Microcannons firing Nanobullets

Sometimes I read papers that enhance my understanding of how the universe works, and sometimes I read papers about fundamental research leading to promising new technologies. Occasionally though, I read a paper that is just inherently cool. The paper by Fernando Soto, Aida Martin, and friends in ACS Nano, titled "Acoustic Microcannons: Toward Advanced Microballistics" is such a paper.