Preparation Of Silver Stretchable Conductive Film And Its Application In Textile Electronics

Textiles are soft,lightweight,water-vapor-permeable and comfortable,providing an ideal platform for wearable devices.However,due to shortcomings such as large surface roughness and porousness of fabrics,it is difficult for printing technology to directly construct electrodes directly on the surface of the fabrics.So far,research has not yet developed a multifunctional wearable device directly on a textile substrate.In order to solve this problem,this paper studies the phase separation phenomenon of silver conductive ink,and uses this phenomenon to prepare stretchable conductive films to build electrodes directly on the fabric.At the same time,using thermoplastic polyurethane and unsaturated resin polyester as the main research objects,and uses two methods to prepare silver conductive inks,and studies the effect of the distribution ratio of different resin groups on their physical properties(adhesion)and conductive properties;Screen printing technology and hot-pressing technology are used to construct multi-functional devices on textiles,providing a valuable reference for silver conductive films in wearable electronics to solve the problem of failing to build electrodes on fabrics and directly to realize wearable electronic applications on textiles.First,in order to study the phase separation phenomenon of conductive ink,thermoplastic polyurethane(TPU)and silver powder(5.295?m)and an isophorone mass ratio of 1:4:3 were used to prepare a stretchable conductive ink.Subsequently,the conductive layer with a printing area of 2×2cm on a glass substrate was annealed at different temperatures,and finally the electrical properties and micromorphology of the conductive layer at different temperatures were analyzed.The results show that the temperature has an effect on the phase separation of the ink.At low temperatures,the solvent evaporates,but the resin does not shrink,which causes the silver flakes to be wrapped by the resin,causing the ink to become non-conductive.However,with the increase of the annealing temperature,the solvent volatilizes,the resin shrinks,and the silver pieces on the ink surface increase,forming a conductive network,making the ink conductive.Secondly,based on the phase separation of the ink,a blending method was used to prepare the conductive ink of a thermoplastic polyurethane and unsaturated polyester resin mixed resin,and the effects of the proportion of different resins on the adhesion,bonding force,and conductivity of the conductive film were systematically studied.The results show that the thermoplastic polyurethane has an influence on the adhesion of the conductive film,and the unsaturated polyester resin has an influence on the adhesion of the conductive layer of the conductive film.When the weight ratio of thermoplastic polyurethane and unsaturated resin polyester in the ink system is 1: 1,the conductive film has good adhesion of 486.9N/m and high electrical stability(rubbing back and forth for 100 times under 10 N pressure and resistance change 25%,The resistance change is 2% under 10 times of washing).Finally,in order to combine with wearable electronics,a large-area stretchable conductive film was prepared using conductive inks,combined with laser cutting technology and hot pressing technology to achieve patterning and high resolution of conductive films on rough woven cotton fabrics.The results show that combined with laser cutting can achieve a variety of complex graphics.At the same time,200?m resolution can be achieved on the fabric.In addition,the conductive film also combines electroluminescent and transparent conductive film technology to build ACEL devices on clothing.In ACEL wearable devices,we have realized the rubbing,washing,high temperature and high humidity performance of the device,which provides effective guarantee for the application of electroluminescence in textile electronics.The conductive film can not only be used in the field of light emission and heating,but also can be used in the field of RFID anti-counterfeit identification.This greatly expands the application range of conductive films,reduces the cost of wearable electronics,and has a good market prospect.