Harvard has made a breakthrough in artificial eye technology with an artificial eye just 30 microns in depth but has the capabilities to exceed the human eye. The technology builds on the metalens technology by adding electrically-controlled flexible muscles. This new technology can make a huge impact in the optical fields including cameras, telescopes, microscopes, glasses and even VR.
The prototype device has the ability to make adjustments simultaneously for image focus, image shift and astigmatism. All these cause blurred images which our own eyes can do nothing about. But, our eyes do have the ability to focus in real time and the technology can accomplish that as well.
“All optical systems with multiple components … have slight misalignments or mechanical stresses on their components … that will always cause small amounts of astigmatism and other aberrations, which could be corrected by an adaptive optical element,” explains Alan She, an author of the research. “Because the adaptive metalens is flat, you can correct those aberrations and integrate different optical capabilities onto a single plane of control.”
The metalens in question is a flat silicon nanostructure with the ability to focus light. However, it does not end there and goes further by adding artificial muscle surrounding the metalens. This presented some challenges to the team, the first of which was increasing the size of the metalens.
The previous prototypes were as big as pieces of glitter and to scale the technology to a 1 cm lens did not prove simple. The data needed to describe the design the lens could very well amount to terabytes owing to the complexity of the nanostructure involved.
The team developed an algorithm to overcome the problem. The algorithm was capable of describing lens production and managed to reduce the size to one that could be handled. The smaller size was necessary to make it compatible with the technology used to make integrated circuits.
The other challenge arose when it came to attaching artificial muscle to the lens without compromising its optical performance. A dielectric elastomer was chosen by the team as it is an elastic polymer and can be controlled by electricity via carbon nanotube electrodes. The elastomer was identified by the team as it allowed light to pass through without scattering it.
There is still no news whether this artificial eye has any potential in human implants. The team is planning to work towards further improvements that include reducing the voltage needed to control the eye and increase the speed of response.
This research was carried out at Harvard John A. Paulson School of Engineering and Applied Sciences and the team’s paper has been published in Science Advances.