Got an idea for a spinoff on the aeroponics tower. The same thing, in miniature almost. 1 inch holes, smaller pipe should be fine. Less gap between holes too. For rooting cuttings. Aeroponics has a good reputation for rooting cuttings. A tower like this could take up less space - possibly could be hung from a hook somewhere. Once cutting grows roots, take it out for regular growing, replace with another cutting.
This is how it is currently done.
Bet @jtd’s design could cap this on efficiency, cost and space. Also, if successful, could be a wildly used gadget by nurseries etc. Plant propagation is big business.
I know regardless of my ability to use the big tower, something like this would be an instant hit. As the lab knows from my meagre plant offerings last week, I run out of plant spares as soon as I can grow them. An efficient way to make cuttings of rare plants would address a major choke point.
May also be a possibility of making this “modular” - 2ft cloning tower. Want to add capacity? Add another 2ft piece or two over/under it. Same fogger and reservoir serving all.
One of the most common way people RUIN cuttings is to pull them out to check for root formation, damaging fragile, newly forming roots in the process. With this system, you can check all you want with no harm to the roots. BONUS.
Just imagine, you could make DOZENS of cuttings in six square inches of floor space. Also mist will be better than that sprinkler thing in the video - finer, less chances of overwetting and rotted cuttings.