Engineering Biomedical and Bioinspired Fiber Devices via Thermal Drawing

Abstract

Fibers are ubiquitous as elements in broad fields from conventional textiles and optics to smart textiles and electronics. One of the fiber fabrication methods, thermal drawing process, has a unique strength on a scalable production of multimaterial fibers. Based on various properties of multiple materials in a single fiber, multifunctional fibers have been studied for diverse applications such as sensing, battery, computing, and biomedical devices. In this thesis, I develop approaches to expand use of thermally drawn fibers in biomedical fields by overcoming a limitation of thermal drawing technique or integrating functional components into thermally drawn fibers. First, via development of thermally drawable photoresist, I combine thermal drawing and photolithography to produce scalable multimaterial fibers which have breaking axial symmetry within them. Microscale patterns along the shaft enable the functional point for biomedical devices to be extended from the tip to all surfaces by customizably exposing internal functionalities of multifunctional fibers. Second, biocompatible magnetic soft robots are designed using thermally drawn exoskeleton fibers. By integrating a specially formulated magnetic composite into thermally drawn fibers and applying strain treatment, the soft robots can show bioinspired locomotion for biomedical applications under simplified magnetic fields. Lastly, artificial muscle fibers advance in selectively controllable form with rapid response. Liquid metal integrated into thermally drawn bimorph fibers serves as an internal heat source which allows for selective actuation of muscle fibers close together with rapid responsive speed. This thesis can be a foundation to expand fiber-based applications using thermal drawing in biomedical fields.