The hardware was originally designed to zap mollusks. Then it adapted some technology from "Star Wars." Now, ultrashort electric shocks may be adapted to treat obesity. Oh, and form the basis of a death ray, too.
Last week Danger Room looked at how quicker-than-quick electric pulses could lead to cancer-fighters -- as well as Taser-type weapons that might be able to stun for tens of minutes, rather than seconds.
It started with a battle against alien invaders known as Dreissenids. More commonly called as zebra mussels, they are a highly invasive species of Russian mollusk which arrived in the U.S. in the 1980s. Since then, they have thrived -- caused innumerable headaches for us humans. The shellfish cluster so thickly that they block pipes and water intakes, causing an estimate $5 billion damage a year. "Biofouling" is still a problem with Navy ships just as it was in the old days when they had to scrub off barnacles.
By 1990, researchers had discovered that electric shocks would stun the mussels, preventing them from sticking. But the power requirements made this too expensive. By 1995, they were using shorter, millisecond pulses- shorter shocks means using less power. Four years after that, they had found the ultimate anti-mussel weapon: it used a pseudospark switch developed by the Ballistic Missile Defense Organization (that's "Star Wars" to the rest of us). Funding from Darpa went to develop a device which could produce shocks as short as a nanosecond - and found they were still effective.
Turns out an electric pulse with a very fast rise time – in the range of microseconds – can cause cell membranes to become permeable.
Shorter pulses impact the organelles within the cell, including the nucleus itself. In effect, ultrashort pulses open up a whole new toolbox with which to tweak cells. The Frank Reidy Research Center for Bioelectrics at Old Dominion University was set up to explore some of these effects, with the aid of a $5 million grant from the Air Force.
One of the more surprising effects that can be induced is apoptosis or programmed cell death. This is the natural process by which the body disposes of cells, so they break themselves down into their constituent parts which can then be recycled. Scientists are still not sure how this works, but somehow the ultrashort pulse appears to give the signal for cells to kill themselves. Moreover, it's selective so that cells of a particular type can be targeted. It's already being used as a means of attacking tumors: unlike chemotherapy or radiation, it offers the possibility of killing cancerous cells without damaging healthy ones.
Another suggestion is that the technique could be used to selectively destroy fat cells to combat obesity as a high-tech alternative to liposuction. Testing continues with mice – and the
Center is now using even shorter pulses.
There are also plenty of other effects to explore. For example, the ultrashort pulses can be used to trigger blood clotting in a specific location. As a non-medical use, ultrashort pulses could be used to kill harmful bacteria in water cheaply and without using chemicals, which might in itself save over a million lives a year from waterborne diseases.
At present, researchers use a needle-like electrode to deliver the electric pulse. But this is only useful for surface applications.
Researchers are now looking at using nanosecond pulses of broadband radio energyusing a special antenna. "An array of such antennas would create... a very high electric field right where we need it," Center chief Dr. Karl
Schoenbach told *New Scientist *magazine.
He was talking about a range of just a few centimeters, enough to affect organs deep inside the body. But it might be able to work at longer ranges, too.
It's worth noting that a key player in the new antenna development is Carl E. Baum, for many years the Senior Scientist at the Air Force Research Laboratory and a leading expert on electromagnetic pulse weapons.
It must have crossed the minds of some of the researchers that an ultra-short, ultra-wideband pulse could be used to trigger apoptosis in the subject's entire body, causing all their cells to die at once. This would be surely the ultimate death ray, killing someone in the most thorough fashion imaginable. And it could be done with a tiny fraction of the energy used by one of those big lasers, raising the possibility that the ray gun could be very small and compact. (Incidentally, ultra-wideband is very hard to screen against.)
The engineering challenges of building a death ray would be formidable. For now, the ultra-short pulse researchers are focusing on medical applications, and the occasional non-lethal weapon.
In any case, it's a good answer to the question of "why are they working on weapons instead of a cure for cancer?" -- the technology for one can lead to the other.
[Photo: USFWS]
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