For several years, microbial engineers have been working to develop a means to create living materials for use in a wide variety of applications such as medical devices. But getting such materials to conform to desired 3D structures has proven to be a daunting task. In this new effort, the researchers have taken a new approach to tackling the problem—engineering Escherichia coli to produce a product that can be used as the basis for an ink for use in a 3D printer. The work began by bioengineering the bacteria to produce living nanofibers. The researchers then bundled the fibers and...