Filament formation via the instability of a stretching viscous sheet: Physical mechanism, linear theory, and fiber applications

Abstract

© 2019 American Physical Society. Many intriguing patterns are driven by fluid instabilities, even down to micrometer and nanometer scales, with numerous technological and industrial applications. Here, we propose a novel physical mechanism for filament formation in a stretched viscous sheet by combining stretching and van der Waals forces. We show that a transverse instability is enhanced while the longitudinal instability is suppressed, resulting in filamentation. We find a close agreement between the experimental data and the predictions of a linear-stability analysis. These results offer a pathway to achieving sophisticated microstructuring-nanostructuring for functional devices in either a single fiber or in integrated fabrics for large-scale textiles.