Nokia develops phone that recharges itself without plug-ins
The Guardian reports on a new prototype phone from Nokia that is able to power itself on nothing more than ambient radiowaves – the weak TV, radio and mobile phone signals that permanently surround us.
The power harvested is small but it is almost enough to power a mobile in standby mode indefinitely without ever needing to plug it into the mains, according to Markku Rouvala, one of the researchers who developed the device at the Nokia Research Centre in Cambridge, UK.
... Instead of harvesting tiny amounts of power (a few microwatts) from dedicated transmitters, Nokia's prototype is able to scavenge relatively large amounts of power — around a thousand times as much — from signals coming from miles away. Individually the energy available in each of these signals is miniscule. But by harvesting radiowaves across a wide range of frequencies it all adds up, said Rouvala.