A flexible and wearable NO₂ gas detection and early warning device based on a spraying process and an interdigital electrode at room temperature

Flexible sensors used to detect NO₂ gas generally have problems such as poor repeatability, high operating temperature, poor selectivity, and small detection range. This work designed and built a new spraying platform to make a sensitive film (rGO/SnO₂) for NO₂ gas sensors. The study found that a sensor with 0.25 ml of a 0.4 wt% rGO/SnO₂ mixture annealed at 250 °C exhibited the best performance, with a response value of 0.2640 at 25°C for 100 ppm NO₂. A linear relationship between response and NO₂ concentration (20–100 ppm) was observed (correlation coefficient 0.9851). A soft-monitoring node module with an overlimit warning function was integrated with the flexible sensor into woven fabric for wearable applications.

Fuzheng Zhang, Qijing Lin, Feng Han, Zuowei Wang, Bian Tian, Libo Zhao, Tao Dong, Zhuangde Jiang