Homebrew PCBs

Something fun to think about or play around with:

FeCl (and probably other etchants as well) is quite conductive.

Now, conductive materials like to stay fixed with respect to magnetic
fields. See https://www.youtube.com/watch?v=f43fXde2S78 for a
demonstration. The penny is dragged along by a strong magnet.

See where I'm going with this? A spinning magnet (where the poles
sweep around) should be able to drag conductive liquids through a tube
that is wrapped around the spinning magnet.

In fact you don't even need a spinning magnet. You can create a
rotating magnetic field with electromagnets (for example, remove the
rotor from a three-phase motor - but use lower voltage when the rotor
is removed or you'll burn up the windings and/or blow a fuse). You can
pump conductive liquids with no moving parts at all!

As a bonus, induced current in the liquid would cause heating, so you
might get your etchant heated as it is being pumped!

Enjoy!
- Jan