Figure 1. Schematic of the MF channel and unperturbed agarose microgels.

(a) Schematic of the MF channel with a circular cross-section. The diameter, d, of the channel-at-large is 110 ± 5 μm, the diameter, d_c, of the narrow segment (constriction) is 43 ± 2 μm (α of 15°, 45°, or 60°) or 38 ± 2 μm (α = 30°). The length of the constriction is 400 μm. The abscissa x = 0 denotes the starting point of the constriction. A microgel with an unperturbed diameter of D₀ moves along the direction indicated by the blue arrow, under the pressure difference applied along the MF device. (b) Representative optical microscopy image of 100 μm-diameter agarose microgels in an aqueous suspension. The scale bar is 100 μm. Inset shows a microgel with an unperturbed diameter of 80 μm in the channel-at-large (d = 107 μm). The scale bar is 40 μm. (c) Laser scanning confocal microscopy image of an agarose microgel (D₀ = 115 μm) in the swollen state. The image was taken at the equatorial plane of the agarose microgel labeled with fluorescein isothiocyanate (FITC). The scale bar is 25 μm.