Scientists are not yet able to make reconstructions of human organs and limbs with bionic parts. They don’t have the technology. But a new artificial eye brings us a lot closer to sci-fi movie cyborgs becoming a reality.
This device, which mimics the structure of the human eye , is more sensitive to light and has a faster reaction time than a real eyeball. It may not have all the telescopic or night vision capabilities featured in futuristic films, but this electronic eye has the potential for much sharper vision than human eyes provide.
A revolution in the future of ocular implants
In the future we will be able to use this now nascent technology to improve vision prosthetics and humanoid robotics. The human eye owes its wide field of vision and high resolution to the dome-shaped retina, an area at the back of the eyeball covered with light-detecting cells. The researchers involved in the experiment used a curved aluminum oxide membrane studded with nanometer-sized sensors made of a light-sensitive material called perovskite to mimic that architecture in their synthetic eyeball.
Wires attached to the artificial retina send readings from those sensors to an external circuit for processing, much like nerve fibers transmit signals from a real eyeball to the brain. The artificial eyeball registers changes in lighting faster than human eyes, in about 30 to 40 milliseconds, instead of 40 to 150 milliseconds. The device can also see dim light just as well as the human eye. Although its 100-degree field of view is not as wide as the 150-degrees that the human eye can see, it is better than the 70-degrees visible to common planar image sensors.
More resolution than a human eye
In theory, this synthetic eye could perceive much higher resolution than the human eye, because the artificial retina contains about 460 million light sensors per square centimeter. A real retina has about 10 million light-detecting cells per square centimeter. But that would require separate readings from each sensor. In the current configuration, each wire connected to the synthetic retina is about a millimeter thick, so large that it touches many sensors at once. Only 100 of these wires pass through the back of the retina, creating images that are up to 100 pixels.
To show that thinner wires can be attached to the artificial eyeball for higher resolution, the scientists used a magnetic field to attach a small array of metal needles, each 20 to 100 micrometers thick, to nanosensors in the synthetic retina, one by one, as in a complicated surgical operation.
REFERENCES:
Hong Kong University of Science and Technology.
