The goal of this research is to gain a fundamental understanding of the process for fabricating lightweight, conformable sensory materials that are compatible with electronic textile products including body-worn sensors. The project aims to use screen-printing to fabricate an elastic and conductive nanocomposite layer of Plastisol, plasticized poly(vinyl chloride) (PVC), and carbon nanofiber (CNF) on compatible textile fabrics to produce a piezoresistive fabric sensor composite (FSC). The project would demonstrate that lightweight sensory materials can be produced by controlling the volume fraction of CNF relative to the percolation threshold at which the insulating polymer layer transitions into a conducting medium. The project marries the demonstrated utility of Plastisol as a print medium with the unique characteristics of CNF-based polymer nanocomposites as applied to FSCs designed for use in electronic textiles. Previous studies have repeatedly identified benefits of CNFs relative to their CNT analogs, but relatively few studies have focused on conformable nanocomposites containing CNFs. The project seeks to establish a fundamental understanding of the physical factors governing CNF dispersion, percolation and subsequent mobility (upon drying) in a solvated polymer system as a necessary prerequisite to the rational development of the target FSC. Insight into the percolation behavior of CNFs embedded in Plastisol and subsequent property evolution will help elucidate and further optimize the piezoresistive behavior of the FSC. Combined electro-mechanical and 3D morphological data should permit the development of structure-property relationships to direct future experimental and theoretical studies. If successful, this research will provide the U. S. textile industry with technologies that employ advanced materials for the emerging market of smart textiles. The project will prepare students to lead new research and drive the commercial development of electronic textiles. A high school teacher, undergraduate and graduate students are involved in the research.
