▎ 摘　　要

NOVELTY - Humidity sensor based on reduced graphene oxide moisture sensitive film comprises a light cover, a silicon dioxide substrate, a humidity sensing element, a humidity sensitive thin film resistance detecting device, circuit signal wire and a base.The upper surface of a light cover is provided with a hollow vent hole. The lower surface is provided with threading hole. The humidity sensitive element comprises a reduced graphene oxide based moisture sensitive film and an interdigitated gold electrode. The reduced graphene oxide based moisture sensitive film is placed on the upper surface of the interdigitated gold electrode. The humidity sensitive thin film resistance detecting device is respectively connected to two pins of the interdigitated gold electrode through a wire. The one end of the circuit signal wire is connected to the humidity sensitive film resistance detecting device and the other end is taken out from the threading hole and connected to the computer or the microprocessor. USE - The humidity sensor is useful for detecting and assessingthe water molecules released by transpiration of plants. DETAILED DESCRIPTION - Humidity sensor based on reduced graphene oxide moisture sensitive film comprises a light cover, a silicon dioxide substrate, a humidity sensing element, a humidity sensitive thin film resistance detecting device, circuit signal wire and a base. The upper surface of the light cover is provided with a hollow vent hole. The lower surface is provided with a threading hole. The humidity sensitive element comprises a reduced graphene oxide based moisture sensitive film and an interdigitated gold electrode. The reduced graphene oxide based moisture sensitive film is placed on the upper surface of the interdigitated gold electrode. The interdigitated gold electrode is placed on an upper surface of the silicon dioxide substrate. The silicon dioxide substrate is placed on an upper surface of the humidity sensitive thin film resistance detecting device. The humidity sensitive film resistance detecting device is placed on the base. The humidity sensitive thin film resistance detecting device is respectively connected to two pins of the interdigitated gold electrode through a wire. The one end of the circuit signal wire is connected to the humidity sensitive film resistance detecting device and the other end is taken out from the threading hole and connected to the computer or the microprocessor. INDEPENDENT CLAIMS are also included for (1) use method of humidity sensor based on a reduced graphene oxide moisture sensitive film comprising (a) preparing a reduced graphene oxide moisture sensitive film, (b) completing the step (a), monitoring the resistance of the humidity sensitive element with a humidity sensitive thin film resistance detecting device, transmitting the data through the circuit signal line and (c) detecting the change in relative humidity by detecting a change in the resistance value of the humidity sensitive element transmitted in the step (b); and (2) preparing reduced graphene oxide moisture sensitive film based on humidity sensor comprising (a1) weighing reduced graphene oxide powder, measuring deionized water to prepare a reduced graphene oxide dispersion having a concentration of 20 mg/ml, (b1) mixing polydimethylsiloxane (PDMS) base solution and curing agent at 10:1, degassing in a vacuum dryer for 20 minutes, preparing a polydimethylsiloxane base solution, introducing into a square ring mold, placing in a dry box for 3 hours, drying at 80 degrees C, and taking out to obtain a 3 mm high polydimethylsiloxane square ring, (c1) covering the polydimethylsiloxane square ring in the step (b1) on the silicon dioxide substrate with the interdigitated gold electrode for limiting the reduced graphene oxide dispersion to the surface of the silicon dioxide substrate, (d1) adding the reduced graphene oxide dispersion in the step (a1)to the polydimethylsiloxane square ring in the step (c1), where the volume of the reduced graphene oxide dispersion per unit surface area is 100 mu l/cm2, drying the humidity sensitive element at 90 degrees C for two hours to obtain a reduced graphene oxide film having a thickness of 1.45 mu m, and (e1) repeating the step (d1)five times, to obtain a reduced graphene oxide moisture sensitive film having a thickness of 7 mu m and then removing the polydimethylsiloxane square ring