These parts were made using additive manufacturing, which creates plastic items and other durable components by adding material, layer by layer, using 3-D printers. (Photo: U.S. Army)

A soldier heads back to camp, grabs a power bar and unloads his gear. The power bar, which was "printed" minutes earlier, contains all the nutrients his body currently needs, according to sensors that are embedded in his uniform. While this may sound like a scene from a sci-fi movie, engineers and scientists at the Army Research, Development and Engineering Command (RDECOM) are looking at ways to use additive manufacturing (aka 3-D printing) to make it a reality.

"The vision is to be able to have additive manufacturing as a tool in the toolbox so that soldiers can manufacture and produce a product as close to the point of need as possible," said Andy Davis, program manager for the Army's Manufacturing Technology program (ManTech).

Using additive manufacturing to supply soldiers with customized, nutrient-dense food, repair critical parts on demand, or print new skin cells to repair burned skin could not only lighten the logistics burden but also improve the efficiency of the acquisition process. One type of additive manufacturing – fused filament fabrication – produces parts from plastic and other durable materials by adding material, layer-by-layer, using 3-D printers. The material, which resembles heavy fishing line or weed-eater string, is precisely pushed through a print head in the pattern of the item being built.

A key benefit of additive manufacturing is that it uses only the material that is required to make a part, which minimizes waste and saves money. Additive manufacturing can also be used to recycle waste and make new products. The Army Research Laboratory is working on a process that takes unwanted material – such as the packaging from soldiers' Meals Ready-to-Eat and water bottles – shreds or melts it and then processes it into a string that can then be used to make items like a door handle or a rack. Recycling waste on the battlefield will not only minimize the cleanup process for soldiers, but also eliminate the wait time for new parts, which can be days or weeks. The amount of time that it takes to print a part will depend on the material and the part, but overall it will be quicker than waiting for a part to be shipped.

"One of the challenges associated with [additive manufacturing] … is that it's still new," Davis said. "Our understanding of the process down to the level that lets us repeat it and get the same results over and over again is not there yet."

RDECOM partners with the Army's Rapid Equipping Force to manage, staff and support expeditionary labs, or "ex labs," which can be deployed worldwide. Ex labs are designed to supply innovative equipment to forward-deployed soldiers as quickly as possible. One lab is currently located at Bagram Airfield in Afghanistan and another at Camp Arifjan, Kuwait. Each ex lab is built into a 20-foot shipping container and two ISU 90 shipping containers, which hold a 3-D printer as well as supporting equipment and the computer-aided design workstation used to create the virtual working models that are then constructed by the 3-D printer. The labs are also stocked with traditional tools, equipment and software to design and fabricate metal and plastic parts.

Once a virtual design is perfected, it will be stored in an enterprise-wide product data management system being developed by RDECOM and Army Materiel Command. Other organizations will have access to the product data management system. The goal is to foster data-sharing and eliminate the need to create designs from scratch.

"The labs have an open-door policy so the soldier can come in and describe his mission capability shortfalls, and the [ex lab] team immediately starts brainstorming ideas and solutions," said Angel Cruz, RDECOM ex lab project lead. "If the item doesn't work or fit right the first time, then the [ex lab] team can revise the design on the spot. [Additive manufacturing] allows us to produce different iterations of a solution very quickly in order to get it just right."

The on-site ex lab team includes a Rapid Equipping Force noncommissioned officer in charge, a RDECOM lead engineer, a support engineer, and a machinist. Together, they develop solutions using textiles, electronics, subtractive manufacturing and additive manufacturing. Additive manufacturing is used to create parts that are difficult to machine and substitutes for parts that would normally be made using injection molding, an expensive process that requires specialized equipment. Other projects require traditional manufacturing or subtractive manufacturing, which takes away material by cutting, grinding, milling and other methods.

When the ex lab cannot complete the work -- whether it's because of the lack of a subject matter expert, the required supplies, or the time to complete the project -- RDECOM's Edgewood Chemical Biological Center can provide reach-back support across the RDECOM network of engineers, scientists and technicians.

RDECOM plans to develop additive manufacturing in three phases. Phase one will use additive manufacturing to repair and replace existing parts. Phase two will reduce multipart assemblies from a series of parts to one part. For example, the receiver on a machine gun is composed of titanium parts that are welded together in a multipart assembly; the goal with additive manufacturing would be to reduce the receiver's cost and its number of parts by printing all the parts as one piece. Phase three will use additive manufacturing to create new parts that don't already exist.