Inkjet printheads are a pretty rare thing to see done in home workshops. We would love to see more and got really excited when we saw this single nozzle, drop on demand, head being built. using a piezo disk intended to be a cheap buzzer and some reprap magic, [Johnrpm] got some results. [Madscifi] has been refining the design of the nozzle and the two have shared the process with us. Since it drops a single droplet of liquid, it can be used in a variety of manners, such as dropping plain old boring ink, or dropping a solvent into a powder for some 3d printing. You can see an example of the 3d printing in sugar above.