A team of US engineers has developed a new flexible "meta-skin" which can be tuned to reduce the reflection of a wide range of radar frequencies to cloak an object.
To prove an idea that electromagnetic waves -- perhaps even the shorter wavelengths of visible light -- can be suppressed with flexible, tunable liquid-metal technologies, a team of engineers from the Iowa State University came up with the new technology.
Their meta-skin, described in the journal Scientific Reports, takes its name from metamaterials - composites that have properties not found in nature and that can manipulate electromagnetic waves.
Test results showed that the new technology suppresses radar waves about 75 percent in the frequency range of 8 to 10 gigahertz. When objects were wrapped in the meta-skin, the radar waves were suppressed in all incident directions and observation angles.
"Therefore, this meta-skin technology is different from traditional stealth technologies that often only reduce the backscattering, i.e., the power reflected back to a probing radar," the engineers wrote.
The technology could be used to coat the surface of the next generation stealth aircraft. But the researchers are hoping for even more -- a cloak of invisibility.
"The long-term goal is to shrink the size of these devices," said lead author Liang Dong, associate professor at Iowa State University.
"Hopefully, we can do this with higher-frequency electromagnetic waves such as visible or infrared light. While that would require advanced nanomanufacturing technologies, this study proves the concept of frequency tuning and broadening and multidirectional wave suppression with skin-type metamaterials," Dong added.
