Techniques for fabricating magnetic nanoparticles are provided. In one embodiment, a method performed under the control of at least one apparatus for fabricating magnetic nanoparticles includes preparing a substrate that defines at least one cavity through a portion thereof, soaking the substrate with a solution, the solution including a multiple number of magnetic nanoparticles, and applying a magnetic field so as to collect at least a portion of the magnetic nanoparticles into the at least one cavity.