Two researchers from the State Key Laboratory of Millimeter Waves at Southeast University from Nanjing, China, have discovered and prototyped a device that acts like a black hole for electromagnetic waves in the microwave spectrum. It consists of 60 concentric rings of metamaterials, a class or ordered composites that can distort light and other waves.
Qiang Cheng and Tie Jun Cui called their device “omnidirectional electromagnetic absorber”. The 60 rings of circuit board are arranged in concentric layers and coated in copper. Each of the layers is printed with alternating patterns, which resonate or don’t resonate in electromagnetic waves.
What is indeed very amazing is that their device can spiral 99% of the radiations coming from all directions inside it and convert them into heat, acting like an “electromagnetic black body” (or “hole”).
The omnidirectional electromagnetic absorber could be used in harvesting the energy that exists in form of electromagnetic waves and turn them into usable heat. Of course, turning the heat back into electricity isn’t a 100% efficient process (far from it), but directly harvesting electromagnetic waves in the classic antenna-fashion is way too inefficient compared to this black hole.
“Since the lossy core can transfer electromagnetic energies into heat energies, we expect that the proposed device could find important applications in thermal emitting and electromagnetic-wave harvesting.”
Possible uses can vary from powering your phone with the existing electromagnetic energy that surrounds it, to wireless power transmission and even powering space ships – it all depends on the wavelength that the device is tuned to.
The question that arises is: would this kind of devices have other uses than these constructive ones mentioned above?