Modeling and Experimental Characterization of an Untethered Magnetic Micro-Robot

Here we present the control, performance and modeling of an untethered electromagnetically actuated magnetic micro-robot. The microrobot, which is composed of neodymium–iron–boron with dimensions 250 m 130 m 10 m, is actuated by a system of six macroscale electromagnets. Periodically varying magnetic fields are used to impose magnetic torques, which induce stick–slip motion in the micro-robot. These magnetic forces and torques are incorporated into a comprehensive dynamic model, which captures the behavior of the micro-robot. By pivoting the micro-robot about an edge, non-planar obstacles with characteristic sizes comparable to the robot length can be surmounted. Actuation is demonstrated on several substrates with different surface properties, in a fluid environment, and in a vacuum. Observed micro-robot translation speeds can exceed 10 mm s 1. KEY WORDS—micro/nano robots, design and control, dynamics simulation, micro mechanics