Additive Manufacturing (AM) has revolutionized the production of complex three-dimensional (3D) structures; however, the efficient and precise fabrication of thin profiles remains a challenge. This study explores the application of femtosecond-laser-based additive manufacturing techniques for the production of thin profiles with micron-scale features, reaching profile thicknesses below 100 µm. The study investigates the effects of scanning strategy, with optimized processing parameters, on the fabrication of thin profiles; wall thickness measurements were carried out using various technologies to analyse the influence of each on the resulting values. The quality of the walls was quantified by means of a visual characterization of the melted volumes, analysing the evolution of the measured thickness with regard to the processing conditions and in relation to the theoretical thicknesses of the walls.

Additive manufacturing (AM) has revolutionized the production of complex three-dimensional (3D) structures, but the fabrication of thin profiles with high precision and efficiency remains a challenge. This study explores the application of femtosecond laser-based additive manufacturing techniques for the production of thin profiles with micron-scale features. The study investigates the effects of scanning strategy, with optimized processing parameters, on the fabrication of thin profiles; the quality of the walls has been quantified by means of visual characterization of the melted volumes and the relation of the theoretical and measured thicknesses of the walls.

The use of ultrashort-pulsed (USP) lasers in Additive Manufacturing (AM) offers a novel approach to process different materials and the possibility to reduce the minimum achievable sizes and shapes manufactured with this technology. This work aims to confirm that USP lasers are a viable alternative for Laser Powder Bed Fusion (LPBF) when a higher precision is required to manufacture certain critical parts. Enabled by the use of tailored own-produced stainless steel powder particles and controlling the energy contribution with a femtosecond pulsed laser, promising results have been obtained beyond powder bed melting, such as consistent square layers. As a result of this work, laser power and scanning speed have been identified as the most influential and critical parameters when using UPS lasers for AM, as a slight deviation of any of them results in an absence of melting; hatch distance becomes a critical parameter for improving the melt quality.

This study presents a real-time methodology for chemical layer detection and closed-loop control during femtosecond (fs) laser micromachining of multilayer metallic substrates using Laser-Induced Breakdown Spectroscopy (LIBS). The objective is to instantly identify transitions between metallic layers (Aluminum, Copper, Stainless Steel) during ablation, enabling automatic process interruption. An experimental setup was developed integrating a high-repetition-rate fs laser and a spectrometer for continuous plasma emission monitoring. The acquired spectra are streamed in real time to a Python-based processing pipeline implementing a Partial Least Squares Discriminant Analysis (PLS-DA) model for material classification. Upon detecting a layer transition, the system communicates directly with the laser controller, issuing an immediate stop command. This closed-loop LIBS-assisted approach achieved reliable layer discrimination and process stoppage within 14 ± 2 ms, limiting substrate damage without compromising process efficiency. These results demonstrate the feasibility of integrating fs-LIBS with real-time feedback control for intelligent micromachining and precision material removal processes in multilayer systems.