A “perfect lens” that could let us zoom into single cells and viruses at a relatively low cost is a step closer to reality, thanks to researchers at Michigan Technological University (MTU) and Washington University in St. Louis. Their research was published in the journal Physical Review Letters.
Often dubbed the “holy grail” of optical science, creating such a device has been dogged by complications since it was theorized 15 years ago. You may be familiar with a scanning electron microscope (SEM), which enables scientists to resolve images down to the nanoscale, but at a price of $1 million (£650,000). A perfect lens (or superlens) would carry the same functionality, but at a fraction of the cost – cheap enough to be used in smartphones in the future.
The perfect lens would be made of metamaterials, which are essentially materials engineered to alter how they interact with light. In this case, silver is engineered at the nanoscale to behave like a glass. Light waves are made to pass through the metal, instead of reflecting off it, far exceeding the optical power of ordinary lenses.
Regular optical devices run into problems when they try to magnify extremely small objects below 200 nanometers in size, as they simply can’t resolve them. For a comparison, think of those distant images of Pluto we had before New Horizons arrived; our most powerful optical telescopes, even Hubble, could only show the dwarf planet to be a blurry dot, because the resolution simply wasn’t good enough.
Now the researchers say they have solved one of the key problems in making a perfect lens. Namely, they have been able to get light waves to pass through a lens without getting consumed. This means objects smaller than 200 nanometers could be resolved by an optical device without losing resolution.
Speaking to IFLScience, lead researcher Durdu Güney of MTU said there was “no theoretical limit" on how small an object a perfect lens could see. The only real limitation – and problem – is the creation (or "fabrication") of the lens with the required nanoscale features. “To modify silver at a nanoscale level, it needs some sophisticated fabrication methods,” he said.
Durdu Güney, pictured, and his team think a perfect lens could be just a few years away. Michigan Tech.
But now the scientists think they are close. Güney thinks that in a few years, he and his team could have a working prototype for a perfect lens. Ultimately, people could eventually have the power of an SEM in the palm of their hands. “Smartphones would be the ideal platform [for a perfect lens],” said Güney.
The possibilities for such a technology are almost endless. From cheaper medical devices to more accessible scientific instruments, people could be given the power of multi-million dollar microscopes to see the nanoscale-world with ease. “It will make life easier to understand because people will be able to see it with their own eyes,” Güney added in a statement.
Of course, there are a number of obstacles still to overcome. But the researchers seem to be fairly confident that, in a few years, the iPhone 10 (or whatever device is around then) will boast technology that many scientists today can only dream of.