TaS₂ nanosheet-based ultrafast response and flexible humidity sensor for multifunctional applications

TaS₂ has great potential in humidity sensing applications due to it having much diverse morphology among the transition metal dichalcogenides (TMDs). However, there are few reports on the application of TaS₂ in humidity sensitive applications. Herein, TaS₂ nanosheets are employed to fabricate a humidity sensor based on various flexible substrates. The humidity sensor shows great humidity sensing performance with a wide relative humidity detection range, ultrafast response/recovery time, high sensitivity, high precision, and great reversibility and stability. Two completely different strategies have been adopted to enhance the humidity sensitivity of the TaS₂ nanomaterials purposefully. The great humidity sensing performance is considered to benefit from a high surface/volume ratio and large exposed specific surface area. Meanwhile, the ultrafast response/recovery time is due to the hydrophobicity and hydrophilicity of the substrate and TaS₂ sensing film, respectively. The flexible humidity sensors we manufactured also show outstanding performance in various applications such as noncontact sensation, real-time monitoring of the moisture levels in human skin, and the monitoring of respiration. Our research might provide a very promising candidate material for humidity sensing and the flexible humidity sensors we manufactured could be great potential candidates for the efficient detection of humidity levels.