Fig. 1: Segmental motif inspired by the structure of the arthropod exoskeleton.

a Segmental structure of arthropod leg. b, c Rotation of tarsal segments under compression. Grey indicates the stiff exoskeleton shell; yellow indicates soft tissue (tendons). d, e Kinematic model of tarsus under compression before and after segment rotation. Each design motif contains two types of material: stiff and strong material (grey) providing strength and soft material (yellow) improving toughness and flexibility. f Comparison of the inspired segmental motif with design motifs in the literature, including suture, layered, helical and overlapping motifs. A detailed comparison and discussion of the overlapping structure and segmental structure can be found in Supplementary Note 1. g Deformation and rotation of segment under loading. h–l Schematic of the realisation of the segmental motif. h Front view of the scaffold. The horizontal elements are denoted as beams and the vertical ones are denoted as columns. Effects of 3D printing orientations and thickness of the scaffold are presented in Supplementary Note 2. i Master view of the segmented scaffold after coating. The coated cement layer on the left side is cut and the surface tension is indicated by arrows. j, k Horizontal cross-sections showing asymmetrical coating. l Vertical cross-section showing asymmetrical coating before loading (left) and segment rotation after loading (right). The locations of the cross-sections are shown in (h) by the dotted lines. m Master view of the polymer scaffold of an artificial bug with a segmented polymer scaffold. n Front view of the polymer scaffold of the artificial bug. o Master view of the artificial bug after coating with cement paste. Scale bar = 1 cm. p Joint rotation of leg under compression. The artificial bug is supported and horizontal translation is constrained during loading. q Lattice Boltzmann method (LBM) simulation of the interaction between fluid and scaffolds under the co-effect of gravity and surface tension. The shear stress of the fluid at different time points is indicated by the colour map. Method of LBM simulation refers to Supplementary Note 3.