Cooperative control of multiple untethered magnetic microrobots using a single magnetic field source

This paper presents a novel method of actuation for multiple untethered microrobots with a global magnetic field generated by a single conical permanent magnet. The microrobots in our experiments were chrome-steel spheres with a diameter size of 500 μm and cubical neodymium magnets of 250 μm and 500 μm in size. These robots can perform cooperative planar motions compatible with micromanipulation tasks such as grasping. The cooperative grasping behavior is produced by the magnetic field gradient controlled by the 5 DOF position of the conical permanent magnet with respect to the robots´ workspace. The microrobots are also capable of swarming motion with a leader and formation following behavior. Simulation and experimental results are offered to validate the potential of this method for automation at the micro-scale.