Experimental Study and Analytical model of Shear Thinning in 3D Bioprinting of Gelatin

This paper presented extrusion-based 3D bioprinting of gelatin hydrogel and optimisation of material properties and process parameters, in order to improve printability of hydrogel. Gelatin hydrogel was prepared by mixing it with water in concentration of 13.04 wt%. Dimensional accuracy of the bioprinting was studied and significant changes in comparison with designed geometry were noted. Gelatin hydrogel made only with water showed inadequate thixotropy for extrusion based bioprinting and poor mechanical properties of the printed sample, and needs additional constituents to enable good printability with satisfying dimensional accuracy. We presented parameter optimisation index (POI), shear thinning model and friction factor of gelatin hydrogel by using analytical approach. Friction factor of the gelatin hydrogel during bioprinting was 0.268·10-5. Analytical models of shear thinning and friction factor were in consistence with experimental data, and indicated that such approach can be used in optimisation of bioprinting parameters and material properties.