We are grateful to Carl Fruth (FIT GmbH, Parsberg) and Alexander Oster (NetFabb GmbH, Parsberg) for post-processing the sample data and producing multiple samples, free of charge. Many thanks to Jürgen Karsten for assistance with the mechanical testing. SN, GEST and KM acknowledge funding by the Deutsche Forschungsgemeinschaft (DFG) through the Cluster of Excellence “Engineering of Advanced Materials” in Erlangen. DD and DR acknowledge funding by the LGA Nordbayern (Leitprojekte Medizintechnik, BayMED). SN, GEST, CHA and MM acknowledge travel support by the German academic exchange service (DAAD) and the Australian Group of Eight universities through a joint program. Supporting Information is available from the Wiley Online Library or from the author.
Tuning Elasticity of Open-Cell Solid Foams and Bone Scaffolds via Randomized Vertex Connectivity†
Article first published online: 21 SEP 2011
Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Advanced Engineering Materials
Volume 14, Issue 1-2, pages 120–124, February 2012
How to Cite
Nachtrab, S., Kapfer, S. C., Rietzel, D., Drummer, D., Madadi, M., Arns, C. H., Kraynik, A. M., Schröder-Turk, G. E. and Mecke, K. (2012), Tuning Elasticity of Open-Cell Solid Foams and Bone Scaffolds via Randomized Vertex Connectivity. Adv. Eng. Mater., 14: 120–124. doi: 10.1002/adem.201100145
- Issue published online: 7 FEB 2012
- Article first published online: 21 SEP 2011
- Manuscript Revised: 2 JUL 2011
- Manuscript Received: 24 MAY 2011
Tuning mechanical properties of and fluid flow through open-cell solid structures is a challenge for material science, in particular for the design of porous structures used as artificial bone scaffolds in tissue engineering. We present a method to tune the effective elastic properties of custom-designed open-cell solid foams and bone scaffold geometries by almost an order of magnitude while approximately preserving the pore space geometry and hence fluid transport properties. This strong response is achieved by a change of topology and node coordination of a network-like geometry underlying the scaffold design. Each node of a four-coordinated network is disconnected with probability p into two two-coordinated nodes, yielding network geometries that change continuously from foam- or network-like cellular structures to entangled fiber bundles. We demonstrate that increasing p leads to a strong, approximately exponential decay of mechanical stiffness while leaving the pore space geometry largely unchanged. This result is obtained by both voxel-based finite element methods and compression experiments on laser sintered models. The physical effects of randomizing network topology suggest a new design paradigm for solid foams, with adjustable mechanical properties.