Fabrication of micro electromagnetic actuator of high energy density

This paper introduced a new technology to fabricate electromagnetic actuator of high energy density without enclosed magnetic circuit. This technology includes fabricating multi-turns planar microcoils and the thick magnetic (NiFe) core on the silicon wafer. The multi-turns planar microcoils were fabricated by the electroplating method from surface to along the line and dynamically controlling the current density of the copper electrolytes. In order to fabricate thick magnetic plating, the adhesion properties between the NiFe plating and the silicon substrates were improved by changing the surface roughness of silicon substrates and increasing the thickness of seed layer. Lastly, the micro electromagnetic actuator was tested and the energy density of actuator was evaluated by the force of testing. Experiment shows this microactuator is efficient in producing magnetic energy density, magnetic force and has flexibility in application.