It should be possible. Make sure the mixture is thoroughly mixed as
inhomogeneities can cause parts to be incompletely cured (which may be less
of a problem when doing it at higher temperatures). Small feature would be
more critical in this case. You could try more curing agent especially if it
is old.

Curing at room temperature does lead to a lower Young's modulus and it can
be harder to peel from the mould. Release agents can help but some may
inhibit polymerisation at the interface which could cause strange results
with very small structures.

Someone on this list once mentioned cooling the mould to improve release so
that could also be worth trying.


On Mon, Apr 4, 2011 at 18:14, righeira carnegie wrote:

> Hi, we are been trying to make PDMS mold from sylgard 184. instead of the
> curing temperature with the same mixture of ODMS and curing agent, Is it
> possible to make PDMS mold in room temperature, just skipping the heating
> process after pouring the mixture into the mold. We tried once, there is so
> much  of difference when followed heating process. The structures where not
> defined properly. Is this due to effect of temperature, but the dowcorning
> people claim it should not change. they say the heating process is only for
> making the procedure faster, so if the heating procedure is not followed
> then it might take ,ore than one day to cure. But in our case we cured ot
> for three days but the structure has changed when compared. The change in
> structure is the height profile of the photonic crystal. has anyone tried
> these things.
>
> Thanks!
> RIGHEIRA
> IMEC