Capillary Toys (Educational / Experimental)

prusaprinters

Just add water.  Notes: Print in PLA – although the ideal material would be NylonThe top reservoir is for reagent, and should stop flowing when it reaches the main branch, unless there is liquid in the main branchUse a paper towel as a capillary pump to “pull” the sample and reagent For demos, just use water; perhaps add some food coloring to one or the other (or both)This would work better if it were smaller; however, it is hard to create macro-scale capillary demonstrations (that is the intent here)     Mk1:Infill modifier is used to create the capillary pump structure (see image #2)Note that pressing a paper towel over this is still best for good pumpingI do feel there is room to make effective capillary pumps using infill structures, but for most demonstration / educational purposes, having some kind of capillary network that ends in a paper towel will provide 100x more pumping action. For an actual laboratory application where a filament-based solution is desired, an all-printed solution may be viable for early testing, prototyping, or first-run experiments while the “real” microfluidics are being fabricated. If you don't like the idea of this now, come back in a few years after you have a resin sensitivity.      Mk2:Open-channel designStill works best with a paper towel as a capillary pump     Mk3:Open-channel with an “on” switch for the sample reservoirWet the printed slug used as the on switch and place in the holeCan be best to drag a bead of water from the sample reservoirThis setup lets you prepare the demo ahead of timeThere is a video for this one:  References/inspiration: doi:10.1039/c8lc00458gdoi:10.15760/etd.2914 (ch. 4)youtube / watch?v=pct3JhVFSLoand thing:4116612