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Information about Neuropixels electrode arrays
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Dovetail cap fixation #42

Closed juliencarponcy closed 4 years ago

juliencarponcy commented 4 years ago

Hi everyone,

Following advices from the community here, we have purchased Sensapex dovetail caps as our neuropixels were bought without it. I have been browsing and asking around but I can't find instructions or tips on how to fix them to the probes. Sensapex has suggested epoxy, but I remember it was mentioned somewhere here to use meta-bond for another purpose (I think it was to consolidate the base of the shank). As I am also quite happy and familiar with this cement, i was thinking of possibly using it as well for dovetail fixation. Still the main uncertainty for me is on how to properly align the dovetail cap with the shank. Anyone having experience on this or similar issues ?

Thank you very much,

Julien

juliencarponcy commented 4 years ago

Hi,

I asked to the person replying to a related issue (https://github.com/cortex-lab/neuropixels/issues/34#issuecomment-597701411) directly, and Graham kindly replied quickly with precious suggestions:

"Attached is the document from Janelia that I was referring to. You will see that they use a profile projector in order to ensure that the dovetail cap is aligned to the shank BEFORE the two surfaces touch, because these surfaces will bond on contact. I just lay the probe flat with the silicon spacer facing up and the shank facing away from me under a microscope. I drop one of the Sensapex dovetail caps onto this silicon spacer, then tap it until it is aligned with the shank. I just judge this by eye. Once it is aligned, I drop a droplet of cyanoacrylate into the hole of the cap. This fixes the cap in place. Then I add a little more cyanoacrylate around the edges just to be safe. It is a very quick and simple process." ... I just lay the probe down on thick rubber pad, or in an old NeuroNexus probe box (it has a strip of sticky foam that you can press the probe into to keep it in place), but I have also fixed it in place on little ThorLabs breadboard with antistatic tape. As long as it is stable and not in danger of being bumped, anything works! I just lay the probe on the edge of whatever raised work surface I'm using, so the shank is in the air. You are right that you wouldn't want to just lay the probe flat on a table or something. Anything you can use to raise the probe up a bit so that the shank is in the air should be fine.

Neuropixels 1.0_Dovetail Mounting Instruction.pdf