Metal particle compaction during drop-substrate impact for inkjet printing and drop-casting processes

Abstract

Direct coating methods using metal particles from aqueous solutions or solvent-based inks become central in the roll-to-roll fabrication processes as these methods can lead to continuous or predefined conductive layers on a large variety of substrates. For good electrical conductivity, the metal particles have to be brought into contact, and traditionally, additional sintering treatments are required. Such treatments can degrade the sensitive substrates as paper or polymer films. In this study, the possibility of obtaining conductive layers at room temperature is investigated for direct coating methods with an emphasis on drop-casting and inkjet printing. Thus, it is shown that electrical conductive layers can be achieved if the metal particles can compact during the dropsubstrate impact interaction. It is theoretically shown that the compaction process is directly related to the particle and ink drop size, the initial fractional particle loading of the ink, solvent viscosity, and drop velocity. The theoretical predictions on compaction are experimentally validated, and the particle compaction's influence on changes in the electrical conductivity of the resulting layers is demonstrated. V C 2016 AIP Publishing LLC. [http://dx

Investigating Polymer–Metal Interfaces by Grazing Incidence Small-Angle X-Ray Scattering from Gradients to Real-Time Studies

“…The efficient preparation techniques of polymer and nanoparticle thin films incorporates a wealth of methods [ 6 ]. Among them are spray-coating [ 7 , 8 , 9 , 10 , 11 , 12 ], spin-coating [ 13 , 14 , 15 , 16 , 17 , 18 ], Langmuir-Blodgett [ 19 , 20 , 21 ], dip-coating [ 22 , 23 , 24 ], printing [ 25 , 26 , 27 ], and flow stream deposition. Concerning the latter, exploiting the selective interaction of metal with polymers, Metwalli et al investigated the growth of necklace metal nanostructures by laminar flow of gold colloidal dispersions onto block-copolymer (BCP) thin films as templates [ 28 ].…”

Infiltration of commercially available, anode supported SOFC’s via inkjet printing

“…The drops jetted towards the surface of the anode support had a defined kinetic energy prior to their contact with the porous medium, as discussed in [19]. Hence, while the axial momentum of the impact was transformed to radial spreading, the pressure of the impact facilitated the ink penetration into the substrate.…”

“…The efficient use of potentially expensive precursor materials and reproducibility of the inkjet infiltration process are significant advantages for both research and scale-up. Additionally, the non-contact nature allows more delicate electrolyte supported cells to be infiltrated safely whilst the drop impact velocity, in the range or 1-2 m s -1 [19] improves infiltration without having to employ vacuum processing.…”

Flexible Printed Monolithic-Structured Solid-State Dye Sensitized Solar Cells on Woven Glass Fibre Textile for Wearable Energy Harvesting Applications

“…Screen printing, for example, is a common approach for patterning textiles with colour inks bonding to yarn fibre and can withstand washing and friction. Drop casting can be performed using dispensing equipment to deposit an isolated droplet or continuous liquid film and this has been fully automated in inkjet printing 32 . Spray coating is a blanket coating process used in the textile industry to deposit continuous films across large fabric areas.…”