Cut-Pile Textiles as Transformative Substrates for Wearable Electronics

Clothing is ubiquitous in daily life, making textiles an ideal platform for the next generation of wearable electronics. New electronic textiles (e-textiles) will incorporate sensors to detect biometric data, light-emitting devices to display data, and integrated wiring and power sources. The fabrication of these e-textiles requires the integration of functional materials into the textile, while maintaining wearability, softness, and stretchability. Our approach has relied on solution-based electroless metallization to fabricate conductive textiles, in which aqueous plating solutions can permeate into the textile structures to deposit conformal, uniform metallic coatings on the surfaces of individual fibers that comprise the yarns, preserving the mechanical properties of the fabric.<br/>In this presentation, we focus on incorporating textile structures into the device design. In this textile-centric design paradigm, textiles play an integral role in the operation of e-textile devices rather than acting merely as passive device carriers. Specifically, we discuss the use of cut-pile fabrics in wearable pressure sensors and energy storage devices. Cut-pile fabrics consist of a knitted framework with cut yarn (piles) looped through at regular intervals. We present the use of solution-based metal deposition to selectively metallize the framework of this fabric structure to fabricate textile-based electrodes. We show the use of these electrodes in energy storage devices in which selectively coating the cut-pile fibers with electroactive materials forms the basis for an architectural engineering approach that isolates the brittle materials from strain. We furthermore demonstrate the use of uncoated cut piles as the dielectric medium for textile-based capacitive pressure sensors. The cut piles provide a structure that effectively traps air, which is integral to the sensor's functionality and performance, enhancing sensitivity, flexibility, breathability, mechanical response, and comfort.