If you have no UV/Ozone or RIE, you could try a liquid solution of
H2O/H2O2/HCl, as the group does in this reference:

Sui G, Wang J, Lee C C, Lu W, Lee S P, Leyton J V, Wu A M, Tseng H R.
Solution-Phase Surface Modification in Intact Poly(dimethylsiloxane)
Microfluidic Channels. Analytical Chemistry (2006) 78 (15)

-JP Hilton
Grad Student/MechE/Columbia University

On Wed, Sep 24, 2008 at 9:10 AM, DEBASHIS MAJI  wrote:
> Hi all,
>
>      I am trying to convert the hydrophobic nature of PDMS layer into
> hydrophilic. I have referred to some texts, where they have mentioned about
> the PDMS surface treatment with Oxygen plasma. But currently there is no
> provision here for treating with oxygen plasma. Can anybody please suggest
> me an alternative method for making the PDMS surface hydrophilic?
>
>      Also can anybody suggest me how to put a layer of SU8 over the PDMS
> layer? I observed that SU8 is not staying over the PDMS surface due to its
> hydrophobic nature.
>
>      Thanks in advance.
>      Debashis Maji.