Snakes’ mind-bending ‘heat vision’ inspires scientists to build a 4K imaging system that could one day fit into your smartphone
Chinese scientists have developed a unique artificial imaging system, inspired by snakes, capable of “seeing” heat emanating from their prey in complete darkness. The sensor captures ultra-high resolution infrared (IR) images in 4K resolution (3840 × 2160 pixels), which matches the image quality of the iPhone 17 Pro camera.
Any object with a temperature above absolute zero (-460 degrees Fahrenheit or -273 degrees Celsius) emits electromagnetic radiation. For normal body heat, its wavelength is in the IR range. The human eye can only sense shorter wavelengths in the visible light range.
Snakes can also see visible light, but some species, like vipers (Crotalines), also have a special heat-sensing organ right next to their nostrils that allows them to view longer wavelength IR radiation.
It is called a “pit” organ because it includes a hollow chamber with a thin membrane suspended across it. When IR waves heat specific areas of the membrane, a thermal “image” is sent to the brain via attached nerves.
Scientists at the Beijing Institute of Technology used this concept to create their own infrared detection system. They stacked layers of different materials on an 8-inch disk, through which the radiation passes until it manifests itself as a high-quality image visible to the human eye. The system was described in a study published August 20 in the journal Nature. Light: science and applications.
The first layer of the imaging system is an infrared detection layer, formed of “colloidal quantum dots” — tiny nanoparticles made of mercury and tellurium atoms that release electrical charges when they absorb infrared radiation. The charges then pass through several noise reduction layers to a layer of organic light-emitting diodes (LEDs) known as an “upconverter.”
Here, electrons encounter “holes” (absences of electrons) and release energy, which phosphorescent molecules convert into visible green light. Finally, the visible light encounters the “complementary metal oxide semiconductor” (CMOS) layer and is converted into an image.
IR vision in future smartphones and cameras
This is the first system capable of transforming short and medium wave IR (wavelengths from 1.1 to 5 micrometers) into an ultra-high resolution image at room temperature. Since the CMOS sensor sits directly above the upconverter, the weakest IR signals are captured before noise can drown them out. In other systems, where the CMOS and boost converter are separated, expensive cryogenic cooling is required to prevent noise buildup as signals pass between them.
Being able to see infrared radiation effectively extends the range of wavelengths visible to humans by more than 14 times. A camera equipped with sensor technology will be able to detect hot objects in low light conditions, such as in fog, through smoke or at night.
“Extended machine vision in the infrared range could work in all weather, day or night, regardless of extreme weather conditions, and be useful in new areas such as industrial inspection, food safety, gas detection, agricultural science, and autonomous driving,” the researchers wrote in the study.
They added that tens of millions of pixels using their system “could be obtained at extremely low cost”, making the technology more feasible for consumer cameras and smartphones in the future.
In fact, these devices already use standard silicon CMOS sensors on which the layers could be attached.
