Print Email Facebook Twitter The effect of porosity gradients on compressive strength of hydroxyapatite scaffolds Title The effect of porosity gradients on compressive strength of hydroxyapatite scaffolds Author van Heijningen, Irene (TU Delft Mechanical, Maritime and Materials Engineering) Contributor Dankelman, J. (graduation committee) Jelinek, Filip (mentor) Degree granting institution Delft University of Technology Date 2021-02-16 Abstract Nowadays, the main treatment for children with bone cancer is limb salvage. To prevent this, a new design for an expandable endoprosthesis for the knee has been developed. This proposal contained a bioresorbable ceramic component, made out of hydroxyapatite (HA), with a porosity gradient which will be subjected to a compressive load. In order the prevent mechanical failure of the prosthesis, the compressive strength of the ceramic component must be investigated. Therefore, the influence of a porosity gradient on the compressive strength compared to a homogeneous porosity is researched in this study. Six different designs, one containing a porosity gradient (ranging from 23% to 30% to 37%) and five containing a homogeneous porosity (18% ,23%, 30%, 37%, 50%) were manufactured and tested on their ultimate compressive load (UCL) and first maximum compressive load (FCL). The UCL seemed to decrease with an increasing porosity and the FCL was around 400 N for every configuration. Heterogenous scaffolds seemed to have a lower UCL compared to homogeneous scaffolds containing a porosity equal the heterogenous lowest porosity. However, this heterogeneous UCL seemed to be higher than the UCL of a scaffold with a porosity equal to the average and highest porosity present in the layered configuration. Significant differences were only found between the UCLs for the 18% and 37% porosity configuration. Not all scaffolds showed the required UCL for the current application. However, HA is still a promising material, although the manufacturing of the scaffolds and other production techniques should be investigated further to obtain the desired UCL and FCL To reference this document use: http://resolver.tudelft.nl/uuid:30897d96-871e-43e1-aa7d-5dd3d09d6d5f Embargo date 2026-02-16 Part of collection Student theses Document type master thesis Rights © 2021 Irene van Heijningen Files file embargo until 2026-02-16