Dynamics of Red Blood Cells and Vesicles in Microchannels of Oscillating Width

Abstract

We have studied the dynamics of red blood cells and fluid lipid vesicles in hydrodynamic flow fields created by microchannels with periodically varying channels width. For red blood cells we find a transition from a regime with oscillating tilt angle and fixed shape to a regime with oscillating shape with increasing flow velocity. We have determined the crossover to occur at a critical ratio of channel width L_y and red blood cell velocity v_m approx. 10⊥-3s. These oscillations are superposed by shape transitions from a discocyte to a slipper shape at low velocities and a slipper to parachute transition at high flow velocities.Ref.:H. Noguchi, G. Gompper, L. Schmid, A. Wixforth, T. Franke, EPL (Europhysics Letters) 2010, 89, 28002S. Braunmueller, L. Schmid, T. Franke J.Phys. Condens. Matt. accepted