FIG. 2.
Experimental images of the sample fluid (black) focused inside a microchannel downstream of the focusing junction. These images are taken from video frames of the experiments whose focused flow average diameter ds = 59 μm, and the frames are selected at an interval of 50 ms. Brightfield images of the focused flows controlled by (a) hydrostatic pressure and (b) constant flow-rate syringe pumps. Thresholded images of the same focused flows produced with (c) hydrostatic pressure and (d) constant flow-rate syringe pumps. The image sequences show qualitatively that the hydrostatic-controlled focused flow has a more consistent diameter, ds, than syringe pump driven flow. Syringe-pump driven focused flows also exhibit more erratic flow behavior. Flow is in the direction indicated by the x-axis. The scale bars represent 50 μm.