Enhancing the Flexibility of Carbon-Based Composite Electrode via an N-Type Conducting Polymer PBFDO

Highly flexible carbon-based electrochemical sensing electrodes remain a challenge. Introducing conducting polymers into carbon-based materials is an effective strategy to enhance mechanical flexibility. In this work, an n-type conducting polymer, poly(benzodifurandione) (PBFDO), with intrinsic flexibility and ultrahigh conductivity (2000 S cm –1 ) was introduced into carbon-based ink (named C:PBFDO ink). PBFDO covers the cracks in a carbon-based film, enabling a uniform surface to dissipate stress. The electrical conductivity of the C:PBFDO composite film (6.0 ± 0.5 S cm –1 ) was twice that of the carbon-based film, supporting a half-thickness electrochemical sensing electrode design and further improving the mechanical flexibility. After 10,000 bending cycles (a bending radius of 1 mm), the sheet resistance of the C:PBFDO electrode increased by less than 15%, and the electrochemical performance did not decline significantly compared with that of the severely attenuated carbon-based electrodes (CEs). The C:PBFDO composite electrode demonstrates excellent mechanical flexibility, electrochemical performance, and storage stability, making it a promising candidate for applications in flexible wearable electronics.