High-energy-density permanent micromagnets formed from heterogeneous magnetic powder mixtures

TitleHigh-energy-density permanent micromagnets formed from heterogeneous magnetic powder mixtures
Publication TypeConference Paper
Year of Publication2012
AuthorsOniku, O. D., and D. P. Arnold
Conference Name2012 IEEE 25th International Conference on Micro Electro Mechanical Systems (MEMS)
Conference LocationParis, France
ISBN Number978-1-4673-0324-8

In this paper, we report the microfabrication and magnetic characterization of parylene-bonded permanent micromagnets. Mixtures of two different sized and shaped isotropic Nd-Fe-B powders are used to form 255 μm × 255 μm × 315 μm thick micromagnets embedded in silicon substrates. The best properties are obtained for a 50:50 mixture of the powders, yielding remanence Br = 0.69 T, intrinsic coercivity Hci = 680 kA/m, and energy product BHmax = 45 kJ/m3. Enabled by newly released commercially available magnetic powders, the results show a doubling in the energy density and remanence values over previously reported parylene-bonded magnets. The rapid, simple, low-temperature fabrication of these magnets, as well as their thermal and chemical stability, makes them attractive for magnetic MEMS applications.

Refereed DesignationRefereed