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Triply periodic minimal surfaces (TPMS) are mathematically defined minimal surfaces that exhibit zero mean curvature and repeat periodically along all three Cartesian axes. They integrate mathematically defined geometry with extensive functional adjustability. Their smooth, non-self-intersecting topology enables systematic control over relative density and improves load transfer efficiency within the lattice. Their large surface area-to-volume ratios further enhance specific energy absorption (SEA) and enable diverse functional uses. Recent developments in additive manufacturing (AM) have made it easier to create TPMS structures. As a result, they are now considered as the architected materials that combine biological, thermal, and mechanical functions within a single framework. This study presents a comprehensive overview of the major TPMS structures. It further highlights several AM techniques used for their fabrication and provides a critical evaluation of how geometric design, relative density, and post-processing influence their mechanical and thermal performances. This work also discusses recent developments in graded and hybrid TPMS structures. It further identifies the main challenges and future research directions related to multi-material additive manufacturing and data-driven topology optimization. 

Origami-inspired mechanical metamaterials have gained significant attention in recent years due to their unique capacity for programmable deformation, mechanical multistability, and e!cient energy absorption. Among these, the Kresling origami structure stands out as a non-rigid, twist-coupled cylindrical or conical geometry capable of exhibiting bistability under specific geometric configurations. While studies have examined the mechanical behavior of metallic or polymer-based Kresling tubes under quasi-static and dynamic compression, the influence of bistability in Kresling origami tubes (KOTs) under impact loading has remained largely unexplored. This study investigates the impact-induced energy absorption performance of bistable and non-bistable Kresling origami chains fabricated from traditional origami paper. The samples are constructed using a laser cutting and scoring technique, ensuring precise crease definitions and repeatability. Each sample comprises a chain of multiple Kresling units connected along the axial direction, with three test configurations: (i) bistable chains designed with geometric parameters satisfying the multistable folding condition, (ii) geometrically similar chains with a different internal angle resulting in a single stable configuration (non-bistable), and (iii) chains with a combination of both unit types. To evaluate and compare the energy absorption efficiency of these systems, a drop-weight impact test is conducted with high-speed camera. This setup that we consider enables evaluation of absorbed energy and collapse behavior and finds the importance of geometric bistability in dynamic loading conditions. These findings suggest that the programmable nature of origami structures—particularly through manipulation geometry offers a viable route to lightweight, tunable, and efficient energy absorbers. This work will be applicable to the broader objective of designing lightweight, foldable, and tunable energy-absorbing systems for applications in aerospace structures and impact mitigation technologies, such as unmanned aerial vehicles (UAVs), electric vertical take-off and landing (eVTOL) systems, and deployable satellite solar panels.