I. Machines made of Machines: self-spinning microgears [A. Aubret].

We introduce a new type of self-assembly through a novel approach to devise spinning microrotors that self-assemble and synchronize, from a single type of building block — a colloid that self-propels. Using photo-active particles and light patterns, we demonstrated the potential of non-equilibrium (phoretic) interactions to program self-assembly and control dynamical colloidal architectures.

 

II. Active Noise for Self-Assembly
Developments on active colloids have surged in recent years, mainly as a “toy for physicists” focused on exotic collective behaviors of ​collections of active particles. ​It overlooked their practical impact to deploy materials science beyond equilibrium and actually control matter. Active particles added to a material regulates its activity, i.e “temperature”, internally, opening a broad range of novel opportunities to thermal treatments, known in metallurgy. It ushers materials science to a new age, where the properties of matter are not controlled macroscopically but microscopically and in real time by active dopants.