Improved steel armor and cutting-edge solar cell technology will soon provide soldiers with better protection and lighter loads when they venture into harm’s way.

Keeping soldiers safe is a high-tech operation. Today’s modern military force relies on modern technology—such as night-vision goggles, GPS, radio systems and specially equipped armored vehicles. A lot of research goes into bringing technology to today’s soldiers. U.S. Department of Energy (DOE) labs have a hand in creating and improving technologies that push the boundaries of safety and performance for soldiers in the field. These often translate into advancements that will improve civilian life.

Improvised explosive devices (IEDs) pose a significant threat to soldiers on the ground, and present a challenge to engineers charged with outfitting military vehicles with armor able to withstand the deadly blasts. However, scientists at the National Energy Technology Laboratory (NETL) have developed a type of steel-cast armor that’s especially designed to protect tanks and transport vehicles from IEDs.

The secret to their success is a process developed by NETL called “lost-foam casting.” Lost-foam casting was originally developed for use with aluminum, but NETL scientists adapted the process to cast steel, which previously had never been attempted due to its higher density and melting temperatures. As the name implies, it starts with a model of a part, created from polystyrene foam. The foam is then dipped into a solution that coats the foam pattern and leaves a thin, heat-resistant layer. Molten metal is then poured into the mold, vaporizing the foam. When the metal cools and solidifies, all that remains is the metal part.

The advantage of this technique over traditional rolled and forged steel is that it allows for the creation of parts in a variety of complex sizes and shapes. This not only makes it possible to specially design armored plates for different types of vehicles, but to generate patterned steel parts that are better at deflecting IED blasts. Today’s high-tech armor uses a pattern that incorporates hundreds of rows of angled slots called P-900. This armor was designed by the Army Research Laboratory, which asked NETL to develop a casting process to produce this new armor. While it may seem counterintuitive to create armor with holes, Paul Turner, who works on the project at NETL, explained that those slots serve an important function. “Essentially it fractures the projectiles into smaller pieces so they don’t have the energy to penetrate the armor,” Turner said.

The process has been in development since the late 1980s. At least 25,000 units of armor have been tested in the field. Castings produced with the lost-foam process are up to 10 percent lighter and perform better in ballistics tests. Now the same concept is being adapted to lighter weight materials. “You can use a lot of the lessons learned from this to develop other materials,” Turner said. “For example, titanium armor is being developed for aircraft applications.”

But weight is an issue on the ground as much as in the air, and the National Renewable Energy Laboratory (NREL) in Golden, Colorado, is concerned about the weight that soldiers carry, not tanks. Many soldiers already carry 100 pounds or more on their backs. Electronic gadgetry can take that number even higher. Consequently, NREL is working on advanced solar-cell technology, designed to help reduce soldiers’ dependence on battery power and lighten an individual’s load by as much as 20 pounds. The challenge is that current solar cells are either too large or cannot generate sufficient power to reliably charge electronic devices. But NREL is working toward producing a solar cell that is small enough to integrate into portable electronics, yet efficient enough to meet modern power requirements.

To achieve these goals, researchers plan to use a specially designed lens to concentrate sunlight onto a special layer of photovoltaic materials. Instead of using just one material, they plan to combine different types of materials that convert sunlight into electric current—each optimized to specific portions of the light spectrum.

NREL believes that through new breakthroughs in materials and solar-cell design they can create a technology that will enhance the functionality of portable electronics and help push energy demands towards renewable and environmentally friendly sources. In fact, they hope that through their research, they can turn solar-cell research upside down—literally. One of their designs involves layering photovoltaic materials in reverse—from top to bottom instead of one on top of another as in most current designs. The new process has been aptly named the “inverted metamorphic multijunction” solar cell. This reverse approach, the team believes, holds the promise of advantages in performance, engineering design, operation and cost. The hope is it will lighten the battery load not only for soldiers in the field, but ultimately for the environment and technology users everywhere.