‘Thermal cloak’ hides objects from heat
Posted by Xeno on March 28, 2012
The thermally cloaked region is shown in the centre of this heat map
The range of physical phenomena that scientists are trying to “cloak” objects from has a new entry – heat.
… “Heat isn’t a wave – it simply diffuses from hot to cold regions,” he said.
“The mathematics and physics at play are much different. For instance, a wave can travel long distances with little attenuation, whereas temperature usually diffuses over smaller distances.”
The trick was to apply the mathematics of transformation optics to the equations describing diffusion; the result, Dr Guenneau and his colleagues found, was a means to shuttle heat around at will.
The approach is fundamentally different from temperature-changing cloaks that heat and cool actively to mimic objects of different temperatures and have proven to “hide” a tank.
In the new technique, the researchers propose a cloak made of 20 rings of material, each with its own “diffusivity” – the degree to which it can transmit and dissipate heat.
“We can design a cloak so that heat diffuses around an invisibility region, which is then protected from heat,” Dr Guenneau explained.
“Or we can force heat to concentrate in a small volume, which will then heat up very rapidly.”
It is this ability to direct and concentrate heat that may find first application, for instance in the microelectronics industry, where the heat load in specific areas remains a difficult challenge to engineers.
Use it to divert the heat of the sun to solve the climate change and energy problems.