[domdelomeese]

Hello, I am attempting to design a voltaic cell for 3-D printing (using tinkercad). As far as the salt bridge goes, I am trying to incorporate it straight into entire system itself (as opposed to a seperate "u tube" I suppose). Does anyone have an idea of how large I would have to make the membrane holes in order for the salt bridge solution to diffuse into each electrolyte solution? I hope I have been clear enough, thank you!

[billnotgatez]

Are you trying to make something like the first image below on a 3D printer
and not like the second image below

The images came from
https://en.wikipedia.org/wiki/Galvanic_cell

I assume you are trying to replicate the porous disk in the first image using a 3D printer.
 

[domdelomeese]

Are you trying to make something like the first image below on a 3D printer
and not like the second image below

The images came from
https://en.wikipedia.org/wiki/Galvanic_cell

Yes, that it essentially what I am trying to do.

[billnotgatez]

I assume you are trying to replicate the porous disk in the first image using a 3D printer.

[domdelomeese]

I assume you are trying to replicate the porous disk in the first image using a 3D printer.

Yes, but I know it has to be super porous for the ions to go through. I'm not sure I could actually replicate the smallness of the holes in a membrane like that using a 3D printer? Or could they be a few mm wide?

[Intanjir]

Just so we are clear. A porous barrier is not a salt bridge. A proper salt bridge contains its own special electrolyte(the 'salt') distinct from that of the two electrodes.

The point of a porous barrier is just to prevent the two electrolyte solutions from being mixed by any bulk motion of the fluids, ie stirring, convection, etc, while still allowing diffusion. Holes that were multiple mm in diameter would be rather bad at preventing bulk flow. You should be able to print somewhat smaller holes with polyholes, but I'm not sure if you could make them small and numerous enough for good performance.

[domdelomeese]

Alright. Thanks.