The PDMS should be fine - I agree with Joe that it has to be related to the SU-8 solvent. Can I ask what exactly you are trying to achieve? If it's what I think it is, I may be able to assist. On Mon, Mar 30, 2009 at 06:34, Shao Guochengwrote: > thx for the info Joe. I'll try to bake only the PDMS mold to rule out the > temperature factor. However, if I understand ur theory correctly, with PR on > the top side, PDMS mold should bend like a up-side-down bowl. but what I got > is the other way around, i.e. the side without PR is actually the side which > expanded. > any way, thx for the info, I'll let u know if I get this tackled.