Navigation of Microswimmers and Microrobots in Microflows

Microswimmers, from motile microorganisms to synthetic and biohybrid microrobots, operate in a physical regime where viscous forces, confinement and interactions with the surrounding medium dominate their dynamics. While microscale locomotion is comparatively well understood in simple Newtonian fluids, natural and technological environments are rarely so idealized. Microswimmers may encounter viscoelastic polymer networks, colloidal and particulate suspensions, crowded cellular environments, porous media, biological fluids, wastewater and chemically heterogeneous aqueous systems. In these media, fluid microstructure, elasticity, shear-dependent viscosity, suspended particles and local gradients can profoundly modify swimming speed, orientation, trajectories and collective behaviour. External flows introduce further complexity through shear, rheotaxis, dispersion and interactions with boundaries. Understanding these coupled effects is therefore a fundamental challenge in active-matter and low-Reynolds-number physics, with relevance to microbiology, environmental remediation, sensing, targeted transport, biomedical microrobotics and microfluidic technologies.The goal of this Research Topic is to advance the physical understanding and control of microswimmer and microrobot navigation in realistic microflow environments. A central challenge is to bridge the gap between locomotion studied in idealized fluids and motion through heterogeneous, crowded and non-Newtonian media, where swimmers, suspended components and surrounding flows interact dynamically. We seek contributions that clarify how fluid rheology, microstructure, imposed flow, confinement and swimmer properties determine transport, orientation, stability, targeting and navigation. Particular emphasis is placed on identifying general physical principles that connect biological microswimmers with synthetic and biohybrid microrobots across biomedical, environmental and engineered settings. Experimental studies using microfluidics and advanced imaging, theoretical models and numerical simulations are encouraged, together with approaches for characterizing and controlling individual and collective motion. The Topic aims to establish design principles for predictable and controllable navigation in complex microscale environments.We welcome Original Research, Reviews, Perspectives and Methods addressing the physics, characterization and control of microswimmers and microrobots in microflows. Relevant themes include natural, synthetic and biohybrid microswimmers; bacterial motility and rheotaxis; locomotion in viscoelastic, shear-thinning and other non-Newtonian fluids; swimming in colloidal, particulate and cellular suspensions; navigation in biological, environmental and engineered fluids; swimmer-particle and swimmer-boundary interactions; confinement and porous media; transport under shear and pressure-driven flows; collective motion and active suspensions; externally actuated microrobots and navigation strategies; hydrodynamic modelling and numerical simulation; and experimental methods for tracking and characterizing microscale motion. Contributions connecting fundamental mechanisms to applications in biomedicine, environmental remediation, pollution monitoring, water treatment, sensing and microfluidic transport are particularly encouraged. Topic editors: Viviana Clavería Source: https://www.frontiersin.org/research-topics/86272/navigation-of-microswimmers-and-microrobots-in-microflows