Fig. 2.

(A) Schematic of the microfluidic device. The area shown by the dashed-line is perforated to provide open access. (B) SEM image of the SU8 master mould, taken at an angle of 20° from the vertical to show the height difference between first and second layer of SU8. The channel height is 5 μm and the channel widths are 2, 3, 4, 5, 7, 10, 15 and 20 μm from left to right. The scale bar represents 100 μm.