Hard Magnetic Material for Perpendicular Magnetic Anisotropic Field in Electromagnetic Actuator Fabrication

This paper describes a high power electromagnetic microactuator fabrication method that combines the hard magnetic Fe/Pt process, Ni/Fe permalloy magnetic circuit design, bulk micromachining, and excimer laser ablation. The hard magnetic material Fe/Pt is deposited under low temperature less than 300◦C by sputter onto a suspension diaphragm to produce a perpendicular magnetic anisotropic field. The magnetic circuit with closed loop design is applied to concentrate the magnetic flux and increase the magnetic force. The magnetic field induced by the planar coil and Ni/Fe permalloy enhances the interaction with Fe/Pt to induce attractive and repulsive displacement, provide a large output force, and operate at high frequency. This high power electromagnetic microactuator is demonstrated with minimum dimensions with a magnetic force two times greater than conventional magnetic micro-actuators.