Complex magnetization

A flat disk with north and south maxels arranged on one face is the most common Polymagnet configuration. It covers a wide range of attachment, latching, alignment, and spring applications. But it’s not the only geometry we can magnetize. Complex magnetization is our umbrella term for non-standard Polymagnet work. It includes codes printed onto curved or cylindrical surfaces, combined force functions layered on the same face, and magnetic fields engineered in multiple dimensions.

This is where Polymagnet technology moves beyond incremental improvement and into territory that conventional magnetization equipment can’t reach.

Beyond flat surfaces

Conventional magnetization equipment treats magnets as simple slabs. A fixture magnetizer charges the entire volume of a magnet blank with a single pulse. The fixture orientation determines the pole direction. North on one face, south on the other. Any deviation from that uniform charge requires a different fixture, and building fixtures for curved surfaces is expensive and slow.

Our MagPrinter operates on a different principle. The magnetizing coil moves under software control across the surface of the magnet blank. It deposits individual maxels at prescribed positions, each with a specified polarity and saturation level. The coil accommodates flat, curved, and cylindrical surfaces equally. We’ve printed maxel codes onto ring magnets, arc segments, tubes, and compound-curved surfaces.

Ring magnets are a common request. We print maxels on the outer diameter, the inner diameter, or the end face, depending on the application. A ring Polymagnet on the inner bore provides precision alignment for a shaft passing through it. One coded on the outer surface can engage with a mating ring or a flat surface nearby.

Cylindrical magnets can receive maxel codes along their length. This produces a magnetic field that varies as you move along the axis. We’ve used this for linear positioning applications where a cylindrical magnet moves through a bore and locks at specific axial positions. The lock force at each position and the resistance between positions are both programmable through the code. Conventional magnets can’t produce discrete axial positions on a cylinder without mechanical hardware.

Multi-function surfaces

A single Polymagnet can carry more than one magnetic function on the same face. We layer maxel codes to produce combined behaviors. The individual functions don’t interfere because their spatial frequencies are different. High-frequency elements operate at close range. Low-frequency elements operate further out.

An attachment magnet with built-in alignment is one example. The alignment code has a high spatial frequency and provides self-centering precision at close range. Its attachment counterpart has a lower frequency and provides the holding force. Both are printed on the same surface in the same pass. The magnet aligns first, then pulls into full attachment as the mating pair comes together.

We also ship a shear-plus-alignment combination into production assemblies. The alignment function guides two components into position during assembly. Shear-optimized codes then hold them against lateral displacement after attachment. A conventional approach would require separate magnets for each function. Our combined-function Polymagnets consolidate both into one part.

Multi-level behaviors are also a form of multi-function magnetization. Repel and attract components coexist on the same surface, and their relative contribution changes with separation distance. That capability has its own page on this site.

Dimensional control of magnetic fields

Standard magnets produce a field that extends in all three dimensions without selectivity. The magnet doesn’t restrict where its flux goes. Polymagnet codes direct and constrain the field.

A one-dimensional code varies in one direction across the magnet surface. The stripe code is a good example: north-south-north-south in a line. Field strength is high along the coding axis and weak perpendicular to it. This is the simplest form of Polymagnet coding.

Two-dimensional codes vary in both directions across the surface. They produce a checkered or grid-like field that constrains flux to the near-surface region. Most of our standard catalog products use two-dimensional codes because they offer the best combination of surface concentration and far-field cancellation.

Three-dimensional codes vary in all spatial directions. This requires either stacking coded layers or printing on a three-dimensional surface such as a cylinder or sphere. The field structure is more complex, and the possible behaviors are more varied. Rotary coupling applications use three-dimensional coding where the force interaction must be controlled in both radial and axial directions.

Four-dimensional coding adds a time component through electromagnetic maxels. The current through each electromagnetic maxel can be varied during operation, which changes the force curve in response. We’ve demonstrated this as a proof of concept. The technology allows magnets that change behavior while in use, switching from spring to latch or from attract to repel on command.

Variable saturation

Every maxel on a Polymagnet has a saturation level that we set during printing. Full saturation produces the strongest possible field for that maxel size and material grade. Reduced saturation produces a weaker field.

We use variable saturation within a single Polymagnet to fine-tune the force curve. A maxel at the center of the magnet might be printed at full power, while maxels near the edge are set to a lower level. This produces a radial gradient in the field strength. The gradient affects how force changes with lateral displacement.

Variable saturation is also our primary tool for controlling transition points in multi-level designs. The short-range and long-range components have different saturation levels. Their ratio determines the transition distance and the force curve profile around the inflection point.

Our MagPrinter can adjust saturation on a per-maxel basis. No conventional magnetization system provides this level of control. Fixture magnetizers charge all poles at the same level. We treat each maxel as an independent element.

Materials and compatibility

Complex magnetization is possible on any material that our MagPrinter can process:

• Neodymium (NdFeB). Highest energy product, used for most high-performance Polymagnets. Grades from N35 through N52.
• Samarium cobalt (SmCo). Higher temperature tolerance than neodymium. Used in applications above 150 degrees C. Available in both SmCo5 and Sm2Co17 formulations.
• Ferrite (ceramic). Lower cost and lower performance than rare-earth materials. Suitable for high-volume consumer applications where force requirements are moderate.
• Flexible magnetic stock. Rubber-bonded ferrite or rare-earth powder. Used in gaskets, closures, and conformal applications where the magnet must bend.

The MagPrinter process is non-destructive and operates at room temperature. We can re-magnetize a blank that has already been coded without damaging it. If a prototype doesn’t meet specifications, we erase and reprint. The same blank is reusable across multiple iterations.

Applications of complex magnetization

Product designers bring us complex magnetization projects when their application requires something beyond a standard flat-surface code. A pump that needs a coded magnetic coupling on a cylindrical rotor. Medical devices that must combine alignment and attachment on a curved housing. An instrument that needs a variable-behavior magnetic mount controlled by software during operation. Each of these is a production project that we’ve taken from design through prototyping and into manufacturing.

Complex magnetization is our most engineering-intensive service, and it’s where the software-defined nature of our technology has the largest impact relative to conventional magnets. Our engineering team evaluates feasibility early and produces prototypes within days. We publish performance data for every complex Polymagnet we deliver. The designer receives measured force curves, transition points, and field profiles before committing to production volumes.