Design, Modelling, and Control of Soft-Bodied Magnetic Miniature Robots

Miniature robots promise radical improvements in microengineering and disease diagnosis and therapy. Their microscopic sizes allow them to access small and constrained workspaces that cannot be reached previously and perform tasks with accuracy and delicacy. However, their minute bodies also prevent them from carrying on-board components, such as electronics, batteries, and sensors. Thus, there exist a number of unique open problems in miniature robotics, which require novel strategies other than the conventional ones for robots at a larger size scale. In particular, the design, modelling, and control of soft-bodied magnetic miniature robots, which deform in magnetic fields to realize functionalities, have not been well studied, whilst their potential significant impacts have been shown on several areas. In this research, I design, fabricate, model, and control soft-bodied magnetic miniature robots to achieve functionalities at the millimeter and submillimeter scale. A microgripper, a miniature swimmer, and a microobject sorter are developed for cargo picking-and-placing, microscopic propulsion, and microobject sorting, respectively. A global magnetic field serves as the sole medium to deliver power and signals to these small-scale devices that work as robotic end-effectors. The magnetization pattern of each robot is programmed such that it exhibits the desired reactions in the magnetic field. Models are derived to explain and predict the behavior of these devices. Feedback controllers are developed to manipulate them in autonomous robotic tasks. Moreover, novel schemes are formulated to independently and simultaneously control two devices of the same kind using a single magnetic field without additional inputs. The successful realizations of these fundamental functionalities at (sub)millimeter scale using soft-bodied magnetic miniature robots indicate their promising potentials of achieving a large variety of complex capacities and being applied to a wide range of applications. The knowledge obtained from this research could provide insights for designing miniature robots with respect to specific task requirements. Preliminary biocompatibility tests reveal no negative effect on living cells from these robots, suggesting a promising outlook of these devices in bio-related areas. Potential applications of the proposed miniature robots include targeted drug delivery, minimally invasive surgery, on-chip cell diagnosis, microassembly, and generic laboratory operations.Ph.D