Cured at 60 degrees, it takes its shape at 60 degrees.  Coefficient of
expansion would reduce the size when measured at 20 degrees.

Marco

Marc Reinig                           Phone: (831) 459-4362
Laboratory for Adaptive Optics        Fax:   (831) 459-2298
UCO/Lick                              Email: mreinig@ucolick.org
University of California, Santa Cruz
1156 High Street
Santa Cruz, CA 95064


> -----Original Message-----
> From: mems-talk-bounces+mreinig=ucolick.org@memsnet.org [mailto:mems-
> talk-bounces+mreinig=ucolick.org@memsnet.org] On Behalf Of Maria
> Matschuk
> Sent: Tuesday, April 05, 2011 5:30 AM
> To: General MEMS discussion
> Subject: [mems-talk] Is it possible to make PDMS mold in room temperature?
>
> Hi,
>
> It sounds fairly strange to me that PDMS should shrink less if cured at room
> temperature compared to curing in an oven if precaution is taken to remove
> entrapped air (as described before). If I don't mix up something, shrinkage
> occurs only due to evaporation of solvent and increased of cross-linking. So
> why should PDMS shrink less if cured at room temperature (if the final
> "hardness" of the cured PDMS) is the same ?! Of course it is very likely that
> the internal stress is higher for fast cured PDMS (oven) than compared to slow
> curing (room temperature).