Chem-Bio Protective Garments: Making Them Lighter, Tougher.

Researchers at the U.S. Army Soldier and Biological Chemical Command in Natick, Mass., ate working on new technologies that, in the distant future, could provide an alternative to the current carbon-based chemical, biological protective suit, the JSLIST (Joint Service Lightweight Integrated Suit Technology).

All military services have used JSLIST since 1997. It replaced the old battledress overgarment (BDO).

Natick project engineer George Costas said that one of the most promising technologies for future protective garments is the selectively permeable membrane.

JSLIST is today's suit of choice by all the military services, Costas explained. "For the next 10 years, they will stay with the design, and all the changes made will be in the fabric." The JSLIST overgarment is a universal, lightweight, two-piece, front-opening suit that can be worn as an overgarment or as a primary uniform over underwear. It has an integral hood, bellows-type sockets, high-waist trousers, adjustable suspenders, adjustable waistband and a waist-length jacket that enhances system comfort, improves system acceptance and maximizes compatibility with the individual user equipment.

Apart from the integral hood, on the waist-long coat, a flap fastened with Velcro covers the zipper. The sleeves also have Velcro wrist-closure adjustment tabs, and the left sleeve has an outside expandable pocket with flap.

The JSLIST liner consists of a non-woven front, laminated to activate carbon spheres and bonded to a knitted back that absorbs chemical agents. Previously, the BDO liner consisted of charcoal-impregnated polyurethane foam and nylon tricot laminate. The BDO foam deteriorated as the soldiers rubbed against it, and that could become messy.

The durability of the JSLIST is 45 days, compared to 22 days for the BDO. While the old suit was not washable, the JSLIST can be washed six times. Costas said the suit nor only feels a lot cooler, but it is one pound lighter than the BDO, and when packaged, it is 60 percent less bulky.

But Gene Wilusz, a developer of the selective permeable membrane, explained that a suit that uses the membrane system, instead of charcoal, is actually half the weight of the current JSLIST.

"Quite a lot of charcoal is needed to provide the necessary protection and that results in a suit that is heavier and builder than ideal," said Wilusz. "Activated charcoal has worked very well so far as a universal absorbent, but we are trying to reduce the dependence on charcoal. The membrane essentially replaces charcoal as a protective material."

Wilusz noted that charcoal can absorb other chemicals in the area, such as exhaust fumes, smoke and other things that soldiers can come in contact with on the battlefield. "They are absorbed just like the [chemical and biological] agents can be absorbed in the charcoal. That is not really an issue with the membrane," said Wilusz.

He explained that the membrane is used as part of a system that has outer-shell material and inner lining made out of a traditional textile.

The membrane acts as a barrier to chemicals and biological agents, while still allowing the movement of vapor moisture. Thus, Wilusz said, "there will be some measure of release from heat stress, through an evaporative cooling mechanism.

"Some of the swear that occurs just by wearing additional clothing will be able to pass through the suit to the outside, right through the membrane," he added.

"The carbon-based suits only last in the field for 45 days, without being contaminated because the carbon itself gets poisoned," said Elizabeth McCoy, chemical defense coordinator at Natick. However, she said, the membrane suits can last as long as the JSLIST or longer. "You don't have to worry about the carbon being poisoned, and you can wear it our as long as the membrane is still viable," she said.

"Membrane technology protects against everything, it just doesn't let anything go through, but it let's moisture vapor go our, so that you can have the cooling," McCoy said.

"One of the big challenges is where to close the suit up," said Costas. "Close it around the head to interface with the helmet, close it around the legs to interface with the boots, close it around the wrists to interface with the gloves."

But researchers at Natick also are looking at how to increase protection through the closure systems of the suit.

Wilusz explained that they were testing rubber seals at the sleeve and neck area. "The rubber parts meet together to form a seal," he said. "O-rings are very tight seals, so they give a superior seal," added Costas.

Another way to increase the protection of the suits is to make them one-piece. "The coverall has an advantage over the two-piece suit," said Wilusz. But he said the one-piece may also be more difficult to fit everyone properly, and many soldiers prefer the two-piece. "We may have to end up with both," said Wilusz.

"When we have prototypes and have them evaluated we get a lot of feedback about what they like and what they don't like," Wilusz said. "It's a back-and-forth process.

So far, some Army and Marine Corps users tried out the new membrane suits in short-term exercises, Wilusz said. "The garments have done very well, but they need to be tested in much larger scale field exercise."

The two contractors working on membrane technology are W.L. Gore & Assoc., in Elkton, Md., and Texplorer, based in Germany. So far, W.L. Gore has spent about $6 million to produce the membrane technology, according to Natick program manager Quoc Truong. Natick provided technical guidance and testing assistance. Texplorer, which produces the Spiratec membrane technology, has a 50 percent co-share agreement with Natick to produce 400 garments, which will then be tested in the necessary operating environments.

Since 1997, the Army has spent $500,000 a year to develop the membrane technology. Natick also will receive $1.25 million from the Memorial Institute for the Prevention of Terrorism.

Tex-Shield, in Mount Laurel, N.J., is the sole fabric supplier and is a subcontractor to the four manufacturers of the JSLIST suit.

"If that fabric [membrane technology] gets to the point where it will stand up to all the rigors of the battlefield with soldiers crawling on the ground, jumping out of vehicles, and it is durable and meets all the requirements, we may take the [JSLIST] design and use the membrane technology," said Costas.

"If the past is any guide," he said, "the BDO was around for 20 years, so the JSLIST will be around for 20 years. It's quite a new suit."

Costas said that, in his opinion, one of the most important features of the JSLIST is a hood that is directly attached to the suit coat. "It gives a lot more protection, because it eliminates leakage around the neck area," he said.

The membrane technology, Wilusz said, is a candidate for the joint protective aircrew ensemble (JPACE). If the membrane technology gets accepted in that program, "it will also be a candidate for the next generation JSLIST garments," said Wilusz.

"That's futuristic, it's way out," said Costas.

The chemical and biological protection gear for Navy and Air Force comes with the M-40 mask. Michael T. Benham, a representative of the Army's program office for NBC Defense, said that the JSGPM mask will replace the M-40. Because it is more close-fitting to the face, the visibility in the new mask is much higher, said Benham. He also said that it would be lighter with smaller filters and have simplified maintenance requirements. "It would be less expensive and less of a logistics burden," Benham added. An M-40 mask costs approximately $300. The new mask will go into production in 2006.

Another development is the Helmet-Out-vision 22, which is just a concept, "but it is going to give the same capability as a helmet and also provid hemical protection," Benham said.

Futuristic Soldier Suits to Be Chameleon-Like

One look at Sgt. Joe Patterson, and you could see what the U.S. Army envisions for the soldier of 2020. He is chameleon-like, wearing an all-purpose, single-layered uniform that not only changes colors to blend in with the natural environment, but also guards against chemical and biological agents.

The cornerstone technology to turn this concept into reality is the selectively permeable membrane, which scientists are developing and testing at the U.S. Army Soldier and Biological Chemical Command in Natick, Mass.

"We want integrated protection-chembio, environmental and multi-functional," said John Munroe, of the warrior systems integration team. An issue that will have to be considered, he said, is how to bring the weight of the uniform down when adding new features.

"We are not the most mobile people in the world," Munroe said. "We have to reduce the weight of chemical suits and make them more mobile.

"The selectively permeable technology is very thin and light, it keeps the water and the chemical agents out," he said.

Single-layer uniforms will perform functions such as cooling, conduction and will have embedded wires, according to Munroe.

Soldiers have to be able to go under water, walk in swamps and deal with rough terrain, he said. The current bulk of the uniforms-with their added features-impedes movement to a certain extent. Cables are a big hindrance. "What do you think cables can do--they can snag, and they can break. All those pins and stuff break and it is really tough to keep our systems going if our cables don't work," Munroe said.

The membrane technology being developed for the chemical and biological suits, he added, will be used in standard military uniforms. However, he noted, "that is not enough. We want to integrate the environmental protection, the stealth, the cables and the electronics. The chemical and biological suit is just a stepping stone for us."

At a recent Army exhibition on Capitol Hill, Sgt. Patterson was wearing a suit that epitomized the type of garment that researchers at Natick hope for. On his uniform, just on a patch on the right arm, cable was replaced with a piece of webbing with conductive fibers. Another patch had cooling tubes that could circulate both cold and warm water.

"We would like to maintain a physiological level of high performance," Munroe said. "If you are working hard on a dog day afternoon in your yard, eventually, you get beat, and your mind goes and your body goes. That is a problem, and our soldiers are getting into that situation. The enemy is hot and beat and we are fresh and ready. That would be a big advantage."

Natick also is looking at physiological sensors to monitor soldiers remotely. Other capabilities based on active electronics will allow the suit to change colors and blend with the background. "That is why he is wearing black," Munroe said, pointing at Sgt. Patterson. "He can change to any color he'd want."

However, he cautioned, "we are not promising that just now."