ELECTRONID TEXTILES BY PROGRAMMABLE OVERCOAT OF FUNCTIONAL MATERIALS
Creators: name: Chang, Tae Hoo
Publisher: name: Purdue University Graduate School
Year: 2023
Subjects: Functional materials
Wearable materials
Biomedical instrumentation
Flexible manufacturing systems
Additive manufacturing

description: Textiles have gained popularity in wearable products due to their potential for wearability, comfort, flexibility, breathability, and seamless fit to the human body. The growing demand for remote telehealth monitoring has led to advancements in the field of e-textiles. Various approaches, such as dip coating, screen printing, inkjet printing, and vapor deposition, are utilized to overcoat fabrics with active nanomaterials. However, practical deployment still faces challenges due to a lack of rapid prototyping for scalable and customizable e-textiles. To meet the requirements of large-scale batch production, high-resolution electrode line width, and long-term durability, new platform technologies have been established to convert existing textiles into multifunctional e-textiles. These studies have also revealed the process-structure-property relationships of various e-textiles. Chapter I overviews the recent results and current limitations of e-textiles in wearable sensing and display. Since people stay and work in various circumstances, continuous monitoring of physical, electrophysiological signals on skin in ambulatory manners is necessary to evaluate hazardous situation or chronicle symptoms. For these reasons, fabrication of smart e-textiles is crucial. In this chapter, various conductive materials, overcoating methods, and sensor structures for physical and electrophysiological sensors are reviewed. In addition, as a useful user communication tool with different sensor system, e-textile formats of displays are developed. The comprehensive e-textile displays from DC-driven to AC-driven are presented. Chapter II introduces a dual-regime spray technique that enables the direct writing of functional nanoparticles onto commercial 4-way stretchable textiles up to a meter scale with high-resolution mask-free patterning. The resulting e-textiles maintain the intrinsic properties of the fabric and can conform to various body shapes, enabling high-fidelity recording of physiological and electrophysiological signals under ambulatory conditions. Field tests have shown the potential of these e-textiles for minimally obtrusive remote telehealth monitoring of large animals. Chapter III presents an in-situ polymerization and patterning technique that utilizes the dual-regime spray method to synthesize conductive polymers directly onto commercial stretch textiles. The resulting e-textiles are utilized for strain sensors that conform closely to the human body, providing exceptional measurement accuracy and fidelity in capturing physical signals and motion detections. Conclusion section summarizes this dissertation with pointing out important results and discussions of each study. As an innovative additive manufacturing technology, dual-regime spray system, was established and developed to open new field in manufacture of e-textile. At last of this section, the potential research opportunities and perspectives are addressed.