Research And Application Of High-performance Flexible Pressure Sensor Based On Structural Desig

With the rapid development of economy and the popularity of intelligent terminals,intelligent wearable textiles show great application prospects.In particular,high-sensitivity pressure sensors that can monitor tiny stimuli and pressure sensors with a wide detection range are key components in the fields of human-computer interaction,intelligent wearable devices,electronic skin and soft robots in the future.In recent years,researchers have improved the performance of sensors through the design of surface microstructure or internal porous structure.However,the current structural improvement does not solve the contradiction between high sensitivity and wide detection range.Based on this research background,from the aspect of structural design,different kinds of flexible pressure sensors are prepared through the surface microstructure,internal porous structure and the synergistic effect of different structures.On the basis of maintaining high sensitivity,the detection range is expanded,and the influence of structural design on the performance of the sensor was explored.Firstly,in order to improve the performance of the sensor,a flexible capacitive sensor was assembled by using polypyrrole（PPy）/filter paper with rough surface structure as electrode material and flexible Polydimethylsiloxane（PDMS）with internal porous structure and through-hole structure as dielectric layer.Thanks to the design of different pore structures,the sensitivity of the sensor reaches 1.15 k Pa^-1 in the pressure range of 0-1 k Pa.Under the pressure of 400-1000 k Pa,the sensitivity response of 0.004k Pa^-1 is still maintained.Secondly,taking multi-walled carbon nanotubes（MWCNTs）as conductive material and PDMS as flexible substrate material,the surface elliptical bulge and internal porous structure of the flexible sensing layer were designed,and the sensing layer was stacked‘back-to-back’to prepare a high-performance piezoresistive sensor.The sensitivity of the sensor reaches 10.805 k Pa^-1 within the pressure range of 0-1 k Pa.Even in the pressure range of 1-10 k Pa,the sensitivity is still high,which is 2.015 k Pa^-1.In addition,the pressure sensor based on ion conduction not only simulates the mechanical transduction mechanism of biological ion channels across human skin,but also has a higher biological interface compared with electronic skin devices.Therefore,the high flexibility ionic organogel was prepared by polyacrylonitrile,and the self-wrinkled and surface elliptical structure of the organogel surface were designed.As a sensing layer,a pressure sensor with high sensitivity was obtained.At the same time,the good conductivity of flexible organogel can also be used as electrode to prepare high performance flexible capacitive sensor and obtain very high linearity response in the range of 0-1000 k Pa.In addition,the ion-based pressure sensor also has a good function of self-powered.Under the stable impact of circulating pressure,the stable output voltage is 70 m V and the corresponding output current is 1600μA.The self-powered function makes the sensor miniaturized and portable.It can prepare smart gloves,smart insoles and smart bandages with different functions to monitor human physiological signals and motion signals in real-time.