Preparation And Performance Study Of PDMS Pressure Sensor On Flexible Substrate

The integration of pressure sensor on flexible substrate has the advantages of thinness,portability and superior performance,especially in wearable electronic device with outstanding advantage,and has received widespread attention from all walks of life.The active layer of piezoresistive pressure sensor is generally a conductive composite material consisting of flexible substrate and conductive filler.The properties of the flexible substrate（e.g.,ductility,porous structure,elasticity,etc.）and the type and performance of the conductive filler together form the constraint node for the development and application of excellent pressure sensor,and have become an important research direction for technological progress in the industry.Polydimethylsiloxane（PDMS）was chosen as the flexible substrate and carbon nanotubes（CNTs）was chosen as the conductive filler to prepare an active layer composite for the assembly of CNTs/PDMS pressure sensor.The sensing performance of the conductive filler was enhanced by nano zinc oxide,graphene,conductive polyaniline and sodium dodecylbenzene sulfonate.The relationship between the added materials and the performances of the CNTs/PDMS pressure sensor including sensitivity and response time was obtained,and the integration of the home-made sensor on the flexible Polyimide（PI）substrate was investigated,and experimental samples were obtained.To investigate the effect of flexible substrate and conductive filler on the performance of a pressure sensor.The relationship between the process parameters of making PDMS gel by the sacrificial template method and its size,porosity and elasticity were investigated,and the PDMS gel with good performance was prepared under the optimal parameter conditions.The CNTs/PDMS composite with good conductivity was developed by optimizing the process parameter of filling the PDMS gel with CNTs by the solution immersion method and efficient adsorption method.The CNTs/PDMS pressure sensor was fabricated,and the performance test results showed that the sensitivity was0.046 k Pa^-1 in 0～10 k Pa,the linearity was 0.97 and the response time was 63.17 ms,with good static stability,dynamic stability and cycle stability,and excellent application capability.The material morphology and the composition of the active layer of the sensor have an important influence on the pressure sensor.The relationship between the additive type and dosage with the performance of the new pressure sensor was obtained by optimizing the addition amount of nano zinc oxide,graphene,conductive polyaniline and sodium dodecylbenzene sulfonate as additives of the active layer composite material,and the new composite pressure sensor was obtained by the orthogonal test method with superior performance:The sensitivity was 0.22 k Pa^-1 in 0～10 k Pa,the linearity was 0.98 and the response time was 33.47 ms.