What is a programmable magnet?

Reach for the word “magnet” and most people picture a fridge magnet: one flat North face, one flat South face, and a single job - stick to steel. A programmable magnet is the same raw material, but organized differently. Instead of one big North and one big South, its face is divided into many tiny magnetic cells, each set North or South in a deliberate pattern. That pattern is the code, and choosing it is what “programming” means here.

Because the poles are patterned rather than plain, the magnet no longer does just one thing. Line it up with a matching partner and it snaps together hard. Slide it sideways by a hair and the same faces can weaken, cancel, or push apart. Those behaviors are decided when the magnet is made and then repeat every time - the force is engineered, not accidental.

The other names you’ll see

Searching around, you will run into several terms for the same idea. They emphasize different aspects but describe one technology:

• Coded magnet - highlights that the poles carry a designed code.
• Correlated magnet - the technical name; the effect comes from correlation codes borrowed from radar and RF.
• Programmable magnet - emphasizes that the behavior is chosen at design time.
• Multipole magnet - describes the physical result: many poles on one face instead of two.
• Polymagnet - the commercial brand name for these magnets (see where to buy).

What “programmable” actually means

It is worth being precise, because the word can mislead. You do not reprogram a coded magnet on the fly the way you flash new firmware to a chip. The code is written into the magnet during manufacturing, when a machine magnetizes each cell - each cell is called a maxel - in the chosen North/South arrangement. After that, the behavior is fixed and repeatable. “Programmable” means the designer programs the force before the magnet is made, the way a machinist programs a part before it is cut.

Why anyone bothers

An ordinary magnet gives you one blunt tool: attraction that falls off gradually with distance and grabs any nearby steel. Patterning the poles buys you control. You can make two parts that hold firmly but release with a small twist, that align themselves into one exact position, that float at a set gap like a contactless spring, or that engage only with their matching coded partner and ignore everything else. Those are the programmable behaviors, and they are why coded magnets show up in aerospace, medical devices, robotics, and consumer electronics.