Material Magic: Meet This Incredible Invisibility Cloak
For centuries, scientists have tried to make visible object invisible. Now, a team of scientist from the University of California San Diego have taken a huge leap forward with a super thin ‘invisibility cloak’ design that conceals both an object’s 3 dimensionality and its shadow.
The research team claims the principles behind the cloak are really quite simple: Take an object such as a ring and lay the cloak over it. By bending light, the surface of cloak erases the three dimensionality of the ring – along with any shadows – leaving just the illusion of a completely flat surface.
The surface of this incredible cloak is made of ultra thin Teflon sheets embedded with tiny, cylindrical ceramic particles. The Teflon has a low refractive index, while the ceramic particles have a high refractive index, allowing the material to scatter the light without absorbing any of it. The nature of this light scattering closely mimics that of light reflecting off a flat surface, leading observers to think they are seeing a completely flat surface even though they are not.
While in past years a number of invisibility cloaks have emerged, none appear to have been as successful as this latest version. This is partly because earlier invisibility cloak concepts used metal particles that absorbed light, rather than reflecting it. This caused the cloaks to look less vibrant than their surroundings and somehow not right. Additionally, previous invisibility cloak designs required numerous layers of material to hide the object, so the cloak ended up being thicker than the size of the object covered.
The team believe their design has many exciting commercial possibilities ranging from art to options to interior design. “Doing whatever we want with light waves is really exciting,” said senior team researcher Boubacar Kanté.
The details of the discovery were published in the journal Progress in Electromagnetics Research.