Dear MEMS comunity

to come to permanent hydrophilic systems we experienced that
any after processing (like plasma is) is not long time stable
so we process materials which are intrinsic hydrophilic (down to 130)
(or hydrophbic if needed up to 130)

For details please see downloads at our website

Best regards
Andrea
www.microtec-d.com

-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of Bill Moffat
Sent: Tuesday, April 10, 2007 9:25 PM
To: General MEMS discussion
Subject: RE: [mems-talk] how to make SU8 (permanent) hydrophlic?

Wang Yang,
          Typically we use plasma to produce hydrophilic surfaces and
silanes to produce hydrophobic surfaces.  In time factors I found for
example taking Teflon with a contact angle of 120 degrees, a 1 minute
Argon plasma can produce a 2 to 3 degree surface.  A week later it had
changed to 15 degrees a week later 30 degrees.  Months later it is back
to 120 degrees.  While writing this I conferred with our silane/plasma
engineer.  He agrees with your statement of a week to return to the old
contact angle. Discussing Hydrophilic silanes with our silane expert it
turns out that Gelest has a line of silanes it describes as hydrophilic,
Polar non-Hydrogen bonding.  Of 20 compounds listed about 90% are
cyano's We have not used these compounds so we have no direct experience
or results.  Ken our silane expert is interested in testing one of these
compounds so we may have later news for you.