Heat Cloak. A series of concentric rings lets heat propagating from left to right across a metallic sheet flow more readily around a thermally isolated disk than toward its center, leaving no sign of the disk in the temperature distribution on the right side. The colors represent temperatures measured with an infrared camera and are superimposed on a photo of the structure before the rubbery insulating material was added to the holes and gaps. The white lines connect points at the same temperature.
Credit R. Schittny/Karlsruhe Inst. of Tech.