Abstract
<jats:p>Active matter systems exhibit autonomous motion by continuously converting locally available energy into mechanical work through complex physicochemical interactions. Among the mechanisms governing these systems, nonlinear interfacial phenomena play a central role in regulating propulsion efficiency, trajectory stability, collective dynamics, and adaptive responses under nonequilibrium conditions. This review provides a comprehensive synthesis of recent advances in understanding the influence of surface tension gradients, Marangoni stresses, diffusiophoretic transport, electrokinetic interactions, capillary forces, and interfacial hydrodynamics on the propulsion of catalytic Janus colloids, chemically active droplets, microswimmers, self-propelled rods, and emerging artificial active matter. A structured literature review methodology was adopted to integrate theoretical developments, computational modeling approaches, and experimental investigations reported across the active matter community. Furthermore, a unified mathematical framework based on conservation laws, transport equations, and interfacial force balances is presented to establish the quantitative relationships between physicochemical transport processes and propulsion behavior. Comparative analysis of the reviewed studies demonstrates that active matter propulsion arises from strongly coupled nonlinear interactions rather than isolated mechanisms, with multiphysics feedback governing motion across molecular, interfacial, and continuum scales. The review also highlights recent progress in computational simulation, advanced experimental characterization, and programmable active materials while identifying persistent challenges associated with multiscale modeling, experimental reproducibility, and predictive design. Finally, emerging opportunities involving intelligent interface engineering, machine learning-assisted modeling, digital twins, and adaptive active materials are discussed as promising directions for advancing autonomous microsystems and functional soft matter. By integrating theoretical, computational, and experimental perspectives within a unified framework, this review provides a comprehensive reference for researchers seeking to understand and engineer nonlinear interfacial regulation of active matter propulsion for applications in biomedical engineering, microfluidics, environmental remediation, and advanced materials science.</jats:p>