Interface-engineered reduced graphene oxide assembly on nanofiber surface for high performance strain and temperature sensing.

Conductive polymer nanofiber composites (CPNCs) based wearable sensing electronics have aroused great attention of scientists in recent years. However, it is still difficult to obtain CPNCs with good water proof, excellent durability, and multiple sensing performance. Herein, we develop a multifunctional CPNC with a wrinkled reduced graphene oxide (RGO) shell and polymer nanofiber core, which is prepared by ultrasonication induced decoration of RGO onto the pre-stretched polyurethane (PU) nanofibers, followed by the release of the strain. The RGO assembly with a wrinkled structure not only greatly increases the surface roughness and thus the hydrophobicity but also enhances the strain sensing sensitivity (with a gauge factor of 154.8 in the strain range of 85%-100%) of the nanofibrous membrane. The obtained CPNC strain sensor also shows excellent sensing durability (over 1000 cycles) and can be used for body motion monitoring. The CPNC shows a negative temperature coefficient effect, which holds promising applications in high performance temperature sensors.