Nanostructured polyaniline/poly(styrene-butadiene-styrene) composite fiber for use as highly sensitive and flexible ammonia sensor

- Nanostructured PANI composite fibers are fabricated through in-situ dilute polymerization.
- Nanostructured PANI composite fiber exhibits remarkable sensitivity, fast response, good reproducibility as well as excellent mechanical reliability.
- The sensor is capable of sensing a concentration of ammonia gas as low as 0.1 ppm at room temperature.
- The practical application of the flexible fiber based ammonia sensor for flexible electronics is demonstrated.

Sensors with flexible and stretchable features are of great interest owing to their potential applications in flexible electronics. To this date, to fabricate gas sensors with both high sensitivity and flexibility is still a challenge. Herein, we have successfully coated thin film of polyaniline (PANI) onto flexible poly(styrene-butadiene-styrene) (SBS) fiber using in-situ dilute polymerization. The SBS/PANI composite fibers were evaluated as ammonia gas sensor. Morphological analysis of the nano-composite fiber revealed that the thin film consists of interconnected PANI nanofibers. Due to the high surface areas of the interconnected PANI nanofibers and the super flexibility of SBS fiber substrates, the SBS/PANI composite fiber based sensor demonstrated fascinating performance, including superior sensitivity (5.8 for 25 ppm, 16.4 for 100 ppm), fast response (≤13 s), good reproducibility as well as excellent mechanical reliability. Notably, the gas sensor is capable of sensing a concentration of ammonia gas as low as 0.1 ppm at room temperature. Based on its superior performance, its application in detecting ammonia gas leak is demonstrated, signifying its tremendous potential for applications in flexible electronics.

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