  Biconcave-discoid (empirical shape of a red blood cell) capsule finds
numerous applications in the field of bio-fluid dynamics and rheology, apart
from understanding the behavior of red blood cells (RBC) in blood flow. A
detailed analysis is, therefore, carried out to understand the effects of the
uniaxial extensional flow and electric field on the deformation of a RBC and
biconcave-discoid polymeric capsule in the axisymmetric regime. The transient
deformation is computed numerically using axisymmetric boundary integral method
for Stokes flow considering the Skalak membrane constitutive law as the model
for the area incompressible RBC/biconcave-discoid capsule membrane. A
remarkable biconcave-discoid to prolate spheroid transition is observed when
the elastic energy is overcome by the viscous or Maxwell electric stresses.
Moreover, the significance of membrane stresses developed during the
deformation and at steady state and different modes of deformation are
presented. This study should be useful in designing an artificial system
involving biological cells under an electric field.
