Researchers at ETH Zurich have unveiled a major innovation in optics and materials science, developing a new type of pixel that can not only create images but also capture them. This pioneering technology is expected to be used in devices that function as both a screen and a camera at the same time, opening the door to a new generation of electronics with unprecedented capabilities.
Playing With Light
Pixels, the microscopic building blocks that make up every digital image, have until now served just one purpose: either projecting images on screens or capturing light in digital camera sensors. In other words, screens and cameras have relied on different types of pixels, each engineered for a different job.
In commercially available devices, screens and cameras still work as separate systems, each requiring its own components for displaying and capturing images. A research team led by Professor David Norris at ETH’s Optical Materials Laboratory has managed to break past that limitation, unveiling so-called “bidirectional” pixels capable of performing both functions at once. The technology brings us a step closer to a new generation of devices where screen and camera exist within the same system.
The research, published in the journal Nature, is based on a fundamental physical phenomenon: the interference of light waves. When light interacts with a specially engineered surface, the waves it produces overlap. If their phases align, they reinforce each other; if they’re opposite, they cancel out. The scientists harnessed this exact phenomenon to control light with remarkable precision.
One Pixel, Maeny Properties
The technology’s secret lies in microscopic patterns etched onto the surface of a specialized optical chip. These act as “guides,” letting researchers control the chip’s behavior and generate light waves with specific physical properties. The interaction of these waves produces images and shapes, while mathematical algorithms help researchers design the exact conditions needed for each desired optical effect. The new pixels can not only display images but also “read” the light they receive. By controlling properties like phase and polarization, they shift from simple display elements into smart optical sensors.
In the future, phones, computers and other electronic devices could feature screens that double as cameras, removing the need for separate image sensors. The new pixels could also upgrade fields like optical communications, advanced imaging systems, high-precision sensors and photonic AI applications. The research team is already working to scale the technology from individual pixels to full arrays, aiming to make functional, high-resolution camera-screens a practical reality. The team’s new creation, developed under Professor Norris, has also been nominated for this year’s ETH Spark Award, which recognizes the most innovative research ideas with real-world potential.
This technology marks another step toward the “smart” optical devices of the future, ones where imaging, sensing and light processing all happen at once, with greater speed, smaller size and improved energy efficiency
