A practical approach for extracting mechanical properties of microcapsules using a hybrid numerical model

In this paper, the deformation of compliant microcapsules is studied in narrow constrictions using a hybrid particle-based model. The model combines the Smoothed Particle Hydrodynamic (SPH) method for modelling fluid flow and the Mass Spring Model (MSM) for simulating deformable membranes. The model is initially validated for the dynamics of microcapsules in shear flow. Then, several quantitative parameters such as the deformation index, frontal tip and rear tail curvatures and the passage time are introduced and their variations are studied with respect to capillary number and constriction size. Subsequently, a dependency analysis is performed on these quantitative parameters and some recommendations are made on fabrication of microfluidic devices and analysis of microcapsules for extracting their mechanical properties. It is revealed that the deformation index and frontal tip and rear tail curvatures are the most suitable parameters for correlating the elastic properties to the dynamics of microcapsules.