SOI Integrated Micromagnets for Mechanical Magnetic Field Detection

The integration of micromagnets into micromechanical systems presents promising opportunities for the development of passive magnetic field sensors that do not rely on continuous electrical energy. Therefore, micromagnetic transducers are required, which allow a conversion of external magnetic fields into a force or displacement that can be further processed within a micromechanical system. In this letter, we present the integration of powder-based permanent magnets in silicon-on-insulator technology on wafer-level and with in-plane magnetization. Based on this technology, demonstrators consisting of a magnetic actuator and a mechanical amplifier are designed, fabricated, and characterized. Measurement results show that external magnetic fields of about 223 mT enable either the generation of a displacement of 76 μm at the mechanical amplifier or a force of 1.68 mN.