Vacuum electron devices operating at sub-THz frequencies require miniaturized high-frequency electromagnetic interaction structures manufactured using high-precision micromachining technologies. In this article, we present the results of microfabrication of 2-D planar microstrip periodic slow wave structures (SWSs) on dielectric substrate using magnetron sputtering and laser micromachining. A multistage optimized process that allows a substantial improvement of the fabrication accuracy is presented and discussed in detail. A batch of V -band meander-line SWS circuits is fabricated. Characterization of the fabricated structures by optical microscopy and scanning electron microscopy (SEM) demonstrates dimensional deviation less than 5 $\mu$ m. Experimental investigation of cold-test electromagnetic parameters shows good transmission and reflection characteristics.

The development of high-power millimeter and THz-band vacuum microelectronic devices (μVEDs) demands structural materials with special properties. In particular, key components of μVEDs must retain their dimensions when heated while operating at higher power levels. A molybdenum-copper alloy is a promising material, thanks to the low thermal expansion of molybdenum and the remarkable thermal and electrical conductivity of copper. However, such alloys can only be obtained by a limited number of techniques that are rather complicated. Thus, the goal of this work is the implementation of vacuum magnetron co-deposition as a facile method in the fabrication of μm-thick Mo–Cu films. Such films are very promising for the microfabrication of microstrip slow-wave structures for high-power millimeter and THz-band μVEDs. This study is focused on controlling the morphology, resistivity, and roughness of the fabricated thin films by changing the deposition process parameters, such as the sputtered Cu and Mo ratio and substrate temperature.

A promising approach to targeted drug delivery is the remote control of magnetically sensitive objects using an external magnetic field source. This method can assist in the accumulation of magnetic carriers in the affected area for local drug delivery, thus providing magnetic nanoparticles for MRI contrast and magnetic hyperthermia, as well as the magnetic separation of objects of interest from the bloodstream and liquid biopsy samples. The possibility of magnetic objects’ capture in the flow is determined by the ratio of the magnetic field strength and the force of viscous resistance. Thus, the capturing ability is limited by the objects’ magnetic properties, size, and flow rate. Despite the importance of a thorough investigation of this process to prove the concept of magnetically controlled drug delivery, it has not been sufficiently investigated. Here, we studied the efficiency of polyelectrolyte capsules’ capture by the external magnetic field source depending on their size, the magnetic nanoparticle payload, and the suspension’s flow rate. Additionally, we estimated the possibility of magnetically trapping cells containing magnetic capsules in flow and evaluated cells’ membrane integrity after that. These results are required to prove the possibility of the magnetically controlled delivery of the encapsulated medicine to the affected area with its subsequent retention, as well as the capability to capture magnetically labeled cells in flow.

Ongoing active development of modern radio frequency electronic devices operating in the millimeter (V) band, such as fifth-generation wireless communications, demands new materials to control electromagnetic interference, compatibility, and reliability of such systems. This work investigates feasibility absorptive non-reflective thin coatings deposition on dielectric substrates using simultaneous magnetron co-deposition. For this, electromagnetic waves propagation in the millimeter band through in micrometer-thick Al–Si films of varied composition was studied. The co-deposition process was controlled by the ratio of sputtered atoms fluxes. Graded segregation was observed under certain parameters of the co-deposition process, resulting in a depth gradient of an aluminum content, as confirmed by the secondary ion mass spectrometry study. A qualitative model was proposed involving aluminum-induced silicon recrystallization happening in the course of a known aluminum interlayer exchange process. The observed Al–Si segregation effect in micrometer-thick films allows for preparation of the non-reflective and absorptive material for operation in the V-band with reflection losses more than 10 dB and transmission losses around 5 dB in the bandwidth of up to 20 GHz.

In recent years, non-invasive methods for the analysis of biological fluids have attracted growing interest. In this study, we propose a straightforward approach to fabricating silver nanoparticle (AgNP)-coated non-woven polyacrylonitrile substrates for surface-enhanced Raman scattering (SERS). AgNPs were synthesized directly on the substrate using borohydride reduction, ensuring uniform distribution. The optimized SERS substrates exhibited a high enhancement factor (EF) of up to 10⁵ for the detection of 4-mercaptobenzoic acid (4-MBA). To enable glucose sensing, the substrates were further functionalized with glucose oxidase (GOx), allowing detection in the 1–10 mM range. Machine learning classification and regression models based on gradient boosting were employed to analyze SERS spectra, enhancing the accuracy of quantitative predictions (R² = 0.971, accuracy = 0.938, limit of detection = 0.66 mM). These results highlight the potential of AgNP-modified substrates for reliable and reusable biochemical sensing applications.