Preparation Of Ionogel Composite Fibers Flexible Sensor And Its Application Research

As intelligent electronic devices become more popular,higher demands are being placed on their functionality and practicality,and flexible stress/strain sensors are becoming a hot topic of research as key components.The ability of flexible sensors to sensitively detect and recognise different stimulus perceptions is a prerequisite for them to meet the challenges in many applications.Ionic gel materials have received great attention in recent years as new sensing materials with many unique properties that offer great advantages in flexible sensing,but little has been reported on flexible stress/strain sensors in ionic gels,especially for tangential force sensing.In this thesis,two types of flexible stress and strain sensors were prepared,and their sensing performance was investigated and their feasibility as sensors for application was explored.The main studies are as follows:1.This work demonstrates a high-performance flexible stress sensor that combines pyramidal micropatterns and ionogel nanofibers and is capable of detecting both normal and tangential forces.The microscopic morphology and structure of the components as well as the crystalline state and elemental distribution of the sensing materials were investigated.Combinations of pyramidal structures with different sizes and ionogel fibers of different ionic liquid ratios were used to investigate the sensing performance and to analysis the sensing principle and the influencing factors of the sensors to finally select the best device.The best device was subsequently characterised for sensing performance,with a measured sensitivity of 1.145 kPa^-1for normal force,a response time of less than 30ms and a hysteresis of 3.8%.More importantly,the sensor is sensitive to identifying sliding speeds,normal force loads,tangential forces and oil lubrication environments with varying viscosities under reciprocating friction conditions.It can also sensitively identify the entire relative sliding process from zero sliding to stick-slip.The ionogel nanofiber flexible sensor has great potential for friction sensing applications due to its good friction force and friction state recognition under high frequency reciprocating friction as well as its durability over 600 cycles.2.In order to improve the mechanical strength of ionogel nanofibers,we prepared ionogel nanofibers from poly（vinylidene fluoride-co-hexafluoropropylene）（P（VDF-HFP））and ionic liquid[EMIM]TFSI and designed nuclear-sheath structure fibers to compare their tensile properties.P（VDF-HFP）ionogel nanofibers have excellent tensile properties（>200%）with The sensor has a wide tensile strain range（Lower detection limit down to 0.1%）,fast response time and good stability.The sensor also has excellent temperature sensing capability with good linearity,high accuracy and fast response times（<20s）.Through demonstration experiments,the sensor can monitor different frequencies of breathing and different degrees of flexion of the finger joints,which demonstrates the potential of the sensor for human movement and health monitoring.