Team led by the Hong Kong University of Science and Technology (HKUST) developed the world’s first 3D artificial eye with a retina, bringing vision to humanoid robots and hope to patients with visual impairment.
An international group of scientists have developed the Electrochemical Eye (EC-Eye) at HKUST. It not only replicated the structure of a natural eye for the first time, but also offer the potential for sharper vision than a human eye and extra functions such as the ability to detect infrared radiation in darkness.
Developed by Professor Fan Zhiyong and Dr Gu Leilei from the Department of Electronic and Computer Engineering at HKUST, the 3D artificial retina is made of an array of nanowire light sensors which mimic the photoreceptors in human retinas.
The team connected nanowire light sensors to a bundle of liquid-metal wires serving as nerves behind he man-made hemispherical retina during the experiment, and successfully replicated the visual signal transmission to reflect what the eye sees onto the computer screen.
For future developments, the nanowire light sensors could be directly connected to the nerves of visually impaired patients. In a human eye where bundles of optic nerve fibres need to route through the retina via a pore - from the front side of the retina to the backside before reaching the brain, thus creating a blind spot in human vision. The light sensors eliminate the blind spot issue by scattering across the entire man-made retina could each feed signals through its own liquid-metal wire at the back.
The higher density of nanowires compared to photoreceptors in a human retina allows the artificial retina to receive more light signals and potentially attain a higher image resolution than the human retina.
The team collaborated with the University of California, Berkeley on this project and their findings were recently published in the journal Nature.
“In the next step, we plan to further improve the performance, stability and biocompatibility of our device. For prosthesis application, we look forward to collaborating with medical research experts who have the relevant expertise on optometry and ocular prosthesis,” Prof. Fan said.
The artificial eye involves an electrochemical process adopted from a type of solar cell. In principle, each photo sensor on the artificial retina can serve as a nanoscale solar cell.
The team hopes that with further modifications the EC-Eye will be able to become a self-powered image sensor without the need for an external power source when used for ocular prosthesis.