| With the continuous development of Internet of Things technology,artificial intelligence and biomedical technology,the complex environment and special signal acquisition difficulties that need to be faced are increasing.The new flexible pressure sensor has been more widely used and has gradually become a research hotspot in recent years.Researchers use various methods to improve the sensitivity of the sensor,but more complex methods,high energy consumption,and high cost methods are used to prepare new flexible sensors,which are not easy to prepare in large quantities and will limit their application in reality.It is still a big challenge to realize the detection of flexible pressure sensors with high sensitivity,high linearity,fast response and complex signals at this stage.Therefore,this paper proposes and successfully implements a new preparation method of sensor sensitive elements-differential temperature thermo-imprint spatial confining forced network assembly method,which solves the bottleneck problem of the composite material's conductivity and flexibility,and effectively avoids PDMS(polydimethicone)in the early stage of the formation of the sensor sensitive element,it is easy to cause premature crosslinking due to the high mold temperature.The main research contents are:(1)V-cut and semi-cylindrical microstructure piezoresistive flexible pressure sensors were designed,and the simulation was conducted to obtain the relationship between the pressure and the contact area.Through the simulation and experiment comparison,it was determined that the performance of the V-cut microstructure was better than cylindrical microstructure;the high-speed rubber spring is simulated,based on the maximum strain position,the installation position of the sensor is determined.(2)The differential temperature thermo-imprinting spatial confining forced network assembly method was used to experimentally prepare a PDMS/SCF/CNT composite piezoresistive flexible pressure sensor with a V-cut microstructure.The relationship between the concentration of the conductive filler SCF and the dispersion effect in the PDMS matrix,as well as the influence of processing parameters on the properties of the composite material were explored.The sensor unit formed by superimposing the V-cut microstructure conductive sensitive sheet and the planar structure conductive sensitive sheet as a piezoresistive flexible pressure sensor was tested.The results show that the sensor devices with different contents of SCF have good linear response characteristics in the stress range of 0?700kPa;the sensors prepared with PDMS/4wt%SCF/1wt%CNT as raw materials are in the pressure range of 0?350N,Themaximum sensitivity is-3.16?/N,and the repeatability error is 7.8%.(3)Successfully prepared a planar piezoresistive flexible pressure sensor without microstructure.The differential temperature thermo-imprinting spatial confining forced network assembly method is used to prepare a flat sheet of PDMS/SCF/CNT composite material without microstructure.The flat sheet is used as a pull-sensitive element,and electrodes are drawn at both ends of the flat sheet and packaged as a piezoresistive flexible pressure sensor.The test results show that the sensor with different SCF content has good linear response characteristics in the stress range of 0?1800kPa;the sensor prepared with PDMS/1wt%CNT/4wt%SCF as raw material has a pressure of 0?425N within the range,the sensitivity is 1.08?/N,in the stress range of 0?1800kPa,the linearity is 98.5%,and the repeatability error is 5.5%.Although the sensitivity of the flat-plate sensor is low,its stability is high and it is easy to manufacture.It is also an option for high-speed rubber spring sensors. |
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