Research On Humidity Sensor Based On Carbon Nanocomposite

With the rise of a variety of wearable devices such as electronic skins,people's needs for sensor devices have also become more precise,and research linked to sensor has gradually increased.Conventional rigid sensitive materials have long been far from meeting the current market demand.As one of the common sensors in daily life,humidity sensors are widely used in meteorological monitoring,biomedicine,agriculture and forestry planting,and energy storage.In recent years,with the increasing application of the Internet of Things,the application field of the evoloing humidity sensor has been enhanced to the daily range of smart homes and human health monitoring.Therefore,people have not only increased the humidity sensitivity of the humidity sensor,antiinterference The requirements for performance and accuracy,and the integration,miniaturization,systemization and low-cost mass production of the device of the humidity sensor itself are put forward in many aspects.Carbon nanomaterials have made many achievements in electrochemical and biosensors due to their large specific surface area,excellent electrical conductivity,and large elastic modulus.In this paper,hydrophilic graphene oxide and hydrophobic carbon nanotubes are selected to build a flexible surface with hydrophilic-hydrophobic bidirectional characteristics through surface treatment and self-assembly impregnation process to develop a flexible humidity sensor.First,the surface adsorption dip coating method is used to uniformly stick the graphene oxide to the surface of the nonwoven fabric to form a hydrophilic layer,and then a layer of carbon nanotubes is deposited on the surface of the graphene oxide by adsorption self-assembly to form a hydrophobic layer,thereby constructing a Hydrophilic-hydrophobic bidirectional surface moisture-sensitive structure and moisture-sensitive sensor.On this basis,through those two experimental corrections to adjust the hydrophilic-hydrophobic ratio,thereby controlling the adsorption and desorption of water molecules on the surface speed and balance,improve response speed and reduce recovery time.Finally,a flexible humidity sensor with fast response and fast recovery characteristics is realized.The two options are:1.Change the compound ratio of GO/r GO and adjust the compound ratio of the two by controlling the reduction time of GO in the ascorbic acid solution.The best performance parameters of the prepared humidity sensor are dynamic response time of 2 seconds and recovery time of 24 seconds.Compared with other materials,such as VS2,WS2,and Sn S2,the performance of our humidity sensitive materials is better.At the same time,the sensitivity of the sensor is 12.8% and the humidity detection range is 10%RH to 98%RH by using a saturated salt solution to control humidity.2.Changing the composite ratio of graphene/CNTs,the best performance parameters of the prepared humidity sensor are: response time 1.6s,recovery time 13 s,humidity detection range from 10%RH to 98%RH,which is higher than the previous GO/r GO composite material The sensitivity is higher(34.2%).Therefore,the effect of compounding with carbon nanotubes has a better effect on improving the performance of the humidity sensor.The sensor has potential applications in the field of flexible wearables.The flexible sensor is attached to the mask fabric to realize an electronic mask with a humidity sensing function,which can measure the breathing frequency of the wearer in real time,and qualitatively reflect the humidity content in the body through the humidity of the breathing gas,and then determine whether the person under test is in Water deficit.Another application is to respond quickly when a surface with a certain humidity is close.It can be used for the intelligent perception of the humidity environment and humidity objects by the bionic robot.