Active matter describes systems in which the elementary constituents consume energy to produce work. In the past three years we have tailored an artificial system that combines activity and elastic architecture and demonstrated that selective and collective actuation is a hallmark of active solids https://twitter.com/i/status/1561626005520932864. These results open a brand-new avenue of research, from further experimental and numerical investigations to theoretical analysis. Examples of open questions are: - What is the fate of collective actuation in the thermodynamics limit? - Is there a transition controlled by noise and of what type? - How does the sound propagate in such active solids? - What is the mechanical response of such materials? Depending on you, the internship can take a more experimental, more numerical or more theoretical direction.