Fabrication of Biomedical Prototypes with Locally Controlled Properties Using FDM

Biomedical structures have complex geometries and mechanical behaviors, and are difficult to manufacture using traditional machining processes. This paper reports a study of fabrication of biomedical structures using fused deposition modelling (FDM) processes. The theoretical and experimental analyses of mechanical behaviours of FDM prototypes were carried out to establish the constitutive models. A new set of equations is proposed to calculate the elastic constants of FDM structures as functions of the constituent properties and geometric characteristics, taking into account of imperfect bonding among filaments and void geometries. The manufacturing parameters of deposition orientation and density are modeled for fabrication of prototypes with functionally graded properties. Examples are included to illustrate the fabrication of bone structures with locally controlled properties.