Taking inspiration from Harry Potter movies, Chinese scientists may have finally created the ‘Cloak of Invisibility’, that could make us disappear in plain sight. Researchers at China’s University of Electronic Science and Technology have devised a camouflage material that adjusts its molecular composition to blend into the background — making the wearer imperceptible to the naked eye. The details regarding the ‘chameleon’ material have been published in the journal Science Advances.
The researchers said they managed to achieve ‘invisibility’ through a process called self-adaptive photochromism (SAP) in which molecules rearrange themselves when exposed to certain wavelengths of light. This causes the substance to change colour and effectively become unseeable. Notably, in nature, both chameleons and octopuses rely on active camouflage to change their appearance by blending into the surroundings.
“Applying this technology to clothing could make an individual effectively ‘invisible’,” head researcher Wang Dongsheng was quoted as saying by South China Morning Post (SCMP).
As per Wang, the SAP technology offers a simpler and more efficient way to achieve adaptive camouflage effects. Currently, most man-made systems achieve the effect using complex electronic devices, resulting in high costs and limited usability.
How was invisibility achieved?
According to the study, the “SAP materials are in primary black state under dark”. They spontaneously switch to another colour after being triggered by transmitted and reflected light in the background.
The researchers tested the material by placing a transparent container of SAP solution in coloured acrylic boxes. In turn, the SAP solution changed colour, matching the acrylic box. Next, the scientists placed a SAP solution-filled container in environments with matching colours. The solution adapted its colour to blend seamlessly with the surroundings within 30 to 80 seconds.
“A white light LED (10,000 lux) was used as the light source for triggering photochromism and illumination,” the study added.
Despite the advancement, scientists are yet to mimic the entire spectrum of colour with Mr Wang hopeful of achieving the same in his future work.
“We have not yet fully mimicked all colours within the visible light spectrum in this work, that would be revealed in our future work. By adding more photochromic molecules to the material or adjusting its composition, we aim to achieve finer distinctions in colour, and faster changing speed.”
The scientists added that SAP can also be used as a spray-on coating by adding polycaprolactone – a biodegradable polyester.