Context. The emergence of collective behavior in systems, such as animal groups [2-3] or mechanical models [4], has become a crucial area of study in recent years. This phenomenon relies on two key components: active individuals and the ways they interact. Typically, a change at the individual level—like a fish sensing a threat— can trigger a rapid collective response, akin to a wave in a stadium. While much research has focused on aspects like the transition to global order and spatial scales [5], the specific mechanics of how these waves propagate remain less understood. This project aims to fill that gap by using simple mechanical models made of active units connected by flexible beams. This work will serve as a foundation for further investigation at the PhD level, delving deeper into the dynamics of active elastic systems. Objectives. This internship will provide an opportunity to explore the dynamics and the propagation of waves in active elastic structures. We aim to elucidate the role of activity and highlight how the system's spatial structure influences its final state. We will rely on very simple model systems, inspired by recent studies [6], involving flexible strings, beams, and plates. These structures will incorporate active elements, such as robots, for instance.