Hi!

I am fabricating microchannels in PDMS from an SU-8 on silicon master.
I am having a hard time getting a rectangular cross section.  My cross
section has both "ears" at the PDMS side, and a bit of a "lip" at the
open side.  From talking with some others, I believe that the "ears" on
the PDMS side are due to overexposure of the SU-8.  Does anyone have any
ideas what may be causing a "lip" on the open side and how to get rid of
this and get a more rectangular cross section?
Thanks,
Joie


Joie N. Marhefka
marhefkaj@upmc.edu