Addressing of Micro-robot Teams and Non-contact Micro-manipulation

This manuscript presents two methods for the addressable control of multiple magnetic microrobots. Such methods could be valued for microrobot applications requiring high speed parallel operation. The first uses multiple magnetic materials to enable selective magnetic disabling while the second allows for independent magnetic forces to be applied to a set of magnetic micro-robots moving in three dimensions. As an application of untethered magnetic microrobots, we also present a non-contact manipulation method for micron scale objects using a locally induced rotational fluid flow field. The micro-manipulator is rotated by an external magnetic field in a viscous fluid to generate a rotational flow field, which moves the objects in the flow region by fluidic drag. Due to its untethered and non-contact operation, this micro-manipulation method could be used to quickly move fragile micro-objects in inaccessible or enclosed spaces such as in lab-on-a-chip devices. In addition to introducing the operation and capability of these fabrication and control methods, we discuss the implications of scaling these systems to smaller scales for comparison with other microrobotics actuation and control techniques.