This STL contains the parts for making a bubble membrane dropper, which allows a drop of liquid to be dropped through any number of bubble membranes of other liquids, which can be used to build up different layers of material in the formation of structured alginate beads.

The bubble ring is just hoops made from 2mm wide pipecleaners from amazon. A nine gram servo is used to actuate the arms, which also have a pipecleaner wiper to replenish bubble membranes periodically. You can print and stack as many of the ring segments and arms as you desire, and attach the stack to the base plate which fits over a 500ml beaker.

Print with 2 perimeters, 25% grid infill, PLA, fan on medium high.