Electrochromic Adaptive Infrared Camouflage

The goal of this research program was to create a technology for artificially programmable infrared emissivity of surfaces. As an example, this would permit a vehicle, or a person to blend into its surroundings, and become invisible to an infrared camera. A great deal has been accomplished in this research program, that will help convert this technology into a practical reality. The main technical objective is the controlled reduction of infrared emissivity. An emissivity reduction not an increase is desired, since objects of interest are generally hotter than their surroundings. The tunability of emissivity is made possible by electrochromics. Today, electrochromics is becoming a common technology that is used, for example, in self-dimming rear view mirrors in automobiles. Electrochromic materials change their color by undergoing an electronic transition of some form. In the most common type the electronic transformation is induced electro-chemically in special polymeric materials. In effect this is a type of electrochemical doping, with the material thereby undergoing a transition from an insulator to a metal, with the corresponding changes in color.