Design and realization of thermal camouflage with many-particle systems

An object can be found and identified by detecting its scattering signature of various physical fields, e.g., electromagnetics, acoustics, thermotics, etc. Similar to optical illusion, a thermal camouflage device can replace an expected object without altering the heat scattering pattern. Here, we propose and realize a two-dimensional metasurface, which is capable of controlling the heat flow and can be used as a device for misleading thermal sensors. The thermal metasurface is composed of conventional particles with many-body local-field effects. Our experiments and finite-element simulations have confirmed the thermal camouflage effect for both line and point heat sources, demonstrating the performance of thermal illusion. Also, we show that this many-particle structure can be extended to three-dimensional systems, which opens a door for designing applicable camouflage devices in the future.