Search Results (79)

The object of the study is a permanent joint of thin wires made of nitinol alloy. The problem of ensuring the formation of a joint of wires made of nitinol alloy was solved based on minimising changes in the structure of the welded joint material relative to the materials being joined. The properties of the welded joint material of the nitinol were studied using scanning electron microscopy and micro-X-ray spectral analysis. The studied permanent joint was obtained by TIG, microplasma (PAW) and capacitor discharge (CDW) welding. It was found that TIG welding can ensure the proximity of the microstructures of the wire and welded joint materials under conditions of sufficient protection in an argon atmosphere. Such TiNi welded joints have a welded joint material that retains its superelastic properties (within the limits of the shape memory effect). Capacitor discharge welding allows the joint to be brought closer to the required level of microstructure of the weld material. The results of mechanical tests demonstrated the limited capabilities of joints made of thin nitinol wires. At the same time, the appearance of only newly formed TiNi + TiNi₃ eutectics in the weld material and a sufficient level of restoration of the welded joint shape give reason to consider capacitor discharge welding promising for joining thin nitinol wires. PAW leads to the formation of a significant amount of oxides in the weld and an increase in the number of Ti₂Ni inclusions, which leads to brittle fracture of the welded joint even at low degrees of deformation. The results of the study can be used, in particular, for the manufacture of nitinol wire joints in medical devices. Full article

The combination of microplasma generation and optical multi-material fiber technologies enables real-time diagnostics. The stack-and-draw technique has emerged as a promising method for creating multimaterial fibers suitable for plasma-based diagnostics. The elaboration of such devices for the generation of long-lasting microplasma for real-time and remote analyses remains challenging due to the difficulties of reaching long lengths without defects and with continuous electrodes. Post-functionalization of the electrode surface is also required to increase the plasma emission duration. In this study, glass was preferred over polymers for producing rectangular fibers (ribbons) that are easy to stack without wasting space and are resistant to high operating temperatures. Conversely, an aluminum alloy was chosen for the electrodes to reduce discontinuity defects. With the chosen bi-electrode geometry, the cooling rate during drawing has to remain between 200 and 300 °C/s to limit defect formation and guarantee low electrical resistivity. During plasma generation, an in situ oxide layer forms on the tip of each electrode. This results in a significant increase in plasma emission duration without the need for an additional post-functionalization step after drawing. These ribbons were tested in combination with an optical emission spectrometer to create a miniature gas detector for hydrocarbons. Full article

Dielectric barrier discharge (DBD) was used as a source of low-temperature plasma generated in a mixture of air and argon at atmospheric pressure for the deposition of a TiO₂ layer from a precursor on a brass or glass substrate. The DBD was generated between two plane-parallel electrodes covered with a dielectric barrier and supplied with an AC high voltage at a frequency of 5 kHz. In this paper, a TiO₂ layer was deposited from vaporised titanium tetraisopropoxide (TTIP), as a precursor, conveyed via argon as a carrier gas in air. The deposited layer was then annealed at a temperature of 450 °C for a time of 2 h. The results of laboratory investigations show that DBD plasma generated in a mixture of air and argon at atmospheric pressure with a precursor can be a useful tool to produce an anatase TiO₂ thin porous layer. The physical properties of the obtained layers were characterised by scanning electron microscopy, energy-dispersive spectroscopy, and Raman spectroscopy. Layer morphology was different depending on the substrate used: in the case of the brass substrate, the layer was built from particles with an average size larger than that of the layer built on the glass substrate. The effect of substrates with different electrical properties on TiO₂ layer morphology deposited in DBD has not yet been investigated. Full article

Plasma medicine is a field of research that focuses on the sterilization of bacteria, wounds and cancer treatment, tissue regeneration and other biomedical applications using plasma. Dielectric barrier discharge microplasma was used for biomedical applications such as sterilization of bacteria and skin treatment for transdermal drug delivery. In this study, we investigated the feasibility of using microplasma for improving blood coagulation parameters. Blood samples collected from one dog and one cat were treated with microplasma, and the blood coagulation effect of this treatment was compared with the effect achieved by treating the blood with air flow only. The microplasma electrodes were energized using a negative pulse voltage power supply and environmental air was used as discharge gas. The microplasma treatment produced clear coagulation effects that increased proportionally with treatment time, discharge voltage and frequency. In contrast, the treatment with air flow only had no coagulation effects after the same treatment time as for the microplasma treatment. The observed blood coagulation effects induced by microplasma treatment could be attributed to the reactive oxygen and nitrogen species generated by microplasma. The blood sample subjected to microplasma treatment had a slight temperature increase (≈4 °C) confirming the nonthermal operation. In conclusion, this study shows promising results that suggest the potential of using microplasma treatment as a tool for improving blood coagulation parameters. Furthermore, microplasma’s suitability for portability and integration indicates the potential for developing a compact microplasma device tailored for use by first responders in cases of bleeding. Full article

Skin cancer is the most frequently diagnosed form of cancer worldwide. Diagnostic uncertainty can arise when macroscopic or dermoscopic evaluations do not clearly differentiate between benign and malignant lesions. Laser-induced plasma spectroscopy (LIPS), traditionally used in fields like materials science and environmental analysis, has recently gained attention for its applications in human tissue assessment. LIPS works by generating a (micro)plasma when a laser interacts with tissue, producing element-specific light emissions that can be analyzed in real time. In this study, we explored the potential of LIPS to differentiate between benign and malignant skin lesions using the Spectra-Scope^® Score (SSS). Our results revealed a clear distinction: benign lesions showed a median SSS of 1.7, while suspicious and malignant lesions had a significantly higher median score of 8.1 (p < 0.001). Receiver operating characteristic (ROC) curve analysis demonstrated strong diagnostic performance, with an area under the curve (AUC) of 0.82 (p < 0.001). The findings of this preliminary study support the high accuracy of LIPS in identifying malignancy and underscore its promise as a non-invasive, real-time diagnostic aid. Integrating SSS into clinical workflows could enhance the early detection of skin cancer and reduce reliance on invasive diagnostic procedures. However, further validation is needed to fully establish its role in routine dermatological practice. Full article

Hydroxyapatite (HA) has become a widely used material for bone grafting and surface modification of titanium-based orthopedic implants due to its excellent biocompatibility. Among various coating techniques, microplasma spraying (MPS) has gained significant industrial relevance. However, the clinical success of HA coatings also depends on their adhesion to the implant substrate. Achieving durable fixation and reliable biological integration of orthopedic implants remains a major challenge due to insufficient coating adhesion and limited osseointegration. This study addresses challenges in dental and orthopedic implantology by evaluating the microstructure, mechanical properties, and biological behavior of bilayer coatings composed of a zirconium (Zr) sublayer and an HA top layer, applied via MPS onto titanium alloy. Surface roughness, porosity, and adhesion were characterized, and pull-off and shear tests were used to assess mechanical performance. In vitro biocompatibility was tested using rat mesenchymal stem cells (MSCs) to model osteointegration. The results showed that the MPS-fabricated Zr–HA bilayer coatings achieved a pull-off strength of 28.0 ± 4.2 MPa and a shear strength of 32.3 ± 3.2 MPa, exceeding standard requirements. Biologically, the HA top layer promoted a 45% increase in MSC proliferation over three days compared to the uncoated titanium substrate. Antibacterial testing also revealed suppression of E. coli growth after 14 h. These findings support the potential of MPS-applied Zr-HA coatings to enhance both the mechanical integrity and biological performance of titanium-based orthopedic implants. Full article

Conventional ultraviolet microplasma sources typically lack a back-reflection structure, resulting in radiative power loss from the backside. To enhance the emission efficiency of ultraviolet microplasma devices around 220 nm, we propose a multilayer reflective coating composed of alternating high- and low-refractive-index layers of Al₂O₃ and SiO₂, within a V-shaped groove. Key structural parameters, including the number of alternating film layer pairs, groove width, and light source position, are investigated to show their effects on ultraviolet reflection characteristics. The results show that reducing the groove width greatly enhances light reflection. When the groove width is 6.5 μm, the device exhibits a reflection efficiency of 47.82% and power enhancement of 91.66%, representing improvements of 2.5-fold and 4.2-fold, respectively, compared to non-optimized cases. Device performance is also influenced by the offset of the light source, which is more sensitive along the horizontal direction. This study provides a practical solution for developing high-efficiency ultraviolet emission devices. Full article

Spatters in the powder-based metal additive manufacturing processes influence deposition quality, part surface quality, and internal defects. We developed a novel video analysis method to monitor and count the melted spatter particles of biomedical-grade Co-Cr-Mo-4Ti powder particles in depositing layers using a micro-plasma transferred arc additive manufacturing (M-PTAAM) process. We captured the spatters using a weld-monitoring camera and building datasets of videos and monitored different combinations of M-PTAAM process parameters. We captured videos of the melted spatter particles and counted the melted spatter particles in real time using a Kalman filter. The weld-monitoring camera captured the melted spatter particles and the fumes generated by the evaporated spatter particles. The video processing algorithm was developed in this study to accurately capture melted spatter particles. In images without fumes, nearly all melted spatter particles were successfully detected. Even in images with the presence of fumes, the algorithm maintained a detection accuracy of 90%. The real-time melted spatter count particle exhibited a powder feed rate changing from 30 to 35 g/min and then to 50 g/min. The melted spatter particle count was lowest at a powder feed rate of 30 g/min and increased with the increasing powder feed rate. Full article

Lipids are the primary components of cell membranes, and their properties can be temporarily modified by microplasma-generated species to enhance drug uptake. The ability of microplasmas to influence membrane dynamics has made them effective tools for facilitating drug uptake into cells. Despite this, the effect of microplasma irradiation on cell membranes is yet to be investigated. We investigated the effects of microplasma irradiation on fluorescein isothiocyanate-dextran 150 (FD-150) uptake in Human Promyelocytic Leukemia (HL-60) cells, with the focus on transmembrane potential and lipid order changes. Plasma was applied to HL-60 cells for five, seven, and ten minutes. Fluorescence intensity measurements showed that an uptake of FD-150 increased with treatment time, before declining at ten minutes of treatment. Following treatment, transmembrane potential analysis indicated transient hyperpolarization followed by gradual depolarization until 60 min, corresponding to increased FD-150 absorption. Analysis of the lipid order showed a more disordered membrane state, with the most pronounced changes observed at ten minutes. The increase in lipid disorder increases membrane permeability while excessive disruption of the lipid order impairs cell viability. These findings demonstrate the potential of plasma-generated reactive species in modulating membrane characteristics for intracellular drug delivery. Full article

The blood–brain barrier (BBB) limits drug delivery to the brain, particularly for large or hydrophilic molecules. Brain microvascular endothelial cells (bEND.3), which form part of the BBB, play a critical role in regulating drug uptake. This study investigates the use of cold atmospheric microplasma (CAM) to enhance membrane permeability and facilitate drug delivery in bEND.3 cells. CAM generates reactive oxygen species (ROS) that modulate membrane properties. We exposed bEND.3 cells to CAM at varying voltages (3, 3.5, 4, and 4.5 kV) and measured drug uptake using the fluorescent drug FD-150, fluorescence intensity, ROS levels, membrane lipid order, and membrane potential. The results showed a significant increase in fluorescence intensity and drug concentration in the plasma-treated cells compared to controls. ROS production, measured by DCFH-DA staining, was higher in the plasma-treated cells, supporting the hypothesis that CAM enhances membrane permeability through ROS-induced changes. Membrane lipid order, assessed using the LipiORDER probe, shifted from the liquid-ordered (Lo) to liquid-disordered (Ld) phase, indicating increased membrane fluidity. Membrane depolarization was detected with DisBAC2(3) dye, showing increased fluorescence in the plasma-treated cells. Cell viability, assessed by trypan blue and LIVE/DEAD™ assays, revealed transient damage at higher voltages (≥4 kV), with recovery after 24 h. These results suggest that CAM enhances drug delivery in bEND.3 cells by modulating membrane properties via ROS production and changes in membrane potential. CAM offers a promising strategy for improving drug delivery to the brain, with potential applications in brain-targeted therapies. Full article

Energy and environmental challenges are driving researchers to explore cost-effective and eco-friendly nanomaterial fabrication methods. In this study, Atmospheric Pressure Microplasma (AMP) was used to synthesize iron oxide nanoparticles at varying molar concentrations of ferrous sulfate (0.5 M, 1 M, and 1.5 M) under a 15 kV discharge voltage for 90 min. The X-ray diffraction (XRD) results confirmed the formation of mixed cubic and hexagonal phases of magnetite and hematite nanoparticles. The particle size, calculated using the Debye–Scherrer formula, ranged from 9 to 11 nm, depending on the precursor concentration. Scanning electron microscopy (SEM) images revealed spherical nanoparticles at 0.5 M, while agglomeration occurred at 1.5 M. The energy-dispersive X-ray spectroscopy (EDS) analysis confirmed the presence of iron and oxygen in the synthesized nanoparticles. Fourier-transform infrared (FTIR) and UV spectroscopy showed characteristic absorption bands of iron oxide. The impact of the particle size and lattice strain on the optical properties of the nanoparticles was also studied. Smaller nanoparticles exhibited an excellent specific capacitance (627) and a strong charge–discharge performance in a 3 M KOH solution, with a high energy density (67.72) and power density (2227). As photocatalysts, the nanoparticles demonstrated a 97.5% and 96.8% degradation efficiency against methylene blue (MB) and methyl orange (MO), respectively, with high rate constants. These results surpass previous reports. The enhanced electrochemical performance and photocatalytic activity are attributed to the high-quality iron oxide nanoparticles, showing an excellent cyclic stability, making them promising for supercapacitors and environmental remediation. Full article

Cellular senescence plays a pivotal role in aging and stress response mechanisms. Controlling cellular senescence is essential for developing novel techniques to prevent aging or aging-related diseases and promote a healthy lifespan. This study explores the efficiency of cold atmospheric microplasma (CAM) for controlling cellular senescence in yeast Saccharomyces cerevisiae. Reactive oxygen and nitrogen species (RONS) generated by CAM influence key processes, such as the regulation of oxidative stress, alterations in membrane potential, and senescence-related epigenetic modifications. As a marker of cellular senescence, the expression of β-galactosidase was assessed in response to different plasma treatments. At a frequency of 1 kHz and a discharge voltage of 5 kV_p-p, a significant reduction in β-galactosidase activity was observed in cells treated for 10 s and 30 s compared to the control, indicating a reduction in cellular senescence. Additionally, cell viability, metabolic activity, and plasma membrane potential were also found to be higher for the treated cells compared to the control under the same conditions. This study confirms that a physiologically tolerable level of ROS and RNS is sufficient for cellular signaling, but not for damage induction. The findings from this study provide insights on the potential of microplasma as a tool for controlling cellular senescence and the development of therapeutic innovations involving eukaryotic cells. Full article

This study investigates the microplasma deposition of molten tantalum (Ta) onto a rotating Grade 5 Ti Extra-Low Interstitial (ELI) alloy, producing multilayer film coatings with a porous microstructure. Optimal parameters for microplasma spraying Ta were experimentally determined to improve the surface properties of elbow joint implants. The physical and mechanical properties of the Grade 5 Ti ELI substrate and the Ta-based coating were analyzed. Moreover, mathematical modeling was utilized to determine the optimal parameters for the plasma coating process, including key factors such as spray distance, current, and rotational speed, which were systematically applied across three experimental series. A Ta coating thickness of 250 μm was achieved at 35 A current, 410 mm spray distance, and 7 rpm rotation speed under optimized deposition conditions. The results showed a microhardness increase on the Ta-coated surface, peaking above HV1000 with an average of HV742, while the Ti substrate averaged HV325. Additionally, the XRD patterns revealed the presence of metallic Ta alongside Ta oxides, such as Ta₂O and Ta₂O₅, in the Ta coatings. Full article

Dielectric-barrier-discharge microplasma has various applications such as flow control, surface treatment, air treatment, or biomedical applications. Microplasma was used for the inactivation of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Bacterial strains spread on Petri dishes containing Nutrient Agar were treated with microplasma and, after incubation, inhibition zones were observed. By comparison, the experiments carried out with the already-grown bacteria on the Petri dish did not show any inhibitory response. Environmental air was used as discharge gas. The reactive oxygen and nitrogen species mainly carry out the inactivation process. A negative pulse voltage energized the microplasma electrodes. The microplasma treatment was the most potent against S. aureus, followed by E. coli, and P. aeruginosa, which was the least susceptible bacteria from the tested strains. An increase in the inhibitory efficiency was observed with the increase in discharge voltage from −1.5 kV to −1.7 kV. This research proved the efficiency of microplasma in biological decontamination and provides valuable insights of the inactivation of bacteria carried out with a technology that is suitable for easy integration and portability. Full article

Nose-to-brain (N2B) drug delivery is a promising technique for the treatment of brain diseases. It allows a drug to enter the brain without passing through the blood–brain barrier. However, the nasal cavity and nasal mucosa can restrict the amount of drug absorbed. Recent studies of non-thermal plasma (NTP) have shown improvement in in vitro drug delivery to cells and tissues. However, whether NTP treatments can enhance the in vivo delivery of drugs for neurodegenerative disease like Alzheimer’s disease (AD) into the brain via the N2B technique remains unclear. The drug used in this study was galantamine hydrobromide. Galantamine is used to treat patients with mild to moderate AD. Based on the principle of NTP, a type of dielectric barrier discharge (DBD) plasma, which we called spiral DBD microplasma, was designed. It was inserted into the nose of a rat to a depth of 2 mm. The spiral DBD microplasma was driven by a sinusoidal voltage for 4 min, followed by the immediate administration of galantamine. The effect of the microplasma treatment on the distribution of galantamine in the brain was evaluated using matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS). The results showed a high distribution of galantamine in the left and right brain hemispheres of the rat treated with plasma discharge compared to a control treated without plasma discharge. The spiral DBD microplasma is a novel contribution to DBD plasma designs. In addition, this technique for drug delivery has also created a novel approach with potential for becoming a non-invasive method of enhancing drug distribution in the brain for the treatment of neurological disorders. Full article