A sensitive and flexible sensor enhanced by constructing graphene-based polyaniline conductive networks

• Published in: Sensors and actuators. A. Physical. 2021-10, Vol.330, p.112862, Article 112862
• Main Authors: Shen, Xinyan, Zhao, Shuqiang, Wan, Ailan
• Format: Article
• Language: English
• Subjects: Conductive network; Conductivity; Flexible components; Flexible sensor; Graphene; Human motion; Hydrochloric acid; Hydrogen chloride; Morphology; Motion perception; Nanocomposites; Nanorods; Nanowires; Networks; Polyaniline; Polyanilines; Reduced graphene oxide; Self-assembly; Sensors; Sodium dodecylbenzenesulfonate; Studies; Warp; Wearable technology
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2021.112862

[Display omitted] •Improving the performance of strain sensor is mainly through the construction of effective conductive network and the selection of elastic substrates.•Knitting fabrics can be used as elastic substrates due to their comfort, stretchability and porosity.•Graphene-based polyaniline conductive materials, with synergistic effect, can construct effective conductive network.•Doping with acid gives polyaniline different microstructures, which affects the properties of conductive composites. A sensitive and flexible sensor with dissimilar 3D conductive networks was fabricated by coating reduced graphene oxide (RGO) and polyaniline (PANI) on warp-knitted polyester-spandex fabric. In this study, the average length of 40∼80um 1D PANI rods or 2∼10um 1D PANI nanowires combined with 2D RGO sheet, forming 3D conductive networks. First the graphene oxide (GO) sheets was coated on the surface of fabric, then the GO was reduced to RGO, and the PANI array with ordered shapes was prepared on the surface of RGO fabric by self-assembled method and using sodium dodecyl benzene sulfonate (SDBS)/hydrochloric acid (HCl) or HCl as dopants. It could be found that the obtained 3D conductive network mainly presents two morphologies, one is nanorods-sheet shape (1:90 SDBS/HCl concentration ratio), and the other is nanowires-sheet shape (HCl 1 mol/L). The results show that the fabric with 3D nanorods-sheet conductive network exhibits outstanding conductivity (resistance = 0.228 KΩ/sq), strain sensitivity, wide strain sensing range (tolerable strain up to 100 %), and repeatability (withstand 500 stretching-releasing tests), precisely detecting human motion in flexible wearable devices.