Table 1 Capabilities of major existing methods to pattern magnetic particles. 1D: Only binary magnetization can be patterned, e.g., longitudinal or perpendicular recording in a hard disk drive. 2D: Direction of magnetization in each layer is restricted to a single plane. 3D: Magnetization in each layer can be patterned in arbitrary direction. Discrete: Magnetization in each area is independent of adjacent areas. Continuum: Magnetization in each area cannot have sudden changes with respect to adjacent areas. N/A, not applicable.
MethodMagnet typeShape of media*Template or mold requiredStates of magnetization
Electrodeposition of
magnetic particles on
lithographically printed
microstructures (18, 21, 22)
Soft3DNoN/A
Lithographic patterning of
magnetic nanoparticles
(2628)
Soft2DNoDiscrete, 3D
Magnetic particles linked by
DNA (44)
SoftN/ANoDiscrete, 1D
Microassembly of magnetic
components (33, 34, 45)
Hard3DYesDiscrete, 3D
Magnetic recording
technology (46)
Hard2DNoDiscrete, 1D
Template-aided magnetizing
(2931)
Hard2DYesContinuum, 3D
3D printing of ferromagnetic
domains (35)
Hard3DNoDiscrete, 2D
This workHard2DNoDiscrete, 3D

*Shape of media refers to the structure of the composite materials in which the magnetic particles are dispersed. 2D refers to planar structures, whereas 3D refers to solid 3D structures.

†States of magnetization is defined as degrees of freedom related to the orientation of hard magnetic particles or preferred magnetic axes of soft magnetic particles in each area.