The World's Smallest Petrol Engine

Compliments from racers, Ted & Nancy James

Originally posted by The Register, June 19, 2003

small engine01SCIENTISTS have allegedly 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 centimeter 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. 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. Dr Kyle Jiang, lead investigator from the Department of Mechanical Engineering, said: “We are looking at an industrial revolution happening in peoples’ pockets. The breakthrough is an enormous step forward. Devices which need re-charging or new batteries are a problem but in six years will be a thing of the past.” 

Other applications for the engine could include medical and military uses, such as running heart pacemakers or mini reconnaissance robots. 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. Professor Graham Davies, head of the university’s engineering school, said: “We’ve brought together all the engineering disciplines, materials, chemical engineering, civil engineering, and mechanical engineering. What better place to have the second industrial revolution in nano-technology than where the first took place, in the heart of the West Midlands.

V-8 and V-12 Engines in Miniature!

For those who enjoy miniature craftsmanship, check out these model engines that could run on your workbench or kitchen table. Fully operational they were machined from billet stock and castings.

Some of these photos were taken from the Joe Martin Foundation Craftsmanship Museum but many more images can be found elsewhere on the web, and engines like these can be found and admired at model engineering shows around the country. Here are some fine examples:


Click on any image to enlarge. Tour the Joe Martin Craftmanship Museum by clicking here.

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  1. Haha, 17 years later… none to be seen

    • The article was published in 2014

  2. None to be seen, and never will be. Imagine a world where every laptop and phone has a miniature piston engine buzzing away, where you have to be adding flammable fuel. Where does the exhaust go? How do you start it? How often do you change the oil? The whole idea is absurd.

    • That’s just being unimaginative. Once upon a time when smoking was still fashionable, men carried gas lighters in their pockets all the time. All the where and how questions you’re asking are simple design considerations that engineers can easily manage. If it can power a laptop for a month on just a squirt of lighter fluid, I see several compelling use cases for it.

      • A gas lighter (actually liquid) is a bit different from carrying an actual fire burning in an engine. I can see applications, but I wouldn’t put wearables at the front of the list. Government grants have led to quite a few technological advances, including the advent of the Internet?

  3. And to up the ante, physicists have made molecule-sized engines and electric motors which also do not have application, but they still research miniaturizing. Government grants at work, lol.


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