Abstract:
Silver nanowire (AgNW) based conductive inks have gained considerable attention for realizing printed flexible electronics (PFE). The present work discusses a novel approach to producing highly dispersible silver nanowires, easing the formulation of screen-printing inks with high nanowire loading. A perforated encapsulation of polyvinylpyrrolidone (PVP) with an average thickness of 5.03 ± 1.16 nm was produced on the AgNWs’ surface through a controlled washing procedure, which increased the dispersibility of AgNWs at higher mass loadings. A screen-printing ink formulation with nearly 36% AgNW loading was developed, which generated highly conductive traces with a conductivity of (1.16 ± 0.06) × 106 S m−1 at a low annealing temperature of 120 °C. The printed traces exhibited superior adhesion (ASTM Class 5), stability towards bending (10 000 cycles), resistance to accelerated ageing (ΔR/R0 < 2.5% at 60 °C – 95% RH), and stability towards sweat exposure (ΔR/R0 = 0.5%), making them a suitable candidate for PFE. Utilizing this conductive ink, a highly flexible UHF antenna operating at 945 MHz was fabricated, and an RFID tag was developed by integrating the antenna with a chip. The fabricated tag exhibited exceptional communication performance with a handheld reader and had high stability toward bending (at a bending radius of 1.5 cm for 500 cycles). A wearable smart band for Android-based human position sensing was also developed using the tag, which precisely located the wearer's position.
