Biblio

This paper proposes a magnetic actuator using a partially magnetized FePt thick film as a permanent magnet and membrane material for bi-directional micropumps. The magnetized areas act as flux sources, while the magnetized and unmagnetized areas play a role of the membrane part. The mechanical and magnetic characterization results show FePt has a large tensile strength and a lower Young’s modulus than Si crystal, and a comparable remanence to NdFeB. A magnetic pattern transfer technique with a post thermal demagnetization is proposed and experimentally verified to magnetize the FePt partially. Using the proposed magnetic actuator with partially magnetized FePt film is beneficial to simplify the complicated structure and fabrication process of the bi-directional magnetic micropump besides other magnetic MEMS devices.

This paper reports electroplated CoPt permanent magnets samples yielding thicknesses up to 100 μm, deposition rates up to 35 μm/h, coercivities up to 1000 kA/m (1.25 T), remanences up to 0.8 T, and energy products up to 77 kJ/m3. The impact of electroplating bath temperature and glycine additives are systematically studied. Compared to prior work, these microfabricated magnets not only exhibit up to 10X increase in thickness without sacrificing magnetic performance, but also improve the areal magnetic energy density by 2X. Using a thick removeable SU-8 mold, these high-performing thick-film magnets are intended for magnetic microactuators, magnetic field sensors, energy conversion devices, and more.