How do you become invisible to a device that doesn’t need visible light to see you? Thermal imaging cameras, which can be useful in daylight as well night, work by detecting infrared radiation. An effective thermal camouflage requires an engineering hat-trick. You need a material that is flexible, can adapt to different temperatures, and can do so extremely quickly.
Some of the difficulties encountered in the development of thermal camouflage so far include poor temperature variability, slow response times, and the requirement for rigid materials, to name a few. Now Coskun Kocabas at University of Manchester in Manchester, England, along with colleagues at the Massachusetts Institute of Technology (MIT) in Cambridge, Mass., as well as Bilkent University and the Izmir Institute of Technology in Turkey, have developed a flexible camouflage system that blends with background temperatures within seconds. To achieve this, they needed graphene, a few ions, some nylon and a little gold. The system involves two flexible electrodes: the top electrode is made up of layers of graphene while the bottom electrode is made of heat-resistant nylon coated with gold. Between them sits a liquid of positively and negatively charged ions. In the presence of a small voltage, the ions travel into the graphene, which is then able to absorb infrared radiation being emitted by the wearer.
