Magnetic Fluid





Introduction: Magnetic Fluid

*-* This Instructable is in English. Please click here for the Dutch version,

*-* Deze Instructable is in het Engels. Klik hier voor de Nederlandse versie.

Did you ever see a ‘magnetic fluid’? Some kind of metal-looking fluid that gets spiky when near a magnet? Here you’ll find instructions to make a ‘ferrofluid’ yourself. But beware … this experiment can be very addictive!

Curious how this works? Read about it in our blog about ‘Magnetic fluids’ (only in Dutch). Long version short: the ink powder in modern laser printers or copiers contains the mineral magnetite (Fe3O4). It's needed for the particles to be able to 'stick' to the paper (search for 'triboelectric effect). It is - indeed - magnetic and thus the ideal base for a ferrofluid (a fluid containing nano-particles of magnetic material). The fluid every nerd just loves!

Step 1: Materials

  • Protective gloves
  • A mouth mask
  • A glass beaker
  • An (old) ink cartridge from a printer or copier
  • Oil (e.g. a plant-based oil like olive oil)
  • Stirring rod
  • A small container and a piece of paper
  • A strong (neodymium) magnet

Step 2: Collect Toner

  • Carefully put some toner out of the cartridge into the glass beaker. You’ll only need about 50 ml.
  • Use the magnet on the outside of the beaker to test whether the toner has magnetic properties.

*-* Watch out: toner is not without danger – as long as you don’t drink it or breath it in, you’ll be quite safe (but since it’s a big mess and as instructed by our insurance agent, we recommend you to wear protective gloves and a mouth mask). Don’t throw away the rest, but bring it to the civic amenity site or to a specialised firm. *-*

Step 3: Add Oil

  • Add two table spoons of oil to the toner.

Step 4: Disperse

  • Use a stirring rod to mix it until all toner is dispersed.

Step 5: Reaction to Magnet

  • Put a little of your mixture into a small container.
  • Bring the magnet close to the bottom of the container.
  • The fluid gets all spiky!

*-* When the result is nothing like the picture, maybe it’s a toner problem. Some brands contain more or less magnetic particles. It might help to add some oil. Or to remove some. Some brands contain no magnetic particles at all – then you should look for a new cartridge. *-*

Step 6: Magic Ink

  • Now put some of the fluid on a piece of paper.
  • Move the magnet below the paper.
  • You’re making a ‘magnetic drawing’!

*-* Did you make a mess, despite our warnings? Toner washes away easily with cold water. Don't use hot water or rub the toner, because that will likely make it permanent. *-*



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The ferrous powder would have to be very fine, nano-particles will make the best colloid. If you don't want to waste toner, you can use magnetite (Fe3O4).

Any chance you can post a link to an English explanation of how this works?

What makes the "spiky"?

Rather than just attraction (like "ferro putty" I have).

why use Plant-based oil? Why not synthetic motor oil?

No specific reason, just easier to find at home for most people. Synthetic oil should work fine too.


Glycerol should work even better, I believe

Thanks for the tip! We'll surely try that in the future.

If you make a mess with toner, clean up with COLD water,it washes away easily, but if you you use hot water or rub it (friction produces heat) it will become almost permanent. This is as designed,....ex laser printer engineer.

No need to discuss with ex laser printer engineers :-).'ll We take your word for it! We'll include this in our manual right away.