Fig. 3: The typical structures fabricated by the proposed printing method.

a The appearance and SEM image of a small inductor (60 turns, 10 μm line width). b The appearance and SEM image of interdigital electrodes (IDEs) pattern with line width of 10 µm and line spacing of 10 µm. c The LED array connected by printed silver circuit (power on and power off). d The SEM image of a silver wire with an area of 40 mm × 40 mm and a line width of 10 μm on an Al₂O₃ substrate with a roughness of Ra = 153 nm. The inset is the enlarged view of (d). e The SEM image of a silver line with an area of 40 mm × 40 mm and a line width of 10 μm on an AlN substrate with a roughness of Ra = 386 nm. The inset is the enlarged view of (e). f The SEM image of a silver wire with an area of 40 mm × 40 mm and a line width of 10 μm on a ZrO₂ substrate with a roughness of Ra = 62 nm. The inset is the enlarged view of (f). g The SEM image of a five-pointed star array (line width of 7.8 μm, side length of 470 μm). h The SEM image of a circular array (line width of 14 μm, diameter of 500 μm). i The SEM image of a 2 layers silver wire with a line width of 10 μm and an AR of 0.46. j The SEM images of a 6 layers silver wire with a line width of 10 μm and AR of 1.75. k The SEM image of a 8 layers silver wire with a line width of 10 μm and an AR of 2.3.