• Additional dipping cycles resulted in a more homogeneous coating. • The sheet resistance distribution of SG is unaffected by the build orientation. • The data-aided layered simulation method reduces discrepancies by 26%–56% for HC. • HC is more conducive to forming gradient coating materials. Dip-coated electromagnetic-wave-absorbing metastructures have been widely explored owing to their multifunctional benefits, including simple fabrication, strong absorption, and high load-bearing capacity. However, a significant gap persists between design and fabrication, with mismatches in resonance frequency and reflection loss often inaccurately attributed to manufacturing precision. This discrepancy severely limits accurate design, and research on the molding laws of surface coatings around these structures remains scarce. This study investigates the formation processes and characteristics of surface coating materials on metastructures with different build orientations, while revealing the correlation between surface sheet resistance and surface roughness, as well as morphological features. The results showed that the FDM-45° honeycomb (HC) metastructure exhibited a uniform sheet resistance distribution, and that for all HC and sheet gyroid (SG) metastructures, additional dipping cycles led to a more homogeneous coating on the metastructures. Although the sheet resistance distribution of the SG metastructure was unaffected by build orientation, it exhibited excellent robustness. Based on the sheet resistance, an experimental data-aid layered simulation method was proposed, this method effectively enhances simulation accuracy for HC metastructures, reducing discrepancies by 26%–56%. This study provides a critical foundation for the precise and predictable performance design of metastructures, bridging the gap between design models and additive-manufactured components.
An et al. (Sun,) studied this question.