Thin, Active Invisibility Cloak Demonstrated for First Time


JK Rowling may not have realized just how close Harry Potter’s invisibility cloak was to becoming a reality when she introduced it in the first book of her best-selling fictional series in 1998.


Professor Gorge Eleftheriades and PhD student Micheal Selvanayagam in The Edward S Rogers Sr Department of Electrical and Computer Engineering have designed and tested a new approach to cloacking- by surrounding an object with small antennae that collectively radiate an electrical field. The radiated field cancels out any waves scattering off the cloaked object.

Picture a mailbox sitting on the street. When light hits the mailbox and bounces back into your eyes, you see the mailbox. When radio waves hit the mailbox and bounce back to your radar detector, you detect the mailbox. Eleftheriades and Selvanyagam’s system wraps the mailbox in a layer of tiny antennae that radiate a field away from the box, cancelling out any waves that would bounce back. In this way, the mailbox becomes undetectable to radar.

Beyond obvious applications, such as hiding military vehicles or conducting surveillance operations, this cloaking technology could eliminate obstacles for example, structures interrupting signals from cellular base stations could be cloaked to allow signals to pass by freely. The system can also alter the signature of a cloaked object, making it appear bigger, smaller, or even shifting it in space.