Mechanical reinforcement strategies for hollow fiber membranes: materials design, structural approaches, and future perspectives

• A comprehensive review of mechanical reinforcement strategies for hollow fiber membranes (HFMs), covering materials, structures, and fabrication techniques. • Detailed comparison of porous matrix, filament, and braided reinforcements with quantitative mechanical benchmarks • Integration of emerging approaches including nanocomposite, hybrid multilayer, and homogeneous reinforcement designs. • Critical discussion on the strength–permeability trade-off and strategies to achieve simultaneous mechanical robustness and high flux. • Future-oriented insights into sustainable fabrication (green solvents) and predictive modeling (FEM–CFD coupling) for next-generation HFMs. Hollow fiber membranes (HFMs) are among the most versatile configurations in membrane separation technology due to their exceptionally high surface–area–to–volume ratio, which enables high packing density and compact module design. These advantages have led to their widespread use in water treatment, gas separation, and biomedical applications. However, despite their structural efficiency, many polymeric HFMs suffer from limited mechanical strength, which can compromise long–term operational stability under elevated pressures, turbulent flow conditions, and repeated backwashing cycles. To overcome these limitations, numerous mechanical reinforcement strategies have been developed in recent years. This review presents a comprehensive and critical overview of recent progress in reinforcement approaches for HFMs, focusing on the relationships between material selection, structural architecture, and fabrication techniques. Major strategies—including porous matrix scaffolds, embedded fibers or yarns, and advanced braided structures—are systematically examined with respect to their ability to enhance mechanical robustness while maintaining effective separation performance. Particular attention is given to the trade–off between mechanical durability and transport properties, which remains a central challenge in membrane design. Furthermore, emerging research directions such as nanomaterial–assisted reinforcement, hybrid multilayer architectures, environmentally friendly fabrication solvents, and predictive computational modeling are discussed as promising pathways for the development of next–generation HFMs. By integrating recent advances and identifying key design considerations, this review provides a clearer framework for developing mechanically resilient and operationally reliable hollow fiber membranes suitable for demanding industrial applications.