Active matter and active turbulence: a review of mass flow phenomena in biological and synthetic systems

Abstract

Active matter comprises a broad class of systems in which individual components continuously consume energy to generate movement and mechanical stress, resulting in complex emergent phenomena that are far from equilibrium This review focuses on the principles, mechanisms, and collective behaviour of active matter. Particular emphasis is placed on active turbulence in active nematic liquid crystals, Janus particles, and self-moving colloids Experimental observations are integrated with computational simulations and theoretical frameworks, including Toner dual theory, continuum hydrodynamics, active nematic models Comparative analysis of organic synthetic systems Highlighting similarities and differences between, and underlining the importance of defect-mediated dynamics, bonding effects, and energy injection mechanisms In the broader context of soft-material physics, materials science, and biophysics, this paper identifies key successes, unresolved questions, methodological challenges, and promising directions for future research

Keywords: Active matter, Active turbulence, Active nematic, Collective behaviour, soft matter physics