Research On Wearable Flexible Sensor Based On MXene/SWNT Composite Film

In recent years,flexible sensors have gradually attracted widespread attention,and they have broad application prospects in the fields of electronic skin,implantable medical devices,human health monitoring,and human motion detection.Traditional electronic sensors are generally based on materials such as metals or semiconductors,which are limited in flexibility and stretchability.Flexible sensors benefit from the flexibility,stretchability,and stability of sensitive and substrate materials,overcoming the shortcomings of traditional electronic sensors that are not easily bent.In general,the performance of flexible wearable sensors mainly depends on the sensitive material properties and device structure design.Metal carbon nitride(MXene)is a two-dimensional material like graphene,which has been widely used in photothermal conversion,catalysts,field-effect transistors and other fields due to its large specific surface area,good hydrophilicity,metallic conductivity and other unique physicochemical properties.However,there are few reports on the related research on MXene in the field of flexible sensors.In this thesis,MXene based flexible pressure and stretchable sensors are fabricated respectively,and the effects of materials and structures on sensor performance are tested in detail,and their practical applications in real-time human motion monitoring and pressure detection are explored.The main research work of the paper is as follows.1.Single-walled carbon nanotubes(SWNT)can be used to prevent the buildup of MXene lamellae and improve the electrical conductivity,therefore,MXene/SWNT composite films were prepared by adding SWNT to MXene.The films were characterized by SEM,XRD,and Raman tests to improve the sensitivity by forming a wrinkled structure through the "extraction + heat shrinkage" technique.2.we fabricated a flexible pressure sensor based on MXene/SWNT film,printed forked finger electrodes on polyimide substrate by inkjet direct writing technique,and encapsulated the sensor using a "sandwich" structure;and conducted performance and human testing on the sensor,which showed that the sensor can be used for real-time monitoring of human physiological signals The sensor was tested with human subjects,which showed that the sensor could be used for real-time monitoring of human physiological signals,such as finger movements,sound recognition and pulse wave detection.In addition,the 4×4 sensor array was successfully applied to pressure distribution maps of different objects,which showed that the pressure sensor can be applied to electronic skin,medical devices and other wearable devices.3.a flexible stretchable sensor based on MXene/SWNT film was fabricated,and the sensitivity of the sensor was improved by stretching and recombining.The tests found that the sensor can be used to detect small and large deformations with up to 600% stretchability,high sensitivity(strain coefficient up to 917),excellent reliability and stability(> 5000cycles),and in addition the stretch sensor can be used to monitor human physiological signals.