Hi Joie,

What is the cross-section size of your channels?  Have you tried
increasing your pre-bake time?

Best,

Kevin

-------------------------
Kevin V. Christ
Turner Research Group, http://ktgroup.me.wisc.edu
Department of Mechanical Engineering
University of Wisconsin, Madison
-------------------------

----- Original Message -----
From: "Marhefka, Joie" 
Date: Monday, August 7, 2006 1:17 pm
Subject: [mems-talk] channel cross section
To: [email protected]

> 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?