Because mixing species
featuring a diffusion coefficient 10) would require higher laser energy and longer
fabrication time. Figure 8 represents a white-light microscopy
image of the zigzag microchannel filled with fluorescein and
phosphate buffer at 0.4 mL h-1. The dashed line at the end of the
channel depicts a linear distance of 2000 ím down the Y junction
and is the point where the fluorescence intensity profiles across
the outlet channel are analyzed. To investigate the effect of the
zigzag geometry on the mixing process, the residence time is
always maintained lower than the diffusion time (i.e., 10 s). As a
consequence, the flow rates studied for each feeder range from
0.02 to 1.2 mL h-1 (0.1 < Re < 9 in the zigzag channel, based on
the experimental hydraulic diameter). As a result of sealing
problems at the inlet, higher Reynolds numbers could not be
reached.