Numerical modelling of shear and normal stress of micro-porous ceramics for stimulated in-vitro cultivation of bone cells

Tissue engineering is a multidisciplinary job and has been of great challenge to scientist since its emerge in the 1980s. Special problems arise in this science, since bone cells are usually growing inside humans under moderate cyclic mechanical loadings (0.66–1.5 MPa); it is expected to grow them in a similar background. An innovative contribution is made where the shear stress is modelled inside in micro-channels reporting the various important design considerations of scaffolds, providing a more appropriate understanding of geometry change versus shear stress and Darcy’s Reynolds number in micro-channels. The geometry of the scaffolds was captured by analysing and processing batches of images with edge detection techniques which mainly works on the colour contrasts. A novel edge detection algorithm which spots the colour change by means of gradient calculations was successful to scan the Micro-CT (computer tomography) images and gather a binary file for the 3-D scaffolds of 430 sections for a 3 mm. The 3-D Lattice Boltzmann was successful in modelling the transport phenomena and reporting the shear stress distribution in straight micro-channels and in the complicated micro-scaffolds. An analogical study is as well made between the realistic stresses expected in humans and the simulated ones, reporting different discussion aspects to bring the designed structures to a more realistic stage. Using micro-porous scaffolds have proven much more realistic in imitating the human bone shear load conditions (0.1 MPa) with at least two orders of magnitude closer (5.3 × 10−4 MPa) than previously published results (1.09 × 10 Pa). Further study should be done to realise closer shear loads to measured data in humans.