Versatile graphene/polyelectrolyte aqueous dispersion for fiber-based wearable sensors and electroluminescent devices

Conductive dispersion is a crucial building block for obtaining conductive fibers/textiles used in wearable sensing, energy supply, and flexible display devices. However, despite the graphene’s stable chemical properties and high electrical conductivity, fabricating graphene dispersions compatible with fiber/textile materials remains challenging. Here, an eco-friendly and stable graphene aqueous dispersion was fabricated by introducing poly(sodium-p-styrenesulfonate) (PSS) dispersant based on non-covalent interactions. Due to the modification of PSS, graphene carries negative charges, and the resulting electrostatic repulsion promotes the stable dispersion of graphene. Moreover, PSS assists graphene in forming a robust adhesion to substrates. Flexible mechanical sensors using graphene-modified fibers and fibrous membranes, including stretchable strain sensors and pressure sensors, were developed, showing high stretchability of up to 100% with a sensitivity of 144.6, capable of a sensing strain as small as 0.1%. Flexible electrophysiological electrodes were also fabricated to record electromyography and electrocardiograph signals for a long time. As a proof of concept, a coaxial electroluminescent fiber was demonstrated to provide illumination for a submarine model to complete complex tasks. This advancement will further propel the advanced nanomaterials into wearable fields.