These aren't exactly RepRap-friendly. The piezo buzzers are too soft. For a proper multilayer piezo actuator you have to either go to Thorlabs (a bit expensive) or other manufacturers (either expensive or "don't bother us until you are ready to buy a few thousands"). AFAIR MLCC ceramic capacitors actually can make half-decent actuators, but not sure if these are suitable for precision position. Baking your own would be doable, but who wants to deal with lead? And once you got the chips, there is another problem: how do you couple it to a plastic flexture? "Adult" stuff uses wire-EDM-cut metal flextures. While not completely impossible to DIY, wire-EDM a whole undertaking in itself, and an expensive one.

Piezos are sure the way to go for a fab-in-a-shed youtuber, but not yet for those who want to make it reproducible by others.