title: Bioinspired lightweight cellular materials--understanding effects of natural variation on mechanical properties.
abstract: Cuttlebone is a natural marine cellular material possessing the exceptional mechanical properties of high compressive strength, high porosity and high permeability. This combination of properties is exceedingly desirable in biomedical applications, such as bone tissue scaffolds. In light of recent studies, which converted raw cuttlebone into hydroxyapatite tissue scaffolds, the impact of morphological variations in the microstructure of this natural cellular material on the effective mechanical properties is explored in this paper. Two extensions of the finite element-based homogenization method are employed to account for deviations from the assumption of periodicity. Firstly, a representative volume element (RVE) of cuttlebone is systematically varied to reflect the large range of microstructural configurations possibly among different cuttlefish species. The homogenization results reveal the critical importance of pillar formation and aspect ratio (height/width of RVE) on the effective bulk and shear moduli of cuttlebone. Secondly, multi-cell analysis domains (or multiple RVE domains) permit the introduction of random variations across neighboring cells. Such random variations decrease the bulk modulus whilst displaying minimal impact on the shear modulus. Increasing the average size of random variations increases the effect on bulk modulus. Also, the results converge rapidly as the size of the analysis domain is increased, meaning that a relatively small multi-cell domain can provide a reasonable approximation of the effective properties for a given set of random variation parameters. These results have important implications for the proposed use of raw cuttlebone as an engineering material. They also highlight some potential for biomimetic design capabilities for materials inspired by the cuttlebone microstructure, which may be applicable in biomedical applications such as bone tissue scaffolds.
authors.affiliation: School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia.
authors.forename: Joseph
authors.initials: J
authors.lastname: Cadman
authors.forename: Che-Cheng
authors.initials: CC
authors.lastname: Chang
authors.forename: Junning
authors.initials: J
authors.lastname: Chen
authors.forename: Yuhang
authors.initials: Y
authors.lastname: Chen
authors.forename: Shiwei
authors.initials: S
authors.lastname: Zhou
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
mesh_terms: D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry*; D001842:Bone and Bones / Q000737:chemistry* / Q000473:pathology; D049832:Decapodiformes / Q000378:metabolism; D017886:Durapatite / Q000737:chemistry; D020342:Finite Element Analysis; D008958:Models, Molecular; D016062:Porosity
chemical_list: D017886:Durapatite