David R. Smith built the world’s first working “invisibility cloak” at Duke and helped launch an entirely new field of physics and engineering.
The technology is called metamaterials, and it produces physical objects that bend all sorts of waves in unexpected – some would say impossible – ways. These waves might be sound, water or even earthquakes, but they can also include the invisible waves of electromagnetic energy. And that opens up a world of possibility to send and receive signals in new means.
“Metamaterials give us a way to control those waves in ways that we haven’t had before,” explains Smith, who is the James B. Duke Distinguished Professor of Electrical and Computer Engineering. “You’d turn light backward, you’d change the Doppler shift.”
Smith and his Ph.D. graduates have built and commercialized working metamaterial devices. That first “invisibility cloak” in 2006 was a set of concentric rings made from circuit board material that worked only in a two-dimensional test and only in microwaves, but it could indeed create the impression that an object placed at the center of the rings was simply not there.
Since then, Smith’s metamaterials group and its alumni have developed a wall that scans people walking past for weapons, and a flat-panel satellite “dish” that doesn’t need to be aimed like your TV dish – meaning it can be mounted on a moving vehicle or a ship.
The metamaterials work done at Duke has so far led to more than 10 spinout companies which have raised more than $1 billion in startup capital and count Microsoft founder Bill Gates among their investors.
You may be seeing metamaterials around you soon, though given their nature, you may not.
