| MadSci Network: Engineering |
Refrigerator magnets are made of a compound of ferromagnetic material and a polymer. The metal provides the magnetism, and the polymer provides the flexibility. I can't tell you for sure the exact components of "regular" commercial 'fridge magnets, but I found that in the education and outreach program at U. Wisconsin - Madison, they make home-made refrigerator magnets from strontium ferrite and polydimethylsiloxane. The polymer is commercially available from Dow Corning, and cures clear, which would make it a nice candidate for a fridge magnet, since you could add whatever pigments you wanted in your design. I don't know for sure if this is the standard polymer used or just a convenient one for the Wisconsin folk because they have a research program on the properties of the material.
Sorry I couldn't be of more definitive help. Perhaps you could email someone in the Wisconsin program.
Stay curious,
Jay
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