The Fabrication And Applications Of A Novel Flexible Electronic Skin With Micro-structures Based On Silver Nanowires And PDMS

Wearable and flexible electronic skins(e-skins)have attracted increasing research interests because of their potential applications for personalized medicine,artificial intelligence,and biomedical engineering.However,the physiological signals of the human body are tiny and the skin is dynamic.Therefore,the preparation of electronic skin with higher sensitivity,ductility and lower cost has become an urgent demand to ensure accurate signal collected.Based on the micro-structured polydimethylsiloxane(PDMS)with high sensitivity and ductility under stress,and the high electrical conductivity of silver nanowires(AgNWs).In this work,a novel e-skin with micro-structures consisted of PDMS and AgNWs was fabricated by a facile strategy,which is multifunctional,low cost and its sensitivity could be adjusted by simply modifying the design of the polymethyl methacrylate(PMMA)template.The main research contents and conclusions are as follows:Initially,the PMMA template with micro-column structures was prepared by carbon dioxide laser engraving,and then the uncured PDMS was injected into the template to realize the construction of the micro-column structure of PDMS.Moreover,to assess the effect of different micro-column structures on the mechanical and electrical properties of the electronic skin,PMMA templates with different micro-column structures were prepared,including the bottom surface radius,the spacing and the geometric arrangement between the micro-columns.Further,we synthesized AgNWs with high aspect ratio by modified polyols method,and the conductive film was molded on the one side of the PDMS with micro-column structure through AgNWs drop-casting.Finally,a thin planar PDMS was encapsulated on the one side of the PDMS surface with AgNWs film and micro-column to construct a double-layer electronic skin.In addition,it well-established that the impact of materials on the mechanical properties,electrical properties and transmittance of the electronic skin was highly dependent on its dosage and micro-column structure.Therefore,we optimized the amount of conductive material on the flexible substrate and further calculated the sensitivity of the electronic skin with differently variable micro-column structures before the application of the electronic skin.Based on the resistance changes of the electronic skin along with diverse tensile conditions,and the surface morphology and conductivity properties of the conductive film formed on the PDMS flexible substrate with different amounts of conductive materials,we obtained the variables to achieve the optimal performance of the electronic skin.Thanks to the optimized variables,the electronic skin showed excellent performance in the detection of human motion,temperature changes,and spatial distribution of the applied pressure,indicating its potential application in personalized medicine.