(Invited) Garment Integrated Sensors Created Using Reactive Vapor Deposition

Abstract

Wearable sensors are uniquely suited for personalized health monitoring and activity tracking. In particular, fiber- and fabric-based sensors that can be seamlessly integrated into everyday clothing have the power to create smart garments that can monitor health statistics and alert a wearer to impending medical problems or chemical/biological threats. However, natural fibers and fabrics--which would be the preferred platform for such garment-integrated sensors--are demanding substrates, and printing electronic materials and electrochemically-active sensors onto natural fibers and fabrics is nontrivial. Solution-processed active materials either soak into natural fibers or nonhomogeneously wet their surfaces, thus creating buried/inaccessible active sites or broken conduction pathways, respectively, that prevent isolation of functioning sensors. Further, the rough and disordered structures of fibers and fabrics also attenuate the baseline bulk conductivities of any electronic material, creating troublesome series resistances that are otherwise absent in conventional, glass- or plastic-backed devices. Our lab uses reactive vapor coating to form conjugated polymer films directly on the surface of any premade garment, prewoven fabric or fiber/yarn, without the need for specialized processing conditions, surface pretreatments, detergents or fixing agents. This feature allows for electronic coatings to be applied at the end of existing, high-throughput textile and garment manufacturing routines, irrespective of dye content or surface finish of the final textile. Further, reactive vapor coating produces conductive materials without any insulating moieties and yields uniform and conformal films on fiber/fabric surfaces that are notably wash- and wear-stable and withstand mechanically-demanding textile manufacturing routines. These unique features mean that rugged and practical textile electronic devices can be created using sewing, weaving or knitting procedures without compromising or otherwise affecting the surface electronic coating. In this talk, we will highlight selected electronic garments and garment-integrated sensors created by melding reactive vapor deposition with traditional textile manipulation processes, including: (1) smart joint braces for movement/activity sensing; (2) fabric electrodes for bioimpedance spectroscopy; (3) fiber-based radiation monitors; and (4) garment-integrated chemiresistive sensors for detecting selected biomarkers in sweat.