Controlled additive microtexturing of polymer and metal alloy surfaces using algorithm-aided design

Abstract This paper presents an algorithm-aided design approach that supports the 3D printing of microtextures on both polymeric and metallic surfaces. A Grasshopper-based algorithm was developed that combines control curves for pattern arrangement, with a mathematical function to define unit geometry. This enabled textures with variable shape, size, and gradients to be applied to flat and curved surfaces. Polymer microtextures were printed using Fused Filament Fabrication (FFF) and Selective Laser Sintering (SLS). A benchmark with concave and convex circular features established minimum printable feature sizes. Parts produced by FFF and SLS achieved minimum diameters of 0.3–0.9 mm, depending on orientation, except for SLS-concave, for which the minimum diameter was 1.2 mm. Sharkskin-inspired microtextures were found to exhibit accurate length and width (< 1% deviation), while feature heights were undersized by on average 10–21%, depending on the technology. The dimensional deviations of circular features were quantified and modelled using second-order regression. The output was integrated into the Grasshopper algorithm to enable automatic compensation for print design deviations. Parts printed with compensation exhibited a 62% reduction in average deviation. Printing textured parts was shown to increase FFF build time by 2.8 × but only by 3% for SLS prints. The microtexturing approach was also successfully demonstrated for titanium alloy parts printed using Laser Powder Bed Fusion, highlighting the potential of the developed algorithm-aided microtexturing approach for use in conjunction with a broader range of additive manufacturing technologies.