Soldiers' efforts are driving breakthroughs in materials science. Resultant technologies and systems should provide better aircraft, armor and other equipment to those in the armed forces.

The military has long been at the forefront of innovative technologies. For instance, autonomous vehicles have had a dramatic impact on the battlefield in recent years, permitting commanders and individual fighters to understand and develop a situation before making contact, maneuver largely out of contact, and only then initiate decisive action, bringing all inherent capabilities to bear with accuracy and lethality.

Composite materials have been making strides in a big way and are already reshaping aerospace. Boeing's 787 Dreamliner and Airbus' A350 both use record levels of composites for their commercial aircraft. Lockheed Martin, too, is using composites. Yet "the transition to composites has long been under way in military aircraft," IndustryWeek recently noted. One major supplier of composite fabrication systems cited by IndustryWeek this month has been supplying composite application equipment for more than 25 years.

The result in the use of this material is dramatic weight reduction and fuel savings, as well as operating advantages such as fatigue strength and corrosion resistance.

Yet the military is developing even more "out there" aviation features as they relate to materials technology and science.

In today's 5 High-Tech Advance in Materials, IMT's Ilya Leybovich writes, "Some defense contractors are investing in nanomaterial research to develop vehicles that could theoretically 'heal' themselves after being damaged." What Lockheed Martin is looking for are smart materials for self-healing aircraft.

One applicable breakthrough could come from aerospace engineers at Bristol University, who, with funding from the Engineering and Physical Sciences Research Council, are developing a new technique to enable damaged aircraft to mend themselves automatically, even mid-flight.

It works like this: if a tiny hole or crack appears in the aircraft, a composite material made from hollow fibers filled with epoxy resin leaks out and seals the break and returns it to 80 percent to 90 percent of its original strength. By mixing dye into the resin, any "self-mends" could be made to show as colored patches that could easily be pinpointed during subsequent ground inspections, at which point a full repair could be carried out if necessary.

"This approach can deal with small-scale damage that's not obvious to the naked eye but which might lead to serious failures in structural integrity if it escapes attention," according to Dr. Ian Bond, who has led the three-year research project. "It's intended to complement rather than replace conventional inspection and maintenance routines, which can readily pick up larger-scale damage... ."

With the U.S. Army Natick Soldier Research Development and Engineering Center (NSRDEC), which is under the Army's Research, Development and Engineering Command, the MIT Institute for Soldier Nanotechnologies is working to find smaller, integrated solutions.

In a condensed agency announcement, effective through March 2009, the following are some of the items on the Army's materials wish list:

• Ballistic protection — New polymers with improved tensile properties that can increase ballistic protection and reduce weight over current individual protection systems. One goal is liquid-crystal polymer fibers.

• Integrated protective helmet — New and improved polymers for fiber-reinforced plastics and resins to provide increased ballistic protection and lighter weight, as well as new materials for energy absorption and moisture vapor permeability/cooling management. Also wanted: improved lightweight, integrated communications devices.

• Modular personnel protection system — A modular personnel protective system that can be tailored to protect areas of the body not currently protected by standard armor vests and plates from threats such as fragmentation/blast munitions, hand-gun and small-arms projectiles.

• Chemical and biological protection — Novel materials and concepts that could provide protection against highly toxic compounds, including toxic industrial chemicals and military offensive chemical agents (blister, nerve, etc.) in gross contamination amounts for extended periods (greater than four hours), and biological agents.

• Flame and thermal protection — Integration of new flame-retardant systems into low-cost fibers for flame and thermal protection in clothing (woven, non-woven, knit and batting fabric structures), as well as such improvements to existing fibers.

• Counter-surveillance — Enhancement of textile systems that cloak soldiers' uniforms, equipment and skin-camouflage paints from infrared and other sensors used in enemy surveillance.

• Body-worn interactive materials — Novel materials, technologies and manufacturing methods to integrate miniaturized electronics into protective clothing, textiles or combat field equipment. Unique materials providing sense and respond, or actuation capabilities, power generation, or radio frequency tagging are of interest.

• Biomechanics — Biomechanical devices that help soldiers in the field handle larger loads. This might include an exoskeleton. "Biomechanical tools and data are currently being developed to inform the design of boots, individual body armor, and load carriage gear that reduce injuries, delay fatigue and enhance dismounted soldier mobility," according to the report.

• Materials nanotechnology — Specific areas of application for materials incorporating nanotechnology include personnel armor, clothing, airdrop systems, shelters and load carriage systems, packaging materials, textile-integrated electronic systems, chemical/biological reactive materials and tactical optics.

• Lightweight, low-cost power sources — Power source solutions that demonstrate substantial reductions in lifecycle cost and logistics burden. For example: wearable solar and fuel cells for soldiers; the Army wants power levels of 20W to 30W, and the cell can weigh no more than 0.6 kg.

The MIT center is funded by the Dept. of Defense, MIT and private partners, including DuPont and Raytheon.

"Dismounted infantry soldiers often carry backbreaking loads of equipment, which can exceed 140 pounds," says the MIT Institute for Soldier Nanotechnologies. "Their equipment is not designed to work together, and they are inadequately protected from ballistic, chemical and biological weapons."

Moving forward, there is a notable ambition for more lightweight systems in both aircraft and armor for protecting vehicles and soldiers — ambitions that, if fulfilled, will represent a new revolution in materials science and tech.

Resources

Broad Agency Announcement: Solicitation Number "07 - 09 Natick BAA"
U.S. Army Natick Soldier Research Development and Engineering Center, May 15, 2007, effective April 1, 2007-March 31, 2009

Competing with Composites
by John Teresko
IndustryWeek, Nov. 1, 2008

Self-Repairing Aircraft Could Revolutionise Aviation Safety
Bristol University, May 19, 2008

Self-Repairing Aircraft Could Revolutionise Aviation Safety
The Engineering and Physical Sciences Research Council, May 19, 2008

Myth Busted: Scientists Unveil High-Tech Army
by Jacqueline M. Hames
Army News Service, Oct. 9, 2008

Innovation in the Crucible of War
by Johna Till Johnson
Network World, Sept. 11, 2008