Shape Dynamics of Nearly Spherical Membrane Bounded Fluid Cells

Abstract

This paper considers the hydrodynamics of low Reynolds number shape fluctuations of incompressible fluid cells with incompressible membrane boundaries. It is assumed that the membrane can be characterized by a shear modulus μ, a bending modulus k_c , an intrinsic mean curvature C_o , and a surface viscosity η_M. The problem is formulated for the general case, and is solved analytically in the spherical limit. The observable hydrodynamics is found to depend sensitively on membrane parameters, and in particular a marked difference between solid and fluid behaviour is apparent.