'Invisibility cloak' metamaterials could shrink cellphones antennas

London, Aug 22 (ANI): An international team of physicists have revealed that metamaterials, which are currently being used to make real-life invisibility cloaks, may soon shrink cellphone antennas, leading to smaller gadgets.

The new metamaterial antennas could be tuned to a range of different frequencies as required.

It could be tuned to work efficiently across a small frequency range, and retuned to a different band for roaming.

Tom Driscoll at the University of California, San Diego along with Dimitri Basov and collaboraters from Duke University in Durham, North Carolina, and ETRI in the Republic of Korea developed the new "frequency-agile" design by attaching a thin film of vanadium dioxide to a gold metamaterial structure.

They found that applying a voltage to the film alters the frequency at which the gold metamaterial interferes with light waves, tuning it to a new "setting".

This occurs because voltage causes nanoscale "puddles" of conducting vanadium metal to form within the insulating vanadium dioxide.

They interact with the design's electrical properties and alter the metamaterial's tuning.

"The effect continues after the electrical current is gone because the metal puddles, once formed, will not readily disappear without some cause," New Scientist quoted Driscoll as saying

He added that there is evidence to suggest the effect should last for months or more.

"Metamaterials are often narrowband, but at least with this scheme one could adapt the material to new frequencies," said Ulf Leonhardt, a metamaterial researcher at the University of St Andrews in the UK.

That removes an obstacle to the wider use of metamaterial antennas. Such antennas would be attractive because they could help to shrink the size of cellphones.

Driscoll said that a tunable metamaterial antenna would allow a wireless gadget to work "outstandingly well" at the frequencies used in one country, but also carry the option of retuning for use abroad.

The findings appear in journal Science Express. (ANI)