MONDAY, 14 JUNE 2010
The device, officially called an 'omnidirectional electromagnetic absorber', consists of a thin cylinder containing 60 strips of circuit board arranged in concentric layers and coated in copper. Each layer is imprinted with alternating patterns, which either resonate or do not resonate with electromagnetic waves. The device can trap and absorb electromagnetic waves coming from all directions by spiraling the radiation inwards and converting its energy into heat with an absorption rate of 99%. Hence it behaves like an 'electromagnetic black body' or an 'electromagnetic black hole' and has been compared to an astrophysical black hole (which, soaks up matter and light).
This experimental result is in agreement with the theoretical work proposed in 2009, where theoretical analysis and numerical simulations showed that all optical waves hitting the non-magnetic metamaterials are trapped and absorbed. This device at present only works at microwave frequencies, but the researchers are planning to develop a black hole for visible light next.
Written by Nitika Somani