Design And Performance Of Graphene/Polypyrrole Foam-Based Pressure Sensor

With the rapid development of electronic information equipment,various portable intelligent devices have been widely used.Pressure sensor technology,as one of the key sensing components,greatly promotes the development of touch sensitive electronic devices.At the same time,it has shown good application potential in the fields of health monitoring,wearable devices,human-computer interaction,and artificial intelligence.Pressure sensors convert external stimuli into recognisab le electrical signals.The evaluation indexes of sensors mainly include sensitivity,stabilit y,recovery ability and response time.Ultrahigh sensitivity has been one of the most important parameters widely pursued.At present,high performance pressure sensors are mainly sought through sensing mechanism,sensing materials and structural design.Among the various materials,graphene is widely used due to its excel ent electrica l conductivity and mechanical performance.In this paper,three kinds of piezoresist i ve pressure sensors are designed based on the preparation of sensing materials and the design of sensor structure.They achieve excel ent sensing performance with ultrahigh sensitivity in small pressure range and large pressure range.The research content of this paper mainly includes the following parts:(1)Ultrahigh sensitive pressure sensor based on graphene/polypyrroleFirstly,the reduced graphene/polypyrrole foam(r GO/PPy F)was successfully prepared by freeze drying and in-situ solventless polymerization.The pressure sensor based on this foam has high sensitivity(32.32 KPa^-1)in the pressure range of 0-21 Pa,good cycling stability and high resolution(0.1 Pa).The excel ent sensing performance of the pressure sensor is mainly attributed to the introductio n of semi-rigid PPy,the elasticity of r GO/PPy F and the synergistic effect of PPy and r GO.Finally,the pressure sensor also shows excel ent recognition ability in sign language translation system,which indicates that it has broad application prospect in speech conversion system and artificial intelligence field.(2)Adjustable pressure sensor based on graphene/polypyrroleThe adjustable pressure sensor with special structure was constructed by adding gaskets between two layers of r GO/PPy F.The sensor shows high sensitivity(14.20,15.89,17.95 and 34.13 KPa^-1)in pressure range of 66-118,130-169,197-221 and 260-280 Pa,and present good cycling stability in different pressure range.The differe nt pressure ranges can be adjusted by the thickness of the gaskets,which opens up the idea of the application in the high pressure range.(3)Microdistance sensor based on hollow graphene/polypyrrole microfoamThe hollow r GO/PPy F microfoam were prepared by freeze-direct writing technology combined with in-situ polymerization.The preparation method is simple,and the samples can be produced in large quantities.The assembled hollow r GO/PPy microfoam-based sensor delivers an ultrahigh sensitivity(587 m^-1)in the distance range of 0-90?m,fast response time and ultralow detection limit.Furthermore,the 3×2microfiber sensor arrays can distinguish the visual distribution of pressure,demonstrating its application potential in wearable devices and electronic skin.