Tattoos are all the rage at MIT these days: researchers at the university have recently produced prototypes that point to the future of biotech, from electronic tattoos that serve as interfaces to tattoos that change color based on body chemistry.
The latest? A tattoo made of living ink–genetically programmed cells that activate when exposed to different types of stimuli. While right now that means they light up when they come in contact with particular molecular compounds, there are exciting potential applications: the tattoos could be designed so that they respond to environmental pollutants or changes in temperature. That means that sometime in the future, we could all be walking around with living, responsive tattoos that tell us when it’s not safe to go outside because air pollution levels are dangerous, or even just act as a temperature gauge right on your body.
MIT researchers in mechanical engineering and bioengineering recently published a paper on their work in Advanced Materials, where they demonstrate a method to 3D print living cells–combined with a gelatinous material called hydrogel, which keeps the bacteria alive–on top of each other. This layering allowed them to build up the cell “ink” into patterns. Their prototype tattoo looks like a branching tree graph, where different parts of the graphic respond to different types of external stimuli. The next step is to create more patches designed to light up when they come in contact with particular chemicals.
The researchers also programmed some of the living bacterial cells to communicate, so that they light up in response to messages from other cells. “This is very future work, but we expect to be able to print living computational platforms that could be wearable,” graduate student and co-author Hyunwoo Yuk tells MIT News. Using this technique, scientists might be able to build a “living computer,” where layers of cells talk to each other like transistors do in electronics today.