Research On Microfiber Humidity Sensor Sensitized Based On Three-Dimensional Network Molybdenum Disulfide

With the rapid development of science and technology and the rapid improvement of people’s living standards,humidity control,sensing and detection play an important role in agriculture,food industry,electronics industry,health and medical care.A humidity sensor that responds to recovery is extremely necessary.Due to its simple structure,small size,high sensitivity and surface evanescent field strength,microfiber have broad application prospects in the field of optical fiber sensing.In this paper,combined with the advantages of microfiber,three-dimensional network molybdenum disulfide is used as the sensitizing material to prepare and study an ultrafast microfiber humidity sensor based on three-dimensional network molybdenum disulfide microstructure cladding.The research contents of this paper mainly include:1.Molybdenum disulfide/polystyrene（Mo S₂/PS）composite microspheres were prepared by electrostatic self-assembly method,and the surface morphology of Mo S₂/PS composite microspheres was analyzed by scanning electron microscopy（SEM）and transmission electron microscopy（TEM）,and Raman spectrμm was used to characterize the quality of molybdenum disulfide two-dimensional material itself and its coating quality on polystyrene microspheres.2.A three-dimensional network molybdenum disulfide microstructure cladding was prepared on the side surface of the microfiber and applied in the field of humidity sensing.The three-dimensional network molybdenum disulfide microstructure cladding is made by depositing molybdenum disulfide/polystyrene（Mo S₂/PS）composite microspheres on the side surface of the microfiber by self-assembly method to support the microstructure of molybdenum disulfide,and the molybdenum disulfide material acts as a moisture-sensitive material.Compared with the monolayer or few-layer molybdenum disulfide cladding,the three-dimensional network molybdenum disulfide microstructure cladding has a larger specific surface area and porous structure,which is conducive to strengthening the interaction between molybdenum disulfide and water molecules,greatly The sensitivity of this type of fiber optic humidity sensor is improved,and the ultra-fast response speed is realized.3.The humidity response characteristics of the microfiber humidity sensor covered with three-dimensional network molybdenum disulfide microstructure cladding were tested experimentally.The experimental results show that in the humidity range of 10%RH～60.8%RH,the sensitivity of the sensor is-0.139d B/%RH,and the linear correlation coefficient is 91.5%;in the humidity range of77%RH～90%RH,the sensitivity of the sensor can reach-1.501d B/%RH,and the linear correlation coefficient is 92.0%,which is twice the sensitivity of the reported fiber-optic humidity sensor based on few-layer molybdenum disulfide sensitization.The experimental results show that when the relative humidity is switched between10%RH and 90%RH,the response time and recovery time of the sensor can reach 90ms and 130 ms respectively,which is an order of magnitude higher than the existing fiber-optic humidity sensor based on few-layer molybdenum disulfide sensitization.It is the fastest responsive and recovery humidity sensor based on molybdenum disulfide material（including electrochemical humidity sensor）.