New Laser Igniter Might Be Beginning of the End for Classic Spark Plug

By Patrick Morgan | April 26, 2011 1:39 pm

What’s the News: Scientists have developed a laser that’s small and tough enough to work in the combustion engine of a vehicle yet powerful enough to ignite the fuel-air mixture that drives combustion cylinders. The researchers say that laser-ignited combustion engines could be more fuel efficient than traditional spark-plug ones: Unlike spark plugs, which transmit their sparks in milliseconds, lasers transmit energy within nanoseconds. Inventor Takunori Taira says that “timing—quick combustion—is very important. The more precise the timing, the more efficient the combustion and the better the fuel economy.”

Why Now: The new laser used in this laser igniter can withstand the harsh environment of an engine because it’s made from ceramic powders, which are stronger, more thermally conductive, and more durable than conventional lasers, say the inventors.

Lasers vs Sparks:

  • In conventional engines, spark plugs send high-voltage electricity sparking across the electrode gaps in a combustion engine: This results in a controlled explosion in the engine, which drives the piston that generates the vehicle’s horsepower.
  • Spark plugs only directly ignite the fuel-air mixture near the wall of the combustion cylinder, but lasers can reach to the center of it, allowing for a more symmetric explosion that’s up to three times faster than spark-plug ignition.
  • Also, the electric sparks erode the electrodes over time, increasing the gap between them and resulting in less efficient combustion. Lasers don’t have such erosion, leading to a longer-lasting engine.

What’s the Context:

  • A laser in a standard automotive engine needs to generate 100 gigawatts per square centimeter to ignite combustion. In the past, “lasers that could meet those requirements were limited to basic research because they were big, inefficient, and unstable,” says Taira.
  • The problem with inefficient fuel burning is that it increases the emissions of harmful gasses, such as nitrogen oxides (NOx), which are a major component of smog.

Not So Fast:

  • As pointed out by Autoblog’s Dan Roth, “None of this research work has been applied to an actual engine yet, making any claims of superiority mere academia at this point.”

The Future Holds:

  • Now the team is working on a three-beam laser that will make for even more uniform combustion.
  • And their working with the DENSO Corporation (part of the Toyota Group) to potentially start putting these lasers in car engines.

Reference: Conference on Lasers and Electro-Optics. 1 May 2011. Baltimore, Maryland.

Image: The new combustion laser (right) and a standard spark plug (left). National Institutes of Natural Sciences, Japan /  Takunori Taira.

CATEGORIZED UNDER: Environment, Technology
  • fintin

    This seems like a really good idea, considering that our fuel economy is not the best. This could be a revolutionary invention for years to come.

  • Alex Degen

    I think the mere mention that it has the potential to be used in the combustion engine means there might be research into the application.
    However the cost will always be the factor that dictates the use of the new technology.

  • http://DiscoverMagazine Templar 7

    I agree. Whats described in this article is the right direction!!

  • Kevin Jackson

    Don’t get too excited, it will only make a small improvement. Spark plug ignition timing is variable so nano seconds or micro seconds doesn’t mean much. Starting the fire in the middle will help some on some engines, but others won’t work as well. Spark plugs last over 100,000 miles these days and are cheap.

    Now, if you install multiple lasers with adjustable target areas then you could control combustion by varying the ignition timing, varying the ignition location and, when/if needed, creating multiple ignition points to create customizable flame fronts that can be manipulated electronically. Then you might have something.

  • Henryk

    Read about this solution, existing for 11 years in the U.S. Patent unwanted plasma ignition by a candle FireStorm Spark Plug

    The FireStorm Plasma iPlug is a new entry in the formerly mundane area of Spark Plugs. All Spark Plugs produce “sparks” to ignite the Air Fuel Mixture in the combustion Chambers. FireStorm is different, it produces “PLASMA”. By doing that, it eliminates the Catalytic Converter and EGR Systems and can still pass future emission requirements in California.

    Here is a clip:

    Further testing after that clip was shot in Detroit proved a 70% savings in fuel all while affording a 125 More Horsepower.
    It is a Paradigm Shift in Air Fuel Ratio as this plug operates at 30 to 1 Air to Fuel Ratio. All current IC engines operate at 14.7 to 1 and require a Cat and EGR.

    FireStorm can even crack water right in the Combustion_Chamber thereby eliminating so-called HHO Generators. Can I hear fill your car up at the side of your house with the garden hose?

    The automotive industry is not interested, and the inventor, without financial support is unable to produce the same


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