Blood tests are widely used in modern medicine to diagnose certain illnesses and evaluate the overall health of a patient. To enable testing in resource-limited areas, there has been increasing interest in point-of-care (PoC) testing devices. To process blood samples, liquid mixing with active pumps is usually required, making PoC blood testing expensive and bulky. We explored the possibility of processing approximately 2 μL of whole blood for image flow cytometry using capillary structures that allowed test times of a few minutes without active pumps. Capillary pump structures with five different pillar shapes were simulated using Ansys Fluent to determine which resulted in the fastest whole blood uptake. The simulation results showed a strong influence of the capillary pump pillar shape on the chip filling time. Long and thin structures with a high aspect ratio exhibited faster filling times. Microfluidic chips using the simulated pump design with the most efficient blood uptake were fabricated with polydimethylsiloxane (PDMS) and polyethylene oxide (PEO). The chip filling times were tested with 2 μL of both water and whole blood, resulting in uptake times of 24 s for water and 111 s for blood. The simulated blood plasma results deviated from the experimental filling times by about 35% without accounting for any cell-induced effects. By comparing the flow speed induced by different pump pillar geometries, this study offers insights for the design and optimization of passive microfluidic devices for inhomogenous liquids such as whole blood in sensing applications.

This study systematically compares the surface polishing performance and finishing results of the following two different electrolytic plasma polishing technologies on stainless steel AISI 316L: (i) plasma electrolytic polishing (PEP) and (ii) plasma electrolytic polishing jet (PEP-Jet). The two techniques are compared against an industrial standard polishing method, electropolishing (EP). For comparable energy density consumption, the samples treated with the PEP-Jet technique showed the highest removal rate, up to three times less than the initial roughness, resulting in the highest surface roughness reduction from Sa = 249 nm to Sa = 81 nm. Microstructure characterization of samples treated using PEP-Jet also showed well-defined crystalline grain boundaries with a distinct appearance of predominantly inter-crystalline structures within individual grains, which is uncommon with EP techniques. The surfaces treated using PEP-Jet exhibited the lowest corrosion rate of $6.79\times {10}^{-5}$ mm/year, and no signs of areal corrosion were detected in the performed corrosion tests in contrast with the other samples and their respective treatments. The comparative analysis revealed that the high ionic current delivered by the electrolyte jet flow in the PEP-Jet process effectively stabilizes the plasma at the contact zone, thereby enhancing the plasma polishing of austenitic stainless steel samples. The efficacy of this method has been demonstrated in terms of reducing energy consumption and enhancing corrosion resistance in comparison with (PEP) and (EP) as state-of-the-art processes in corrosive environments of high-alloyed steel.

Lateral flow immunoassays (LFIAs) were integrated into microfluidic chips and tested to enhance point-of-care testing (POCT), with the aim of improving sensitivity and expanding the range of CRP detection. The microfluidic approach improves upon traditional methods by precisely controlling fluid speed, thus enhancing sensitivity and accuracy in CRP measurements. The microfluidic approach also enables a one-step detection system, eliminating the need for buffer solution steps and reducing the nitrocellulose (NC) pad area to just the detection test line. This approach minimizes the non-specific binding of conjugated antibodies to unwanted areas of the NC pad, eliminating the need to block those areas, which enhances the sensitivity of detection. The gold nanoparticle method detects CRP in the high-sensitivity range of 1–10 $\mu$g/mL, which is suitable for chronic disease monitoring. To broaden the CRP detection range, including infection levels beyond 10 $\mu$g/mL, fluorescent labels were introduced, extending the measuring range from 1 to 70 $\mu$g/mL. Experimental results demonstrate that integrating microfluidic technology significantly enhances operational efficiency by precisely controlling the flow rate and optimizing the mixing efficiency while reducing fabrication resources by eliminating the need for separate pads, making these methods suitable for resource-limited settings. Microfluidics also provides greater control over fluid dynamics compared to traditional LFIA methods, which contributes to enhanced detection sensitivity even with lower sample volumes and no buffer solution, helping to enhance the usability of POCT. These findings highlight the potential to develop accessible, accurate, and cost-effective diagnostic tools essential for timely medical interventions at the POC.

The advent of the additive manufacturing of Ti-6Al-4V (Ti64) alloys has facilitated the production of complex geometries for various industrial applications. Nevertheless, the inherent surface roughness of selective laser melting (SLM)-produced parts remains a critical limitation, adversely affecting fatigue life, wear, corrosion, and compliance with stringent surface quality standards, for example those required in hygienic applications. Conventional post-processing methodologies, encompassing grinding and electropolishing, are frequently multi-stage, labor-intensive, and reliant on hazardous electrolytes, which thus limits their use for certain applications. In this study, plasma electrolytic polishing (PEP) was evaluated as a single-step finishing process for 3D-printed Ti64 components. The findings indicate that PEP efficiently diminished surface roughness from initial values of approximately 9–10 µm to as low as 0.38–0.5 µm within a time frame of 15–20 min, depending on the initial surface condition. These outcomes meet hygienic surface requirements while ensuring the use of environmentally compatible electrolytes. The findings establish PEP as a non-mechanical, efficient, and scalable additive-manufacturing post-processing strategy. It has the capacity to supersede conventional multi-stage workflows and offer substantial reductions in cost, time, and environmental impact.

Capillary-driven microfluidic chips have emerged as promising platforms for point-of-care diagnostics, offering portable, inexpensive, and pump-free operation. Accurate tracking of cell flow in these systems is vital for quantitative applications such as on-chip cytometry, cell counting, and biomechanical analysis. However, tracking in capillary-driven devices is challenging due to rapid cell displacements, flow instabilities, and visually similar cells. Under these conditions, conventional tracking algorithms such as TrackPy, TrackMate, SORT, and DeepSORT exhibit frequent identity switches and trajectory fragmentation. Here, we introduce FloCyT, a robust, high-speed centroid tracking tool specifically designed for capillary-driven and microfluidic flow. FloCyT leverages microchannel geometry for tracking and uses anisotropic gating for association, global flow-aware track initialisation, and channel-specific association. This enables precise tracking even under challenging conditions of capillary-driven flow. FloCyT was evaluated on 12 simulated and 4 real patient datasets using standard multi-object tracking metrics, including IDF1 and MOTA, ID switches, and the percentage of mostly tracked objects. The results demonstrate that FloCyT outperforms both standard and flow-aware-modified versions of TrackPy and SORT, achieving higher accuracy, more complete trajectories, and fewer identity switches. By enabling accurate and automated cell tracking in capillary-driven microfluidic devices, FloCyT enhances the quantitative sensing capability of image-based microfluidic diagnostics, supporting novel, low-cost, and portable cytometry applications.

This study investigates electrolyte jet processing of metals by plasma polishing, focusing on the polishing regimes and their governing flow dynamics, which result in different current density distributions and, consequently, different plasma polishing regimes. Experimental investigations performed at 350 V using a fixed-diameter electrolyte jet included localized current measurements and surface topography characterization, while finite element method (FEM) simulations were used to evaluate four plasma vapor–gas envelope (VGE) geometries. The experimental results revealed two distinct polishing regimes: a contact zone coinciding with the nozzle diameter, where the highest local cur-rent density reached 10.8 mA/mm² and produced a maximum material removal rate of 1.17 µm/s, and a surrounding electrolyte splash zone extending to approximately twice the nozzle diameter, where the local current density progressively decreased to 2.6 mA/mm², corresponding to a minimum material removal rate of 0.16 µm/s. Unlike previous, studies the numerical simulations showed that a constant plasma vapor–gas envelope thickness of 15.8 µm provided the closest agreement with the experimentally measured polishing profile. Based on the combined experimental and numerical results, the contact zone is interpreted as a plasma-dominated region characterized by high current density, whereas the splash zone is interpreted as a transient plasma regime in which electrochemical polishing increasingly dominates as current density decreases. This study improves the understanding of plasma electrolyte polishing (PEP), which involves both plasma-assisted and electrochemical material-removal mechanisms. The results provide guidance for im-proving surface quality and process efficiency in electrolyte-jet PEP of stainless steel.