Characterisation of space holder removal through water leaching for preparation of biomedical titanium scaffolds

Abstract

Scaffolds for bone tissue engineering are highly porous materials having interconnected and homogeneously distributed pores to facilitate the formation of new bone tissue. At the same time, appropriate mechanical strength is required in the scaffolds to withstand stresses in the in vivo environment. The space holder method has been used to fulfil these contradictory requirements in the fabrication of titanium scaffolds. Space holding particles are mixed with titanium particles then removed before or during sintering, to leave pores in the scaffolds. Despite its importance, the removal of space holders has rarely been studied. In the present study, removal by water leaching was investigated. Leaching was characterised using a novel real-time measurement technique adopted from ASTM B963-08 that achieved precise scaffold weight loss data reflecting the removal of space holding particles. The acquired data fit existing solvent debinding models for powder injection moulded parts, allowing the mechanism involved during water leaching to be determined.

Acknowledgements

This work was performed as part of the first author’s PhD project at Delft University of Technology, The Netherlands, with financial support from Directorate General of Higher Education, Ministry of Education and Culture, Republic of Indonesia. This paper is based on a presentation at Euro PM 2013, organised by EPMA in Gothenburg, Sweden on 15–18 September 2013.