Naoji Matsuhisa1, Daishi Inoue2, Peter Zalar1,3†, Hanbit Jin1, Yorishige Matsuba1,3, Akira Itoh1,3,Tomoyuki Yokota1,3, Daisuke Hashizume2 and Takao Someya1,2,3,4*
In this composite, Ag flakes are used as a cost-competitive conducting filler. Scanning electron microscopy (SEM) images and the size distribution of Ag flakes are available in Supplementary
Figs 1 and 2, respectively. The fluorine rubber was chosen for its stretchability, environmental stability, and high polarity to attract ions32. The fluorine-rubber-compatible surfactant is a nonionic polymeric surfactant consisting of a hydrophilic ethyleneoxide group and a fluorophyllic perfluoroalkyl group. MIBK is an organic solvent used to dissolve the fluorine rubber. The ink’s viscosity is 14.5 Pa s at a shear rate of 10 s−1 (Supplementary Fig. 3). This viscosity is suitable for stencil, screen, and dispenser printing methods. After printing, traces are dried at 80 ◦C for 1 h, followed by additional heating at 120 ◦C for 1 h, which is critical for the formation of AgNPs as described below.