Laser beams on a car windshield, photo courtesy of Wikimedia CommonsEnlarge Photo
Great line, but unfortunately for old Bruce he wasn't quite technically accurate, as a research team in Japan and Romania is looking into using lasers to ignite the fuel-air mixture in combustion engines.
Using a laser to ignite fuel seems like a great idea and you may be wondering why nobody has thought of it before. The answer is that they have, but previously lasers capable of delivering sufficient power to ignite a fuel-air mixture have been too large and too fragile to be practical in internal combustion engines.
The potential benefits of lasers are great. In an ideal application, they wouldn't need replacing like spark plugs, which suffer erosion of the anode and cathode. They can also be focused to emit pulses of energy at different depths within the cylinder. Regular spark plugs only ignite the mixture very near the spark gap, and this then spreads throughout the rest of the combustion chamber.
Lasers allow greater control over the combustion process, in the same way that direct injecton allowed for the fuel air mixture to be metered with greater accuracy. More accuracy over combustion means a more thoroughly combusted mixture, giving the potential for better performance and increased gas mileage.
New technology allows the lasers to be both smaller and more hardy, using ceramics rather than crystalline materials that are more resistant to the high temperatures and pressures inside a modern engine.
The new laser plug offers another step towards the continuing evolution of the internal combustion engine, and the Japanese-Romanian team is now looking to commercialize the technology, and are engaged in talks with auto-parts maker Denso.