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The growing interest in advancing microfluidic devices for manipulating fluids within micrometer-scale channels has prompted a shift in manufacturing practices, moving from single-component production to medium-size batches. This transition arises due to the impracticality of lab-scale manufacturing methods in accommodating the increased demand. This experimental study focuses on the design of master benchmarks 1–5, taking into consideration critical parameters such as rib width, height, and the relative width-to-height ratio. Notably, benchmarks 4 and 5 featured ribs that were strategically connected to the inlet, outlet, and reaction chamber of the master, enhancing their utility for subsequent replica production. Vat photopolymerization was employed for the fabrication of benchmarks 1–5, while replicas of benchmarks 4 and 5 were generated through polydimethylsiloxane casting. Dimensional investigations of the ribs and channels in both the master benchmarks and replicas were conducted using an optical technique validated through readability analysis based on the Michelson global contrast index. The primary goal was to evaluate the potential applicability of vat photopolymerization technology for efficiently producing microfluidic devices through a streamlined production process. Results indicate that the combination of vat photopolymerization followed by replication is well suited for achieving a minimum rib size of 25 µm in width and an aspect ratio of 1:12 for the master benchmark. [ABSTRACT FROM AUTHOR]

The attachment or entrapment of microbial cells and enzymes are promising solutions for various industrial applications. When the traps are beads, they are dispersed in a fluidized bed in a vessel where a pump guarantees fresh liquid inflow and waste outflow without washing out the cells. Scientific papers report numerous types of cell entrapment, but most of their applications remain at the laboratory level. In the present research, rigid polymer beads were manufactured by two different additive manufacturing (AM) techniques in order to verify the economy, reusability, and stability of the traps, with a view toward a straightforward industrial application. The proposed solutions allowed for overcoming some of the drawbacks of traditional manufacturing solutions, such as the limited mechanical stability of gel traps, and they guaranteed the possibility of producing parts of constant quality with purposely designed exchange surfaces, which are unfeasible when using conventional processes. AM proved to be a viable manufacturing solution for beads with complex shapes of two different size ranges. A deep insight into the production and characteristics of beads manufactured by AM is provided. The paper provides biotechnologists with a manufacturing perspective, and the results can be directly applied to transit from the laboratory to the industrial scale. [ABSTRACT FROM AUTHOR]

Electron beam melting (EBM) made feasible γ-titanium aluminide (TiAl) alloys. However, the surface roughness resulting from EBM is poor, and the high mechanical properties make γ-TiAl difficult to be machined. Electro-Chemical Machining (ECM) is gaining interest as a finishing process to achieve low surface roughness. Based on the anodic dissolution mechanism, ECM realises a contactless material removal and results particularly suitable for difficult-to-cut materials. The paper investigates the use of ECM for the finishing of Ti-48Al-2Nb-2Cr, a γ-TiAl alloy made by EBM. The effects of current, voltage, feed rate and duty ratio have been accounted for under pulsed machining conditions. [ABSTRACT FROM AUTHOR]

Laser Powder-based Directed Energy Deposition (LP-DED) process is a cutting-edge Additive Manufacturing (AM) technology for metal part repair and production. The disruptive potentialities of LP-DED are nowadays limited by the difficulty in the identification of the optimized set of process parameters, typically obtained from long and expensive experimental trials. In this work, a thermal simulation tool able to predict material deposition behaviour is developed using a finite element code. An original method is defined to model the material addition and energy flow. The forecasting capabilities of the model in terms of penetration depth and track dimensions are evaluated by comparing the numerical outcomes with experimental data. [ABSTRACT FROM AUTHOR]

Laser Powder Bed Fusion (LPBF) technology was used to produce samples based on the Ti–6Al–4V alloy for biomedical applications. Solid-state phase transformations induced by thermal treatments were studied by neutron diffraction (ND), X-ray diffraction (XRD), scanning transmission electron microscopy (STEM) and energy-dispersive spectroscopy (EDS). Although, ND analysis is rather uncommon in such studies, this technique allowed evidencing the presence of retained β in α' martensite of the as-produced (#AP) sample. The retained β was not detectable by XRD analysis, nor by STEM observations. Martensite contains a high number of defects, mainly dislocations, that anneal during the thermal treatment. Element diffusion and partitioning are the main mechanisms in the α ↔ β transformation that causes lattice expansion during heating and determines the final shape and size of phases. The retained β phase plays a key role in the α' → β transformation kinetics. [ABSTRACT FROM AUTHOR]