To create their thermal invisibility cloak, Guenneau and colleagues applied the mathematics of transformation optics to equations for thermal diffusion and discovered that their idea could work.
In their two-dimensional approach, heat flows from a hot to a cool object with the magnitude of the heat flux through any region in space represented by the distance between isotherms (concentric rings of diffusivity). They then altered the geometry of the isotherms to make them go around rather than through a circular region to the right of the heat sourceso that any object placed in this region can be shielded from the flow of heat (see image).
"We can design a cloak so that heat diffuses around an invisibility region, which is then protected from heat. Or we can force heat to concentrate in a small volume, which will then heat up very rapidly," Guenneau says.
The ability to shield an area from heat or to concentrate it are highly desirable traits for a wide range of applications. Shielding nanoelectronic and microelectronic devices from overheating, for example, is one of the biggest challenges facing the electronics and semiconductor industries, and an area in which thermal cloaking could have a huge impact. On a larger scale and far into the future, large computers and spacecraft could also benefit greatly. And in terms of concentrating heat, this is a characteristic that the solar industry should find intriguing.
Guenneau and colleagues are now working to develop prototypes of their thermal cloaks for microelectronics, which they expect to have ready within the next few months.
|Contact: Sarah Cogan|
Optical Society of America