NewsMiniScientists have built the smallest petrol engine, tiny enough to power a watch. The mini-motor, which runs for two years on a single squirt of lighter fuel, is set to revolutionize world technology.

It produces 700 times more energy than a conventional battery despite being less than a centimetre long, not even half an inch. It could be used to operate laptops and mobile phones for months, doing away with the need for recharging; especially useful if you’re on a major overland expedition.

Experts believe it could be phasing out batteries in such items within just six years. The engine, minute enough to be balanced on a fingertip, has been produced by engineers at the University of Birmingham. Other applications could include medical and military uses, such as running heart pacemakers or mini reconnaissance robots.