Swarming intelligence in self-propelled micromotors and nanomotors

Living organisms, from single cells to multicellular systems, are capable of moving as a response to local stimuli using swarming intelligence, a trait researchers aim to replicate in artificial systems. Common strategies observed in natural swarms include motility towards specific signals from the environment, communication among individual units, coordination and cooperation to achieve complex tasks. Inspired by these features, the focus in bioinspired motile nanosystems has shifted from studying individual units to exploring and controlling collective behaviours. Various propulsion mechanisms including magnetic, electric or acoustic fields, as well as onboard chemical reactions, have enabled artificial micromotor and nanomotor (MNM) swarms that can move collectively as a response to environmental inputs. The controlled navigation and improved tissue penetration of MNM swarms is promising within the biomedical field, including in the active transport of medical agents. Despite these exciting advances, artificial MNMs still fall short of the complexity and autonomy seen in biological systems. This Perspective explores the collective behaviour of biological swarms and bioinspired artificial self-propelled nanosystems. We discuss how swarming intelligence applied to synthetic active nanosystems enables swarms to perform various tasks. Finally, we discuss challenges, including material limitations, information storage, communication between swarms and prospects for intelligent swarming systems.