Fabrication Of Flexible Humidity/Gas Sensor Based On Carbon Nanotubes

Smart wearable devices are smart products that highly integrate electronic technology and fabrics.While maintaining comfort,they can also perform their specific detection functions.Therefore,they can be widely used in medical and health,temperature and humidity testing,environmental testing and other fields.Smart wearable devices mainly include three parts:sensors,control units,and actuators.As the core component of smart wearable device detection,sensors are key components for acquiring specific information about the human body.At present,sensors can be divided into rigid substrate sensors and flexible substrate sensors according to the substrate.The improvement in the quality of life has drawn people's attention to their health.Existing gas sensors are the core components of health monitoring equipment,they have a lot of problems such as large size,high cost,and complex preparation processes,which limit its development.Therefore,it has become a research hotspot in this field to explore a method for preparing a flexible gas sensor that is small in size,low in cost,and simple in manufacturing process.According to the above,this article put forward a method for preparing a flexible gas sensor.According to the principle of carbon nanotube adsorption,a flexible gas sensor is prepared using electrospinning technology.The electrospinning process parameters,the type and content of dopants,and the preparation of the sensor are studied.In order to realize the molding and preparation of flexible gas sensors,and lay the foundation for the manufacture of flexible gas sensors in the smart wearable field.The specific research content of this thesis is as follows:(1)Introduction of flexible gas sensor preparation platform and construction of test system.The preparation platform of the flexible gas sensor can be divided into a high-voltage power supply module,a propulsion device module,a spray device module and a collection device module,etc.;the preparation of the sensor is completed through the cooperation of each module.In order to realize the performance test of the flexible gas sensor,the sensor acquisition front-end,the micro-processing module and the upper computer storage module are combined to build a flexible gas sensor test system,which can realize the collection,processing,display and storage functions of the flexible gas sensor signal.(2)A MWCNTs/PVP flexible humidity sensor was prepared.According to the principle of carbon nanotube adsorption,using electrospinning technology,a flexible humidity sensor was prepared,PVP with different qualities was studied,and use an independently designed and manufactured humidity sensor test system to evaluate the humidity sensitivity of the flexible humidity sensor.Researched.At the same time,the human respiratory frequency and skin surface humidity were tested.The results show that the response time of the sensor is 20 s,and the recovery time is 5 s.After 40 repeated measurements,it shows good repeatability.It can be used for the detection of human respiratory frequency and the detection of human surface skin humidity.(3)Prepared MWCNTs/PVP/Sn O₂ flexible gas sensor.According to the principle of gas adsorption by carbon nanotubes,combined with electrospinning technology,a flexible gas sensor was successfully prepared.Researched on carbon nanotubes doped with tin oxide,and tested flexible gas using a gas sensor test system designed and built by ourselves.The results show that the linear correlation coefficient of the sensor is 0.91,the response time is 100 s,the recovery time is 30 s,and it has good repeatability stability,which proves the feasibility of the method to prepare the sensor.