Ink-Drop Dynamics on Chemically Modified Surfaces

Abstract

Inkjet printing provides an efficient routine for distributing functional materials into locations with well-designed arrangements. As one of the most critical factors in determining the printing quality, the impacting and depositing behaviors of ink drops largely depend on the wettability of the target surface. In addition to printing on solids with intrinsic wettability, various ink-drop impact dynamics and deposition morphologies have been reported through modifying the surface wettability including both homogeneous and heterogeneous, which opens up possibilities for applications such as advanced optic/electric device fabrication and highly sensitive detection. In this Perspective, we summarize recent progress in the modification methods of solid surface wettability and their capability in modulating the ink-drop impacting and depositing dynamics. The challenges facing ink-drop regulation by chemical modification methodologies are also envisaged at the end of the Perspective.

Development of Binder-Free Pigment Inks for Direct Inkjet Printing on Cotton Fabric without Pretreatment

“…To verify whether the ink can be adequately ejected, we studied the ejection behavior of the ink drop by designing four trapezoidal waveforms, A, B, C, and D (Figure ). − Figure shows the ink drop formation stage for inks B1 and B2 under waveforms A, B, C, and D (B1–A, B1–B, B1–C, B1–D, B2-A, B2–B, B2–C, and B2–D). The formation of ink drops has three stages: (1) a meniscus-shaped liquid interface formed at the nozzle opening; (2) the ink drop ligament is gradually elongated until it breaks from the nozzle; (3) during the fall of the ink drop ligament, the ligament splits into primary and secondary ink drops, and then the primary ink drop and the secondary ink drops are merged into the stable ink drop.…”

Multipass Inkjet Printing of Lead Halide Perovskite Pixels onto Flexible Substrates

“…Such foils are flexible to bending but withstand distortion under stress. We studied pristine PET foil as delivered (Melinex ST505, 125 μm thick) with different amounts of oxygen plasma cleaning as well as PET foils spin-coated with PS, PMMA, and PEDOT:PSS in our lab to vary the surface energy of ink and substrate. , Finally, we tested a commercial foil with a 20 μm-thick layer of mesoporous silica (JS-220 Novele from NovaCentrix), which had shown superb printing behavior in an earlier study …”

Three-Dimensional Morphology and Contour Quality of Conductive Lines Printed by High-Viscosity Paste Jetting

“…6 To ensure the printing accuracy of the manufactured part, the deposition morphology of a single droplet in inkjet printing requires good shape and size uniformity. 7,8 Simultaneously, the printed lines formed by the coalescence of multiple droplets must exhibit regularity morphology and excellent contour quality. 9−11 The raw materials used in inkjet printing technology have low viscosities that are usually less than 200 mPa•s, with values such as 110.7 mPa•s, 12 17.2 mPa• s, 13 and 34 mPa•s.…”

“…Due to the extremely small size and high positioning accuracy, the application of inkjet printing technology is showing a rapid growth trend in various fields, such as electronic circuits, metamaterial absorbers, and biological tissues . To ensure the printing accuracy of the manufactured part, the deposition morphology of a single droplet in inkjet printing requires good shape and size uniformity. , Simultaneously, the printed lines formed by the coalescence of multiple droplets must exhibit regularity morphology and excellent contour quality. − The raw materials used in inkjet printing technology have low viscosities that are usually less than 200 mPa·s, with values such as 110.7 mPa·s, 17.2 mPa·s, and 34 mPa·s . The good liquidity makes the jetting process more stable and controllable, leading to good regularity and consistency of the droplets and printed lines …”