Hi Yusuf, I'm afraid I have no suggestions to your problem, but I am very interested in photoparternable PDMS from Dow Cornig. Do you have good experience with your old 5351? I would like use it instead of SU-8. What about its transparency and colour, it is really colourless??. Does it swell with developer?? Thank you in advance and good luck with your new pdms. Eowin --- Den tors 2008-08-07 skrev Mohd.Yusuf: Från: Mohd.Yusuf Ämne: [mems-talk] problem with Photopatternable PDMS Till: "General MEMS discussion" Datum: torsdag 7 augusti 2008 18.22 Hello, I am facing some problem with Photopatternable PDMS WL 5351 (from dowcorning corp.) . I am working with 5351 since last 3 months, since old pdms was out dated we ordered new pdms. With new PDMS i tried to get same structures using same old recepie but is is giving bad structures with bubbles or ruptured bubbles on developed structures. I also tried to degass the PDMS in vacuum before spinning on wafer. I have 2inch silicon wafer and pdms thickness of ~6microns. Structures are ~25 x 75 micron rectangles. Any suggestions to solve this problem. -- Yusuf Germany.