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Tuning Elasticity of Open‐Cell Solid Foams and Bone Scaffolds via Randomized Vertex Connectivity
Author(s) -
Nachtrab Susan,
Kapfer Sebastian C.,
Rietzel Dominik,
Drummer Dietmar,
Madadi Mahyar,
Arns Christoph H.,
Kraynik Andrew M.,
SchröderTurk Gerd E.,
Mecke Klaus
Publication year - 2012
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201100145
Subject(s) - materials science , topology (electrical circuits) , scaffold , network topology , finite element method , stiffness , topology optimization , elasticity (physics) , composite material , structural engineering , computer science , biomedical engineering , mathematics , engineering , combinatorics , operating system
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.