Invisibility Screen Closer to Harry Potter Cloak
Science is moving us toward a real invisibility cloak centimeter by centimeter, like a Harry Potter fan steadily re-reading the original series.
The latest advancement comes from scientists in Texas who developed an ultrathin “metascreen” cloak. Similar to other cloaking advancements, this one successfully hid a 3-D object from microwaves — but not yet from visible light.
You might remember the group from Duke University that was able to hide a tiny three-inch-long rod from microwave radiation last year using metamaterials. They used a specially designed diamond-shaped device to achieve the effect.
Metamaterials are man-made materials that can bend light, sound, and other waves in unnatural ways. This time, however, scientists in Texas hid a seven-inch-long cylindrical rod using what they’re calling a “metascreen” – a mantle they made by attaching incredibly thin copper tape to a flexible polycarbonate film in a fishnet design.
This mantle cancels out light (in this case microwaves) as they scatter off the cloaked object — rendering them invisible to the eye.
It seems we may be getting closer to the “cloak” part of an invisibility cloak. Unfortunately for scientists, Harry Potter fans have an insanely high bar set in their minds: The lightweight silvery cloth that “was strange to touch, like water woven into material,” as J.K. Rowling wrote in the first book.
Although you and I can still see the scientists’ metascreen, they think their mantle cloak might have practical applications inside nanotags, nanoswitches and noninvasive sensors for biomedicine.
The research was led by Andrea Alù and his colleagues in the Department of Electrical and Computer Engineering as well as the Department of Physics and published in the New Journal of Physics (abstract).