Wonderful Engineering

New Metalens By Harvard Can Automatically Fix Vision Problems

People who were not born with perfect vision can now rejoice because breakthrough research from Harvard Scholars at the John A. Paulson School of Engineering and Applied Sciences (SEAS) has been done. A tunable metalens that works in conjunction with current standards in artificial muscle technology is the outcome of this research.

This tunable metalens can alter its focus in real-time similar to the natural human eye. The pinnacle of this research is that the researchers have managed to make metalens automatically make corrections for the common anomalies in human vision. Blurry images in vision can be attributed to one of the three factors or a combination of them; astigmatism, image shift, and focus. By incorporating metalens with an artificial muscle, the Harvard SEAS researchers managed to develop an artificial eye that can be electronically controlled. All of the systems of nanostructures that allow metalens to eliminate spherical aberrations is smaller than a single wave of light. Because these lenses are Lilliputian sized, the density of the information per nanostructure is exponentially high.

Metalens technology is not a new concept in science, but this particular project did face an overwhelming challenge; enhancing capability options while minimizing or maintaining a nanostructure size that is not more than a single speck of glitter. Sizing up a lens of 100 microns to centimeter gives birth to humongous amounts of data. The whole idea of going nano is to make things smaller, not bigger. Harvard analysts invented a new algorithm that could work in strong compatibility with the technology that controls the basic integrated circuits. This led the team to create metalens of a centimeter or more in diameter and then incorporate it with semiconductor manufacturing.

The team then approached David Clarke, Extended Tarr Family Professor of Materials at SEAS for attaching the metalens to a dielectric elastomer actuator also known as an artificial muscle. Clarke helped the team achieve a combination of muscle and lens that was only 30 microns thick. You can check out the following video where Federico Capasso, who is the key researcher in this study, talks about creating flat lenses.