Let's get one thing out of the way before we begin - a real invisibility cloak, like in Harry Potter or Star Trek, doesn't exist and will not for many decades, if ever. The laws of physics don't really allow it.
But the laws of physics do allow us to bend light around objects carefully to give the impression - in certain wavelengths - that an object has disappeared. Until recently, the technology to do that has always been pretty bulky.
But now researchers at the University of California in San Diego have developed a far slimmer design for an invisibility cloak. It consists of a Teflon sheet studded with many small, cylindrical ceramic particles that change the way light waves reflect off the surface.
Reflection of light
With the help of simulations to optimise the cloaking effect, the team successfully concealed an object sitting still on a flat surface. "By changing the height of each dielectric particle, we were able to control the reflection of light at each point on the cloak," explained Li-Yi Hsu, first author of the study.
"Previous cloaking studies needed many layers of materials to hide an object, the cloak ended up being much thicker than the size of the object being covered," he said. "In this study, we show that we can use a thin single-layer sheet for cloaking."
The details of the discovery were published in the journal Progress in Electromagnetics Research
