In the future, U.S. military peacekeepers and law enforcement authorities
may use a novel sticky gel to prevent trespassers or troublemakers
from entering a building or to stop a run-away vehicle without having
to use lethal force.
The gel is part of a crowd-control anti-traction technology currently
in development, known as the Mobility Denial System.
MDS is supposed to serve as a deterrent to intruders who may be
trying to break into an embassy or any restricted facility, said
Marine Capt. Joseph Kloppel, a spokesman for the Joint Non-Lethal
Weapons Directorate, in Quantico, Va. “The whole purpose of
a system like this is to see what the person’s intentions
“It gives the commander on the ground options other than
tear gas and more of a flexible response,” he said.
The Mobility Denial System consists of three parts, explained Bill
Mallow, one of the inventors of MDS at the Southwest Institute,
in San Antonio, Texas. One component is a liquid polymer emulsion,
the other component is a polymeric powder that produces a slurry,
which then is pumped into a nozzle where it meets a stream of water.
“When it hits the water it turns into a viscous, elastic,
sticky, slimy, slippery gel,” he said. “The resulting
gel is 95 percent water, and the other 5 percent is a polymer pretty
much used in soft contact lenses and baby diapers as an absorbent.”
The gel remains slippery for many hours. “When it dries,
it can be swept away or be reactivated with water,” Mallow
said. The anti-traction substance is effective at surface temperatures
ranging from 32 to 125 degrees Fahrenheit and lasts for six to 12
The substance sticks to grass, asphalt, concrete, wood, metal,
walls and most other surfaces, Mallow said. “On walls, it
prevents people from bringing ladders. ... The ladder will slip
and the person will fall.”
The gel also can be sprayed on people, in which case, “it
would make them extremely miserable and distract them from any intentions
they had, “ Mallow said. “It makes door knobs and windows
What makes MDS work is the powder that is mixed with water to create
Trying to walk on the slurry substance can cause injuries, explained
Mallow. “People can’t control the way they fall,”
he said. “The fall can be traumatic.” Once the substance
comes in contact with water, it reacts instantaneously.
Mallow said that there are serious concerns about the psychological
and physical dangers of the Mobility Denial System. “I don’t
know who is going to account for the broken legs,” he said.
“ Also, [people] will be a slimy mess of worms.”
“It is non-lethal, but it can be lethal,” he added.
When they fall, people can break their backs and even fracture their
He said the Marines worry about the potential consequences of deploying
MDS and are considering putting up barricades and barbed wire in
addition to the sticky gel. That assumes they would have time to
do that, which often is not the case in military operations.
Two methods are used to dispense the MDS gel. A vehicle-mounted
system provides wide-area coverage and a self-contained, man-portable
dispenser that can focus on specific targets. A man-portable system
weighs about 55 pounds when loaded and carries enough material to
cover a 2,000 square-foot area. It is hand-pumped and has a two-gallon
reservoir of water and a quart of the polymer.
The vehicle-mounted system fits in the cargo compartment of a Humvee
truck and provides about 100,000 square feet of coverage. “That
can cover a couple of football fields and can be pumped at a very
rapid rate,” Mallow explained. “The vehicle can cover
a road, bridge, parking lots in just seconds.” The polymers
are carried in five-gallon pails that can be pumped into a reservoir,
which then can be pumped into the nozzle to come in contact with
The institute received a two-year $200,000 contract to develop
the MDS. The Non-Lethal Directorate is investing $950,000 overall
on mobility denial systems. There is still work to be done on the
dispensing equipment and quality control, said Mallow. So far, the
institute used makeshift devices to test the product. The most expensive
items will be the dispensing equipment and the environmental and
toxicity studies, he said. “The Marines are concerned about
But Mallow contends that the MDS is non-toxic and biodegradable.
The formula needs to be optimized, he noted. “It could be
improved. ... We are looking at materials from the same general
class to see if they are better to remove.”
Disposing of the material is still an unsolved problem. “A
group of Marines that successfully kept a crowd at bay may have
to cross that area too,” Mallow said. “We have to come
up with a countermeasure to deactivate the product.”
According to Mallow, though, the system could be ready for deployment
by 2003 or 2004.
The system could be used by any peacekeepers, police, civil defense
and United Nations forces. But the patent belongs to the U.S. Marine