Research funded by the United States Army Research Lab (ARL) has developed a composite ‘super foam’ material that absorbs ten times more energy than current energy-absorbing foams.
The Texas A&M-led research team behind the advanced, energy-absorbing material said its outsized ability to safely and efficiently disperse energy could offer unprecedented protection for American troops, including applications in helmets and explosion-resistant vehicle seats.
Due to its tunability, simplicity of design, and low cost, the ARL-funded team said their ultra-energy-absorbing super foam could also improve civilian safety, such as applications in motorcycle helmets and car seats, without adding excess weight or compromising comfort.
Super Foam Eliminates the Trade-Off Between Cost and Energy Dissipation Power
In a statement announcing the super foam’s development, study leader Dr. Mohammad Naraghi, the director of the Nanostructured Materials Lab at the Texas A&M College of Engineering, noted that many of the objects people interact with on a daily basis are made in some part out of foam.
“We are surrounded by foams,” Naraghi explained.
In the vast majority of applications, foams are designed to cushion impacts by absorbing energy. According to the ARL-funded team, the material’s secret lies in its construction. Unlike solid materials, foams are filled with tiny air pockets that collapse under pressure. This deformation dissipates impact energy, protecting packages from damage in transport and motorcycle riders from more serious injury in collisions.
However, according to Naraghi, not all foams are created equal. Most low-cost industrial and commercial foams contain chaotic internal structures that limit the amount of energy they can absorb before losing their protective capabilities. While more organized foams exist, their improved energy dissipation ability comes at a substantial cost.
This has resulted in a trade-off between foam cost and quality, motivating the Army to fund research into a more absorbent, low-cost super foam. This hunt led the Texas A&M team to a technique called In-Foam Additive Manufacturing, or IFAM.
Tests Show Material’s Dual Ability to Offer Support and Dissipate Force
According to Dr. Eric Wetzel, team leader for Strategic Polymers Additive Manufacturing at ARL, IFAM is a “simple, computer-driven manufacturing process” that enabled the team to build a customized elastomeric skeleton directly within a conventional, low-cost open-cell foam. When constructing the elastomer internal skeleton, the IFAM process enabled the team to custom-tune the spacing, angle, and elasticity of the internal skeleton. The result is a network of organized plastic struts injected directly into the ordinary foam, imbuing it with its ultra-energy-dissipation super-foam properties.
After creating their own super-foam prototype, the team tested it under various conditions. As expected, these tests revealed two key findings. First, when the material was subjected to pressure, the hybrid composite foam acts as a brace, holding the injected struts steady so they don’t buckle prematurely. However, as the pressure increases, the struts redistribute the force to the surrounding foam.
The team said this alternating between support and spreading the load gave the new material an unprecedented ability to resist pressure, 10 times stronger than existing foam options. According to Wetzel, this “wide range of properties” and simple manufacturing process make their super foam a potential game-changer.
“The IFAM process combines the best of both worlds, providing a low-cost, customizable, high-performance composite energy absorber,” the researcher explained.
“It’s the magic of synergy,” Naraghi added. “A symbiotic composite between the foam and the struts.”
Customized Padding is 10X More Resilient and Tuned for Comfort
When discussing potential military applications, Wetzel highlighted the critical role that energy-absorbing materials already play in ballistic helmets and blast-resistant seat cushions. So, he added, adding a super foam that absorbs ten times more energy, doesn’t add weight, and can reduce injuries and potentially save lives, is more than just an engineering win-win; it’s a “no-brainer.”
“We aren’t just adding layers to military helmets,” Naraghi said. “We are using a composite shield that’s more resilient than current paddings, yet light enough to wear all day without feeling tired.”
When discussing the material’s custom tunability, Wetzel noted that, in addition to preventing head and brain injuries that “remain a significant concern for the U.S Army,” the super foam can also be tuned for comfort.
“With our hybrid foam, you could have different zones of your cushion tuned to your different preferences,” Naraghi explained. “For instance, firm for the neck, soft for the back, and medium for the legs. It could be entirely customized to a person’s needs, comfort, and physiology.”
The ARL researcher also noted that the IFAM process used to create their super foam “is easily transferable to scaled, real-world manufacturing.” For example, the super foam could improve the protective abilities of helmets designed for bicycles, motorcycles, or various sporting activities.
“Really, any gear designed to absorb high-energy impacts,” Naraghi explained.
One application the team is already exploring involves adding their super foam to car bumpers and interiors to potentially reduce collision-related injuries and fatalities. According to the research team, using their foam in this way would imbue vehicles with a high-tech energy ‘trap’ that can “swallow brutal collisions,” to protect passengers from impacts that current padding isn’t optimized to withstand.
“One transition we are interested in exploring is passenger and child safety seats,” Naraghi explained.
Super Foam Could Dampen the Low Rumble of an Aircraft Engine
Another unrelated application involves the super foam’s ability to mitigate noise. Although it is not the material’s intended design, the ARL-funded team said early indications suggest the foam has strong sound-insulation properties.
“You could modify the foam’s properties to become an excellent sound absorber that dampens, or even entirely eliminates, specific frequency bands and vibrations,” Naraghi explained.
Along with reducing road noise for drivers, this material could reduce the deep, low rumble of an aircraft engine that resonates throughout the cabin.
“The acoustic applications are still in the early research stages, but we would like to explore this property more, to turn the foam into an active sonic filter that outperforms current materials,” Naraghi said.
The study “In-foam additive manufacturing: Elastomeric cellular composites with tunable mechanics” was published in Composite Structures.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.