Additive manufacturing of interconnected hierarchically porous zirconia: Utilizing both microspherical and filamentary pore-forming agents via direct ink printing

Osteogenic differentiation and bone regeneration can be effectively aided by porous scaffolds with multiscale cellular structures, making it easier to repair defects in bone tissue. Due to the scarcity of pore-forming agents, it is extremely challenging to fabricate interconnected hierarchically porous zirconia at multi-scale. This work described a novel and straightforward method for directly imprinting a slurry containing two pore-forming agents (microspherical and filamentary) to produce strong and highly porous zirconia (ZrO2) ceramics with four levels of porosity ranging from nanometers to millimeters. The concentration of hemp fibers significantly affected printability when the rheological behavior of a zirconia slurry was examined. Utilizing a scanning electron microscope (SEM) to monitor the development of powder interstices under various sintering techniques. The permeability performance was assessed when simulated plasma had fully filled the scaffolds. The structure had a high compressive strength of 24.18 MPa, a porosity of 80.9 %, an apparent porosity of 55.7 %, and took just 1.11 s to fill a scaffold that was 15 mm high. It is anticipated that the proposed route will be expanded to include various engineering materials for structural and practical applications.