Figure 3.
Effect of flow rate on bacteria margination. (a) Normalized bacteria concentration in the filtered centre outlet for increasing flow rate. Bacteria separation efficiency improved as flow rate increases but remained approximately constant beyond 10 µl min−1. Averaged composite images of the bifurcation indicate increase in concentration of FITC-conjugated bacteria at the channel sides with increasing flow rates. (b) Optical images illustrating the enhanced cell free layer at the expanded bifurcation. Most of the marginated bacteria reside within the cell free layer next to the channel wall which allows their efficient removal from the side channels, while the densely packed RBCs are filtered into the larger centre outlet with minimal loss.