Preparation And Properties Of Rubber/Carbon Composite Flexible Strain Sensing Materials

Flexible strain sensor has wide application prospects in artificial intelligence,medical equipment,health monitoring and other fields,so the research and application of flexible strain sensor materials have become a hot point in the field of materials.In order to prepare flexible strain sensing materials with high sensitivity and wide strain range,a range of new flexible strain sensing materials with superior performance were manufactured,which were based on the selection of materials and the design of conductive network structure.Using cotton bandage as template,reduced graphene oxide(RGO)/multi walled carbon nanotube(MWCNT)/woven fabrics(GMWF)flexible strain sensor was prepared by absorbing graphene oxide(GO)/acidified multi walled carbon nanotube(MWCNT-COOH)suspension of different concentrations,ethanol internal flame treatment method and coating NR.The effects of the ratio of GO/MWCNT-COOH suspension on the properties of NR/GMWF flexible strain sensing materials and devices were studied.The results showed that with the increase of MWCNT-COOH in GO/MWCNT-COOHsuspension,the tensile strength and conductivity of NR/ GMWF increased.When the ratio of GO/MWCNT-COOH was 1:2,the sensitivity of the sensor was the highest,and the gauge factor(GF)was 8225 in the strain range of 49-67%.It could be used to measure the mechanical vibration,the bending of human joints,expression and speech recognition.Two types of NR/GMWF flexible strain sensors were fabricated by using cotton yarns with two different apertures as templates.The effect of the aperture of cotton template on the properties of sensing materials and devices was studied.The results showed that the tensile strength and electrical conductivity of NR/GMWF composite increased with the decrease of cotton yarn aperture,while the sensitivity of sensor decreased.The GF of NR / GMWF1-2S sensor could reach 741.6 in the strain range of 40-55%.It could monitor the movement of human limbs,breathing,writing recognition,etc.PDMS/GMWF1-2 flexible sensor was prepared with PDMS as matrix and cotton bandage as template.The results showed that the GF of PDMS/GMWF1-2 sensor reached75.80,314.1 and 502.9 respectively in the strain range of 0-17%,17-30% and 30-50%,which could be used to test human head movement,complex eating movement,speech recognition,etc.