Many species have the ability to change their coloring to mimic the environment, and camouflage themselves from other animals. For longer than can be guessed, humans have also been advancing our own camouflage techniques, to protect and conceal ourselves from others too. Now researchers at the Harvard School of Engineering and Applied Sciences (SEAS) have created a material that is able to camouflage itself from thermal cameras, and potentially more.
Vanadium oxide is a curious material that will transition from an electrically insulating state to a conducting one as it is heated. This phenomenon has been known of since 1959, but has been difficult to study because the transition could shatter large crystals of the stuff. The discovery of how to produce pure thin films of vanadium oxide though has enabled a great deal of new science, as the films are more resilient. This latest discovery takes advantage of the fact that changes in a material's electrical properties also affect its optical properties, and all of these can be manipulated by adding imperfections. This is how the SEAS researchers were able to make the coating appear to be much cooler to a thermal camera than it actually was.
While thermal camouflage is definitely one avenue many will be looking to explore, this discovery could enable many other technologies. One example would be beacons that respond to only specific infrared frequencies and another would be using a vanadium oxide thin film to accelerate the heating or cooling of a structure.
Source: Harvard University