A chitosan/amido-graphene oxide-based self-powered humidity sensor enabled by triboelectric effect

In this work, amido-graphene oxide (GO-NH2) loaded chitosan (CTS) composite material (CTS/GO-NH2) that acts as both the triboelectric and sensing film was prepared on rotary fan-shaped triboelectric nanogenerator for humidity detection. Compared with the pristine CTS-based triboelectric humidity sensor (CTS-THS) and GO-NH2-THS, the CTS/GO-NH2-based humidity sensor exhibited higher humidity response and better linearity in the relative humidity (RH) range of 18.7%RH-91.5%RH. The above results can be explained by the massive exposed and less concealed hydrophilic functional groups of CTS with the help of the wrinkle structure of GO-NH2. Meanwhile, the CTS/GO-NH2-THS possessed good repeatability and acceptable hysteresis (similar to 6.2%RH). Finally, a humidity sensing mechanism coupling triboelectric contact charging effect with electrons transfer principle under moisture environment was established to interpret the enhanced humidity sensing performance of the composite film-based THS. This work demonstrates that CTS/GO-NH2 composite film can be utilized to fabricate humidity sensors based on the triboelectric effect.

Automated summary

In this study, a CTS/GO-NH2 composite film was prepared for humidity sensing, demonstrating higher humidity response and better linearity, with good repeatability and acceptable hysteresis. Additionally, a humidity sensing mechanism was established to explain the enhanced performance of the composite film-based humidity sensor.