3D printing of living bacteria electrode

The capability of preparing three-dimensional (3D) printable living inks provides a unique way to harness the activity of microbes and use them in functional devices. Here we demonstrate the incorporation of the living bacteria Shewanella Oneidensis MR-1 (S. Oneidensis MR-1) directly into an ink used for creating 3D printed structures. Significantly, S. Oneidensis MR-1 survives the 3D printing process by showing prominent activity in degrading the methyl orange azo dye. Through the addition of carbon black to this ink, we further demonstrate the direct printing of a living microbial fuel cell (MFC) anode. To our knowledge, this is the first report on implementing 3D printed bacteria structure as a living electrode for an MFC system. The capability of printing living and functional 3D bacterial structure could open up new possibilities in design and fabrication of microbial devices as well as fundamental research on the interaction between different bacterial strains, electrode materials, and surrounding environments.