Research On Heating Elements And Strain Sensors Based On Silver-coated Polyester Fabrics

In recent years,nano-silver has been widely used,and its preparation methods and synthesis technology have also been greatly developed.Silver has excellent electrical and thermal conductivity and good infrared thermal effect,which is widely used in thermal textiles,flexible electronics sensors,and other fields.In this study,silver nanowires(Ag NWs)with controllable morphology and uniform size(OD=60-130 nm,L=43.06-114.17?m)and high aspect ratio(?1000)were prepared by the polyol method.Silver-plated fabric(FA)with a dense and uniform silver layer was obtained when the silver concentration was 90 g/L by using the“two-step”silver plating process.Silver structure was prepared on the surface of90 g/L-FA fabric by polyol method,and the best process for preparing silver structure fabric(FAS)was obtained:ethylene glycol as solvent and reducing agent,4 m M Cu Cl₂ as nucleation control agent,polyvinylpyrrolidone(PVP K30)as stabilizer,Ag NO₃:PVP mass ratio of 1:2,bath ratio of 1:100.Ag NWs was deposited on silver-plated fabric.When the deposition concentration of Ag NWs was 0.1 mg/cm²,the fabric with Ag NWs continuous network(FAA)was obtained.Three kinds of silver coated polyester fabrics were characterized by SEM,EDS,and XRD.The heating performance of three kinds of silver-coated polyester fabrics was compared by Agilent digital multimeter and infrared testing system,showing high heating temperature(FA 91.8 ^oC,FAS 113 ^oC,FAA 110.5 ^oC under 1V voltage),fast thermal response(15 s),and low working voltage(0.5 V-1 V),among which FAA fabrics can still reach 117.84 ^oC under 1 V voltage after being washed for 300 min.When the strain sensor is made of FAA fabric,polymer materials ECOFLEX,WPU,and TPU can effectively improve the instability of resistance change when the fabric sensor is stretched.The sensing performance such as sensitivity,linearity,and hysteresis is characterized by flexible sensor testing system.Under the stretching rate of 1%-10%,the sensitivity of FAA/WPU is the highest(GF=11.98),the linearity of FAA/ECOFLEX is the best(?_L=3.13%),the correlation of linear fitting R²>99%,and the hysteresis error is the smallest(?_H=8.59%).In addition,when FAA/ECOFLEX is connected to the knee and other parts,a large range of human motion signals can be monitored.The multifunctional textile electronic device with both heating ability and strain sensing has been successfully manufactured.As a frontier project with deep research,the silver-coated polyester fabric prepared in this work can reach higher temperature under lower voltage,which can effectively reduce energy consumption,and can be applied to human motion detection,hyperthermia,personal health monitoring,and intelligent human-computer interaction.