Carbon dioxide detection is a relevant issue in many fields, and this work focuses on the use of a BaTiO₃-CuO sputtered thin film layer in a gas sensor prototype for air quality measurements. For this, a double side sensor was fabricated, with a Pt heater on one side and the sensing layer over the electrodes on the other side. The uniformity of the temperature on the sensing layer was tested and further tests to check its sensing performance were carried out. Humidity influence in the detection was found to be almost negligible within the usual range in air quality measurements and repeatability tests show satisfactory results for air quality control purposes.

Blazed gratings are periodic surface structures of great interest for applications such as friction control, light trapping, and spectrometry. While different laser processing methods have been explored to produce these elements, they have not yet surpassed conventional surface manufacturing techniques, often based on lithography processes or mechanical ruling. This work introduces a new approach based on the combination of ultrashort pulses and triangular beam shaping, which enables the generation of asymmetrical grooves in a single step. The main advantage of this strategy is that by simply changing the laser processing direction we can induce a significant modification in the ratio of asymmetry between the sidewall angles of the machined channels. The paper includes a comprehensive study, which has been supported by statistical tools, of the effect of this and other experimental parameters on the morphology of grooves machined on stainless steel. As a result, we achieved a wide range of geometries, with asymmetry ratios spanning from 1 to 5 and channel depths between 3 and 15 µm. Furthermore, we demonstrate the validity of the approach through the successful manufacture of blazed gratings of various slopes. The results reflect the versatility and cost-efficiency of the proposed fabrication strategy, and thus its potential to streamline the production of sawtooth gratings and other devices that are based on asymmetrical features.

The objective of this work is to characterize a YSZ solid electrolyte using the impedance spectroscopy (IS) technique. Using the IS, a comparison between two electrode geometries and two electrolyte thicknesses at different temperatures has been performed in order to analyze the obtained impedance patterns and finally determine the optimal fabrication process and the optimal measurement conditions.

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.