Complex Living Materials Made by Light-Based Printing of Genetically Programmed Bacteria

Living materials with embedded microorganisms can genetically encode attractive sensing, self-repairing, and responsive functionalities for applications in medicine, robotics, and infrastructure. While the synthetic toolbox for genetically engineering bacteria continues to expand, technologies to shape bacteria-laden living materials into complex 3D geometries are still rather limited. Here, it is shown that bacteria-laden hydrogels can be shaped into living materials with unusual architectures and functionalities using readily available light-based printing techniques. Bioluminescent and melanin-producing bacteria are used to create complex materials with autonomous chemical-sensing capabilities by harnessing the metabolic activity of wild-type and engineered microorganisms. The shaping freedom offered by printing technologies and the rich biochemical diversity available in bacteria provides ample design space for the creation and exploration of complex living materials with programmable functionalities for a broad range of applications.