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

-----Original Message-----
From: Gareth Jenkins [mailto:gjenkins971@googlemail.com]
Sent: 18 November 2009 16:16
To: General MEMS discussion
Subject: Re: [mems-talk] pdms stuck

Toluene or Chloroform should cause swelling in PDMS and I think are OK
with
SU-8.

Check out this ref for more possible solvents:
Anal. Chem. 2003, 75, 6544-6554



On Wed, Nov 18, 2009 at 09:20, Emanuele Orabona <
emanuele.orabona@na.imm.cnr.it> wrote:

> Hi all,
>
> Some days ago, I used pdms with a silicon master (with SU-8
> structures) to make a microfluidic device. Unfortunately i forgot to
> silanize the silicon wafer and some small piece of PDMS stuck on it.
> I don't have another master, how can remove completely the pdms?
>
> I've already tried unsuccessfully to clean it with Acetone and
> Isopropyl alcohol.
>
> Can you help me?
> Thank you
> Emanuele