Pulsating active particles

What happens when particles in a crowded environment can change their size under the effect of a nonequilibrium drive and size synchronization?

It is known that cells in biological tissues interact and give rise to collective behavior such as size oscillation and wave propagation: we explore the physical mechanisms underlying this collective behavior by introducing a novel class of active matter, where the activity is the ability to change an internal degree of freedom at the single-particle level, which can be eventually related to the particle size. The collective dynamics thus emerges as the interplay of conservative forces, nonequilibrium driving and synchronization. We highlight the minimal ingredients needed for the complex behavior above-mentioned and point out future directions in the emerging field of pulsating active matter.