A new way to generate electricity from water which could be used to power small electronic devices in the future has been developed by Canadian scientists.
The researchers have harnessed what happens to water when it is pumped through tiny channels.
"What we have achieved so far is to show that electrical power can be directly generated from flowing liquids in microchannels," said Professor Larry Kostiuk from University of Alberta.
The team says its "electrokinetic" battery could be further developed to provide a clean, non-polluting power source that could eventually drive small devices such as mobile phones.
But some experts in the field have cast doubt over its potential as a useful source of power.