If you have a laser with a collimated/focused beam that is <10uM, then
<300mW of power should do the trick.

Check out this paper:
http://www.diybioforum.org/projects/jmm9_3_037002.pdf

On Thu, Dec 3, 2009 at 1:57 AM, Kevin Land  wrote:

> Hi
>
> I have a silicon wafer with SU-8 structures (pillars of 100 um - 400 um
> diameter, 200um high). I cast PDMS around these structures, and finally,
> after PDMS peel off,  would like to have fluid flowing through the resulting
> channels in the PDMS. At present, in order to get an even top surface with
> the PDMS level with the SU-8, I cast the PDMS and then use a thin
> polycarbonate sheet to squeeze out excess PDMS and allow the sheet to lie on
> top of the SU-8 pillars.
>
> The process works well in all aspects besides one. A thin membrane of PDMS
> (probably about 10um) remains on top of the pillars. Presently I punch this
> membrane to allow fluid flow, but this is not repeatable.
>
> My question: is there an etch (or similar method) for removing PDMS, so
> that I could etch the top 10um off my structure, thereby opening the
> channels?
>
> Many thanks
>
> Kevin

--
Nathan McCorkle
Rochester Institute of Technology
College of Science, Biotechnology/Bioinformatics