Cotton Fabrics Decorated with Conductive Graphene Nanosheet Inks for Flexible Wearable Heaters and Strain Sensors

Wearable conductive fabrics are an essential part of flexible electronics, which can be used as portable devices for human thermal management, healthcare, and motion detection. However, obtaining low-cost and scalable production of these types of conductive fabrics with high conductivity, low-voltage-activating electrothermal response, and satisfactory washability still has critical challenges. Herein, high-conductive graphene ink-decorated cotton fabrics (CFs) are fabricated via a facial double-side screen-printing technique for flexible wearable heaters and strain sensors. The porous and rough CFs with spatially distributed graphene inks create efficient pathways for electron movement, and the outmost water-soluble polyurethane could dramatically promote the washability, cycling stability, and environmental resistance properties of conductive fabrics. Interestingly, the as-obtained graphene conductive textiles demonstrate high conductivity (1.18 × 104 S/m), which are applied to flexible wearable heaters, showcasing a high steady-state temperature (52.6 °C) at a low voltage of 3 V, excellent washability, cycling stability, and environmental resistance properties. Additionally, the fabricated conductive fabrics can also be applied to wearable strain sensors, which exhibit high sensitivity, excellent recovery, and stability in a refined strain range for responding to human motions. Consequently, the designed graphene conductive fabrics provide a promising strategy to realize low-cost and scalable next-generation wearable electronic textiles.