Microbullet

As a microbullet impacts the graphene, the diameter of the cone it creates – determined by later examination of the petals – provides a way to measure how much energy the graphene absorbs before breaking.

PFC vaporizes when hit with an ultrasound pulse, producing rapidly expanding gas bubbles that "fire" the nanobullets out of the microcannons at speeds on the order of meters per second -- and the fluorescent microbullets light up to show exactly where they landed in the tissue target.