World’s Smallest Gasoline Engine

While I try to be very careful about posting hype masquerading as a legitimate technology breakthrough, this story is too good to pass up (even though it contains a lot of hype). I don’t know about the prospects for commercial success (as I have said before, I have been waiting for my DNA computer for 15 years) but this story is interesting and topical:

New mini petrol engine

There is a copyrighted picture at the link showing the engine resting on a fingertip. Some excerpts from the story:

Scientists 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 revolutionise 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 on end — doing away with the need for recharging.

Experts believe it could be phasing out batteries in such items within just six years.

I guess that depends on the prospects for mass production. If it takes a team of scientists and engineers to build each one, it won’t be replacing batteries any time soon. And the article mentions nothing about the difficulty of manufacture.

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.

Hmm. Not sure I want a combustion engine operating next to my heart, especially in light of:

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.

Anyway, regardless of whether it pans out, it is an interesting story and a neat technological achievement.

11 thoughts on “World’s Smallest Gasoline Engine”

  1. Two years ago there was considerable press about a methanol-powered fuel cell that would be able to power laptops and cell phones for days. Supposedly one would be able to fill the fuel cell with methanol, plug it into a laptop in place of a battery, and then be unconcerned about the constant need to find a place to recharge the battery when in the field or on the road.

    Haven’t heard much about the methanol-powered fuel cell lately. This story reminds me of that.

  2. And I’m reminded of the micro-diesel engine technology that was in EE mags a year ago.

    Wouldn’t the engine still need an air intake and exhaust? Seems like that would rule out enclosed applications (like the heart implant!).

  3. It produces 700 times more energy than a conventional battery

    Only if you exclude the liquid fuel, which is ridiculous. Gasoline energy density is around 10,000 Wh/kg and MEMS engines are notoriously inefficient due to high friction and heat loss. A generous 10% thermal efficiency gives 1000 Wh/kg. Li-ion is 200 Wh/kg, for a factor of 5x instead of 700x.

    Nigel, there are some DMFC vendors shipping low quantities and/or prototypes to the military (e.g. MTI, Ultracell). Numerous vendors, large and small, talk about consumer units Real Soon Now but I don’t know of any laptop-scale units you can actually buy today.

    Jadoo Power sells 5 lb hydrogen fuel cells for broadcasters and such. Energy density is worse than Li-ion, they sell on convenience and durability. Seems like a hard sell to me. Here’s a bare-bones system you can play with.

    Doug, the heart implant version will simply tap into your lungs for air intake and exhaust 🙂

  4. Some folks in New Zealand recently introduced a similar game:

    Personally, I found Electrocity to be a better game, since it dealt with both the issues of city development and supplying power to support that development. It also forced you to deal with fuel issues (including mining opportunities) for fossil fuel energy. It’s actually quite a cool little game.

  5. Robert,
    This post seems to fly in the face of your stated belief that we should be working towards electrification of transportation: if battery-electrics cannot defend their own turf (cellphones and laptops) against ICE, how are they going to invade ICE’s turf?

    It will be facinating to see how this plays out though.

  6. Makes you wonder if larger versions of this motor could be used to charge automobile batteries, on the go. In other words, you would charge your car at night, then sally forth. This little motor could constantly recharge your battery, so the range would be extended.
    Maybe, by this method, we get an 80-mile range on a electric car.
    Over on Energy Blog, there is talk of rapidly recharging batteries, another one of the Holy Grails.
    All in all, fascinating. Imagine batteries which recharge more rapidly, and an onboard recharger. Okay, so you run out of juice before getting home one night. Pull over, have din-din, and have the little gas motor recharge. Then, make that last 20 miles. Interesting.

  7. “Okay, so you run out of juice before getting home one night. Pull over, have din-din, and have the little gas motor recharge. Then, make that last 20 miles. Interesting.”

    This seems like a downgrade of the PHEV concept. Why would you want to stop when the battery ran out? Sure, it might work out in your favor on occasion, but I imagine it wouldn’t more often than not.

  8. What about the exhaust, which presumably includes CO as well as CO2? Each engine might be tiny, but imagine a room densely packed with people, each of them with a gas-engine-powered cell phone in their pocke.

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