Observing Proton–Electron Mixed Conductivity in Graphdiyne

Mixed conducting materials with both ionic and electronic conductivities have gained prominence in emerging applications. However, exploring material with on-demand ionic and electronic conductivities remains challenging, primarily due to the lack of correlating macroscopic conductivity with atom-scale structure. Here, the correlation of proton–electron conductivity and atom-scale structure in graphdiyne is explored. Precisely adjusting the conjugated diynes and oxygenic functional groups in graphdiyne yields a tunable proton–electron conductivity on the order of 10³. In addition, a wet-chemistry lithography technique for uniform preparation of graphdiyne on flexible substrates is provided. Utilizing the proton–electron conductivity and mechanical tolerance of graphdiyne, bimodal flexible devices serving as capacitive switches and resistive sensors are created. As a proof-of-concept, a breath–machine interface for sentence-based communication and self-nursing tasks with an accuracy of 98% is designed. This work represents an important step toward understanding the atom-scale structure–conductivity relationship and extending the applications of mixed conducting materials to assistive technology.