An experimental investigation into plate-to-roll patterning with solid- state superionic stamping

Metallic nanostructures play an important role in micro and nanotechnology, from interconnects in electronics, electrodes in chemical sensors, batteries, plasmonic waveguides, structural color generation in sub-wavelength optics and catalysts in micro-reactor surfaces. Silver, of all the elements, possesses the highest electrical conductivity and (as a result) unique interaction with visible light when patterned at nanoscale, making it ideal for electronics, optics and chemical sensing applications. Solid-State Superionic Stamping (S4) is an electrochemical nano-imprinting process that is capable of directly patterning silver nanostructures. In this paper, we demonstrate a simple method to scale up S4 patterning of silver using a plate-to-roll format to explore the potential of the S4 technology in a roll-to-roll configuration for high-volume manufacturing. In this format, a roller with a silver-coated polymer film wrapped around it is rolled without slip over a planar, patterned (x)AgI(1-x)AgPO₃, x=0.5, stamp while creating an electrochemical cell with the silver film as the anode. This format allows us to explore the advantages of patterning with a moving line contact (as opposed to the large stationary surface contact in the imprinting/stamping format) between the stamp and roller, but without the added complexity of having to make a patterned electrolyte roller. We demonstrate the making of 6x10 mm² patterned silver surfaces with arrays of 200 nm holes or pillars having an aspect ratio of up to 2. The effects of process parameters including rolling speed, contact pressure, patterning voltage and current on the pattern quality and the stamp surface degradation are studied.