(17b) Collective Behavior of Active Cell-like “Flexicle” Microrobots

In recent years the distinction between the functionality of synthetic active microparticles and of their biological counterparts has become increasingly blurred. However, we still lack the fundamental understanding needed to recreate the key facets of autonomous behavior exhibited by microorganisms or macroscopic robots comprised of colloidal particles. In this study, we propose a model for a three-dimensional self-driven, deformable cellular robot composed of self-propelled particles confined to a flexible membrane - a superstructure we call a “flexicle”. Using molecular dynamics simulations, we investigate the collective behavior of dense systems comprised of many flexicles, as well as the behavior of individual flexicles within the collective. We show that individual flexicles exhibit intricate shape changes depending on the membrane’s bending modulus. These differences in shape deformability give rise to a diverse set of motility-induced phase separation phenomena and the spontaneous flow of flexicles, akin to the migration of cells. Our findings establish a foundation for controlling the migration of cell-like active particles and for developing strategies for achieving other autonomous robotic swarm behaviors.