[v7n]

Neat! I've occasionally looked into getting into DIY microfluidics, and one of the lowish-tech ideas I've seen is etching/engraving CD cases or other polystyrene sheets and baking them: this makes them shrink quite predictably, allowing for some really tiny channels. In arts & crafts they call them "Shrinky Dinks". PDMS is another interesting material, and could perhaps be somehow combined with 3D printing channels with alcohol-soluble polymers to print + dissolve the channels...

[yerbymatey]

had a little go around with diy microfluidics with ecoflex (though i still have some pdms on hand) and water soluble printed pva channels for bilayer cast+molding but the process to dissolve them was a bit less than joyful ¯\_(ツ)_/¯ also depending on how perf conscious you were as you size down, layer line artifacts and flow tuning esp as you go around curves could be make or break for some applications at decreasing scale. already finicky to print smaller than 0.25mm nozzle, pva's particularly a diva too and on top of that you're at the whim of batch variations