Inspired by the Harry Potter movies, Chinese scientists have created a "Cloak of Invisibility" that can make someone disappear. Researchers at the University of Electronic Science and Technology in China have developed a special material that changes its molecular structure to blend in with its surroundings. This makes the wearer hard to see. The details of this "chameleon" material were published in the journal Science Advances.

The researchers said they created "invisibility" using a process called self-adaptive photochromism (SAP). In this process, the material’s molecules rearrange when exposed to certain types of light. This causes it to change colour and become invisible. In nature, chameleons and octopuses use similar techniques to blend into their surroundings.

According to the South China Morning Post (SCMP), “using this technology in clothing could make someone effectively 'invisible,'" said head researcher Wang Dongsheng

Wang said that SAP technology provides a simpler and more efficient way to create adaptive camouflage. Right now, most systems that achieve this effect rely on complicated electronic devices, which makes them expensive and not very practical.

The study says that the "SAP materials are initially black in the dark." They automatically change to a different colour when triggered by light from the background, both transmitted and reflected.

The researchers tested the material by putting a transparent container filled with the SAP solution inside coloured acrylic boxes. The SAP solution changed the color to match the box. They then placed the container in environments with matching colours, and the solution adapted its colour to blend in within 30 to 80 seconds.

The study mentioned that a white LED light (10,000 lux) was used to trigger the colour change.While this is a significant step, scientists have not yet been able to mimic the entire spectrum of colours. However, Mr. Wang is hopeful that future work will achieve this.

"We haven’t yet recreated all the colours in the visible light spectrum, but we plan to do this in future work," the researchers explained. "By adding more photochromic molecules or modifying the material’s composition, we aim to achieve more accurate colour changes and quicker response times."

They also noted that SAP could be used as a spray-on coating by incorporating polycaprolactone, a biodegradable polyester.