Statistical Mechanics and transport phenomena in Active Colloidal Solids

The objective of StaMACS is to uncover the dynamics of an active and loosely packed magnetic colloidal crystal. This system will consist of repulsive paramagnetic particles immersed in a bath of light-driven bacteria.

We will have two independent ways to tune the interactions: 1) An external magnetic field will control the strength of the dipolar repulsion between colloids. 2) The intensity of light will control the motility of bacteria and thus the particle’s induced activity, both locally and globally.

By combining experiments with simulations and theoretical analysis, we will reach a general understanding of this system’s dynamics, study its melting and crystallization transitions and examine how a local change in activity propagates throughout the crystal. Our findings will unveil the properties of a novel out-of-equilibrium system: an active colloidal solid.

Furthermore, this work will stimulate theoretical investigation related to the kinetics of such systems, with strong implications on understanding the fundamental process of crystallization in the presence of activity.

By a two-way transfer of knowledge, StaMACS will bring numerous mutual benefits to both the researcher and the host institution.

Its results will represent a major contribution to the soft and active matter field with direct applications in physics, biology and material science.Descriptors: Active Matter, Soft Matter, Statistical Mechanics, Magnetic Colloids