Biological systems show remarkable and robust self-assembly: bacteria form colonies, cells reshape and muscle fibers collectively contract… Those phenomena stem from the non-equilibrium nature of living matter, a prototypical example of active matter in which self-driven units convert an energy source into useful motion and work. Inspired by the biological world, we will show how to build and control man-made materials powered from within.
As a first example, we will see how the doping by active particles allow to accelerate the annealing of a dense monolayer of colloidal particles, reaching the ground state faster along unusual pathways . Then, we will discuss the effect of an active bacterial bath on the aggregation of attractive microbeads and unveil a phase diagram with activity as a parameter. We will notably show that we can control the morphology and mechanical response of a passive gel by assembling it in an active bath .
In a second part, we will show how active particles self-assemble or can be assembled into autonomous and programmable metamachines, or machines made of machines. Because active particles can differentiate to provide multiple functions, machines are readily reconfigurable, merged and annealed, allowing for more sophisticated machinery. Our work shows the potential of active matter for self-assembly and the development of dynamical and reconfigurable materials [3, 4, 5].
Related papers by the group
 Ramanarivo et al, Nature Communications, 2019
 Grober et al, submitted
 Aubret et al, Nature Physics, 2018
 Martinet et al, Advanced Intelligent Systems, 2022
 Aubret et al, Nature Communications, 2021