Harry Potter fans, there is a great news for you! No, we are not talking about the (possible?) new episode of the most famous magician in the world saga, but the accessory that everyone, absolutely everyone, fans of the supernatural or not, would like to try at least once in their life: the invisibility cloak!
Someone has already tried in the past, but with… too bulky results!
To distort the length of the light wave, in and out, in fact, we need layer upon layer of material, to confound the observed object with the background behind it. Now, scientists have finally created a sort of thin fabric using only a single-layer sheet.
“This cloaking device basically fools the observer into thinking that there’s a flat surface” said Boubacar Kanté, from University of California, and senior author of the study that was published in Progress In Electromagnetics Research.
“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,” said Li-Yi Hsu, the first author of the study. “In this study, we show that we can use a thin single-layer sheet for cloaking.”
This new coverage distorts the light rays that strike it. The light rays distorted behave as if they came from a flat surface. Yes, but what this “cloak” is made of? The materials responsible for this effect are ceramic and Teflon, which combined together form a dielectric: a poor conductor material, which has the property of not absorb much light, and reflect most of it. They have been adapted in small scale, for directing light beams reflected in the most suitable way to go to produce the effect of a flat surface.
With this material, it also solves a problem that some other “cloaks” have so far failed to correct. The old concealment systems significantly reduced the brightness of the space behind them, because containing metal particles, able to absorb a lot of light. This single layer has a lower loss of intensity than in previous versions. “Imagine if you saw a sharp drop in brightness around the hidden object, it would be an obvious telltale,” commented Kanté.
“Doing whatever we want with light waves is really exciting,” said Kanté. “Using this technology, we can do more than make things invisible. We can change the way light waves are being reflected at will and ultimately focus a large area of sunlight onto a solar power tower, like what a solar concentrator does. We also expect this technology to have applications in optics, interior design and art.”
And we are looking forward the moment this technology will be available!