Laser micro-printing dynamics and scalability of solution-precursor silver films

Tuta, Janko (author), Mur, Jaka (author), Petkovšek, Rok (author)

Laser micro-printing by reduction of metal salts is an emerging direct laser writing technique, capable of producing precise conductive metallic structures with feature sizes smaller than a micrometer. Previous research focused on effects of chemical composition and additives, miniaturization of features and applications. This work explores variations in laser operating regimes towards micro-printing scalability. Single spot and line scanning deposition dynamics were analyzed by high-speed visible and infrared thermal imaging, comparing the effects of pulse energy, pulse repetition rate, incident pulse count and scanning speed on the dynamics and thermal effects of the silver deposit. The large variation of laser parameters was achieved by using a custom frequency doubled pulsed fiber-based laser, emitting 500 fs pulses in green 515 nm wavelength at up to 30 MHz repetition rate in pulse-on-demand operation regime. Pulse energy for silver deposition was in the range from 0.5 nJ to 6 nJ. Side-effects present during micro-printing, such as bubble formation and deposit ablation, were studied to omit imperfections, such as void formations in the deposit. Scanning speed provided an additional control parameter for line deposition, changing the dynamics and topography dramatically from low scanning speeds and high pulse energies to high speeds and a multi-pass scanning strategy. An optimal average linear density range of ▫$10^{⁻3}$▫–▫$10^{⁻4}$▫ J/mm was determined. Understanding the effects of laser parameters and multi pass, high scanning speed strategy, turned out to be an enabler for homogeneous silver lines printed orders of magnitude faster than previously reported.

• Language: English
• Keywords: femtosecond laser, laser micro processing, silver deposition, laser fabrication, direct laser writing
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: 10 str.
• Numbering: Vol. 742, art. 167181
• PID: 20.500.12556/RUL-182611
• UDC: 621.375.826:621.762
• ISSN on article: 0169-4332
• DOI: 10.1016/j.apsusc.2026.167181
• COBISS.SI-ID: 278586371
• Publication date in RUL: 19.05.2026

Record is a part of a journal

• Title: Applied surface science
• Shortened title: Appl. surf. sci.
• Publisher: Elsevier
• ISSN: 0169-4332
• COBISS.SI-ID: 3283215

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: femtosekundni laserji, lasersko mikro procesiranje, nanašanje srebra, laserska fabrikacija, direktno lasersko tiskanje

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0270
• Name: Proizvodni sistemi, laserske tehnologije in spajanje materialov