A new way to make large ultrathin infrared sensors that don’t need cryogenic cooling could radically change night vision for the military or even autonomous vehicles.
Night vision (thermal) is clunky, power-intensive, and requires cooling components that could be hard to get, especially in the event of a conflict with China. But the U.S. Air Force, Army, and special operations forces have growing needs for night-vision, as do next-generation autonomous vehicle makers.
In a study published today in Nature, researcher Jeehwan Kim of the Massachusetts Institute of Technology, along with collaborators from the University of Wisconsin-Madison, Rensselaer Polytechnic Institute, and Seoul National University, unveiled a process called “atomic lift-off,” or ALO, which creates extremely thin layers of special crystal material that can stand on their own without being stuck to, say, a graphene lattice. The resulting skin is thinner than 10 nanometers.
Most infrared sensors today, like the widely used mercury cadmium telluride detectors, have a big drawback: they need to be kept extremely cold—about -321°F—which means heavy, power-hungry cooling systems. That makes them hard to use in compact military gear, drones, or satellites, where space and power are limited.
The researchers found a way around that problem. They created an ultra-thin film, less than a hundredth the width of a human hair, made from a special material called PMN-PT. This material can sense tiny changes in heat with record-breaking sensitivity—about 100 times better than many older materials such as lithium tantalate.
Most importantly, PMN-PT sensors work at room temperature. That means they can detect a wide range of heat signatures in the far-infrared spectrum without needing to be chilled—potentially transforming how we build night vision and heat-sensing devices. The researchers proved that their new technique could be used to make larger and thinner infrared sensor films without losing quality. They created membranes just 10 nanometers thick and 10 millimeters wide—about the size of a fingernail—while keeping the crystal structure smooth and consistent.
They also built working infrared sensor arrays from slightly thicker membranes (80 nanometers) and found that every single device in the batch of 108 worked perfectly. The thinner 10nm versions were harder to handle during manufacturing, so fewer of those survived the process, but the ones that did still worked well.
The material can respond to wavelengths across the entire infrared spectrum, allowing the wearer to see more clearly than current night-vision would allow, or potentially to enable autonomous vehicles to better detect obstacles, threats, or pedestrians, even in foggy or difficult conditions that might inhibit cameras or other common sensors.
Even after being transferred to a new surface, the sensors kept their electrical performance. In tests, they stayed stable over time and detected heat as effectively as today’s best cooled infrared detectors—without needing heavy cooling equipment.
The project was supported by grants from the Air Force Office of Scientific Research and the U.S. Department of Energy.
The U.S. military isn’t just looking for smaller, more effective night vision, but also for new solutions that don’t rely on minerals, materials, or components from China. China is a major global supplier of thermal imaging equipment as well as germanium and chalcogenide, two key minerals in lenses required for thermal imaging.
This research points to a new kind of vision: not just night vision without cooling, but a production method for faster and cheaper development of night vision equipment with more U.S. components.
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