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Triply periodic minimal surfaces (TPMS), which have zero mean curvature and large surface areas, are discussed in this paper. Two TPMS structures, the Schwarz Primitive (P) and Gyroid, were designed with both uniform and graded density and fabricated using additive manufacturing (Stereolithography). The mechanical properties and energy absorption abilities of the printed TPMS samples were studied. The Schwarz P structure cracked layer by layer and exhibited obvious peak-valley stress feature during the compression test. The total absorbed energy to the densification point was 1.64 MJ/m3 and 2.47 MJ/m3 for the uniform and graded Schwarz P structures, respectively. There was little difference between the uniform and graded Gyroid samples, and only one structural crack appeared during the compression test. The total absorbed energy for the uniform and graded Gyroid structures was approximately 2.49 MJ/m3 and 2.51 MJ/m3, respectively. The results showed that the graded Schwarz P structure absorbed more energy during the compression tests, while energy absorbed in the graded Gyroid structure was close to the uniform Gyroid structure. Furthermore, the relationship between energy absorption and compressive stress was determined and the abnormal characteristics in Gyroid structures were deeply discussed. Unlabelled Image • The idea of designing and fabricating graded triply periodic minimal surface were demonstrated and experimentally confirmed. • The energy absorption ability of Schwarz P structures was improved with graded designs. • The mechanism of the abnormal mechanical behaviours of both graded and uniform Gyroid structures were deeply discussed. [ABSTRACT FROM AUTHOR]

The high integration density of microelectronic devices leads to local heat accumulation, and effective heat dissipation and signal transmission of packaging materials have become the primary issues to be solved. However, existing polymer materials have difficulty meeting the requirements due to their unsatisfactory thermal conductivity and thermal expansion properties. In this work, we proposed the use of digital light processing (DLP) printing technology to construct a triply periodic minimum surface (TPMS) skeleton, and a continuous and efficient heat conduction path was successfully constructed in epoxy resin by impregnating h-BN on the skeleton surface. When the loading of h-BN was 20 vol%, the thermal conductivity of the TPMS(SiO 2)@BN/EP(BN) composites was 1.86 W/(m·K), which was 786 % higher than that of pure epoxy resin. In addition, the thermal expansion coefficient of the composites decreased by more than 70 %. At the test frequencies of 3∼10 MHz, the composites showed stable dielectric properties, and the dielectric constant was always maintained in a low range, between 3.85 and 4.15. This work has realized the transformation of the method for constructing a heat conduction path from disordered to ordered and from random to repeatable. This provides a new strategy for the selection of microelectronic packaging materials. [ABSTRACT FROM AUTHOR]

Electrically assisted water splitting is an endurable strategy for hydrogen production, but the sluggish kinetics of oxygen evolution reaction (OER) extremely restrict the large‐scale production of hydrogen. Developing highly efficient and non‐precious catalytic materials is essential to accelerate the sluggish kinetics of OER. However, currently used catalyst supports, such as copper foam, suffer from inferior corrosion resistance and structural stability, resulting in the disabled functionality of 3D conductive networks. To this end, a novel 3D freestanding electrode with corrosion‐resistant and robust Ti–6Al–4V titanium alloy lattice as the catalyst support is designed via a 3D printing technology of selective laser melting. After the coating of core–shell Cu(OH)2@CoNi carbonate hydroxides (CoNiCH) on the designed lattice, a unique micro/nano‐sized hierarchical porous structure is formed, which endows the electrocatalyst with a promising electrocatalytic activity (a low overpotential of 355 mV at 30 mA cm−2 and Tafel slope of 125.3 mV dec−1). Computational results indicate that the CoNiCH exhibits optimized electron transfer and the catalytic activity of the Ni site is higher than that of the Co site in the CoNiCH. Therefore, the integration of robust catalyst supports and highly active materials opens up an avenue for reliable and high‐performance OER electrocatalysts. [ABSTRACT FROM AUTHOR]