Infrared cameras are extremely helpful for drones in locating their targets even during dense night time and heavy foggy days. Lately a new kind of cloaking material has come up that hides hot objects like human bodies and military vehicles from these cameras.
This sheet is approximately one millimetre thick and has the capability of absorbing almost 94% of the infrared light it encounters. The cloaking material hides the human body from the invisible detectors. This technology helps to a great extent in deceiving an infrared detector by presenting a fake heat signature. This cloaking material is made up of a unique material called black silicon which is incorporated into solar cells usually. Black silicon has the capability of absorbing light because it consists of millions of microscopic needles (called nanowires) all pointing upward like a densely-packed forest. Jiang and colleagues were the first to discover this potential of black silicon. They made nanowires by making use of tiny particles of silver to help etch down into a thin layer of solid silicon, which resulted into a thicket of tall needles. Both the nanowires and the silver particles have helped a lot in being able to absorb infrared light. The black silicon also possesses flexible backing interspersed with small air channels. Those air channels prevent the stealth sheet from heating up too quickly as it absorbs infrared light.
By: Anuja Arora