Magnetic microrobots that navigate the natural pathways of the body have the potential to revolutionize minimally invasive medicine and biomedical research. Current magnetic manipulation systems utilize massive magnets to produce a uniform magnetic field over a relatively small area. Uniform magnetic fields are used to simplify control, but this simplified control comes at a huge cost, and it is difficult to scale up most laboratory field-generation systems to the size required for clinical use. The use of nonuniform magnetic fields makes it possible to place magnets nearer to the patient, which permits the use of smaller, less-expensive magnets, while simultaneously improving actuatable degrees of freedom and force levels that systems can render. The hypothesis being tested is that using nonuniform magnetic fields to wirelessly control medical microrobots results in superior systems?in terms of size, cost, and performance?compared to using uniform fields. This research consists of two thrusts: control of magnetically tipped continuum microrobots, which provide distal dexterity in hard-to-reach locations, and control of fully untethered magnetic helical microrobots, which swim and crawl through fluids, lumens, and soft tissue using a method inspired by bacterial flagella. Understanding how to use nonuniform magnetic fields for wireless control may be the key to translating nearly every previously developed method for microrobot propulsion into clinical practice. Magnetic microrobots may be the ideal platform from which to deploy the numerous BioMEMS devices and magnetic sensors and actuators that have been designed in recent years.
