This Temporary Tattoo Is Made From Living Cells

It’s a little more high-tech than the tattoos you might remember fishing out of the bottom of a Cracker Jack box as a kid.

Engineers at MIT have developed a temporary tattoo that’s 3-D printed with living ink. The tattoo is made up of bacterial cells that are genetically programmed to light up when exposed to different types of stimuli.

While a living, light-up tattoo seems like it might make a great accessory to your office holiday party outfit, the researchers at MIT are not exactly out to make a fashion statement. Writing this week in the journal Advanced Materials, the researchers describe a vision of the tattoo as a sort of living sensor. It could, for example, be designed to detect pollutants in the environment, sending its wearer a signal when they’re in the presence of dangerous toxins.

Here’s how it works: First the bacterial cells are programmed to respond to different compounds. Then those cells are mixed together with hydrogel and cell-feeding nutrients to form an ink. Using a 3-D printer, several layers of ink are printed onto a transparent patch to form a living, three-dimensional, interactive device—in this case in the shape of a tree. In this example, each branch of the tree is made up of cells sensitive to a different substance. When the tattoo is put on the skin, those different regions will light up when exposed to the corresponding compound.

The researchers envision their creation as something that could be used to not just sense pollutants, but to detect changes in things like temperature or pH level. They also imagine it could be used to manufacture things like drug capsules containing cells engineered to produce compounds like glucose which would be released therapeutically over time. One day, it could even form the basis for “living” computers.

In the meantime, with a few more designs and color-combo options, they might also have a hit with the teens on their hands.