China developed an invisibility cloak

Chinese scientists have found a way to produce stealth materials on a large scale and at a cheaper cost.

The South China Morning Post on December 16 reported that a group of scientists in Changchun, the capital of Jilin Province, China, has achieved an important breakthrough to create an invisibility cloak . The shirt can cause objects to become invisible to the human eye through bending the wavelength of light around.

Although this technique called "negative refractive index" is not new, the team claims they have found a way to make a larger sheet of material, significantly reducing costs. Previously, scientists could only use this technology on very small materials.

Normally, the light that touches the object will bounce back, allowing people to observe the object. The new material counteracts that effect by letting the photons pass through in a predetermined direction. As a result, the light moving around the material covered with this material is like water flowing through rocks in the river. The person standing in front of the material covering still saw things behind it, giving off a feeling that the item didn't exist.

Invisibility cloaks can be mass-produced in the future.(Artwork: The dailypedia).

The fabrication of this material is more complicated than computer chip manufacturing. Billions of independent textures are engraved on the surface of the sheet metal to create a stealth effect, causing the cost to rise.

However, the group of scientists, headed by Yang Chengliang at the Applied Optical Laboratory of the Changchun Optical Institute, under the Chinese Academy of Sciences, believed they could solve the problem of size and cost.

According to Yang, the researchers were able to produce a silver crystal stain that had the potential to be in the size of one square meter or more and cost less than an expensive towel. They use chemicals to create large nanofibre structures from silver, altering the direction of light's movement by acting on electrons within the photon, or light particles . The results of the study are published in the journal Optics Express of the American Optical Society.

Yang said the method is relatively simple and easy to put into mass production, but it takes about a decade to bring the product to market.

Despite good light control, this material is still light . This drawback can lose stealth because it makes the wearer look like he's moving in the shade, Yang said. The team is also looking to improve the brightness of the material. Because it was only a few microns thick, it was too thin to sew clothes.

However, this breakthrough still creates interest for researchers. A similar technology research scientist at Shanghai's Fudan University said the method would facilitate mass production of invisibility cloaks. It can also be used to create "super lenses", which help satellites capture the Earth with unprecedented sharpness.