Internet of Things (IoT) applications demand antennas that can integrate into diverse environments. Traditional rigid antennas struggle to conform to curved surfaces, bendable devices, and wearable applications. Flexible antennas offer a compelling solution by overcoming these constraints, enabling seamless integration into various unconventional form factors.

In this work, we report the results of experiments on the application of selective surface activation induced by laser (SSAIL) technology for antenna applications. The inverted F antenna on the Polyvinylidene fluoride (PDVF) substrate was modeled using CST Studio software. The surface of (PVDF) was processed using 532 nm femtosecond laser Femtolux (Ekspla) irradiation. Later, irradiated areas were selectively coated by copper layer using surface activation and electroless plating process.

The S11 parameter of the manufactured antenna was compared to the modelling results. Measurement results were in great agreement with the simulation results. Antenna bandwidth at -10 dB was from 3.35 GHz to 3.72 GHz.

III-V semiconductors (e.g. GaN) are playing an increasingly important role in LED technology and in high-power electronics. However, the current production of these semiconductor devices requires many individual process steps, including lithographic prestructuring of growth substates, which is very cost- and energy-intensive. The targeted laser structuring of substrates in both the micro and nanometer range should enable the production of high-quality layers in isolated dies in a closed process and thus significantly reduce both costs and environmental impact.

With the help of a UV ultrashort pulsed laser, wide tracks are written on various substrates (e.g. sapphire or silicon wafers), which selectively prevent subsequent epitaxial overgrowth and thus enable bottom-up separation into individual dies. Subsequently, nanostructuring is carried out within these dies to enable the overgrowth of high-quality layers. Furthermore, the scalability of this structuring, e.g. with the help of phase masks, and the influence of different processing atmospheres is investigated.

Photoelectrochemical (PEC) etching offers a damage-free surface and high horizontal selectivity which dissolves the light-illuminated areas. However, accurate etch-depth control is challenging due to the absence of a mechanism to limit etch depth. The evanescent light localizes the illuminating area to the vicinity of the interface under the total internal reflection. Owing to the dependence of the etch rate on the light intensity, the etch depth is expected to be restricted by the localization of evanescent light. In this presentation, we demonstrate PEC etching using evanescent light. The cavity shape reflects the distribution of evanescent light, implying a sufficient etchant supply. The time evolution of the etch depth revealed that the evanescent light distribution limited the etch depth to approximately 900 nm from the reflective interface. This evolution matches the model, stating the etch rate is proportional to light intensity. Our results lead to precise etch-depth control and damage-free planarization.

Integrated sensors are becoming increasingly important for structural health monitoring of components. Digitally printed and additively manufactured strain gauges can be used to evaluate the mechanical stress of materials with a greater quality factor than manually applied strain gauges.

We propose an approach that involves the application of strain gauges to tensile stress components using the ink jet-printing process with a nanoparticle silver ink. In a post-processing step, the strain gauges are laser-sintered to functionalize the material and stabilize the resistivity of the thin film. We report on the results of tensile tests with the contacted sensors and characterizing their electrical properties, as well as the proportionality factor of the strain gauges in dependence of the laser process parameters.

Our approach with contactless application and laser-based post-processing has the potential to enhance the reproducibility of the sensor application and strengthen the quality assurance.

The application fields of silicon carbide (SiC) range from high-performance electronics, power semiconductors, and batteries to use in quantum computing. Due to its outstanding properties such as very high hardness and abrasion resistance, silicon carbide is a hard-to-machine material. One possible processing method is high-precision laser ablation with ultrashort pulses.Investigations were performed on the materials 4HN-SiC and 6H-SiC to study material modifications by picosecond laser excitation at 355 nm and 266 nm. Confocal microscopy, scanning electron microscopy, and mass spectrometry were used to determine the ablation threshold fluence and ablation efficiency, study the morphology, and analyze the Si/C ratio changes in the laser-affected area. In summary, silicon carbide's unique properties present challenges in material processing. However, the use of picosecond lasers with Deep-UV wavelength can lead to improved processing results, enhancing its application possibilities in various high-tech fields.

The manufacturing process of 4H-SiC wafers involves slicing the wafers from an ingot using laser cutting, followed by polishing to achieve the required flatness. This study explores the feasibility of micro-polishing 4H-SiC surfaces using femtosecond laser vector beams in combination with wobble-based scanning. Initially, structures measuring tens of micrometers were fabricated using a high fluence of 1.39 J/cm², resulting in a surface roughness (Sz) of 32.3 μm, which replicates the surface morphology of 4H-SiC after laser slicing. Subsequently, a lower fluence of 1.25 J/cm² and defocus were employed to create a smoother surface morphology with a surface roughness (Sz) of 7.7 μm. This approach demonstrates that femtosecond laser vector beams combined with wobble-based scanning can effectively perform micro-ablation on SiC surfaces, highlighting its potential for 4H-SiC micro-polishing applications.