Compressive Strength of DLP 3d Printed Various Micro Lattices for Bone Tissue Engineering

Abstract

This study aims to design and manufacture different lattices and evaluate their success in terms of compression strength. Structures with a high surface area to volume (SA:V) ratio and macroporosity are designed to mimic cancellous bone tissue. The volume-centered cubic and face-centered cubic lattice structures are higher in terms of the SA:V ratio among the designed specimens. Tri Calcium Phosphate (TCP) and Hydroxyapatite (HA) powders, which are calcium phosphates used in healing, growth and adhesion of bone tissues, were used in the specimens. Specimens in the cylindrical form used with four different lattices were successfully produced by 3D (Digital Light Processing) DLP printing. A preliminary evaluation of the lattices was made by searching for the lowest stress and displacement values under compression load with finite element analysis. The lowest von-Mises stress value was 6.37 MPa in the simple cubic lattice structure. The compression test was carried out under quasi-static conditions with equal preloading. The loads at onset damage were compared. The highest fracture average load was in face-centered cubic lattice structures with 10.14 kN. Among the specimens with low standard deviation in the compression test, the simple cubic and gyroid lattice structures' fracture force is higher.