Material design and application progress of flexible chemiresistive gas sensors.

With the development of urban industry and technology, environmental issues have raised increasing concerns toward gas monitoring. Flexible, portable, and low-cost sensors for detecting gas analytes in real-time have emerged as next-generation gas analytical devices. Among them, flexible chemiresistive gas sensors stand out due to their high operability, intuitive response signal and because the conditions required are not harsh. As a result, flexible chemiresistive gas sensors are endowed with huge potential toward a wide range of applications and should be paid more attention. This review mainly covers four types of flexible chemiresistive gas sensors based on different sensing materials, including metal oxide semiconductor (MOX)-based, graphene-based, MXene-based, and polymer-based gas sensors. The definition and sensing mechanisms of gas sensing materials are first combed. Recent advances of flexible chemiresistive gas sensors are summarized to afford design strategies toward different sensing materials, and the current applications are also introduced. Finally, challenges and prospects for flexible chemiresistive gas sensors are further discussed. [ABSTRACT FROM AUTHOR]