Modeling the biomimetic self-organization of active objects in fluids

Abstract Living cells self-organize to perform various complex tasks that a single cell alone could not accomplish. Few synthetic nano- or micro-scale objects can autonomously carry out comparable coordinated behavior. We develop computational models to design fluid-filled microchambers containing both nano- and micro-particles that convert inputs of thermal, optical or chemical energy into mechanical motion to exhibit collective biomimetic activity. For example, the heat generated by illuminating the solution of nanoparticles within the microchamber drives the dispersed microparticles to self-organize into colloidal crystals that follow a moving light source, and thus exhibit life-like photo-tactic behavior. For microchambers containing catalyst-coated flexible sheets, chemo-responsive microparticles and the appropriate reactants, the sheets self-organize into autonomously moving “predators” that effectively collaborate to trap the “prey-like” particles. These computational studies provide valuable guidelines for developing microfluidic devices and soft-robots displaying autonomous bio-inspired properties that greatly expand the functionality of these systems.