Modeling of micropipette aspiration of flaccid human red blood cell using finite elements

Abstract

This thesis aims to analyze the steady state deformation of flaccid red blood cell (RBC) in micropipette aspiration (MA) experiment using finite elements (FE). Three different geometries, namely infinite plane, disk and modified biconcave model are used for undeformed flaccid RBC to see the geometry effects. ABAQUS is used to solve the micropipette aspiration problem. A nearly incom- pressible, isotropic, hyperelastic, 2D material model is used for the cell membrane with the aid of the user subroutine, UGENS. Comparing the experimental results found in literature and the computational results, material characteristics of RBC membrane is investigated where the appropriate in-plane shear modulus value is estimated as 3-4 ¹N/m. It is observed that the cytosol, the fluid inside the red blood cell, modeled as a hydraulic fluid does not affect the deformation of the aspirated membrane portion. Additionally, principal stretches and stress resultants and the fractional area change at maximum applied suction pressure are also computed.