No, seriously. Go read the patent for yourself. The company is proposing "a material attachable to skin [that is] capable of detecting a magnetic field and transferring a perceivable stimulus to the skin, wherein the perceivable stimulus [e.g. a vibration] relates to the magnetic field."
Such an "apparatus," explains the patent application, could come in various forms, so it wouldn't necessarily have to be a tattoo (it could, for example, be a wearable badge... like a vibrating cell phone "patch"). Having said that, the patent application does make explicit mention of both visible and invisible tattoos, and also goes into quite a bit of detail on the inks that could be used to create magnetized images "under the skin." This ink, explains the patent, would be enriched with ferromagnetic or paramagnetic compounds like iron or liquid rare earth materials like neodymium.
But could a tattoo actually respond to a magnetic field? Absolutely. In fact, they already do. Many of the dyes used to create red tattoo ink, for example, contain iron. Iron is magnetic, and reacts to the powerful magnetic fields used in MRI machines, conducting electricity and forming loops of current that generate heat. The more energy the ink pigments pick up, the hotter they get; in fact, according to this study, the pigments can get hot enough to cause second degree burns.
So are vibrating tattoos a cool, futuristic concept? Absolutely. Just remember to be wary of electromagnetic fields. After all, one has to imagine that anything sensitive enough to pick up on an EMF generated by a cell phone would react even more powerfully to the fields generated by something like an MRI machine; if modern day tattoos can cause your skin to blister, how might tomorrow's vibrating tattoos react?
Top image via