Editor | On 13, May 2018

Darrell Mann

I love obvious. Sometimes a solution can look so obvious, you have doubts that it is real. Then you notice that the owner is Lockheed, so you realise, hmm, maybe there’s something interesting happening here. The solution in question is found in our Patent Of The Month this month, US9,753,134, granted on September 5. The subject is neutralization of enemy targets. The exemplar is subsea mines. There’s not much of a description to go by, except to say that the prior art recognizes that the use of pulses of acoustic energy are a potential way to neutralize mines. But then, there’s a problem:

…there may be challenges with the implementation/deployment of such a shockwave-pulse technique. For example, the intensity of a shockwave required to neutralize the mine from a safe distance may be so high that the sizes of the energy source and of the shockwave-generating aperture may be impractical. For example, if it is estimated that the intensity of the shockwave required is 330 dB or higher, then the power needed to generate such a shockwave may be on the order of hundreds of kilowatts (kW), and the size of the aperture needed to generate such a shockwave may be on the order of a few hundred feet in diameter, width, or length. Furthermore, such a high acoustic intensity may harm nearby fish, mammals, and other wildlife, and even divers who may be significantly farther away the from the shock-generating source than the targeted mine is. For example, if the mine to be neutralized is 500 meters from a source that is generating a shockwave pulse that needs to have an intensity of 330 dB of acoustic pressure at the mine, then such a pulse may deafen or otherwise permanently damage the hearing of a diver at a distance of 100 kilometers (km) or more! And it is generally accepted that an acoustic shockwave pulse even as low as 140 dB may harm fish, underwater mammals, and other underwater life; consequently, a pulse of 330 dB at a distance of 500 meters from the generating aperture may have a devastating influence on marine life over a vast area centered at the shock-generating source.

Sounds like a contradiction: we want to neutralize the enemy mine, but we don’t want to neutralize the marine life living within a hundred-mile radius. Here’s what the Contradiction Matrix has to say about the problem:

And here’s what the patent solution does to solve the problem:

…an apparatus includes a transducer array and a controller that is operable to cause the transducer array to generate a signal having a frequency, and to direct the signal toward an object having a resonant frequency that is approximately equal to the frequency of the signal. For example, an embodiment of a mine-hunting-and-neutralizing apparatus may generate an acoustic wave with a transducer array, and may disable or destroy a mine by directing the wave toward the mine. The apparatus generates the acoustic wave having a frequency that is approximately equal to the natural frequency of a component of the mine such that the wave causes the component to resonate in a manner that is sufficient to disable the mine from detonating, or that is sufficient to cause the mine to detonate. For example, if the component is the detonator, then the wave causes the detonator to resonate at an energy level that is sufficient to render the detonator unable to detonate the mine, or that is sufficient to cause the detonator to detonate the mine.

Aah, Principle 18C, where would we (and our marine friends) be without you?