Deposition of ultra-thin coatings by a nature-inspired Spray-on-Screen technology

• Published in: Communications engineering Vol. 2; no. 1; p. 42
• Main Authors: Kumar, Rachith Shanivarasanthe Nithayananda, Ramirez, Andrea Valencia, Verding, Pieter, Nivelle, Philippe, Renner, Frank, D’Haen, Jan, Deferme, Wim
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 22.06.2023; Springer Nature B.V
• Subjects: 639/166/987; 639/925/929/353; 639/925/930/1032; Coatings; Coffee; Computer storage devices; Contact angle; Data storage; Deposition; Droplets; Energy; Energy storage; Engineering; Equilibrium; External pressure; Memory devices; Organic chemicals; Polyesters; Production costs; Screen printing; Substrates; Thickness; Thin films; Zinc oxides
• ISSN: 2731-3395; 2731-3395
• DOI: 10.1038/s44172-023-00093-0

Nanometre-thick, ultrathin coatings applied over a large area are of paramount importance for various application fields such as biomedicine, space and automotive, organic electronics, memory devices, or energy storage devices. So far wet chemical deposition as a cost-effective, scalable, and versatile method can only be used for thicker deposits. Here the formation of uniform ultra-thin coatings with thicknesses below 15 nm using a nature-inspired, roll-to-roll compatible Spray-on-Screen (SoS) technology is reported. For this, the finite micro-droplet generation of Ultrasonic Spray Coating (USSC) is combined with the coating formation from a screen printing mesh. Hydrophobic micro-threads of the mesh, resembling the micro-hair on the legs of water striders, produce millidroplets from micro droplets, and when applying an external pressure to the mesh, dynamic wetting is enforced. The proposed technology is applicable for a wide variety of substrates and applications. It is shown by theory and experiment that ultra-thin coatings below 5 nm homogeneous over a large area can be deposited without the use of extended ink formulation or high substrate temperatures during or after deposition. This simple yet effective technique enables the deposition of ultra-thin films on any substrates, and is very promising to fabricate the organic, inorganic electronics devices and batteries cost effectively. Rachith Kumar and coworkers report a bio-inspired coating technique able to deposit uniform films with thicknesses below 15 nm on various substrates. This method will not require the use of extended ink formulation or high substrate temperature as existing techniques do, potentially reducing the fabrication cost of future electronic devices and batteries.