Elastomeric polymer foams are widely used in sports and other protective padding applications due to their unique properties, such as excellent cushioning and relatively high‐energy absorption to weight ratio. This work investigates the mechanical and energy absorption performance of an elastomeric hybrid structure polyurea foam in response to low‐velocity impact. The examined polyurea foams are synthesized using a novel self‐foaming process that leads to the development of a semi‐closed cellular structure. The quasi‐static response of the foam is first characterized by measuring the global stress–strain and energy absorption characteristics. The evolution of the foam's Poisson's ratio is also characterized by in situ digital image correlation (DIC) measurements. The same properties are also studied in dynamic loading conditions by subjecting the foam samples to controlled impact tests. A strain‐dependent rate sensitivity parameter is used to quantify differences between the quasi‐static and dynamic strength and energy absorption responses of the foam. The examined foam shows significant enhancement in strength at increased strain rates while retaining its excellent energy absorption capacity. This unique characteristic of the examined foam is discussed in terms of the concurrent effects of entrapped gas and the rate sensitivity of the parent polymer.

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Abstract The applicability of additive manufacturing (AM) continues to expand because of research and development efforts in industrial, academic, and governmental institutions. The lure of additive manufacturing lies in the quick time-to-market and ability to produce parts and components with high degrees of topographical complexity empowered by the layer-by-layer production approach. One challenge that is attracting a significant amount of attention is improving the multi-functionality of additively manufactured parts, as enabling multi-functionality will result in transitioning AM to a broader application domain. The objective of this paper is to report novel developments that improve the functionality of polymer-based parts by adding electrical conductivity and fluid management to the existing load-bearing capabilities. A space structure was 3D-printed using Acrylonitrile Butadiene Styrene (ABS) with embedded internal channels throughout the entire structure and then sealed using an acetone-diluted epoxy. The inner surfaces of the embedded channels of the sealed structure were then metallized using an electroless silver-coating process; these processes were found to be robust and independent of the inner diameter and length of the structure. The electromechanical performance of the structure was verified by applying mechanical loading while monitoring the change in electrical resistivity. The latter was found to remain nearly constant up to the point of ultimate mechanical failure. Finite element modeling was used to identify the areas of structural weaknesses and assist in elucidating the failure modes. The results were found to be in good agreement with the experimental data.