ICMCTF 2026 Session MB-ThP: Functional Thin Films and Surfaces Poster Session

The advancement of flexible and wearable electronics has increased the demand for materials compatible with the human body. Polydimethylsiloxane (PDMS) stands out due to its biocompatibility, transparency, chemical stability, and skin-like mechanical properties, making it suitable for bio-integrated devices. Its elastomeric nature also allows conformal contact with curved surfaces, making it suitable for epidermal and implantable electronics. Despite these advantages, achieving reliable inkjet printing of conductive traces on PDMS remains challenging due to poor ink adhesion and inconsistent droplet behavior. This study introduces a scalable surface modification approach using dielectric barrier discharge (DBD) plasma to improve PDMS wettability for inkjet printing of silver nanoparticle films. The DBD plasma treatment was performed under ambient conditions, and the discharge parameters were tuned to ensure uniform activation across the entire surface. The optimized argon flow rate and electrode gap facilitated consistent plasma exposure, resulting in reproducible surface energy enhancement. By optimizing argon flow and electrode-substrate distance, the treated area was expanded to 5 × 5 cm². Water contact angle (WCA) measurements across nine points confirmed uniformity, averaging 50° ± 1.8°, and white-light interferometry verified the surface remained undamaged. Substrate temperature was also found to play a role comparable to WCA in determining film quality, particularly in relation to printed pattern dimensions. At 50 °C, 200 μm-wide lines printed with three layers exhibited slight wrinkling or cracking, while 300 μm-wide lines showed minor edge spreading. Four-layer prints at this temperature led to bulging. At 60 °C, three- and four-layer 200 μm-wide lines suffered from severe wrinkling and cracking, while 300 μm-wide lines showed edge drying or bulging in three layers, and slight bulging in four layers. An appropriate substrate temperature was identified as essential, enabling both 200 μm and 300 μm-wide silver lines to maintain structural integrity and electrical performance across three to four printed layers. Under these optimized conditions, 300 μm-wide, 4 cm-long silver transmission lines exhibited excellent conductivity with low insertion loss. These results demonstrate the effectiveness of the proposed surface engineering and printing strategy for enabling high-quality, large-area conductive patterns on PDMS, supporting the development of next-generation bio-integrated electronic systems.

Conjugated polymers, particularly poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), are extensively studied for their intriguing electronic and optical properties, making them promising candidates for various functional applications. Precise and spatially resolved control over their molecular organization and morphology is one of challenging things for the tailored innovations. Here, we present a comprehensive investigation into the localized and spatially precise surface structural reorganization of PEDOT:PSS films, achieved through Laser-induced photo thermal effect without any chemical agents. Our focus is on delineating the intricate morphological and molecular changes and understanding the underlying mechanism that enables this spatial control.

Our study delineates the morphological evolution on surface of PEDOT:PSS films (~ 10 μm thickness) under varying laser doses (wavelength: 532 nm, spot size: 7 μm, continuous wave). Notably, a moderate laser dose induces significant morphological transformations, including undulating and dome-like micro-scale surface features with color change. Critically, the moving continuous laser induces a localized thermal distribution. This consistent thermal propagation, coupled with the kinetic state of the laser, induces a rearrangement within the PEDOT:PSS molecular system. The evidenced AFM phase images exhibit a distinct geometry, providing direct visual evidence of spatially controlled molecular reorganization on the surface. These observations promise a powerful approach for achieving spatially resolved control over molecular arrangement, enabling precise patterning and local property tuning.

Further characterization using XPS, UV-Vis, AFM, XRD, Raman, and FT-IR spectroscopy provides insights into the mechanisms driving these changes. This comprehensive study not only significantly elucidates fundamental understanding of laser-PEDOT:PSS interactions for functional film design but also suggests the intricate potential of this technique for creating advanced functional surfaces with tailored properties through precisely engineered molecular architectures.

Aluminum nitride-based ceramics are well known for their insulating properties combined with high thermal conductivity. Their range of applications is wide, in both structural components and thin films. However, the electrical conductivity of these materials is highly temperature-dependent. As the temperature increases, the mobility of charge carriers also rises, which poses significant challenges to their insulating performance.

This study investigates the growth of insulating AlSiN thin films using physical vapor deposition (PVD) and evaluates their electrical insulation at temperatures up to 750 °C. Various reactive PVD techniques were explored, including high-power impulse magnetron sputtering (HiPIMS) and bipolar pulsed sputtering. All depositions utilized a 3-inch aluminum target with varying silicon concentrations in an Argon/Nitrogen (Ar/N₂) atmosphere. Depending on the silicon content, either hexagonal AlN films containing an amorphous Si₃N₄ phase or fully amorphous AlSiN films were produced. The target's alloying concept was designed to enhance deposition stability during sputtering. Within this framework, we also investigated the formation of a fully nitride film at lower reactive gas ratios while maintaining excellent electrical insulating properties.

Phase formation has been examined using X-ray diffraction (XRD), while the deposition rate and film morphology were characterized by scanning electron microscopy (SEM). The insulating behavior of the coatings was evaluated via in-situ impedance spectroscopy across a temperature range from 300°C to 750°C, using Ti/Pt lithography pads as electrodes.

The electrical properties are related to the morphology of the films, particularly whether the films were crystalline or amorphous. Additionally, the influence of impurities, such as O₂, plays a significant role in reducing the insulating properties of the films.

Bi₂Se₃ has emerged as a promising candidate for photodetector applications due to its narrow band gap (~0.35 eV), conductive surface states, and insulating bulk properties. In this study, Bi₂Se₃ nanoplatelets were synthesized on Al₂O₃(100) substrates via thermal evaporation, followed by Ag deposition using the magnetron sputtering technique. The rhombohedral crystal structure of Bi₂Se₃ was confirmed by XRD, HRTEM, Raman spectroscopy, and XPS analyses. The presence and distribution of Ag on the Bi₂Se₃ surface were further verified by FESEM–EDS, XPS, and HRTEM. Optical measurements revealed that the UV–visible absorptance of Bi₂Se₃ nanoplatelets decreased when the Ag content exceeded 7.1 at.%. However, photocurrent responses under zero bias were significantly enhanced by the introduction of Ag. Specifically, the Bi₂Se₃ nanoplatelets containing 7.1 at.% Ag exhibited photocurrents approximately 4.3 and 4.6 times higher than those of pristine Bi₂Se₃ under UV and visible light, respectively. This enhancement is attributed to (i) the intrinsic narrow band gap of Bi₂Se₃, (ii) the formation of a Schottky field at the Ag/Bi₂Se₃ interface, (iii) the LSPR effect of Ag, and (iv) the improved surface conductivity at the heterointerface. These findings demonstrate that optimized Ag deposition can effectively enhance the photosensitivity of Bi₂Se₃ nanoplatelets, highlighting their potential for broadband photodetector applications.

Vanadium dioxide (VO₂) thin films are highly attractive for optical coatings and photonic devices due to their reversible metal-insulator transition (MIT) near 68 °C, which produces a sharp change in optical properties. Controlling the MIT through thin-film processing and morphology is critical for achieving tunable infrared functionality.

Amorphous VOₓ layers with thicknesses of 50 - 200 nm were deposited by pulsed laser deposition (PLD) from a V₂O₅ target onto glass substrates, followed by rapid thermal annealing (RTA) at 400 °C for 15 - 120 s in oxygen. Structural and optical responses were characterized using grazing-incidence XRD, Raman spectroscopy, SEM, and UV-Vis spectroscopy.

All films exhibited dewetting, with morphology strongly dependent on initial thickness. Thinner films formed dense, uniform nanoparticles, while thicker films developed larger, less homogeneous features. These differences directly affected the MIT-driven optical response: plasmonic resonances red-shifted with increasing feature size, enabling selective infrared modulation. In contrast to more complex nanoparticle fabrication methods, this simple approach provides precise control over mean particle size, and the plasmonic response is highly sensitive even without monodispersity or long-range ordering.

These results demonstrate that thickness-dependent dewetting can be harnessed to design VO₂ thin-film coatings with tunable, wavelength-selective optical properties.

Gallium oxide (Ga₂O₃) remains a focus of research due to its outstanding optoelectronic properties, including an ultra-wide bandgap of approximately 4.8 eV, a high electron saturation velocity, and its ability to withstand a high breakdown electric field of about 8 MV/cm. Although Ga₂O₃ is typically prepared using methods such as MBE, MOCVD, or ALD, it would be advantageous to find a viable method for preparing this material using magnetron sputtering as well. This is because this method is known for its high deposition and ease of up-scaling the process. Despite some published work in this area, it has not yet been possible to find conditions that lead to layers with satisfactory electrical properties.

In this work, we focus on reactive magnetron sputtering of Ga₂O₃ films using a liquid gallium metal target on different substrates and under various conditions (oxygen and argon partial pressures, substrate temperature, and pulse-averaged target power density). The resulting films exhibit a broad range of morphologies, from compact solid thin films to wire-like microstructures. We present the optical, electrical, and microstructural properties of the films and suggest their correlations with the discharge parameters as well as the substrate used. We found that the crystalline quality of Ga₂O₃ films and their preferential orientation play a crucial role in achieving improved electrical properties. The optimal crystal structure can be obtained primarily by selecting an appropriate temperature and substrate that promotes the crystalline growth of the film.

Keywords: n-layer films; blow molding; polymer composites; recycling; hot-tack

Multilayered films are used recently for many applications like packaging, materials with special barrier properties or with resistance for specific liquids or radiation, e.g. UV. The investigation aimed to obtain the composite in form of 3-layer polymer film and nextly to perform the analysis of the structure and properties of newly developed composite produced using 20 meter high blow moulding technology supported by a precision gravimetric dispensing system. To keep better control, the process was supported by advanced, rotating basket and precise sensors. The film samples were prepared, including a reference film labelled as PE pure and made from standard material, and films with a modified middle layer B, containing regranulate and calcium carbonate in specified proportions. The mechanical strength tests of the sealed films were conducted to verify strength of films in aim to be used for FFS (Form-Fill-Seal) packaging lines and are very promising comparing to single layer films. 3-layer packaging films based on PE recyclates and calcium carbonate in the middle layer, retain their required mechanical properties.

Surface-enhanced Raman spectroscopy (SERS) provides a powerful analytical tool for molecular identification through the amplification of Raman scattering signals from target analytes on plasmonic nanostructures. In this study, we present a plasma–polymer–fluorocarbon (PPFC)-based nanocomposite thin-film platform designed to achieve high SERS sensitivity via controlled nanoparticle formation. By tuning the sputtering power density during mid-frequency magnetron sputtering, the distribution and ratio of Ag and Cu nanoparticles embedded in the PPFC matrix were precisely modulated, as confirmed by X-ray photoelectron spectroscopy (XPS) and ultraviolet–visible–near infrared (UV–Vis–NIR) spectroscopy. The optimized Ag–Cu PPFC (CAP) thin films exhibited distinct localized surface plasmon resonance (LSPR) absorption peaks and demonstrated an enhancement factor (EF) of up to 10⁸ for rhodamine 6G, supported by finite-difference time-domain (FDTD) simulations showing strong electromagnetic localization at the metal–metal nanogaps. Furthermore, a simplified fabrication approach employing a single composite target of Cu, carbon nanotube (CNT), and PTFE powders (5:60–80:35–15 wt.%) was developed to produce Cu–PPFC nanocomposite films with moderate SERS sensitivity (EF ≈ 2.18 × 10⁴). The prepared CAP and Cu–PPFC nanocomposite films successfully detected rhodamine 6G on flexible polyethylene terephthalate substrates, maintaining distinguishable Raman signals even with reduced optical transmittance. These results demonstrate that plasma–polymer fluorocarbon nanocomposites incorporating Cu and Ag nanoparticles offer a scalable, flexible, and cost-effective route toward high-performance SERS-active substrates suitable for on-site and point-of-care molecular detection applications.

Radio Frequency (RF) magnetron sputtering was employed to synthesize CdS–plasma polymerized fluorocarbon (PPFC) nanocomposite thin films. This work presents a comprehensive analysis of the structural, chemical, and morphological characteristics of these films, followed by an evaluation of their potential as anode materials for lithium-ion batteries.

Advanced characterization techniques, including Transmission electron microscopy (TEM), X-ray diffraction (XRD), grazing incidence small-angle X-ray scattering (GISAXS), and X-ray photoelectron spectroscopy (XPS), were utilized to elucidate the film properties. These analyses confirmed the successful incorporation of CdS nanoparticles within the polymeric matrix as shown in Figure 1.

Electrochemical testing demonstrated that the CdS–PPFC nanocomposite thin films exhibit stable performance as battery anodes. Notably, thinner films displayed superior battery performance compared to thicker electrodes. This enhancement is attributed to the evolution of surface morphology; specifically, a reduction in film thickness leads to increased surface roughness, which in turn provides a larger surface area for electrochemical reactions.

Acknowledgments

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government(MSIT) (RS-2025-00516639)

This research focuses on the application of thermal spray technologies aimed at optimizing the functional properties of agricultural components intended for soil tillage. The investigation is based on thermal coatings obtained through Atmospheric Plasma Spray (APS) technology applied to the constructive elements of agricultural ploughs, which are subjected to aggressive operating conditions. The specific properties of these components—microstructural analysis and corrosion resistance—constitute determining parameters for ensuring enhanced durability of agricultural equipment (mainshare and foreshare).

Within the experimental investigation, protective coatings were deposited through thermal spray technology using metallic powders based on WC12%Co (commercial designation WOKA 3101). Characterization of the microstructural properties and electrochemical behavior of the deposited layers was evaluated on laboratory specimens in specific corrosion environments. The obtained results demonstrated that thermal spray coatings presents an optimal method for enhancement and potential reconditioning of components.

The deposited layers exhibited satisfactory adhesion and characteristic microstructure, composed of successive splats with reduced porosity. Analysis of electrochemical behavior revealed superior corrosion resistance compared to the base material, an aspect indicating significant improvement of functional properties and enhanced functional capacity of the coated components.

Acknowledgment: This work was supported by a grant from the Ministry of Education and Research, CCCDI–UEFISCDI, project number PN-IV-PCB-RO-MD-2024-0336, within PNCDI IV

Nanoporous metals offer an important platform for tailoring composition and surface-to-volume ratio, both aspects critical for applications in catalysis where nanoporous thin films can offer further ease of handling. These films are however prone to intergranular cracking during dealloying, limiting their stability and potential applications. Here, we set out to systematically investigate the grain boundaries (GBs) in Au28Ag72 (± 2 at.%) thin films. We observe that sample synthesized at 400 °C is at least 2.5 times less prone to cracking compared to sample synthesized at RT. This correlates with a higher density of coincident site lattice (CSL) GBs, especially the density of Σ3, increased, which appear resistant against cracking. Atom probe tomography (APT) of random high-angle GBs reveals prominent Ag enrichment of up to 77at.%, whereas Σ3 coherent twin boundaries show Au enrichment of up to 30at.%. APT also reveals a strong texture dependence on the dealloying kinetics where the (111)-textured film retains a higher Ag concentration within the nano-ligaments and the untextured film already exhibits coarsening, indicating a faster reaction kinetics, and a lower Ag content. Our study highlights the potential of microstructure engineering in tailoring the properties of nanoporous metals for possible future catalytic and electrochemical applications.

In this study, the corrosion behavior of a β-type titanium alloy, Ti-15Mo, after coating by the Micro Arc Oxidation (MAO) method was investigated in detail under different corrosive environments. Ti-15Mo alloy has recently attracted considerable attention, particularly in biomedical applications, due to its low elastic modulus, high mechanical strength, and superior biocompatibility. However, to enhance its corrosion resistance against aggressive environments that may be encountered under long-term service conditions, surface modification techniques are required.

For this purpose, ceramic-like, porous, and highly adherent oxide layers were formed on the alloy surface using the MAO technique. The effect of the MAO coating on corrosion performance was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods. In addition, the coating morphology and chemical composition were characterized by scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) analyses.

The results demonstrated that the MAO coating shifted the corrosion potential of the Ti-15Mo alloy toward more noble values and significantly reduced the corrosion current density. Comparison of different test environments revealed that, particularly in aggressive chloride-containing solutions, the MAO coating enhanced the stability of the passive layer and markedly improved the overall corrosion resistance of the alloy. These findings indicate that MAO-coated Ti-15Mo alloy exhibits high electrochemical stability, making it a promising candidate for biomedical and other demanding service conditions.

Aluminum (Al) and its alloys are widely used as structural materials in various engineering applications, particularly in the automotive, aerospace, and space industries, due to their high strength-to-weight ratio, corrosion resistance, high machinability, and superior specific strength. Despite these advantages, their relatively low surface hardness, high friction coefficient, limited wear resistance, and poor corrosion performance in aggressive environments restrict their application range. To overcome these drawbacks and expand the usability of Al and its alloys, surface modification processes have been extensively applied.

Micro Arc Oxidation (MAO) is an environmentally friendly coating technique that enables the formation of hard, strongly adherent ceramic oxide coatings on aluminum and its alloys. The aluminum oxide (Al₂O₃)-based ceramic coatings produced by this method significantly enhance the mechanical, tribological, and corrosion resistance of the substrate material. However, prolonged exposure of Al₂O₃-coated substrates to aggressive service environments may lead to coating degradation and deformation.

To mitigate these limitations and to tailor the mechanical, adhesive, and corrosion-resistant properties of the coatings, the incorporation of nanoparticles into the MAO electrolyte has emerged as an effective approach. Among these additives, ultra-high-temperature ceramic (UHTC) materials exhibit exceptional hardness, wear and corrosion resistance, and outstanding stability under extremely high-temperature conditions, making them highly promising for advanced aerospace and space applications. Artificially synthesized ceramics such as hafnium carbide (HfC) and zirconium carbide (ZrC) are among the materials with the highest known melting temperatures and are extensively utilized in extreme environments, including hypersonic systems, missile and rocket components, and thermal protection structures.

This study investigated the use of a tin-based oxide (SnOx) semiconductor layer as the active layer for a light-addressable potentiometric sensor (LAPS) on a commercial indium tin oxide (ITO)/glass substrate. We characterized the optical absorption properties of the SnOx layer, as well as changes in Hall mobility and Raman spectroscopy, using ion beam assisted discharge (IBAD) and varying argon/oxygen flow ratios. The experimental results demonstrate the potential of SnOx as an active layer for LAPS, but the stability and lifetime performance of SnOx LAPS require further process optimization.

The mobility sector is one of the largest emitters of greenhouse gases. Consequently, providers of mobility services and systems are facing a profound transformation towards climate neutrality. A key lever on the path to emission-free production is circular value creation, which significantly reduces the use of primary raw materials and thus lowers environmental impact. The overarching goal of the project is to improve the CO₂ and environmental performance of structural and hybrid components by consistently increasing efficiency, using recyclates, and implementing an ecologically optimized component design.

Conventional biodegradable soft tissue anchors are exposed to severe corrosion due to their contact with blood, causing them to lose their integrity after only 8-12 weeks. PVD coatings are aimed at specifically influencing this corrosion. PVD coatings have long been studied for their corrosion protection properties. Although layers deposited by magnetron sputtering or arc evaporation nowadays have a dense microstructure. However, contact with corrosive media such as blood usually leads to pitting corrosion very quickly, which severely attacks the substrate materials underlying the coating. Such attacks occur primarily at layer growth defects.

In order to prevent controlled degradation of the implants and the negative effects of pitting corrosion, which manifests itself in excessively rapid corrosion, round samples of an Fe-Mn alloy were polished and coated with a thin titanium layer by KCS Europe using a sputtering process. To obtain an antibacterial surface, the samples were coated with a silver layer of 3, 10, and 30 nm in a second coating process. The thickness of the silver layer is decisive for the antibacterial effect of the surface. If the silver layer is too thin, the antibacterial properties of the surface can be lost because individual areas of the surface are not coated. A continuous silver layer, on the other hand, prevents the desired controlled degradation of the implants. A surface on which individual silver cells were deposited locally in island-like formations, but did not completely cover the substrate, proved to be optimal for controlled decomposition and the antibacterial effect of the coatings.

The APLM (Ablation Partielle par Laser dans des Multicouches PVD pour des surfaces Multicolores et nanostructurées in french) project is supported by the INTERREG VI France–Switzerland 2021–2027 program. The project consortium consists of two universities, namely the Bern University of Applied Sciences (BFH) and the University of Technology of Belfort-Montbéliard (UTBM), as well as four industrial partners (Plasmadiam and Gravity for Switzerland, and SILSEF and SAIREM for France).

The objective of APLM is to develop all the technical expertise required to industrialize a process invented and patented by BFH and Plasmadiam in May 2024. The invention combines vacuum deposition technologies for ultrathin coatings using PVD and PECVD, together with partial ablation by means of nanosecond, picosecond, and femtosecond pulsed lasers, enabling the generation of cavities within multilayers with nanometric control and precision. Prototypes of multicolored watch dials, as well as molds for nanoimprint lithography (NIL), embossing, and plastic injection molding, will be produced. These prototypes will help promote the technology and enhance the value of the invention, generating economic benefits for all industrial partners of the consortium within the regions and beyond.

The main actions of the project consist in developing various robust processes for depositing brightly colored layers or layers with specific optical properties by combinatorial PVD sputtering, with or without the use of MW-PECVD plasma, while meeting the mechanical specifications required for the targeted applications. Subsequently, a database of laser ablation thresholds (in J/cm²) will be established for the different colored or functional PVD layers produced (20–500 nm thickness range) at different wavelengths. A predictive model will also be designed to estimate the ablation threshold of a material based on its physical properties. Finally, flagship prototypes demonstrating the patented technology will be developed in the fields of multicolored watch dials and nanostructured molds for NIL, embossing, and plastic injection, through the ablation of nanometric cavities structured on three or four levels.

During this poster presentation, a general overview of the project will be provided, along with a presentation of the first colored coatings obtained by BFH and UTBM. These coatings were produced by reactive magnetron sputtering.

In Vernier Ellipsometry Sensing (VES) two zero-reflection points (ZRPs) in p-pol and s-act in synergy to enable a refinement optical measuring scale akin to a Vernier scale. These new class of sensors are enabled by: i) strong coupling between p-pol surface plasmon polariton and p-pol photonic waveguide leading to Rabi splitting with phase singularities of the resulting hybrid resonances; ii) spectrally overlap between the s-pol photonic modes and the hybrid p-pol resonances; and, importantly, iii) the ellipsometric sensing strategy where the s-pol ZRPs provide a stable reference to boost the sensor performance in terms of the amplitude ratio and phase difference of both ZRPs.

In VES fine angle of incidence (AoI) tuning enables resetting the sensor to its optimal sensing point.We will present new numerical simulations that are able to track the performance of this VES with high efficiency to determine the optimum operation conditions in terms of (AoI) and spectral overlap resonance for la large dynamic range in changes of refractive index unit (RIU) in the sensing media. We discuss the implications of these results for the design of a dedicated AoI- and wavelength- resolved ellipsometer system capable to instantaneously track the best-point sensitivity and achieve lowest limit of detection (LoD) and large dynamic range.