AgNW emulsion inks for direct printing of high-resolution and stretchable electrodes with semi-embedded network structure

Achieving directly printed patterns that are conductive, stretchable, and high-resolution is critical for the scalable manufacturing of wearable electronics, but the competing demands of these properties make it an unresolved challenge. Here, we present a one-step fabrication strategy that overcomes these conflicts using a rationally designed silver nanowire (AgNW)/emulsion ink. The thixotropic AgNW-based ink comprises trace hyperbranched molecules as stabilizers and an aqueous polyacrylic emulsion, enabling direct screen-printing of patterns with a fine resolution of 30 µm via a critical stepwise solvent-drying process. This process first allows AgNWs to settle into a percolating conductive network, then triggers the polyacrylic emulsion particles to coalesce and fuse into an elastomeric matrix that semi-embeds the nanowire junctions, thereby establishing an effective mechanism for dissipating strain. The resulting composite electrodes achieve an initial conductivity of up to 1.6×104 S cm−1, remarkable stretchability exceeding 500% strain, and stable electromechanical performance under stretching (R/R0 = 2.3 at 100% strain and 6.6 at 200% strain) and over 10000 stretching cycles under 40% strain. Utilizing relatively environmentally friendly solvents, our work provides a scalable, post-treatment-free platform for fabricating high-performance stretchable electrode materials for wearable electronics. Printing methods are promising for wearable electronics though it is challenging to optimize conductive and mechanical properties. Here the authors design a silver nanowire emulsion ink to print flexible electronics, optimizing these properties.