A better method is to vacuum dehydrate at vacuum/low pressure hot Nitrogen then introduce the fumes of a suitable fluorinated chemical to react with the substrate. It removes the problem with the chemical reacting with moisture at the start of the reaction. There are a number of commercially available units that do this. Bill Moffat ________________________________ From: mems-talk-bounces+bmoffat=3Dyieldengineering.com@memsnet.org on = behalf of Nathan McCorkle Sent: Sat 3/27/2010 7:04 PM To: General MEMS discussion Subject: Re: [mems-talk] Best way to spin PDMS for making sheets? I have access to a Heraeus Oven that can pull vacuum, the gauge on it usually hangs between 50 and 0 mbar at minimum Nitrogen flow, though for baking the lab manual says to keep it at 300 mbar with Nitrogen. When I degass the PDMS mix in there I set it to 50 mbar, I don't use heat, and I use a different oven to bake in. I will have to check if I can bring FDTS into the lab first. I also have access to a plasma etcher that has chloroform (I think, their web server is down right now), oxygen, and a few others. What about the biosafety of these chemicals on the PDMS? -Nathan