High-Resolution and Controllable Nanodeposition Pattern of Ag Nanoparticles by Electrohydrodynamic Jet Printing Combined with Coffee Ring Effect

In order to improve the resolution of deposition patterns and produce the required deposition morphology of functional nanomaterials formed by electrohydrodynamic jet (E-jet) printing, it is vital to control the evolution of the coffee ring during droplet evaporation. Herein, the mechanism of the coffee ring effect at the nanoscale is studied, which will enable to realize a high-resolution deposition pattern of Ag nanoparticles (AgNPs) formed by E-jet printing. Under different substrate treatment conditions, the morphologies of the AgNP solution deposits with various chemical compositions are examined by atomic force microscopy for precise statistics and analysis. Thus, the formation mechanism and 3D morphology parameters of the deposition pattern generated by the coffee ring effect are studied in detail at the nanoscale. Structures with different morphologies are controllably fabricated, and a ring with a line width of the order of sub-50 nm is obtained. This fabrication process for the nanodeposition pattern is suitable for other types of nanomaterials as well; therefore, this work will have immense potential and significance for functional material patterning, nanodevice fabrication, and flexible electronic devices.