If you try to cut a water droplet precisely in half, the original drop shatters into multiple, and often unusable, droplets.In this video I use a specially treated super hydrophobic knife to cut water droplets in half! I see how small of a water drop I can get!
source/image: The Action Lab
If you make your knife ‘superhydrophobic’, meaning that water can’t stand to touch it, the droplet will slice cleanly in two.
This video from stochasticscientist. shows the researchers trying to bisect a water droplet sitting on a hydrophobic Teflon surface using a superhydrophobic knife. Once the two loops were pulled slightly to stretch the droplet. Superhydrophobic means that the substance tends to repel, or does not mix with, water.
This just leaves one question: why would you need to chop a water drop in half? There are actually a lot of medical and industrial uses. The important difference between this method and shattering a drop is that by slicing the droplet in half you don’t lose any volume.