Abstract

Dynamic order is observed in natural systems at all length scales, from the schooling of fish to the coordinated beating of cilia and flagella. These systems, including flagella and cilia from the same organism and cell type, often transition between different modes of coordinated motions. For example, Chlamydomonas biflagellates switch from in-phase to anti-phase beating and ependymal cilia periodically change their collective beat orientation. While there is a substantial body of evidence supporting the hypothesis that hydrodynamic interactions provide a robust mechanism for synchrony, little is known about the mechanisms responsible for the transition between multiple synchronization modes. Here, I will present a series of models of increasing level of complexity that examine the emergence of collective coordination in microfluidic systems of swimmers and rotors. I will report new findings on flow-mediated synchrony in chains of swimmers and rotors and I will focus on the existence of bi-stable synchronization modes in systems of rotors. These results could have important implications on understanding the biophysical mechanisms underlying transitions between multiple synchronization modes, as well as on the design and self-assembly of active materials.