Permanent Magnets for MEMS

This paper reviews the state of the art for the microfabrication of permanent magnets applicable to microelectromechanical systems (MEMS). Permanent magnets are a key building block for the realization of magnetically based MEMS sensors, actuators, and energy converters. In this paper, the basic theories and operational concepts for permanent magnets are first described. Then, different classes of permanent-magnet materials and associated performance tradeoffs are introduced. Challenges relating to the integration of permanent magnets into MEMS applications are then discussed. Last, a summary and review of previously reported fabrication strategies and material properties is provided.