Self-Organization of Interacting Micromotors: From Synchronization to Phase Coherence

Over the past two decades, a host of motorization techniques have been developed to motorize the fundamental building blocks of soft condensed matter, such as colloids, polymers, and droplets, thereby turning them into active matter. At the same time, advances in 3D printing technology now allow for the fabrication of complex but inert microscopic structures.

In this talk, I will show how to combine 3D printing and colloidal motorization to self-organize collections of thousands of electric micromotors all driven independently. Through a combination of experiments, simulations, and theory, I will show and explain how transverse forces structure the spatial organization of the micro-motor dynamics: when sufficiently coupled, their rotation rates display a robust form of antiferromagnetic order. After having explained the ordering of the angular frequencies in rotor lattices, I will explain how to leverage electrostatic interactions and geometry to control their phase coherence, yielding to the spontaneous propagation of metachronal waves over system-spanning scale.