The scientists have created the smallest petrol engine in the world (less than a centimeter long not even half an inch),small enough to power a watch or any small gadget.The mini-motor which runs for two years on a single squirt of lighter fuel is set to revolutionize technology associated with it. It generates 700 times more energy than a conventional battery. It could be used to operate laptops and mobile phones for months doing away with the need for charging.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. At present, charging an ordinary battery to deliver one unit of energy involves putting 2,000 units into it. The little engine, because energy is produced locally, is far more effective. One of the main problems faced by engineers who have tried to produce micro motors in the past has been the levels of heat produced. The engines got so hot they burned themselves out and could not be re-used. The Birmingham team overcame this by using heat-resistant materials such as ceramic and silicon carbide, finally.