Dear all,

I was fabricating a microfluidic device which consists of glass substrate,
SU-8 channel (30um thick) and PDMS cover lid. The device has 2 inlets and 1
outlet. 2 inlet channel are 100um wide and once they mix into one outlet
channel, the channel shrink to 24 um. It is easy to suck the water from 2
inlet tubes into the channel. But after liquid reach the channel it is
impossible to suck it out from the outlet. The liquid can go from inlet to
inlet easily but not to outlet. Is this related to the hydrophobic property
of SU-8 and PDMS? How could I solve it? Thank you very much.

Yifan
University of Missouri