“…In recent years, humiditysensing materials such as nanometallic, carbon, and polymers have been used to prepare exible humidity sensors. Nanometallic materials include metal suldes and metal oxides, [10][11][12][13][14][15] and carbon materials mainly include graphene oxide (GO), reduced graphene oxide (rGO), [16][17][18][19][20][21] which have good moisturesensitive properties by virtue of their abundant hydrophilic functional groups on the surface and highly exposed surface area.…”