Researchers have now built a 3D thermal cloak that could prevent infrared detection. The device was created by engineers at the University of Illinois Urbana-Champaign (UIUC) and the Technical University of Denmark, who describe it as the first free-form, omnidirectional 3D thermal cloak. In laboratory tests, the cloak kept the temperature inside relatively uniform while restoring the heat pattern outside, effectively concealing a complex 3D object from an infrared camera when heat was applied from different directions. A convincing thermal cloak cannot conduct heat uniformly. With the cloak, heat flowed around the core and returned to its original path, leaving the external temperature pattern largely undisturbed.