FIG. 4.

Mobility of rigid and elastic particles. The mobility of (a) PS beads and (b) PDMS particles is plotted as a function of confinement. The red and green triangles represent continuous phase viscosities corresponding to Re_p = 0.92 and Re_p = 0.09 for PS beads and Re_p = 1.33 and Re_p = 0.13 for the PDMS particle, respectively. Two mobility model curves using Eq. (3) are shown where the dashed line represents a particle in the center of the channel (b/R_h = 0) and a particle with the maximum off-centeredness (b/R_h = 1 − λ). The inset in (a) shows a particle in focus that is in the center of the channel (1) and a particle out of focus that is at the roof of the channel (2). The insets in (b) show experimental images of the PDMS particles at different confinements. The scale bar in all the images is 15 μm.