Steven,
I can't comment on SU-8 being used in microfluidics but I think there =
should not be a problem as SU-8 does not swell in organic solvents =
unlike PDMS.  If I get a chance to do microfluidics work, I would =
probably use SU-8 as my material of choice due to its excellent =
properties.
=20
As for lifting off evaporated metals from SU-8, I have not encountered =
much success.  The reason is that the adhesion of SU-8 to silicon or =
glass is poor even when using Omnicoat (but this depends on how the SU-8 =
is processed, the viscosity of SU-8 used, exposure dose used and how =
many coats of Omnicoat are used, etc.).
=20
So instead of using lift-off, I first evaporate the metal with its =
adhesion layer such as Ti or Cr and then coat and pattern a photoresist, =
say AZ9260.  Then I etch back using a wet etch chemistry.  This =
technique is relatively successful compared to lift-off.
=20
Hope this helps.
=20
Jeffrey

________________________________

From: mems-talk-bounces@memsnet.org on behalf of Steven Yang
Sent: Thu 9/6/2007 7:48 PM
To: mems-talk@memsnet.org
Subject: [mems-talk] SU-8 dissolvable in Methanol solution?



Hi, all
I plan to do some SU-8 patterned microfluidic channel, and it might be
used for methanol flow. Does anybody have experience that SU-8 will be
dissolved in methanol or not?

btw, I also like to know is it possible to sputtering some metal like
Cr/Au for patterned electrode on SU-8 layer? what will be the PR for
this lift-off process?

and has anybody done the glass to SU-8 (which on Si sub) adhesion
bonding before? what will be the procedure for this?