Mag-microbots: Design, modeling, and implementation of an untethered magnetically controlled micro-robotic system

Though several miniature robots currently exist at the centimeter size scale, true micron-scale robots, with all characteristic lengths on the order of tens to hundreds of microns, are still quite rare. The fundamental challenge with decreasing robot size below the centimeter scale is providing power and actuation to the device. To address this challenge, this thesis presents the design and implementation of a novel micro-robotic system that uses macro-scale electromagnets for actuation of a micro-scale permanent magnet, which acts as an untethered end-effector. System design, capabilities, and limitations are explored with regard to the control of the end effector, or micro-robot, and its ability to operate and interact within its environment.;Simultaneous control of multiple devices is achieved in two different ways with both homogeneous and heterogeneous groups of micro-robots. First, by designing individuals to respond uniquely to the same input magnetic fields, those fields are used as selection methods for individuals or small groups to locomote in a parallel fashion. A second method employs an array of individually addressable electrostatic surfaces to selectively anchor individual micro-robots. Coupled parallel and uncoupled serial motion of multiple devices is demonstrated in both cases, and individuals are shown capable of combining to form assemblies that are also capable of motion and micro-object manipulation. Models based on the magnetic, fluidic, electrostatic and surface forces and the various physical phenomena are developed and used to create a dynamic simulation to explain and predict the micro- robot's experimental behavior.;Actuation of the micro-robot is based upon a stick-slip type motion and is achieved in several environments, including vacuum, air, and liquid. By pivoting the micro-robot about an edge, movement over large, non-planar obstacles with characteristic sizes comparable to the micro-robot's length is possible. Manipulation of micro-scale objects in both water and silicone oil is demonstrated in two ways: contact and non-contact pushing modes. Contact manipulation is based on the micro-robot physically pushing the micro-objects while non-contact manipulation relies on the fluid flow generated by micro-robot's motion.