I did my undergraduate work at Ohio State, so I really hate to give props to Michigan for doing something cool, but this is truly extraordinary. You see that Michigan logo to the left? It’s only 12 microns wide. That’s one-sixth the width of a human hair. You couldn’t see it even if it was a few millimeters in front of your face.
Ah, says the Buckeye faithful, but look at how fuzzy it is! The resolution is terrible!
Yeah, because it has been magnified 5,000 times.
In a paper recently published in Nature Communications, a team of scientists from the University of Michigan’s Macromolecular Science and Engineering Department demonstrate the ability to use relatively straight-forward design strategies to create nanostructures capable of making the smallest pixels known to man.
Eat your heart out, Apple iPhone.
The theory behind it involves beams of light interacting with a thin layer of electrons on the surface of a metal. When the electrons begin to oscillate back and forth, they’re constrained by tiny slits cut into the surface. The distance between these slits controls the frequency of their oscillation, which in turn controls the color of light that is emitted by the same electron/light interaction on the other side.
In case you’re curious, the electrons movements are called plasmons and the entire process is called surface plasmon resonance.
The theory sounds fairly simple. In fact, it is. But we’re not talking about creating precise slits on a table top. Fabricating a structure with three layers combining to a thickness that is about as long as a single rabies virus isn’t easy. Neither is precisely cutting the slits less than a wavelength of light apart.
Specifically, we’re talking about sandwiching a 100 nm-thick zinc selenide layer between two 40 nm-thick aluminum layers. Then, cutting 360 nanometers between slits to create red light, 270 nanometers for green and 225 nanometers for blue.
The potential resolution is incredible. Projecting the three colors into a single area only microns wide creates a pixel that is about an order of magnitude smaller than those on a typical computer screen. What’s more, they’re about eight times smaller than the pixels on the iPhone 4, which are about 78 microns. Eventually, this technology could be used in projection displays, as well as wearable, bendable or extremely compact displays.