I am not sure of the temperature limitations of PDMS.  If it is the same
as most photosensitive material and below 90 C is safe for the
sensitizer.  The following may work.  It is a tried and true recipe for
our image reversal process.  Set oven at 90 C pull a vacuum of close to
50 Torr to avoid violent out gassing of any solvent.  Then fill with
pre-heated nitrogen at 90 C.  This enters all the available pores of the
material that have been vacated by the first vacuum pull.  The PDMS now
has 90 C Nitrogen trapped in the pores.  Then a vacuum to 50 Torr again.
 At 50 Torr water boils at approx. 30 degrees C and you get dehydration.
 We repeat this process 2 more times for complete dehydration.  Then
pull a vacuum to 1 Torr to ensure complete dehydration.  If you want to
run some free tests let me know.  Bill Moffat

________________________________

From: [email protected] on behalf of A. AhmadShukri
Sent: Wed 11/25/2009 8:54 AM
To: General MEMS discussion
Subject: [mems-talk] Moisture in PDMS



Dear all,

I am using water droplets on PDMS surface and am wondering water could be
trapped between my features on the PDMS. If so, is there a way to dehumidify
PDMS without altering its properties?

Thanks,
Aimi