Defects introduced during additive manufacturing strongly influence the mechanical response of architected materials, yet their evolution under load is difficult to resolve at the micrometer scale. Laboratory-based X-ray nanotomography (nanoCT) at 128 nm voxel size was used here to image tetrahedral polymeric microlattices, printed defect-free and with three omitted beams, during in situ compression. Image registration yielded three-dimensional displacement fields, and finite element simulations reproduced the measured behavior. Displacement was markedly reduced at the defect and recovered in neighboring unit cells, with an accompanying stiffness reduction. Laboratory nanoCT thus provides a practical route to validate models of architected materials.
This study presents the design and performance evaluation of hybrid bio-nanocomposite microcapsules engineered from sodium alginate and aluminum-pillared clays (Al-PILCs) for the enhanced encapsulation and controlled release of thymol. Prepared via ionotropic gelation, the microcapsules were characterized by Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), confirming successful bioactive entrapment and thermal stabilization. The incorporation of Al-PILCs yielded spherical microcapsules with encapsulation efficiencies reaching 78.4
We report the influence of alloying (Ag, In, Cu, Sb) on the temperature-dependent (25–90℃) electrical resistivity of near-eutectic Sn–Bi low-temperature solders. Microalloying refined the Bi-rich phase and increased hardness, with Sb producing the strongest strengthening. Ag and Cu reduced room-temperature resistivity, attributed to disruption of high-resistivity Bi pathways and improved Sn-phase connectivity. In showed negligible impact due to competing solid-solution scattering and increased β–Sn phase. Sb increased resistivity owing to solute and precipitate scattering. Temperature coefficients of resistance remained comparable to the base alloy. The results help establish composition–microstructure–property relationships governing electrical performance of Sn–Bi-based solders.
Infill density is an important 3D printing parameter that influences both mechanical strength and cost. Considering the importance of both strength and cost efficiency, this study examines mechanical properties of specimens fabricated with vat photopolymerization to determine the optimum infill density. The specimens were printed at infill of 20 to 100
Thermal systems increasingly operate under time-varying conditions, making transient analysis essential alongside steady-state analysis for thermal metamaterials. We introduce HeatFlow, an open-source, implicit, cell-centred finite-difference solver for Fourier and Cattaneo heat transport in structured materials. The code is verified against an analytical heated-bar solution, reproduces established Fourier-regime benchmarks for cloaks, rotators, and concentrators, and is demonstrated on a simplified hemispherical shield with isotropic conductivity contrasts. We also connect the solver to published non-Fourier metamaterial disc designs. These examples establish HeatFlow as a practical platform for thermal-metamaterial design and a foundation for investigating transient non-Fourier thermal effects.
