2D and 3D graphical datasets for bamboo-inspired tubular scaffolds with functional gradients: micrographs and tomograms

Presented in this article are 2D and 3D graphical datasets in the form of micrographs and tomograms that were obtained as part of a systematic microstructural characterization by scanning electron microscopy and X-ray microtomography to illustrate freeze-cast bamboo-inspired tubular scaffolds with functional gradients (“Bamboo-inspired Tubular Scaffolds with Functional Gradients” [1]). Four material combinations of the coaxial ‘core-shell’ molds and their two end pieces were used to freeze cast highly porous tubes (Tube/Rod/Holder): ASA (Aluminum, 316 Stainless Steel, Aluminum), ASP (Aluminum, 316 Stainless Steel, Epoxy (Plastic)), SCA (316 Stainless Steel, Copper, Aluminum), and CSP (Copper, 316 Stainless Steel, Epoxy (Plastic)). Three techniques were used to coat the best performing CSP freeze-cast tubes: spray freezing (SF), spray coating (SC), and brush freezing (BF). The structure and density profile of the uncoated and coated tubes was quantified using X-ray microtomography and their functional gradients, and the resulting mechanical performance in bending were determined and compared. The structure-property-processing correlations determined for the coated and uncoated coaxially freeze cast tubular scaffolds offer strategies for the biomimetic design of bamboo-inspired porous tubes, which emulate bamboo's stiff outer shell supported by a porous, elastic inner layer to delay the onset of ovalization and failure, thereby increasing the tubes’ mechanical efficiency.