Design and Fabrication of Scalable Multifunctional Multimaterial Fibers and Textiles

Multimaterial fibers eschew the traditional mono-material structures typical of traditional optical fibers for novel internal architectures that combine disparate materials with distinct optical, mechanical, and electronic properties, thereby enabling novel optoelectronic functionalities delivered in the form factor of an extended fiber. This new class of fibers developed over the past two decades is attracting interest from researchers in such different fields as optics, textiles, and biomedicine. The juxtaposition of multiple materials integrated at micro- and nanoscales in complex geometries while ensuring intimate smooth interfaces extending continuously for kilometers facilitates unique applications such as non-invasive laser surgery, self-monitoring fibers, e-textiles, and extreme-environment tethers. In this work, I focus on the scalable manufacturing of novel multimaterial fibers that make possible the fabrication of hundreds of kilometers of optical micro-cables and producing fibers at volumes commensurate with the needs of the textile and apparel industry. Although a multiplicity of fabrication schemes exists, I have investigated thermal drawing and melt-extrusion for thermo-forming of multimaterial fibers. Such fibers can be readily integrated with a broad range of downstream processes and techniques, such as textile weaving, precision-winding of fiber micro-cables, and inline functional coating. Specifically, I have developed a hybrid fabrication approach to produce robust optical fibers for single-mode and multi-mode mid-infrared transmission with the added possibility of high-power-handling capability. Second, I describe an optoelectronic fiber in which an electrically conductive composite glass is thermally co-drawn in a transparent glass matrix with a crystalline semiconductor and metallic conductors, which is the first fully integrated thermally drawn optoelectronic fiber making use of a traditional semiconductor. Third, I appropriate the industry-proven system of multicomponent melt-extrusion traditionally utilized for the scalable production of textile yarns and non-woven fabrics to produce our multimaterial fiber structures previously fabricated via thermal drawing. This has enabled melt-spinning of user-controlled color-changing fibers that are subsequently woven into active color-changing fabrics. I additionally report the design and prototyping of structured capacitive fibers for potential integration into advanced functional e-textiles. Finally, I have produced a new class of optical scattering materials based on designer composite microspheres by exploiting a recently discovered capillary instability in multimaterial fibers produced by thermal drawing, multifilament yarn spinning, and melt-extruded non-woven fabrics