3D Bioplotter Research Papers

Treatment of critical-sized bone defects remains challenging despite bone’s regenerative capacity. Herein, a combination of a biodegradable polymer possessing bone-bonding properties with bioactive β-tricalcium phosphate (βTCP) particles coated with osteogenic (Zinc) and angiogenic (copper or cobalt) ions has been proposed. βTCP was coated with zinc and copper (Zn/Cu) or zinc and cobalt (Zn/Co) using 15 mM (low) or 45 mM (high) metallic ion solutions. Composites were obtained by a combination of the βTCP with poly(ethylene oxide terephthalate)/poly(butylene terephthalate) (PEOT/PBT) copolymer in a 50:50 ratio. Composites were additively manufactured into 3D porous scaffolds and their osteogenic and angiogenic properties evaluated using a direct…

Ni-Co-Fe-based high-entropy superalloys (HESAs) are fabricated into microlattices via a three-step process: (i) layer-by-layer extrusion of inks containing elemental powders (Ni, Co, Fe, Cr, Ti) and TiAl3 powders; (ii) sintering to densify and homogenize the struts; (iii) aging to achieve a γ/γ’ microstructure. The struts of the microlattices show a nearly pore-free and fully-homogenized microstructure. Increasing the Ti concentration from 4 at% (Al9Co26Cr7Fe16Ni38Ti4) to 9 at% (Al8Co25Cr7Fe15Ni36Ti9) leads to a significant increase in the volume fraction of strengthening γ’ precipitates, from 51 to 78 %. Furthermore, in the Ti-rich composition, the γ’ precipitates exhibit a sharp-edged cubic morphology with larger…

Liquid ink-printing followed by sintering is used to fabricate WC-Co microlattices and cutting tools. The microstructure of WC-xCo (x=0.5-20 wt.%) is studied for a range of carbide-to-binder ratios and for various sintering temperatures. For 0.5≤Co≤5 wt.%, struts in microlattices exhibit residual porosity due to incomplete densification, even at the highest sintering temperature of 1650 °C. With 10 wt.% Co, fully dense lattice struts are achieved after sintering at 1450 °C for 1 h. For 1450-1650 °C sintering temperatures, the hardness of WC-xCo struts initially increases (due to increasing densification with increased Co) and then gradually decreases (due to an increase…