He has not defeated an evil wizard (or two), nor has he created a Lucky Potion (à la Felix Felicis).
But Northwestern mechanical engineering professor Cheng Sun, Ph.D., is trying to accomplish something equally enchanting — Harry Potter-esque and yet very real: Sun wants to create an “invisibility cloak” of sorts.
Sun is leading a group of researchers in “transformation optics,” — designing a material capable of scattering light so the object underneath the material is essentially invisible, a feat he expects to accomplish by the end of June.
“If we’re seeing a light, it’s refracting from some object because of [the] object’s reflective surface is trying to scatter or disturb the light,” Sun says. “But if we can design the surroundings to compensate [for] that kind of disturbance, then the observer probably won’t be able to see that something exists. That’s the whole principle for this kind of optic design.”
Sun says the research, started in August 2009, is going well. His current experiment aims to make a bumpy object look completely flat by designing a structure such that “when the light comes in, it hits the bumped surface and reflects in different directions,” making it appear to observers that the object is flat.
“If we can design a certain distribution so to hide the kind of scattering feature in objects,” Sun says, “then observers will not be able to distinguish that kind of object.”
The applications for this kind of material are endless. The military could use transformation optics to hide weapons or even people from enemies; Lord Voldemort would also find creative uses for such a material.
“It could have some impact for security purposes,” Sun says. “Because if someone tried to hide something that wouldn’t be detected, the airport would be a disaster.”