This flexible,
stretchable and tunable "meta-skin" can trap radar waves
and cloak objects
from detection. Larger photo. Photo courtesy of Liang Dong.
(March 7, 2016) Iowa
State University engineers have developed a new flexible, stretchable and tunable “meta-skin” that uses rows of small,
liquid-metal devices to cloak an object from the sharp eyes of radar.
The meta-skin takes its name from metamaterials, which are
composites that have properties not found in nature and that can manipulate
electromagnetic waves. By stretching and flexing the polymer meta-skin, it can
be tuned to reduce the reflection of a wide range of radar frequencies.
The journal Scientific Reports recently reported the
discovery online. Lead authors from Iowa State’s department of electrical and
computer engineering are Liang Dong, associate professor; and Jiming Song,
professor. Co-authors are Iowa State graduate students Siming Yang, Peng Liu
and Qiugu Wang; and former Iowa State undergraduate Mingda Yang. The National
Science Foundation and the China Scholarship Council have partially supported
the project.
“It is believed that the present meta-skin technology will
find many applications in electromagnetic frequency tuning, shielding and
scattering suppression,” the engineers wrote in their paper.
Dong has a background in fabricating micro and nanoscale
devices and working with liquids and polymers; Song has expertise in looking
for new applications of electromagnetic waves.
Working together, they were hoping to prove an idea: that
electromagnetic waves – perhaps even the shorter wavelengths of visible light –
can be suppressed with flexible, tunable liquid-metal technologies.
What they came up with are rows of split ring resonators
embedded inside layers of silicone sheets. The electric resonators are filled
with galinstan, a metal alloy that’s liquid at room temperature and less toxic
than other liquid metals such as mercury.