We’re living in the age of miniaturization. Whether it’s a smartwatch, AR glasses, or the many other gadgets we’ve reviewed here at Gizmodo, tech is getting increasingly smaller. New research takes this to yet another extreme, with researchers developing the smallest pixel ever.
In a recent Science Advances paper, researchers report the creation of the smallest pixel ever, using optical antennas that convert radiation into focused energy bits. The pixel measures just 300 by 300 nanometers—around 17 times smaller than a conventional OLED pixel, but with a similar brightness.
To put the size into context, a display with an area of just one square millimeter could fit a resolution of 1920 x 1080 pixels using the new technology. The tiny pixel also glows on its own, making it potentially revolutionary for the next generation of smart, portable devices.
How do things glow?
OLED stands for organic light-emitting diode and, true to its name, consists of several ultra-thin films made from organic materials. These layers sit between two electrodes. When electricity flows through the system, it activates the organic material in the films, releasing energy as light.
A pixel, on the other hand, generally refers to the smallest unit of information for digital image displays. Theoretically speaking, a smaller pixel size would enable a device to carry more pixels and increase image resolution. But existing technologies face “substantial manufacturing challenges and efficiency losses when scaled down to the (sub)micrometer regime,” according to the paper.
Tiny cracks in the light
This becomes especially pertinent when researchers attempt to shrink OLED pixels below the wavelengths of visible light—about 400 to 700 nanometers. Put simply, the geometry of the OLED system, along with other quantum mechanical effects, causes imbalances in electrical distribution within the cell.
“As with a lightning rod, simply reducing the size of the established OLED concept would cause the currents to emit mainly from the corners of the antenna,” Jens Pflaum, study co-author and a physicist at the University of Würzburg in Germany, explained in a release.
What’s impressive about the new paper is that the team identified a way to effectively block these unwanted structures, called filaments, from potentially destroying the pixel. Specifically, they fabricated a thin, insulating layer with a tiny circular opening at its center and layered it over a gold optical antenna.
The arrangement proved surprisingly effective in preventing filaments from forming. The optical antenna additionally helped focus electromagnetic energy and amplify the brightness, according to the paper. As a result, “even the first nanopixels were stable for two weeks under ambient conditions,” said Bert Hecht, study senior author and a physicist at the University of Würzburg, in the release.
That said, the system is still a prototype, with about 1% efficiency. However, the researchers noted that because the current paper eliminates one of the biggest challenges of scaling down pixels, the next steps should be slightly easier.
“With this technology, displays and projectors could become so small in the future that they can be integrated almost invisibly into devices worn on the body—from eyeglass frames to contact lenses,” the researchers added.
