This investigation aims to assess the mechanical behavior and energy absorption properties of the light sandwich panels made of open‐cell polymer and nickel/polymer foam. A portion of the ultralightweight foam sandwich panels (14.23 g) is produced by 3D printing and electrodeposition methods with 35, 45, and 55 seeds numbers, which lead to 4, 5, and 6 pores per inch (PPI); then a uniaxial compression test is applied to measure maximum compressive strength, strength‐to‐weight ratio, energy absorption density, efficiency, and complementary energy. The results indicate that compared with typical open‐cell nickel foams and polymer precursors when the thickness of the nickel layer is about 50 micrometers, the aforementioned properties of the sandwich panel shows a significant improvement. Improvement of properties changes by increasing PPI and CAD seed numbers. In a nickel/polymer sandwich panel with 6 PPI, the first maximum compressive strength, specific energy absorption, and energy absorption efficiency reach 0.93 (MPa), 0.93 (J.boldg−1), and 60%, respectively. 3D‐RP‐Ni‐6 improves 3D‐RP‐6 first maximum compressive strength and specific energy absorption by six times and two times, respectively. These significant improvements in the properties of these sandwich panels make these advanced materials a suitable candidate for the high strength applications.

This investigation aims to assess the mechanical behavior and energy absorption properties of the Cu lattice structures made by investment casting method experimentally and by finite element method (FEM) simulation. The casting pattern of lattice structures is additively manufactured with 2.0, 2.5, and 3.0 mm diameters and the lattice structures produced by investment casting of Cu. Then a uniaxial compression test is applied to measure maximum compressive strength, energy absorption density, efficiency, and specific energy absorption. The simulation and the experimental results indicate that the abovementioned properties of the lattice structures have a significant improvement and properties developments will rise by increasing the diameter of the struts. The mechanical characterization has done for Cu lattice structure with 3.0 mm strut diameter, which endures a stress of 242 MPa at the densification strain and the maximum tolerated stress of 404 MPa. The energy absorption density of this lattice structure is 67 MJ m−3 and has a specific energy absorption of 28 J g−1 followed by an energy absorption efficiency around 70%. The simulation result shows a mathematical connection between the unit cells and the final lattice structures in terms of maximum tolerated stresses, which can help the prediction of the mechanical behavior of these structures.