Sub‐Micrometer Surface‐Patterned Ribbon Fibers and Textiles

The worldwide annual production volume of textiles is nearly one hundred million metric tons. Most of these undergo treatments to achieve specific properties, such as color, hydrophobicity, antimicrobial, or UV protection, using chemicals that lead to collateral environmental consequences. There is great interest in developing alternative and sustainable strategies to achieve textile functionality that do not involve chemical treatment. Here we present a thermal drawing approach to achieve fiber surface gratings on a rectangular cross‐section. We demonstrate directional wetting properties as well as structural coloration based on the gratings. Periods down to ≈ 600 nm were established on the surface of a fiber. Fabrics displaying higher‐order diffraction peaks in the visible regime were produced from surface‐patterned fibers using convetional weaving machinery. An all‐structural‐fiber surface functionalization technique combining conventional macromachining and thermal fiber drawing is reported. Ribbon fibers with a variety of sub‐micrometer surface features extending uniformly over kilometer lengths are produced at rates of tens of meters per minute, enabling a nonchemical, environmentally friendly approach toward functional textiles.