Fabrication And Analysis On Strain Sensor Properties Of The Carbon Nanotube Yarn Embedded In Wowen Fabric

Sensor is an important part of intelligent textiles.Flexible intelligent sensor with flexible and flexible characteristics,it can make the clothing maintain its original comfort performance while gaining intellectualization.The fabric based flexible strain sensor can maximize the seamless integration of the garment and has high application value in the field of intelligent textiles.Strain sensor is a kind of sensor that measures the deformation of objects.Unlike traditional sensors made using rigid materials,flexible strain sensor due to using the flexible material,has good flexibility,can be bent freely even folded features,has a wider application prospect.Especially can be used as an important part of intelligent textiles,textiles for the "smart" at the same time to meet a variety of other mechanical properties,and shall not affect or influence the properties of original textile less as far as possible,such as softness,handle,etc.As new materials and intelligent materials research,the researchers at home and abroad for the average resistance strain sensor substrate was improved,the conductive medium is added in the conductive polymer materials or conductive polymer coating on the flexible substrate for having strain sensitivity of flexible conductive composite materials;this materials with high polymer material are packing of the electrical conductivity and piezoresistive characteristics,having the features of the traditional resistance strain sensor,and is one of the important technical way in the study of large strain sensor.Since carbon nanotubes were discovered in 1991,Because of its special mechanical properties,electrical characteristics and electrical properties,the theoretical value of young's modulus is about 1TPa,the theoretical value of tensile strength is about 100 GPa,the data of young's modulus experiment is about 0.8 TPa,and the data of the tensile strength experiment is about 60 GPa.Carbon nanotubes have significant pressure resistance effect,Pressure resistivity refers to the performance of the variation of resistivity due to the change of carrier mobility when the material is subjected to tension,which is inherent in the carbon nanotube itself.Because of the nanometer size of carbon nanotubes,it is very limited in macroscopic application,so it is usually applied in the macroscopic form of film,coating and yarn.In the field of textile and garment,carbon nanotubes with thin film or coating surface and coating conductive yarn not conductive fabric surface as the sensor,the preparation of the fabric of the sensor sensing performance is good,but lost the unique fabric style,soft and not washable.And carbon nanotube in the form of yarn and knitted fabric or woven fabric of the preparation of sensors,the experiments show that a small amount of carbon nanotube yarns during tensile strain by tiny have demonstrated the excellent sensing properties,and preparation of carbon nanotube yarns and fabrics combined sensor is still maintained the style fabric characteristic of soft.This paper intends to apply the excellent electrical properties of carbon nanotubes to intelligent fabrics,However,the high cost and low cost of carbon nanotube yarns are of high mechanical performance,and the mechanical properties of low carbon nanotubes are poor,and their abrasion resistance is poor.This paper the preparation of carbon nanotubes/poly(vinyl alcohol)composite yarn(after referred to as "CNT/PVA yarn),will be directly embedded into woven composite yarn and embedded in the woven fabric by means of the higher weaving preparation sensing fabric,and the sensing properties of the fabric of each sensor is studied.The research contents are as follows:(1)Compared the mechanical properties and electrical properties of the carbon nanotube yarns treated by 5% of polyvinyl alcohol and not treated,and compared the sensing properties of the carbon nanotube yarn embedded in the woven fabric.The diameter of the uncompounded carbon nanotube yarns is about 45 micrometers,the fracture stress is about 220 MPa,the strain is about 30%,and the sensor coefficient is about 1.32;The composite carbon nanotube yarn has a diameter of about 43 micrometers,fracture stress is about 330 MPa,strain is about 22%,and the sensor coefficient is about 1.64.The diameter and strain of the composite carbon nanotubes decreased slightly,but the sensing performance and stress were improved.(2)By embedding the single carbon nanotube yarns which treated by polyvinyl alcohol and not treated into the plain grain and studying its sensing properties,the results showed that the sensing coefficients of the uncompounded carbon nanotube yarns were 0.33 and 0.23 respectively,the sensing coefficients of the composite carbon nanotube yarns were 0.67 and 0.27 respectively.Then change the length and length of the carbon nanotube yarns embedded in plain grain,the results show that the sensor has the highest sensing coefficient when the length of the embedded carbon nanotube yarn is 3cm,the corresponding sensing coefficients were 0.97 and 1.07 at the time of strain 3% and 7%;The higher the corresponding sensor coefficient of the embedded carbon nanotube yarns,the higher the ratio of the sensor to 0.79 when the floating length is 6.(3)Researched the sensing performance of multi-carbon nanotube yarns in series-parallel combination is studied in this paper,and inferred the relationship between the resistance and strain of the sensing fabric with the carbon nanotube yarn is derived.The results show that the sensor coefficient of carbon nanotube yarn can reach up to 1.08 when it is embedded in the horizontal grain;when the pattern is embedded in parallel,its sensor coefficient is 0.67.(4)The yarn of carbon nanotubes and ordinary polyester cotton blended yarns were used to fabricate the sensing fabric,woven six sensing fabrics and studied their sensing properties.The results show that the higher the density of woven fabric,the more unstable the sensor performance,the density of a reed is inserted into the sensing fabric prepared by a warp yarn,and the sensing coefficient of the carbon nanotube yarns is 0.83.