World’s First Spherical Artificial Eye Has 3D Retina

Hello iMechanica! My name is Ryan and I am the Founder of Mechanical Engineering HQ. I am writing here today to share an interesting development in prosthesis. Scientists have claimed that they have developed a new artificial eye that has more advanced capabilities than human eyes. Read on to see if they have achieved this feat!

The human eyes encompass incredible natural abilities, including an exceptionally wide field of view, and high resolution married with low distortion capabilities, almost impossible to synthetically recreate in their entirety. These factors taken together can make the loss of vision or the physical removal of an eye a highly distressing and adaptive life-event.

Historically vision is not restored through the use of these artificial eyes, however previous studies have indicated ocular prosthesis mimicking natural eyes are highly desirable. The spherical shape and retina of the biological eye pose a mammoth hurdle for biomimetic devices with biomedical engineers attempting to replicate the structure and functionality of a biological eye for over a decade.

HKUST Scientists Make a Breakthrough

Scientists at the Hong Kong University of Science and Technology (HKUST) are claiming to have developed the world’s first spherical artificial eye that has better capabilities than existing bionic eyes. This will bring new hope to patients with visual impairment and will also enable humanoid robots to possess the ability to see.

The replication of the structure of a biological eye has evaded scientists thus far, and vision that is provided by existing artificial sight technology, usually in the form of glasses with external cables, has quite poor resolution and uses 2D flat image sensors. The new eye, called the Electrochemical Eye (EC-Eye), doesn’t just accurately reflect the structure of a natural eye for the very first time, with upgrades in the future it could surpass a human eye in terms of sharper vision. It will also feature new functions like detecting infrared radiation in darkness.

The new 3D retina that allows these new features is made of an array of nanowire light sensors which mimic the photoreceptors in human retinas. The team at the Department of Electronic and Computer Engineering at HKUST connected the nanowire light sensors to a bundle of liquid-metal wires that serve as the nerves that are behind the human-made hemispherical retina. During this experiment the electrical engineers successfully replicated the visual signal transmission that a normal eye would see onto a computer screen. 

The Structure of the EC-Eye

The aim is to connect these nanowire light sensors directly to the nerves of visually impaired patients in the future. This is unlike a human eye where bundles of optic nerve fibers (for signal transmission) need to route through the retina via a pore, from the front side of the retina to the backside (creating a blind spot in human vision) before reaching the brain. The light sensors that now scatter across the entire human-made retina could each feed signals through its own liquid-metal wire at the back, thereby eliminating the blind spot issue as they do not have to route through a single spot.

Nanowires also have a higher density than photoreceptors in human retina, which means the artificial retina can receive a lot more light signals and attain a higher image quality than human retina. Different materials will be used to boost the sensors’ spectral range and sensitivity, with features like night vision also being possible!

At the moment, regardless of angle of views, image resolution or user-friendliness, current bionic eye technology is still no match to their human counterparts. This new technology took nine years to complete from start to finish, with the team collaborating with the University of California, Berkeley.

Future of the Artificial Eye

The artificial eye will further be improved in the future with the stability, performance and biocompatibility of the device being upgraded.

The working principle of the artificial eye involves an electrochemical process which is adopted from a type of solar cell. In principle, each photo sensor on the artificial retina can serve as a nanoscale solar cell. With further modification, the EC-Eye can be a self-powered image sensor, so there is no need for external power source nor circuitry when used for ocular prosthesis, which will be much more user-friendly as compared with the current technology.

What do you think about this new technology for artifical eyes? Let me know your thoughts with a comment below!