Reorganize materials by adding active intruders
In metallurgy or optics, the quality and properties of materials are a direct function of the arrangement of the crystals of atoms composing them.
Selective activation by UV light of self-propelled microparticles in a hexagon containing non-aligned colloidal beads. After 18 minutes, the part of the hexagon with the self-propelled particles (left) shows a much faster reorganization than the part without them..
In metallurgy, the annealing method, in which the metal undergoes several phases of highly controlled heating and cooling, produces the expected result at the cost of significant energy expenditure.
In an article recently published in Nature Communications, Sophie Ramananarivo (Laboratory of Hydrodynamics at École Polytechnique and CNRS), Etienne Ducrot (Center for Soft Matter Research, New York University) and Jérémie Palacci (Department of Physics, University of California , San Diego) demonstrated that the addition of self-propelled microparticles activates the process of rearranging a passive matrix of particles.
The model system, composed of micrometric colloidal beads arranged in a monolayer into which self-propelled microparticles are introduced, indicates what could happen at the atomic scale to control the properties of materials.
These active fluctuations provide a powerful means of controlling the reorganization of crystalline structures and open possibilities for self-assembly and the creation of smart materials.
Nature Communications volume 10, Article number: 3380 (2019)