I'm not sure if there is anything which will actually dissolve the silicone
whilst keeping the SU-8 unharmed.
However, the following may be worth a shot (but I have no idea what it will
do to the SU-8):
http://www.rpm-technology.com/Digesil/Digesil.htm
There are also household silicone removers for removing the sealant from
around bathroom tiling - again this is a long shot.



On Thu, Nov 19, 2009 at 08:58, Dirk Renckens - TNW <
T.J.A.Renckens@tudelft.nl> wrote:

> Dear Gareth and Emanuele,
>
> If you cure PDMS at the recommended temperature of 68 C, it forms a
> monolithic (one piece) structure with older PDMS. You could try
> resilanising the wafer and pouring new PDMS to strip the PDMS that
> remains. If you try it, could you let me know how it works out? Thanks.
>
> Regarding Toluene, in my experience this does not swell strongly enough
> to remove small (<3 mm) pieces of PDMS. However, as gareth says, it is
> okay with SU-8, so feel free to try.
>
> Good luck!
>
> Dirk Renckens
> Chem Eng PhD candidate TU Delft