Multifunctional Reactive Nanocomposites via Direct Ink Writing

3D printing of reactive materials has, to date, primarily focused on controlling reaction velocities and energy release rates by printing novel architectures, which during reaction typically form gaseous and oxide powder products. The utility of printed reactive materials can be increased by designing the material such that its reaction produces both a controlled energy release and a functional product phase without gaseous products. Here, we report the direct ink writing of reactive materials composed of ternary nanocomposite powders that exhibit gasless, exceptionally low velocity reactions. The printed features can be patterned in arbitrary form factors and are brittle and electrically insulating as‐printed. Using a self‐propagating synthesis reaction, these features can be transformed into a mechanically robust, electrically conductive cermet that is capable of handling high currents. This study provides a new paradigm for printing multifunctional reactive materials in which both the energy release of the reaction, as well as the reaction products themselves, are useful for potential applications ranging from printed electronic devices to controlled, directed energy release. This work explores direct ink writing reactive nanocomposite powders which form mechanically stable, electrically conductive products after self‐propagating high temperature synthesis. This material both adds to the selection of printed reactive materials for controlled and directed energy release and opens the door to printing reactive materials which form useful product phases for a variety of applications.