Researchers have created the first "invisibility cloak" that is fueled with battery power.
The external power source would create a wider bandwidth of operation, and would allow users to render devices invisible to radio sensors "over a greater range of frequencies," a University of Texas at Austin news release reported.
The new cloak could camouflage objects as well as improve "cellular and radio communications, and biomedical sensing." As of right now invisibility cloaks are only able to hide objects from radio-detection, but researchers are on the right track to creating one that tricks the human eye as well.
Most of the invisibility cloaks that have been designed in the past used "metamaterials (advanced artificial materials) or metasurfaces (flexible, ultrathin metamaterials)," which scatter light that bounces off the object. Fields scattered from both the cloak and object "cancel each other out," making them undetectable to radio wave detectors.
"Many cloaking designs are good at suppressing the visibility under certain conditions, but they are inherently limited to work for specific colors of light or specific frequencies of operation," Andrea Alù, associate professor in the Department of Electrical and Computer Engineering at the Cockrell School of Engineering, said. "We prove that cloaks can become broadband, pushing this technology far beyond current limits of passive cloaks. I believe that our design helps us understand the fundamental challenges of suppressing the scattering of various objects at multiple wavelengths and shows a realistic path to overcome them."
A combination of "[batteries], circuits and amplifiers" allows the cloak to scatter over a much wider range of frequencies than has been accomplished in the past. The device will also be thinner and lighter than anything similar that has been proposed before.
Past studies have found that other cloaking solutions could become transparent under certain frequencies. While this new model won't be foolproof, it will be the most "broadband and robust performance of a cloak to date," the news release reported.
