Researchers at the University of Tokyo in Japan have created a special paint which can block out wireless signals. The paint, which could cost as little at £10 per kilogram, contains an aluminium-iron oxide which resonates at the same frequency as wi-fi – or other radio waves – meaning the airborne data is absorbed and blocked. While paints blocking lower frequencies have been available for some time, this new technology is the first to absorb frequencies transmitting as high as 100GHz (gigahertz). Signals carrying a larger amount of data – such as wireless internet – travel at a higher frequency than, for example, FM radio.
The paint has a number of interesting potential applications including: keeping wireless networks secure, blocking phone calls during movies, shielding hospital rooms from unwanted electromagnetic radiation, and making clothes that protect people from electromagnetic waves.
[via BBC News]