Capillary Migration of Peptide Nanowires for Surface Strengthening

This study explores the capillarity-guided self-assembly of cyclo-diphenylalanine (FF) nanowires on surface defects with engineered topographies, emphasizing the interplay between geometric confinement and evaporation-driven flow. Evaporation on v-groove and trench substrates induces directional migration and alignment of FF nanowires, forming ordered, surface-adherent structures. Numerical simulations support these observations by illustrating flow behavior and deposition patterns. Guided by this mechanism, we fabricated nanowire-reinforced polyvinyl alcohol (PVOH) composite fibers with high stiffness (20.29 ± 6.57 GPa) and tensile strength (581.7 ± 34.69 MPa) at 10 wt % loading. Thermally treated, physically damaged fibers exhibited autonomous healing without external agents. Capillary migration and nanowire reassembly at fracture interfaces restored continuity and improved ductility, reflecting dynamic nanowire organization. These results present a geometric strategy for nanowire alignment and demonstrate the dual function of peptide nanowires in mechanical reinforcement and self-repair, highlighting their potential as active components in bioinspired, damage-tolerant materials.