Idea for new part primitives (dam)

[aj-automation]

One issue I had when creating our design in both 3DuF and Neptune was that neither had a primitive for a dam. A dam can have a variety of designs but the most common are one pillar that closes off a section of the channel to a certain size (say 200um channel -> 20um gap) or multiple pillars with regular gaps between them (say a 300um channel that has 3 20um pillars such that there are 4 60um gaps for fluid). In 3DuF we were able to approximate the structure with a droplet generator, but I think a proper primitive would be nice.

-Andrew and Tanner