Wearable Applications And Construction Of A Smart Electronic Textile Based On 3D Conductive Networks

In recent years,the integrated application research and the development of flexible smart wearable devices in health,medical care and other fields has been a major research field,and flexible smart wearable electronic devices can monitor human health status or provide other intelligent functions in real time,which enrich people’s life greatly.However,achieving wearable electronic devices with functions such as personal healthcare and thermal management remains a huge challenge.Moreover,manufacturing wearable electronics on traditional thin-film substrates such as rubber elastomer and plastic films always limit gas permeability and increase the risk of inflammation.Therefore,this paper designs and constructs a three-dimensional conductive network conductive fabric on a flexible non-wovens substrate,which can realize its research and application in different directions in the field of intelligent wearable devices.The main contents of this work are as follows:（1）In order to ensure the durability,stability and comfort of flexible wearable electronic devices,metal nanomaterial silver nanowires（AgNWs）are prepared by multivariate alcohol method as one-dimensional（1D）material,and MXene（Ti₃C₂T_x）by etching MAX phase with lithium fluoride（Li F）and hydrochloric acid（HCl）as two-dimensional（2D）conductive material to build a conductive network.At the same time,the high-elastic spandex polypropylene nonwoven is selected as the substrate to prepare smart conductive fabric.By characterizing and analyzing of the conductive materials,the preparation effect and size and the internal connection mechanism of silver nanowires and MXene conductive networks are clarified.The experimental results of the performance test and characterization analysis of the fabric substrate show that the substrate not only has excellent mechanical properties,the fracture elongation rate and fracture strength of original sample can reach 700%,170MPa,respectively,and the air permeability is 2035 mm/s,but also has certain water resistance because of the special folding structure and preparation process.Therefore,the substrate and conductive materials are the best choice to build a smart conductive fabric,and it also lays a solid foundation for the subsequent application of smart wearable devices.（2）In order to improve the electrical and thermal properties of intelligent conductive fabrics,by atomization-spray coating method,the highly conductive metal nanomaterials AgNWs and the new 2D nanosheets carbide nitride MXene were combined on the substrate surface,and its internal connection mechanism is through the combination of hydrogen bond to build a 3D conductive network system.The preparation of stretchable smart conductive fabric is realized on the substrate surface by a simple spraying-drying preparation process.The experimental results show that the 3D conductive network-based stretchable smart fabric has excellent electrical performance,and the AgNWs/MXene@polyurethane-polypropylene nonwoven（AMPP）shows better electrical performance compared with the AgNWs@polyurethane-polypropylene nonwoven（APP）at the same concentration（2.5 mg/ml）.The sensitivity（GF）with a 100%tensile strain is up to 1085.Electrothermal and photothermal performance test experiments show that it has good electrothermal and photothermal performance.At 4V input voltage and 1.4W input power,the smart fabric is capable of having a rapid electrothermal response（30 s,112℃）.With an optical temperature density of 0.3 m W/cm²,its surface temperature response is up to 125℃with 150 s continuous illumination,showing the great promise of intelligent conductive fabrics for wearable electronics applications.（3）In order to realize the application of the smart conductive fabric in the wearable electronic devices,the nickel-plated conductive fabric is used as the electrode,and the conductive silver glue is used to connect the sample as the tensile strain sensor,which can monitor human physiological signals in real time,such as wrist bending,pulse signals,etc.Moreover,the preparation of a temperature visual Joule heater can be achieved by combining the thermochromic layer with smart fabric,which can display different colors at different temperature intervals.This effectively avoids skin burns.Further,the combination with the phase transition material PEG4000 endows the intelligent fabric with the heat storage and temperature regulation function,and the effective human thermal management can be realized.The experimental results show that the smart fabric has excellent functional application of human healthcare and thermal management,which can meet the needs of wearable electronic devices for different application scenarios,and provides a novel solution for realizing the multi-function of wearable electronic devices.