Published October 05, 2011
Researchers have created a working invisibility cloak using one of nature’s common yet bizarre phenomena -- the “mirage effect.”
The new design from the University of Texas at Dallas was demoed on YouTube and even has an on and off switch -- and it's best used underwater.
"It is remarkable to see this cloaking device demonstrated in real life and on a workable scale. The array of applications that could arise from this device, besides cloaking, is a testament to the excellent work of the authors,” an Institute of Physics spokesperson said.
Often portrayed in movies where those stuck in the desert mistakenly “see” water, the so called “mirage effect” is an optical phenomenon in which light rays are bent to produce a displaced image of distant objects or the sky, according to the Institute of Physics (IOP), which featured the innovation in the most recent edition of its journal Nanotechnology.
With the help of carbon nanotubes, researchers were able to replicate this effect to successfully create an invisibility cloak. When the nanotubes are electrically stimulated, the resulting temperature gradient causes light rays to bend away from whatever object is being concealed behind the device, making it appear completely invisible.
"Using these nanotube sheets, concealment can be realized over the entire optical range and rapidly turned on and off at will, using either electrical heating or a pulse of electromagnetic radiation,” said Dr. Ali Aliev, lead-author of the study.
Building a working invisibility cloak is certainly a cool achievement, but Aliev stresses the scientific implications of his work, such as using a similar technique to produce sound instead of a mirage.
"The research results provide useful insights into the optimization of nanotube sheets as thermoacoustic projectors for loud speaker and sonar applications, where sound is produced by heating using an alternating electrical current."