Functionalization of polypropylene nonwoven fabrics using cold plasma (O2) for developing graphene-based wearable sensors

Melt blown-Nonwoven Polypropylene based materials have numerous applications, such as nonwoven fabrics, filtration membranes used in clothing and potential industrial use due to its higher breathability, durability, absorbency, and filtration properties. Nonwoven PP-fabrics are very often used to develop wearable articles such as garments. In this research melt blown-nonwoven polypropylene (NW-PP) membranes were functionalized using (O 2 ) cold plasma for the conversion of highly hydrophobic into hydrophilic nature to enhance the absorption and adhesion of graphene films on the fiber surface. The graphene oxide (GO) and NW membrane was successfully introduced on the fibrous mat and reduced into reduced Graphene oxide (rGO) with green chemical and thermal reduction. L-Ascorbic Acid was used as a reducing agent at a low-temperature microwave-assisted reduction at 90 °C. The as developed NW membrane was connected two copper electrodes and used as wearable pressure (WP) sensors. The physical sensor responds with different stretching and bending cycles under dynamic pressure of loading and unloading. The sensitivity of the developed pressure sensor was 0.050 kPa −1 in a wide pressure range (0–60 kPa). The resultant rGO coated NW-PP wearable pressure sensor (RNPWP) is capable of responding to human body movement and motion. The study demonstrates that mass production on an industrial scale graphene-based conductive nonwoven PP fabric potentially replaces the metal-based conductive wearable textiles for physical sensors.