Ames, Iowa – Engineers and material scientists at Iowa State University have created a “meta-skin” that makes objects invisible to radar. The stretchable polymer sheet is capable of absorbing radar waves at any angle and researchers believe this new cloaking technology has the potential to replace the stealth strategies currently used by the U.S. military’s B-2 bomber.
Radar waves are trapped by liquid-metal devices that are lined up across the meta-skin. The paper published in the journal Scientific Reports states that the small devices are split ring resonators that appear in a row and placed in layers of silicone sheeting.
These resonators act like electric inductors and the gaps between the rings serve as electric capacitors. The liquid metal alloy inside the resonators is called galinstan.
The inductors and capacitors combined absorb radar waves within a specific frequency. The U.S. military’s B-2 stealth bomber uses a cloaking technology that can only negate direct reflection of radar waves whereas this new stretchable skin can be pulled tight to broaden the range of radar frequencies the resonators are able to trap.
“It is believed that the present meta-skin technology will find many applications in electromagnetic frequency tuning, shielding and scattering suppression,” scientists wrote in the paper.
The study authors have shown they can use the same sheet of material to trap 75 percent of radar waves across the whole frequency range between 8 and 10 gigahertz, as reported by United Press International.
With further development, scientists could come up with optical cloaking devices
Although researchers say the cloaking technology requires further testing and tweaking, Liang Dong, who teaches electrical and computer engineering at Iowa State, said in a press release that he and his colleagues hope to shrink the size of the devices in the long term and then they would be able to use the meta-skin with higher-frequency electromagnetic signas, including visible or infrared light.
To do that, Dong said they would need advanced nanomanufacturing technologies and some structural changes but they he believes this research proves that it is possible to effectively use skin-type metamaterials for frequency tuning and broadening, as well as for multidirectional wave suppression.
If they succeed at applying the same concept to this, they could create optical cloaking devices with the appropriately delicate construction methods and techniques.
Source: United Press International