Sinter-free stretchable conductive inks composed of polystyrene-block-polybutadiene-block-polystyrene and silver flakes in tetrahydrofuran

Development of sinter-free stretchable conductive inks is critically important to expand the range of materials and applications for flexible electronics. However, conventional stretchable conductive inks require high temperature sintering, which may damage the heat-frail substrates. In this study, we developed sinter-free stretchable conductive inks composed of polystyrene-block-polybutadiene-block-polystyrene (SBS) and silver flakes in tetrahydrofuran (THF). The high volatility and polarity of THF induced the densification and alignment of silver flakes in the SBS matrix, where silver flakes with large surface area and high aspect ratio were formed into the multistacked structure, resulting in the increase of conductive pathways in the stretched wiring.