Enhanced tribological performance and nanostructuring speed on AlTiN by beamshaping technology

T. Primus, P. Hauschwitz, T. Vitu, R. Bičišťová, P. Zeman, M. Cimrman, J. Brajer, T. Mocek, M. Smrž

2023 — Surface Engineering — DOI: —

For the first time, a dynamic beamshaping technology has been utilized for the efficient production of periodic nanostructures on top of AlTiN coating to enable dry machining without costly and environmentally hazardous cutting fluids. First, a variety of periodic nanostructures with periods in a range of 740–273 nm were produced utilizing different wavelengths. Additionally, beamshaping technology increased productivity by 4008% up to 105 cm2 min−1 by shaping the Gaussian beam into a rectangular beam of 500 × 30 µm. To simulate the application load and resulting heat production during manufacturing, friction analysis was performed at room and elevated temperature to 500°C. The analysis revealed a significant reduction in the friction coefficient – up to 27% and 19% at room temperature and 500°C, respectively. The combination of these results demonstrates that the proposed method can be scaled up for the mass production of functionalized machining tools for dry machining.

Laser-assisted two-step glass wafer metallization: an experimental procedure to improve compatibility between glass and metallic films

Albin Antony, Michal Hejduk, Tomáš Hrbek, Peter Kúš, Radka Bičišťová, Petr Hauschwitz, Ladislav Cvrček

2023 — Applied Surface Science — DOI: —

We report a simple and efficient two-step experimental procedure of glass metallization using laser microstructuring at ambient conditions. An adhesive pattern was created on the glass substrate using a laser, which imposes mechanical interlocking. An adhesive Cu layer was deposited on the glass substrate by magnetron sputtering and then electroplated with a functional Cu layer. Due to the unique surface structure created on the glass using laser, we achieved a thick layer of Cu metal film with high adhesion strength, well-defined grains and grain boundaries, and low surface roughness. The total thickness of the grown film was 11.4 µm, with an average surface roughness of 1.2 µm. The magnetron-sputtered coating did not show delamination from the glass substrate at a critical load of 60 N. The proposed method of glass metallization will lead to the realization of glass-based circuit materials that can be used in high-frequency electronic devices. Also, this procedure will be an alternative to chemical-based copper plating, which involves multiple processing steps and high-cost chemicals.

Advanced micro- & nanostructuring for enhanced biocompatibility of stainless steel by multi-beam and beamshaping technology

Petr Hauschwitz, Markéta Klíčová, Senta Müllerová, Radka Bičišťová, Martin Procházka, Jan Brajer, Michal Chyla, Martin Smrž, Jiří Chvojka, Tomáš Mocek

2023 — Biomedical Materials — DOI: 10.1088/1748-605X/acd291 —

Biocompatibility is one of the key issues for implants, especially in the case of stainless steel with medium to low biocompatibility, which may lead to a lack of osseointegration and consequently to implant failure or rejection. To precisely control preferential cell growth sites and, consequently, the biocompatibility of prosthetic devices, two types of surfaces were analyzed, containing periodic nanogrooves laser induced periodic surface structure (LIPSS) and square-shaped micropillars. For the fast and efficient production of these surfaces, the unique combination of high energy ultrashort pulsed laser system with multi-beam and beamshaping technology was applied, resulting in increased productivity by 526% for micropillars and 14 570% for LIPSS compared to single beam methods. In vitro analysis revealed that micro and nanostructured surfaces provide a better environment for cell attachment and proliferation compared to untreated ones, showing an increase of up to 496% in the number of cells compared to the reference. Moreover, the combination of LIPSS and micropillars resulted in a precise cell orientation along the periodic microgroove pattern. The combination of these results demonstrates the possibility of mass production of functionalized implants with control over cell organization and growth. Thus, reducing the risk of implant failure due to low biocompatibility.

LIPSS‑based functional surfaces produced by multi‑beam nanostructuring with 2601 beams and real‑time thermal processes measurement

P. Hauschwitz, J. Martan, R. Bičišťová, C. Beltrami, D. Moskal, A. Brodsky, N. Kaplan, J. Mužík, D. Štepánková, J. Brajer, D. Rostohar, J. Kopeček, L. Prokešová, M. Honner, V. Lang, M. Smrž, T. Mocek

2021 — Scientific Reports — DOI: DOI: 10.1038/s41598-021-02290-3 —

A unique combination of the ultrashort high-energy pulsed laser system with exceptional beam quality and a novel Diffractive Optical Element (DOE) enables simultaneous production of 2601 spots organized in the square-shaped 1 × 1 mm matrix in less than 0.01 ms. By adjusting the laser and processing parameters each spot can contain Laser Induced Periodic Surface Structures (LIPSS, ripples), including high-spatial frequency LIPSS (HFSL) and low-spatial frequency LIPSS (LSFL). DOE placed before galvanometric scanner allows easy integration and stitching of the pattern over larger areas. In addition, the LIPSS formation was monitored for the first time using fast infrared radiometry for verification of real-time quality control possibilities. During the LIPSS fabrication, solidification plateaus were observed after each laser pulse, which enables process control by monitoring heat accumulation or plateau length using a new signal derivation approach. Analysis of solidification plateaus after each laser pulse enabled dynamic calibration of the measurement. Heat accumulation temperatures from 200 to 1000 °C were observed from measurement and compared to the theoretical model. The temperature measurements revealed interesting changes in the physics of the laser ablation process. Moreover, the highest throughput on the area of 40 × 40 mm reached 1910 cm2/min, which is the highest demonstrated throughput of LIPSS nanostructuring, to the best of our knowledge. Thus, showing great potential for the efficient production of LIPSS-based functional surfaces which can be used to improve surface mechanical, biological or optical properties.