Microscopic-scale medical robots represent a promising new type of therapeutic technology. As envisioned, the microbots, which are less than one millimeter in size, might someday be able to travel throughout the human bloodstream to deliver drugs to specific targets or seek out and destroy tumors, blood clots, and infections that can't be easily accessed in other ways. One challenge in the deployment of microbots, however, is developing a system to accurately "drive" them and maneuver them through the complex and convoluted circulatory system, to a chosen destination. Researchers from Korea's Hanyang University in Seoul and Chonnam National University in Gwangju...