ITO Embedding

I recently bought some slides of ITO from Sigma-Aldrich, and have been working to integrate them into PDMS by using the same process as I did for the glass coverslips (seen here)

The main differences between the glass coverslips and the ITO coated microscope slides are the ITO film, which seems to have different wetting properties than glass, and the thickness of the microscope slide which is much, much thicker and rigid than the coverslips. When I tested the process on a few slide fragments, none of them were successfully embedded upon lift-off, remaining attached to the bulk glass plate. When I removed the fragments from the slide using a razor blade, it was evident that a thin PDMS film remained underneath the fragments. This probably adhered and then the sharp corners of the slide tore at the boundary PDMS, leaving only an imprint of the fragment. It appears that the the ITO film is hydrophyllic and thus a thin layer remains when I settle the slides into the liquid PDMS. Alternatively, when the time comes to embed electrodes, I can embed bulk microscope slides in PDMS, pry them out and insert the ITO electrodes in their stead, using ozone bonding to adhere the slide to the PDMS.

Two procedural changes I can do to help correct this problem :

-Use smaller pieces that are narrow and can be picked up easier

-Coat my own ITO on glass coverslips.

Next steps are to characterize an etch of ITO with HCl.