells per square centimeter. But that would require separate readingsfrom each sensor. In the current setup, each wire plugged into the synthetic retinais about one millimeter thick, so big that it touches many sensors at once.Only 100 such wires fit across the back of the retina, creating images thathave 100 pixels.

Toshow that thinner wires could be connected to the artificial eyeball for higherresolution, Fans team used a magnetic field to attach a small array of metalneedles, each 20 to 100 micrometers thick, to nanosensors on the syntheticretina one by one. Its like a surgical operation, Fan says.

The researchers current method of creating individual ultrasmall pixels is impractical, says Hongrui Jiang, an electrical engineer at the University of WisconsinMadison whose commentary on the study appears in the same issue of Nature. For a few hundred nanowires, okay, fine, but how about millions? Engineers will need a much more efficient way to manufacture vast arrays of tiny wires on the back of the artificial eyeball to give it superhuman sight, he says.

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A new artificial eye mimics and may outperform human eyes - Science News