Magnetic Nanoparticle Dosing of MEMS Structures by Solvent Evaporation in Capillaries

This paper describes a low cost method to deliver magnetic nanoparticle materials using a liquid suspension deposition into ¿m-sized structures that would comprise an inductor core. The delivery structure consists of a well and capillary where the well is the target for liquid delivery. Prior theory describing the dosing of MEMS capillaries with polymers is extended to NiFe2O4 nanoparticles in suspension for dosing capillaries constituting inductor type passives with ~200 times larger volumes (2 mm × 15 ¿m × 10 ¿m). Well and capillary structures were dosed with the magnetic nanoparticles suspension with and without the presence of a permanent magnetic field. Magnetization measurements show a difference in relative permeabilities of 4.2 and 3.3 with and without the presence of the magnetic field, respectively.