Avid fans of Harry Potter and his magical invisibility cloak may one day don a cloak of their own, thanks to new research by professors in the Pratt School of Engineering.
David Smith and David Schurig of Pratt's department of electrical and computer engineering-along with Sir John Pendry, professor of physics at Imperial College London-believe they have developed a practical blueprint for an invisibility cloak that could someday shield objects from the human eye.
"Our blueprint proposes redirecting electromagnetic fields around an object-in essence, creating a black hole in place of the object," said Smith, an associate professor.
"But real-life Harry Potter invisible disguises will likely be a long way away," he added.
The proposal was published in the May 25 issue of Science Express, the online version of the publication Science.
Researchers conceived the cloak, which is the first such device to redirect electromagnetic waves around an object, with funding from the Defense Advanced Research Projects Agency.
A blueprint for the invisibility cloak calls for the use of exotic metamaterials, which gain electromagnetic properties from their structure rather than the materials from which they are composed.
The metamaterials are artificial structures in which tiny circuits replace the molecules and atoms that make up materials until the original image is reformed around the object, Smith said.
He compared the process of light waves moving around the cloak to that of stream water flowing around a rock.
But before objects become invisible to the human eye, scientists must alter the use of metamaterials to function on the scale of a nanometer-a six-fold decrease in wavelength compared to radio waves.
"We can envision maybe making something that would work as low as at radio frequency," Smith said. "Scientists are working towards these things, but first the concepts need to be successfully merged and applied."
The cloak could potentially be used for various applications, including military and communication devices.
"Besides use for obstruction of objects from the human eye, devices could also be used to divert an array of other electromagnetic waves," Smith said.
In the past, Smith and others have used metamaterials with radio waves to clarify antenna reception, making small antennae work as if they were larger ones.
Next the researchers, whose work focuses on the applications of metamaterials, will apply the improved technology to new wavelengths, which should make visible waves appear invisible in theory, the team reported.
The "artificial materials," which consist of the same materials as a pentium chip, are currently used to manipulate various larger wavelengths, and are used in antennae, optical devices and switches, Smith said, noting they come at a cheap price in large quantity.
Based on the blueprint, however, those eventually donning the cloak would have to keep their eyes closed, as it would hinder their ability to see.
"I think everyone would have their own personal uses of the cloak," Smith said.
Get The Chronicle straight to your inbox
Signup for our weekly newsletter. Cancel at any time.