Electrohydrodynamic Printing of Ultrafine and Highly Conductive Ag Electrodes for Various Flexible Electronics

Silver nanoparticle (AgNP) based inks are widely used in printed electronics to form conductive patterns. However, high resolution and high electrical conductivity are still hard to achieve at the same time for the patterning of AgNP-based electrodes. Herein, Ag patterns with a high resolution of sub-10 µm and a high conductivity are realized by the electrohydrodynamic (EHD) printing. The parameters including the composition of Ag ink, printing speed, voltage, and working height are carefully controlled to increase the resolution, and the process window of the cone jet mode is established. With the help of the finite element simulation, the generation mechanism of the Taylor cone is clarified. Ag electrodes with various patterns and shapes are easily produced, which exhibited excellent patterning qualities, such as superior uniformity and flatness, narrow spacing, and clear edge definition. Finally, flexible light-emitting diode (LED) circuits, transparent heaters, and supercapacitors are fabricated by EHD printed Ag grid electrodes. These results indicate that this work provides a simple and scalable strategy for fabricating ordered metal conductive patterns in the emerging printed electronics.