Scientists have come one step closer to an “invisibility cloak” by cloaking a free standing object in three-dimensional space.

While previous cloaking technology has been limited to two-dimensional boundaries, researchers at the University of Texas have successfully cloaked a 7.2 inch long cylindrical pipe from microwave light. They were able to do this on the three-dimensional level as well, meaning that the pipe would appear to be hidden from any angle it was viewed from.

Unfortunately, since human beings cannot see microwaves, the pipe would still be visible to the naked eye even under cloaked conditions. However the pipe appears to disappear completely when examined by a device that ‘sees’ microwave light. The method behind this process called “plasmonic cloaking” proves that cloaking is possible, but obviously more research has to be done for it to work at the human visible level.

Plasmonic cloaking only works successfully if the object being cloaked is covered with plasmonic meta-materials, which are composites of metal and non-conductive synthetics made of nanometre-sized structures that are far smaller than the wavelength of the light that strikes them.

When the incoming light hits the meta-material, instead of bouncing the photons back in one direction, it excites and scatters them in random outward directions, which makes it impossible to see.

While work on visible light cloaking may still be a bit far away, the uses of microwave cloaking can be applied to present day technologies such as military reconnaissance aircraft. Given how high they already fly, they could also escape radar communication towers using microwave transmissions allowing them to achieve “super-stealth”.

Co-lead investigator Andrea Alu sad that “camouflaging to radar is one important application, a super-stealth device to make objects invisible to radar.

“What we are thinking about is not necessarily cloaking the whole warplane but some hotspots, a part such as the tailplane that you would want to cloak because it reflects most of the energy (from microwave radar).”