Cheap Invisibility Cloaks Can Be Built Using 3D Printers: Researchers

According to researchers from Duke University, people can make their own invisibility cloaks at home by using 3-D printing called stereolithographic fabrication.

Yaroslav Urzhumov, assistant research professor in electrical and computer engineering at Duke's Pratt School of Engineering, said that anybody who can get a 3-D printer worth a couple of thousands can make the cloak. The cloak can be made on a non-industrial strength 3-D printer.

Duke University researchers had created an invisibility cloak in 2006. Now, a variation of the cloak can be made using a 3-D printer and this new cloak can deflect microwave radiation. The team is confident that in the near future we might get cloaks that can deflect visible light.

"We believe this approach is a way towards optical cloaking, including visible and infrared," Urzhumov said in a news release. "And nanotechnology is available to make these cloaks from transparent polymers or glass. The properties of transparent polymers and glasses are not that different from what we have in our polymer at microwave frequencies."

In the current study, researchers created a kind of cloak that resembles Frisbee^TM disc. An algorithm decides the holes in the disc that deflect the microwaves. The entire fabrication of the disc takes about 3-7 hours. In theory, larger invisible devices can be made using the printer.

Researchers placed an object in the middle of the disc. The disc along with the object was then exposed to microwave radiations. However, the disc deflected the radiations and made it appear as though there was no object.

"The design of the cloak eliminates the 'shadow' that would be cast, and suppresses the scattering from the object that would be expected. In effect, the bright, highly reflective object, like a metal cylinder, is made invisible. The microwaves are carefully guided by a thin dielectric shell and then re-radiated back into free space on the shadow side of the cloak," said Urzhumov.