Foldable and Wearable Fabric Ammonia Sensor Based on a Polyaniline/Polyacrylonitrile Nanofiber for Smart Home Applications

Flexible gas sensors are gaining increasing recognition for their potential applications in the realm of electronic skin and smart textiles. However, owing to the insufficient adhesion property between the organic flexible substrate, metal electrodes, and sensing film, traditional flexible sensors often suffer from terrible durability under intense bending or folding conditions. In this study, a flexible fabric ammonia (NH₃) sensor composed of an electrospun preoxidized polyacrylonitrile (PAN) fiber-based flexible substrate and an in situ self-assembled polyaniline (PANI) sensing film/electrode was rationally designed. Owing to the favorable adhesion capability on the polymer substrate, excellent conductivity, and outstanding sensitivity to NH₃, the in situ self-assembled PANI film endowed the sensor with exceptional flexibility. Meanwhile, the low elastic modulus of the fabric sensor guarantees its comfortable wearability. Apart from the superior sensing performances toward 2-50 ppm of NH₃, the fabricated fabric sensor revealed little response fluctuation (4%) to 10 ppm of NH₃ under the bending angles from 0° to 180° and maintained negligible response changes (3.2%) under 1000 cycles of bending treatment with a bending angle of 120°. The designed fabric gas sensor is further developed into wearable devices for validating its versatility and reliability in multiscenario smart home applications. The design strategy presented here not only addresses the challenges associated with the durability of flexible sensors but also paves the way for the exploration of next-generation flexible gas sensors tailored across various wearable applications.