According to HRL Laboratories, its “architected elastomeric material” is capable of absorbing 27 percent more energy than the highest-performing expanded polystyrene, and 48 percent more energy than vinyl nitrile foams with repeated impacts —materials used to absorb shock in football, bicycle and military helmets.
“Our microlattice is composed of solid polymer struts and air. Unlike foam, it has an ordered architecture that enables improved performance in airflow, energy absorption, stiffness, and strength,” said Eric Clough, lead researcher for the new material. “Under high impact, microlattice stiffens to absorb energy and significantly reduces acceleration and force transmitted to the wearer.”
While HRL’s lattice is disruptive in performance, its manufacturing method is also unique and hints at profound opportunities for those developing elastomeric components with complex geometries.
HRL builds its microlattice by growing the material through a process called light casting.
In light casting, a UV beam is projected upon a vat of specially formulated, photosensitive liquid resin. To structure the geometry of the light interacting with the resin, a template of the desired geometry is placed in between the light source and the resin vat. Wherever UV light comes in contact with resin, a solid polymer strut is formed. These struts then grow to form the HRL’s shock absorbing lattice.
“With light casting, we can make a set of pads for a helmet in under a couple minutes,” Clough remarked. “Methods such as stereolithography 3D printing would take a much longer.”
Aside from endowing helmets with greater shock absorption, the airy nature of the microlattice material also makes any equipped domes much cooler, especially when compared to the solid nature of materials previously used for the same purpose.
HRL touts the adoption of their microlattice material by Vicis, but Vicis, a technology first helmet maker funded to the tune of $85 million, including a grant from the NFL, was reported to have run out of cash in late 2019, laid off workers at its Seattle offices and appears to be shutting its doors. On the Vicis website is this note “Despite our best efforts, we have been unable to attract the capital needed to sustain our operations.”
So, that begs the possibly inappropriate question of, whether on the gridiron, or the battlefield, would the deployment of helmets infused with HRL’s lattice material allow for cooler heads to prevail?
I guess that might depend on whether one, or both sides, were wearing the upgraded headgear.