What's even better is they've published the instructions online if you want to build one yourself.
Pierre Emm came up with the idea and converted a MakerBot Replicator 3-D printer as part of a challenge set by France's Cultural Ministry.
Students were allowed eight hours and in that time they made a machine that could trace an image on skin in pen.
They wrote on the Instructables website: "The young designers didn't want to stop there. They wanted the machine to make REAL tattoos, on REAL skin, so they kept working on the project during their spare time, with some help from teachers and other students.
"They borrowed a manual tattoo-machine from an amateur tattoo artist and found some artificial skin for the first tests ...
"The big difficulty was to repeat the same exercise on a curve surface and on a material that has much more flexibility than silicone. Many tricks were tried to tighten the area around the skin (a metal ring, elastics, scotch tape...) but the most effective one was a scooter's inner tube, open on the area to be marked."