During the last decade, active matter has been attracting increasing interest because its study can shed light on far-from- equilibrium physics and provide tantalizing options to perform tasks not easily achievable with other available techniques on the micro- and nanoscale. We are now on the threshold of breakthroughs that will permit us to gain a deeper understanding of the fundamental challenges associated with far-from-equilibrium physics (e.g. the physics of living organisms, tissue formation and cancer growth) and to address several key technological challenges of great societal and economic impact (e.g. biomimetic materials, targeted localization, pick-up and transport of nanoscopic cargoes in drug delivery, bioremediation and chemical sensing). However, there are still several open challenges that need to be addressed in order to achieve the full scientific and technological potential of active matter in real-life settings: 1. to develop biocompatible active particles, reducing their footprint by scaling them down towards the nanoscale; 2. to determine their emergent and synergistic behaviors in complex and crowded environments; 3. to engineer self-assembly in dense active and living matter systems. This ETN will provide the necessary infrastructure to train a new generation of physicists in the highly interdisciplinary fields related to active matter. ESRs will master the theoretical, numerical and experimental tools currently employed in the study of active matter, will create new tools for understanding active matter systems, and, through collaboration with companies, will be able to transfer this knowledge to biomedical, bioremediation and sustainability applications. Our ESRs will acquire highly demanded transferable skills increasing their future employability in academia and industry. Extending the reach of this ETN, we will also prepare interdisciplinary and interactive lecturing material to serve as foundation for study programs in active matter.