Hierarchical structures observed in biomaterials. (a) beetle elytron scales with multiscale tessellated irregular polygon shapes, observed on the hardened forewings (elytra) of beetle insects, (b) spiderweb designed with polygon shapes of different scales by a spider, (c) various levels of hierarchical levels seen in a skeletal muscle, (d) various hierarchical levels, from nano-to-micro scales observed in a tendon tissue, (e) macro-to-nano hierarchical structuring of a femur bone, (f) pomelo peel with hierarchical structures observed from the flavedo to the vascular bundles seen at the micro scales, and the (g) bamboo tree with hierarchical scales seen after analysing a bamboo joint, in which the hierarchical structures form part of the vascular bundles, parenchyma cells, fibers and vessels [15].