A new type of “invisibility” cloak could take the heat off hot devices. A theoretical cloak that can shield a protected area from intense temperatures is described online March 26 in Optics Express.
“You can just dress your satellite in a thermal cloak,” says study author Sebastien Guenneau, of the French National Center for Scientific Research and the University of Aix-Marseille. A heat cloak just 1 or 2 centimeters thick might potentially protect a satellite from overheating as it re-entered the atmosphere, he says.
Until now, most invisibility cloaks have been made from metamaterials that guide light waves around a certain region of space, obscuring anything that lies within from sight. Similar cloaks have been designed to distort the trajectory of sound waves.
In the new study, similar ideas were applied to bend heat as it disperses in space. In a two-dimensional cloak, most of the heat could be manipulated to move around a cloaked region 300 micrometers across, or the size of a typical amoeba.
Though heat isn’t completely blocked, but only slowed, from dissipating into the cloaked area, Guenneau says there are potential applications for preventing materials from heating up too fast.
As computers are made on smaller scales, it’s harder to incorporate fans or heat sinks to deal with heat, says Nicholas Fang, a professor in mechanical engineering at MIT. This paper “opens up new opportunities to dissipate the heat laterally, uniformly through all directions,” he says.
Guenneau’s team also describes another theoretical tool that uses metamaterials to direct heat within a specific region, which could be useful in building better solar panels.