Vertical Nanowire Substrate Removal

[Sarkreth]

First post! Yay!

 

Okay, if you work with nanowires, here's the short version:

What methods would you recommend to get them off of the substrate?

 

If you don't work work with them, here's the long version:

I grow nanowires around 10 microns in length and 200 nanometers in diameter perpendicularly out of silicon wafers. I then put a layer of PDMS on top, which coats them on top and in between. What I need help on is getting them off of the silicon substrate so I have a bunch of nanowires embedded in PDMS.

 

This is difficult, of course, because of material size and the fact that the nanowires are more strongly bonded to the substrate than to the PDMS. So far, my best results have come from simply scraping the PDMS and hopefully the nanowires off with a fresh razor, but this is still unreliable. I'm looking for ideas on how I may be able to achieve the aforementioned results reliably and hopefully simply. I have quite a few resources at my disposal, so virtually any suggestion is game. Thanks in advance.

[Sarkreth]

Is my explanation unclear, or are people just unable to come up with ideas?

[swansont]

Are the nanowires made of Si as well, or are they another material? I know KOH etches Si (though anisotropically), so if the nanowires were not etched, they would break free.

[Xittenn]

ultrasound?

[Sarkreth]

These are Si nanowires.

 

Also, keep in mind that PDMS etches much more easily than Si, so putting it in an etching solution would probably etch through the PDMS and get to the nanowires before going through the substrate.

 

Sonication doesn't really work because, although it could break the nanowires off at the substrate, it tends to just shatter them.

[Klaynos]

I assume you need the Si substrate directly connected to the nanowires, you cannot coat it in anything before you grow them?

 

 

This is a doozy of a pickle....