Temperature-independent relative humidity sensing properties of polymer micro-bottle resonators coated with graphene oxide

A polymer-based micro-bottle resonator coated with graphene oxide (GO) film is presented to improve the relative humidity (RH) sensing performance. Polymeric material Loctite 3525 was coated onto a quartz fiber and cured by using UV light irradiation and thermal reflow technology. A layer of GO film was prepared on the micro-bottle resonator by the dip impregnation method, which realized a high Q-factor (>10(4)) transmission of energy by appropriately designing a wave-guide resonator coupling. By optimizing the concentration of GO dip impregnation solution, high sensitivity and figure of merit (FoM) of 0.161 nm/%RH and 2.01/%RH were achieved in the RH range of 22-81%. In addition, after high-temperature annealing at 300.C, the temperature sensitivity decreased by an order of magnitude from 0.793 nm/degrees C to 0.068 nm/degrees C, which significantly reduces the cross-sensitivity between humidity and temperature. The proposed resonator has the advantages of being compact in size, low in cost, high sensitivity, and low in temperature crosstalk.

Automated summary

A polymer-based micro-bottle resonator coated with graphene oxide film is proposed for improving relative humidity sensing performance. The resonator achieved high sensitivity and figure of merit by optimizing the concentration of GO dip impregnation solution. The proposed resonator also showed reduced cross-sensitivity between humidity and temperature after high-temperature annealing.