Magnetically levitated micro-robotics

The use of magnetic levitation (maglev) as a microrobot drive is examined theoretically and experimentally. Microrobots are small, programmable, multi-degree of freedom mechanical devices. Maglev drive appears capable of addressing a number of important microrobotics issues, including friction, wear, material transport, and ability to tolerate adverse environments. These issues, often involving problems beyond the technical feasibility of single microrobots, must be dealt with effectively in order to realize the goal of low cost, integrated, multi-manipulator systems operating on small scales. Maglev microrobot drive is compared with other possible microrobot drives, particularly electrostatic drive. Various magnetic levitation systems are examined next, showing the rich variety of possible maglev microrobots. Out of 48 physically distinct maglev drive systems, the focus is narrowed using the requirements of an integrated micro-factory (IMF). These requirements suggest that at the present level of technical development the maglev system of primary interest is one which uses air core electromagnets driving a permanent magnet manipulator. Various air core electromagnets are discussed, including planar electromagnets suitable for a high level of silicon integration. Several force/torque environments are considered, such as solid and liquid surfaces. These different environments primarily affect the control strategy's performance and requirements, such as the ability to operate in open loop modes. The analysis was used to build a number of experimental prototypes, including a planar type, 1-D manipulator transport path, and 4. degree of freedom microrobots capable of 0.5 micron resolutions. Finally, future trends in the field such as superconductive systems are discussed.