Elastomeric Microlattice Impact Attenuators

Impact-attenuating materials are designed to absorb impact energy through the collapse of pores within the material below a threshold force (or acceleration), thereby mitigating damage or injury. Recent advances in additive manufacturing techniques have enabled the fabrication of cellular materials with architected lattice topology. Here it is demonstrated that, via design of cellular architecture, the dynamic stress-strain response of elastomeric lattices can be tailored to achieve impact-attenuation performance exceeding state-of-the-art foams for both single- and multi-hit scenarios. The additional degrees of freedom in the design of the cellular architecture of lattice-based impact attenuators are then leveraged to optimize their performance for a typical helmet impact scenario wherein the contact area increases during deformation. An improvement over state-of-the-art vinyl-nitrile foam helmet pads is achieved during a standard helmet test, leading to lower head acceleration. This breakthrough could pave the way to helmets with improved injury protection.