Figure 6.

Dynamics of slipper-shaped RBCs. Panel (a) shows the y position of the cell's center of mass for a simulation (top) during a velocity ramp between $v_{\text{low}}$≈ 1 mm s^–1 and $v_{\text{high}}$≈ 5.8 mm s^–1, and for an experiment (bottom) during an upward pressure ramp from $p_{\text{low}}$= 100 mbar to $p_{\text{high}}$ = 600 mbar within t_ramp = 0.5 s. (b) Oscillations of the slipper-shaped cells over one oscillation period T, corresponding to the time windows marked by the rectangular boxes in (a). Red and black lines represent sinusoidal fits to the simulation and experimental results, respectively. (c) Representative image sequences of the slipper-shaped cells for the simulation (top) and experiment (bottom), corresponding to the points in time marked by large symbols in (b). Dashed black lines indicate the channel centerline, and the black dots represent the cell's center of mass. The scale bars represent a length of 5 μm. The frequency and amplitude of the fits as a function of the applied pressure drop or cell velocity are shown in (d) and (e), respectively. Numerical results are plotted for different viscosity ratios λ as red symbols and experiments are shown as black boxplots with gray dots. Outliers are marked using “+” symbols. Panel (f) shows the oscillation frequency as a function of the cell velocity and for different outer viscosities ${\eta }_{\text{o}}$. Error bars correspond to averaging over different measurements at a set pressure drop. Black full symbols correspond to the experimental results, and red open symbols show the simulation results. Simulations are performed with a constant inner viscosity of ${\eta }_{\text{i}}$= 12 mPa s.