Copper nanowires (CuNWs) are extremely prone to oxidation, which greatly limits their practical applications, even though they are inexpensive, abundant and have high electrical conductivity. Herein, a facile and novel method is developed to alleviate the oxidation of CuNWs by embedding CuNWs into water-dispersible modified graphene (WGP) sheets to form a uniform hybrid conductive film using a simple vacuum filtration process. The CuNWs and WGP films possess electrical conductivity of 3.19 × 103 S m−1 and 5.6 × 103 S m−1, respectively. With the addition of WGP to form a CuNWs–WGP hybrid film, the electrical conductivity of the CuNWs is further improved to 3.02 × 104 S m−1 due to the synergistic effects of the CuNWs and WGP. The CuNWs–WGP hybrid films show excellent antioxidative stability even after exposure in air for 8 weeks without any obvious oxidation. Then, using this conductive hybrid film, a sandwich structured PDMS/CuNWs–WGP/PDMS flexible strain sensor was fabricated. The strain sensor exhibits good flexibility and stretchability with only less than 15% loss of electrical conductivity over 450 times mechanical bending, and was successfully used to monitor human motion, such as finger bending, swallowing and voice recognition.
