Flash sintering of 3D-printed 3YSZ scaffolds for bone tissue engineering

Author(s)

Nunes, Fabio C. ; Lanconi, Patryck A. ; Gomes, Gustavo H. M. ; Santos, Karina F. ; Nagata, Ester Y. ; Campos, Joao, V ; Moraes, Izabel C. F. ; Daguano, Juliana K. M. B. ; Pallone, Eliria M. J. A.

• Document type: Journal article
• Source: CERAMICS INTERNATIONAL; v. 51, n. 13, p. 14-pg., 2025-05-01.

Abstract

Flash sintering is an innovative technique that employs an electric field to significantly accelerate the sintering process while reducing the furnace temperature needed for sintering, offering reduced processing times and energy consumption. This approach enables the rapid consolidation of ceramic materials within seconds, presenting new opportunities for advanced manufacturing. One promising yet not fully explored application is the densification of 3D-printed porous structures, such as scaffolds. In this study, we investigated, for the first time, the application of flash sintering to 3 mol% yttria-stabilized zirconia (3YSZ) scaffolds fabricated via material extrusion. The scaffolds were produced using an ink comprising 70 wt% ceramic particles, poly(ethylene glycol) as a binder, and Laponite nanoclay as a rheological agent. After debinding, flash sintering was performed using an electric field of 80 V cm-1 to consolidate the scaffolds. The rheological properties of the ink were characterized to ensure optimal printability, while the scaffold morphology was analyzed across various regions. The ink exhibited a shear-thinning behavior, ideal for material extrusion processes. Flash sintering resulted in rapid densification of the scaffolds at lower temperatures (1000 degrees C/60s) compared to conventional sintering methods (1500 degrees C/2h). Finite element analysis was employed to model the temperature evolution of the scaffolds during flash sintering. The final scaffolds demonstrated uniform grain size , interconnected porosity, and a robust porous network, emphasizing the potential of flash sintering for fabricating complex-shaped ceramics with tailored microstructures. (AU)

• FAPESP's process: 23/15038-5 - Development of a scaffold-on-a-chip platform using calcium phosphate coated-ZrO2 scaffolds obtained by flash sintering
• Grantee: Fabio Caixeta Nunes
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 21/06509-9 - Ionic conductor glass-ceramics sintering with concurrent crystallisation using flash sintering
• Grantee: João Vitor Campos
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 22/05031-0 - Flash sintering of ZrO2 scaffolds obtained by 3D printing for tissue bioengineering
• Grantee: Fabio Caixeta Nunes
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 23/18168-7 - Ultrafast crystallization of high-entropy NaSICON superionic conductor for all-solid-state batteries
• Grantee: João Vitor Campos
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 22/10604-0 - Development of ceramics scaffolds for application in tissue engineering
• Grantee: Carlos Eduardo Ambrósio
• Support Opportunities: Research Projects - Thematic Grants