The new “thermal camouflage” is actively heated or cooled outside, automatically adjusting to the temperature of the environment, making the carrier invisible to thermal imagers and night vision cameras.
Engineers from the University of California at San Diego presented a prototype of a “smart” metamaterial that can completely hide the media from thermal imagers. Unlike all analogues, the system successfully works at different ambient temperatures and quickly adapts to its changes. Scientists introduced a novelty in article published in the journal Advanced functional materials. It is briefly described in press release University of San Diego.
The concept, presented by the team of Professor Renkun Chen, is able to quickly heat up or cool down, adapting to the current environmental conditions. In less than a minute, he can raise the temperature of his outer surface from 10 to 38 ° C, while the temperature of the inner layers remains comfortable for the body.
For this, the developers used a soft, wax-like polymer with a melting point of about 30 ° C – like on the surface of the skin. In the heat it becomes more ductile and fluid, and hardens at a colder temperature, although it retains its insulating properties. And for masking, the outer layers of the material are penetrated by thin and flexible conductors of alloys with thermoelectric properties – capable of emitting and absorbing thermal energy during the passage of current.
A small prototype of “thermal camouflage” adapts to outside temperature and is almost indistinguishable in the picture from the FLIR IR camera / © Jacobs School of Engineering, UC San DiegoFinally, the entire system is connected to the battery and automatically adjusted wirelessly, heating or cooling the surface of the material depending on the ambient temperature. According to the developers, it allows you to actively mask an object in a wide temperature range, while all existing versions of “thermal camouflage” act passively, limiting the transfer of heat from the body to the outside, and only work in a certain narrow range.
In fact, despite a number of reports on work on active thermal camouflage, not a single similar project has yet been brought to practical use. Among them, one can recall thermoelectric plates Adaptiv BAE Systems or Eltics Israeli startup of the same name: several years ago they were actively promoted in the media, but neither one nor the other is still used. Perhaps a better future for a new, flexible and wearable system.
Having shown the prototype in action, Renkun Chen and his team are moving towards the next big goal and intend to get a full-fledged wearable jacket with built-in “thermal camouflage”. But for this they will have to significantly improve the development: in its current form, it will make the jacket too impractical. According to the authors, its camouflage will require an additional two kilograms of weight, five millimeters of thickness – and will not be able to function for more than an hour. So they have something to work on.
