This award supports a multidisciplinary team of four investigators using modeling, analysis, computer simulations, and experiments to study using suspensions of active particles to enhance the properties of inks for applications in 3D printing. Active materials represented by suspensions of synthetic self-propelled particles harvest energy from their environment and alter the properties of the surrounding fluid. They have novel materials properties and promising applications. Here, a new concept of ink for 3D printing, termed "active ink", is introduced. Even a small fraction of active self-propelled particles in a fluid results in a dramatic reduction of viscosity, enhancing ink transport through the nozzle and increasing printing speed. This project will facilitate the design and manufacture of new materials, significantly shortening the path from prototype to product. This research will also enable a highly multidisciplinary training and education of students and postdocs who will learn theoretical techniques in applied mathematics and computations, as well as experimental techniques employed in chemistry and nanofabrication. Apart from the development of new 3D printing technology, the work will lead to novel mathematical models and efficient computational algorithms.