Dear Dunham,
  I'm a graduate research assistant from the University of Missouri - Columbia.
I'm trying to re-create the photosensitive PDMS process but with no sucess so
far. I understand that you are a member of a group that has patented this
procedure. If you could spare sometime and look at my procedure and tell me what
am doing wrong that would be great.

  Procedure
  1)       Measure 400 mg of Xylene.
  2)      Dissolve DMPAP (200mg) in Xylene (400mg).
  3)      Stir the solution to dissolve the DMPAP crystals in the Xylene.
  4)      Dissolve the above solution in 10 g of RMS – 033 (the whole
ratio is DMPAP:Xylene: PDMS = 2:4:100)
  5)      Place the solution in a sonicator or use a magnetic stirrer to stir
the solution and remove all the bubbles in the PDMS.
  6)      Spin the mixture on to the wafer in a spinner – We have a 2 inch
wafer… so use the 2 inch chuck.
  7)      After spinning, cover the sample with a Mylar foil.
  8)      Place the wafer wrapped in a Mylar foil in the exposure box and align
the mask on top of the wafer.
  9)  Close the box and expose the wafer for 90 mins.
  12)  After exposure, remove the wafer from the exposure box and develop in
xylene for 90 seconds to remove the unexposed part.

  The experiment is done in a room in which the lights are switched off. I
haven't got a pattern on the PDMS yet. When i develop in Xylene, all the PDMS
floats on top and dissolves away. Please let me know if what am doing in right.
Thank you.

  Vinny


"Dunham, Glen"  wrote:
  Grate, Nelson, and Dunham patented this, still grinding through US
Patent Office.
Glen Dunham
Pacific Northwest National Lab
509 376 4397


-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Vinodh Murali
Sent: Wednesday, November 09, 2005 1:33 PM
To: [email protected]
Subject: [mems-talk] Photosensitive PDMS

Hi all,
I know this topic has been discussed earlier. Some people have stated
about making PDMS photosensitive. Is there any publications on this
process? I'm trying to work with photosensitive PDMS or RMS-033. I tried
contacting the person who had sent an e-mail on this topic in Jan 05,
but I got no response. Any help on this would be greatly appreciated.