Chinese scientists create mini 'black hole'By Ben Coxworth
The microwave-trapping omnidirectional electromagnetic absorber
Researchersat Southeast University in Nanjing, China have created a device thattraps and absorbs electromagnetic waves coming from all directions,spiraling them inwards without any reflections, essentially creating anelectromagnetic black hole. Qiang Cheng and Tie Jun Cui’s“omnidirectional electromagnetic absorber” draws in microwaves comingfrom any direction by spiraling radiation inwards, and converting itsenergy into heat. They plan on developing a device that can absorbvisible light next.
Working in the university’s State KeyLaboratory of Millimeter Waves, Cheng and Cui built their device from60 strips of circuit board, arranged in concentric layers and coated inmetamaterials. The spiraling effect was created by usingnon-microwave-resonant metamaterials on the outer layer, while usingresonant ones in the inner core. Obviously, there was a little more toit than that, but the end result was a gizmo that absorbed 99 percentof incoming microwave radiation.
Besides Lex Luthor and company,who might be interested in such technology? Since the lossy core of thedevice can transfer the electromagnetic energies into heat energies,the scientist expect that the omnidirectional absorber could haveapplications in thermal emission and electromagnetic-wave harvesting,perhaps finding its way into electronic devices, imaging systems, orheating and cooling systems.
The research was published in the New Journal of Physics.
