Microwave weapon intensified by sweaty skin
- 12:27 15 September 2006
- NewScientist.com news service
- David Hambling
"less-lethal" microwave-based crowd-control weapon – the Active Denial
System (ADS) – produces potentially harmful hotspots when used in
built-up areas, and its effects can be intensified by sweaty skin,
tests have revealed. The flaws call into question the weapon’s
usefulness in hot conditions, like those in Iraq.
ADS fires a microwave beam intended to heat skin without causing
damage, while inflicting enough pain to force the victim to move away.
However, tests of the weapon showed that reflections off buildings,
water or even the ground can produce peak energy densities twice as
high as the main beam. Contact with sweat or moist fabric such as a
sweaty waistband further intensifies the effect.
safety concerns, revealed in the details of 14 tests carried out by the
US air force between 2002 and 2006, were acquired under a Freedom of
Information request by Edward Hammond of the Sunshine Project USA,
which campaigns against the use of biological and non-lethal weapons.
Test details released to the organisation last year revealed that
volunteers taking part in the tests had been banned
from wearing glasses or contact lenses because of safety fears.
Denial Systems under development include small, portable versions and
vehicle and aircraft-mounted systems. The new tests ranged from simple
experiments to determine pain thresholds to large-scale war games
involving hundreds of subjects. Some tests involved finding whether
alcohol increased subjects’ ability to withstand the beam and how
trained dogs responded, to determine the effect of accidental exposure
on dog handling teams.
Nevertheless, the weapon
may be safer than some alternatives. More than 9000 experimental
exposures to the ADS have produced just six cases of blistering and one
second-degree burn caused by an accidental overexposure. The US army
wants permission to deploy the system in Iraq, but the decision has
been delayed while tests continue.
secretary of the US Air Force, Michael Wynne, said recently that new
non-lethal weapons like the microwave ADS should be used on Americans
before being deployed to places like Iraq.
we’re not willing to use it here against our fellow citizens, then we
should not be willing to use it in a wartime situation," he told CNN.
hopes these comments may stimulate debate on the use of the ADS and
other non-lethal weapons. "I think that you would see a strongly
negative public reaction and quite possibly an increase in violence if
US police were to use the ADS in riot control," he told New
"I’m sad to say that such an outpouring of concern would probably be
considerably more muted if the weapon was deployed in Iraq first."