Maxwell displacement current induced wireless self-powered gas sensor array

Maxwell displacement current induced by triboelectric nanogenerators (TENGs) endows an efficient route in wireless power transmission and self-powered sensing technique. Herein, we invented a Maxwell displacement current motivated wireless self-powered gas sensor array (WSA) for wireless and passive respiratory analysis and exhaust emission monitoring. The as-prepared WSA exhibited a maximum response value of 147% toward 100 ppm NH3 and 87% toward 0.5 ppm NO2, respectively. By combining experimental characterization and finite element analysis, the influence of induction distance and electrode arrangement on the transducing and sensing properties of WSA was systematically investigated. Meanwhile, the prepared WSA possessed good repeatability, selectivity, and long-term stability towards NH3 and NO2. Finally, triggered by the mechanical energy from human respiration and object rotation, the as-received WSA is capable of actively distinguishing trace-level ammonia and nitrogen dioxide, illustrating the feasibility in respiratory analysis and air quality monitoring. This work opens up a new paradigm for self-powered wireless gas detection with attribute of cost effectiveness, multivariable, easy fabrication, and environment friendliness.