Wednesday, August 10, 2011

Epiphany - I'm Doing Things Backwards

So because my stamping experiments weren't working, I went back to the literature. I did another set of searches to see if there were any papers I missed, and I rounded up the ones I had referenced before. I looked carefully at all the papers that I had collected that listed specific protocols for stamping the ink onto a substrate. And I noticed something odd - they were all using oxygen plasma, not air plasma (as I was doing.)

Could this be it? Simple change of gas in the plasma mix?

Excitedly, I rushed to the clean room, and tried a few lightning experiments.

Sadly, no. That was not my problem.

I went back to the literature, and stumbled across a review paper that just came out in June this year. The paper reviewed a field called "adhesive lithography" which is a term I hadn't heard of. But basically, this paper said, look, when you are transferring a FILM, not a liquid, things are different, and here's how people are doing it. And I had just learned from my microscope photos, that I was indeed transferring a film.

Well now I might be on to something.

I already knew that this stamping process is all about the surface energies. You want the ink to stick to the stamp, but stick to the substrate better, so it's all about tuning the parameters of the surfaces to get things to release and stick how you choose. It turns out - get this - GET THIS - that with my particular material, it's easier to make a film stick to the stamp, than the substrate. So instead of coating the stamp with ink, and transferring it, people instead coat the substrate with ink, stick the stamp down, and use the stamp to PEEL away the ink from areas you don't want it.

It's like telling the ink: "If you like sticking to the stamp so much, well then by golly, STICK to it why don't you!"

*faceplam* I'm doing things backwards. I'm stamping the wrong direction. Instead of doing additive stamping, where the stamp transfers ink to the substrate, I need to do lift-off, where the stamp removes the ink from the substrate.

Fine. So I did.

And look!

I get lines! They are ugly, but they are not strings! Give me a week, I'll make them pretty, just you watch...

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