Virginia Commonwealth University,
Keywords: silver, nanowire, conductors, flexible device
Summary:During past few years, flexible and stretchable conductors have attracted many researchers’ attention for a variety of application. Silver nanowires (AgNWs) has been widely used as the conductive material for stretchable electronics in view of their excellent conductivity, superior flexibility, and high technological maturity in material synthesis. In this talk, I will present our recent research work on the development of AgNW-based stretchable conductors through inkjet printing and direct ink writing. Specifically, the ink of silver nanowires is directly printed through inkjet printing process onto a flexible substrate and the printed patterns are then transferred to a stretchable substrate. The second approach involves inkjet printing the AgNW ink droplets into an uncured elastomer layer. Because of the reflow of the viscous liquid elastomer, the printed silver nanowires are aligned along the printing direction, resulting in linewidth of tens of micrometers upon solvent removal. Such high-resolution conductors with embedded silver nanowires have been obtained in a single step. The third scheme consists of multiple processing steps, namely generation of patterns by direct ink writing, water-induced swelling, and AgNW deposition on the printed patterns. Hierarchical wrinkled structures have been obtained on those conductors which enables superior stretchability. The assembly mechanisms of AgNWs in each fabrication schemes will be elaborated in this talk. The electrical performance of the stretchable AgNW-based conductors has been characterized through cyclic stretching tests under various strains. Stretchable heaters and wearable strain sensors have been demonstrated to showcase their potential applications in wearable electronics for healthcare monitoring and rehabilitation.