Journal Description
Micro
Micro
is an international, peer-reviewed, open access journal on microscale and nanoscale research and applications in physics, chemistry, materials, biology, medicine, food, environment technology, engineering, etc., published quarterly online by MDPI.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within Scopus, ESCI (Web of Science) and other databases.
- Journal Rank: CiteScore - Q2 (Engineering (miscellaneous))
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 23.2 days after submission; acceptance to publication is undertaken in 2.7 days (median values for papers published in this journal in the second half of 2025).
- Recognition of Reviewers: APC discount vouchers, optional signed peer review, and reviewer names published annually in the journal.
- Micro is a companion journal of Micromachines.
Impact Factor:
1.9 (2024);
5-Year Impact Factor:
2.0 (2024)
Latest Articles
Smartphone-Based Microscope with Integrated Reflective Illumination for On-Chip Dynamic Characterization of Microparticles
Micro 2026, 6(2), 38; https://doi.org/10.3390/micro6020038 - 19 May 2026
Abstract
This work presents the Smart-Reflex-Scope, a compact and accessible smartphone-based microscope with integrated reflective illumination developed for on-chip analysis of microparticle dynamics. In this work, the platform is specifically employed to characterize size-dependent microparticle motion within a microchannel. The Smart-Reflex-Scope simultaneously functions as
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This work presents the Smart-Reflex-Scope, a compact and accessible smartphone-based microscope with integrated reflective illumination developed for on-chip analysis of microparticle dynamics. In this work, the platform is specifically employed to characterize size-dependent microparticle motion within a microchannel. The Smart-Reflex-Scope simultaneously functions as an illumination source and imaging unit by integrating a reversed smartphone camera lens, a custom reflex module, a microfluidic chip, and a precision Z-axis translation stage for focal adjustment. The optical performance was quantitatively evaluated in terms of equivalent focal length, magnification, and object-plane spatial resolution, providing a comprehensive assessment of the system’s microscale imaging capabilities. A comparative design study was conducted between two configurations: Design-1, based on normal reflection, and Design-2, based on angular reflection. The two approaches were analyzed with respect to illumination uniformity and imaging performance to identify the optimal configuration for enhanced visualization. Experimental validation was performed using synthetic microparticles with diameters of and , enabling assessment of the system’s ability to resolve and dynamically track micrometric objects of different sizes. The results demonstrate reliable detection and size-dependent dynamic characterization. A two-factor statistical ANOVA analysis confirmed the significance of the observed differences between microparticle groups under the tested experimental conditions (p-value ). Overall, the proposed platform represents a scalable and miniaturized microscopy solution bridging conventional benchtop instruments and portable analytical devices.
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(This article belongs to the Section Analysis Methods and Instruments)
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Open AccessArticle
Microstructure-Controlled g-C3N4: From Photocatalyst to Potential UV-Shielding Pigment with Enhanced Skin Feel
by
Masanori Sakamoto, Akari Nakata, Misa Shimizu, Ayuka Tagashira, Hideyuki Hirazawa, Yugo Imai, Hazuki Saka and Kokona Okabe
Micro 2026, 6(2), 37; https://doi.org/10.3390/micro6020037 - 18 May 2026
Abstract
Conventional organic and inorganic ultraviolet (UV) filters often face limitations related to photostability, skin penetration, and potential toxicity arising from their photocatalytic activity. In this study, graphitic carbon nitride (g-C3N4) was investigated as a candidate biocompatible UV-shielding pigment. g-C
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Conventional organic and inorganic ultraviolet (UV) filters often face limitations related to photostability, skin penetration, and potential toxicity arising from their photocatalytic activity. In this study, graphitic carbon nitride (g-C3N4) was investigated as a candidate biocompatible UV-shielding pigment. g-C3N4 powders were synthesized via thermal polymerization using urea and melamine as precursors. The melamine-derived samples exhibited a dense, block-like morphology with a strong yellow coloration and poor spreadability. In contrast, the urea-derived samples formed a distinctive porous and rounded structure. This morphology, originating from multistage gas evolution during polymerization, significantly reduced the static friction coefficient, resulting in a smoother texture and improved skin adaptability. Preliminary biological evaluation indicated high cell viability in cytotoxicity tests. Combined with the observed low photocatalytic activity, these findings suggest a favorable biocompatibility profile for topical applications. Overall, the results demonstrate that precursor engineering using urea enables the synthesis of high-performance g-C3N4 pigments with improved texture, desirable optical properties, and reduced biological reactivity.
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(This article belongs to the Special Issue Functional Micro- and Nanomaterials: Design, Modulation, and Applications in Energy and Sensing)
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Open AccessReview
Imidazole Antifungals Against Fungal Pathogens: Resistance Mechanisms and Emerging Delivery Strategies
by
Manita Saini, Syed Arman Rabbani, Mohamed El-Tanani, Shrestha Sharma and Rakesh Kumar
Micro 2026, 6(2), 36; https://doi.org/10.3390/micro6020036 - 13 May 2026
Abstract
Fungal infections remain a major and growing global health concern, particularly in immunocompromised populations and in settings where antifungal resistance is increasing. Imidazole antifungals continue to play an important role in the treatment of superficial and mucocutaneous mycoses because they inhibit lanosterol 14α-demethylase
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Fungal infections remain a major and growing global health concern, particularly in immunocompromised populations and in settings where antifungal resistance is increasing. Imidazole antifungals continue to play an important role in the treatment of superficial and mucocutaneous mycoses because they inhibit lanosterol 14α-demethylase (CYP51), a key enzyme in ergosterol biosynthesis. This mechanism disrupts fungal membrane integrity and underlies their clinical utility. However, the effectiveness of imidazoles is increasingly limited by resistance mechanisms such as CYP51 mutations, efflux pump overexpression, and biofilm-associated tolerance. In parallel, several biopharmaceutical constraints, including poor aqueous solubility, limited tissue penetration, short residence time, and variable local drug exposure, further reduce therapeutic performance. This review critically examines the medicinal chemistry, mechanism of action, and resistance biology of imidazole antifungals, while also highlighting the role of pharmacokinetic and pharmacodynamic limitations in treatment failure. Particular attention is given to emerging drug delivery approaches, including lipid-based systems, vesicular carriers, nanocarriers, and other advanced topical formulations, which are being developed to improve solubility, enhance tissue retention, and sustain antifungal exposure at the site of infection. By integrating resistance mechanisms with formulation science, the review provides a translational perspective on how imidazole antifungals may be optimized for improved clinical utility and resistance management.
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(This article belongs to the Topic Antimicrobial Agents and Nanomaterials—2nd Edition)
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Open AccessReview
Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges
by
Tomasz Blachowicz, Guido Ehrmann, Johannes Fiedler, Reinhard Kaschuba and Andrea Ehrmann
Micro 2026, 6(2), 35; https://doi.org/10.3390/micro6020035 - 11 May 2026
Abstract
Freeform optics belong to the increasingly important elements in optical research and industry, which pose several challenges regarding design and highly precise manufacturing. First being used in cameras and for focusing, nowadays freeform optics are used in a broad range of applications, from
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Freeform optics belong to the increasingly important elements in optical research and industry, which pose several challenges regarding design and highly precise manufacturing. First being used in cameras and for focusing, nowadays freeform optics are used in a broad range of applications, from lighting to LiDAR, from endoscopy to photovoltaics, and from astronomical instruments to quantum cryptography. Designing freeform optics can be based on different theories and methods. Fabrication is possible by mechanical methods, such as diamond turning or high-precision milling, often followed by different polishing techniques, as well as laser-based techniques, mainly applying different lithographic techniques. Here, we give an overview of recent design and optimization methods, production methods used during the last years, and applications of freeform optics, including the possibility to combine freeform optics with tunability for different applications. We describe the opportunities of new applications as well as common problems and give an outlook towards future directions of research and development.
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(This article belongs to the Section Analysis Methods and Instruments)
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Open AccessArticle
Composition-Dependent Thermoresistive Behavior of PLA/PCL/GNP Composites: From Monotonic PTC Response to Tunable PTC–NTC Transition
by
Vladimir Georgiev, Evgeni Ivanov, Todor Batakliev and Rumiana Kotsilkova
Micro 2026, 6(2), 34; https://doi.org/10.3390/micro6020034 - 9 May 2026
Abstract
The present work investigates the composition-dependent thermoresistive behavior of polylactic acid/polycaprolactone (PLA/PCL) composites reinforced with 4 wt.% graphene nanoplatelets (GNP), prepared by twin-screw extrusion at PLA/PCL ratios of 95/5, 70/30, 60/40, and 30/70 wt.%/wt.%. Their morphology, thermal properties, and structure were characterized by
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The present work investigates the composition-dependent thermoresistive behavior of polylactic acid/polycaprolactone (PLA/PCL) composites reinforced with 4 wt.% graphene nanoplatelets (GNP), prepared by twin-screw extrusion at PLA/PCL ratios of 95/5, 70/30, 60/40, and 30/70 wt.%/wt.%. Their morphology, thermal properties, and structure were characterized by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and wide-angle X-ray diffraction. Thermoresistive measurements over four cycles (30–130 °C) revealed two distinct regimes: PLA-rich compositions exhibited a stable, monotonic positive temperature coefficient (PTC) response after the first conditioning cycle, with TCR values up to 0.38% °C−1, whereas compositions with 40–70 wt.% PCL displayed a non-monotonic PTC-to-NTC transition linked to PCL melting and subsequent conductive network rearrangement. The magnitude of both PTC and NTC responses increased systematically with PCL content. These results demonstrate that the thermoresistive characteristics of biodegradable PLA/PCL/GNP composites, including the sign, magnitude, and switching temperature of the TCR, can be effectively tuned through blend composition, offering a practical route for designing thermally responsive sensing materials.
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(This article belongs to the Special Issue Functional Micro- and Nanomaterials: Design, Modulation, and Applications in Energy and Sensing)
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Open AccessReview
Nanoemulsion-Based Delivery of Essential Oils for Controlling Foodborne Pathogens and Spoilage Microorganisms
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Diego Pádua de Almeida, Paula Zambe Azevedo, Ramila Cristiane Rodrigues, Elisa de Paula Reis Lima, Paulo Cesar Stringueta, Pedro Henrique Campelo and Evandro Martins
Micro 2026, 6(2), 33; https://doi.org/10.3390/micro6020033 - 8 May 2026
Abstract
The increasing incidence of foodborne diseases and the limitations of conventional preservation methods have driven the search for safer, more effective, and sustainable antimicrobial strategies. In this context, essential oil nanoemulsions have emerged as promising alternatives to synthetic preservatives due to their broad-spectrum
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The increasing incidence of foodborne diseases and the limitations of conventional preservation methods have driven the search for safer, more effective, and sustainable antimicrobial strategies. In this context, essential oil nanoemulsions have emerged as promising alternatives to synthetic preservatives due to their broad-spectrum antimicrobial activity, natural origin, and potential applicability across diverse food matrices. This study critically examines the mechanisms of action of essential oils against pathogenic and spoilage microorganisms and discusses how their incorporation into nanoemulsions can overcome limitations such as low volatility, poor solubility, and chemical instability. The physicochemical principles governing the formation and stability of these nanoemulsions are addressed, alongside the influence of food matrix components (proteins, lipids, polysaccharides, pH, and ionic strength) on antimicrobial efficacy. Evidence from real food systems indicates that nanoemulsions often outperform free essential oils, although the magnitude of the effect strongly depends on matrix complexity and processing or storage conditions. The review further discusses critical aspects related to toxicity, safety, bioaccessibility, sensory acceptance, and regulatory considerations, as well as emerging evidence on adaptive responses and antimicrobial resistance risks associated with sublethal exposure to essential oil nanoemulsions. It is concluded that, despite their considerable technological potential, the industrial application of essential oil nanoemulsions requires further systematic studies in real foods, standardized protocols, and integrated risk assessments to ensure efficacy and safety under practical conditions.
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(This article belongs to the Section Microscale Materials Science)
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Open AccessArticle
Pretreatment Effects on the Microtensile Bond Strength Between a Bulk-Fill Resin-Based Composite Cavity Base Material and Methyl Methacrylate (MMA)-Based Luting Cement
by
Reiko Kohsaka, Saho Komatsu, Akiko Haruyama, Toshiaki Ara, Akihiro Kuroiwa, Nobuo Yoshinari and Atsushi Kameyama
Micro 2026, 6(2), 32; https://doi.org/10.3390/micro6020032 - 3 May 2026
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The effects of different surface pretreatments on the microtensile bond strength (µTBS) between a bulk-fill resin-based composite cavity base material (Bulk Base HARD II) and 4-META/MMA-TBB resin (Super-Bond EX), which is often used as a luting agent for indirect dental restorations, were investigated.
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The effects of different surface pretreatments on the microtensile bond strength (µTBS) between a bulk-fill resin-based composite cavity base material (Bulk Base HARD II) and 4-META/MMA-TBB resin (Super-Bond EX), which is often used as a luting agent for indirect dental restorations, were investigated. Six experimental treatments were established: 10% citric acid/3% ferric chloride conditioner (10-3), self-etching primer (Teeth Primer; TP), silane coupling agent (M&C Primer; MC), 10-3+MC, TP+MC, and a control group with no treatment. The µTBS was measured after 1 week (immediate group) and 6 months (aged group) of water storage. There were no significant differences in µTBS among the immediate subgroups. However, the aged 10-3+MC group exhibited the highest bond strength, significantly outperforming the control group. On the other hand, the µTBS of the aged TP group was significantly lower than those of both aged 10-3 and 10-3+MC. MC alone did not enhance bond strength, and its application after TP led to a nonuniform surface morphology, raising concerns about adhesive stability. Failure mode analysis indicated that cohesive failure within the luting cement was predominant, with mixed failures being more frequent in the aged TP group. Overall, MC may not be necessary, and 10-3 conditioning does not adversely affect bond strength. Based on the results of this in vitro study, the most effective clinical practice entails pretreatment of the prepared cavity employing a citric acid/ferric chloride conditioner.
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Open AccessReview
Linearization of BTI Degradation Across Si, SiC, and GaN
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Joseph B. Bernstein, Tsuriel Avraham and Bin Wang
Micro 2026, 6(2), 31; https://doi.org/10.3390/micro6020031 - 30 Apr 2026
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Bias temperature instability (BTI) degradation is commonly described using empirical power-law kinetics; however, extraction of the time exponent and projection of lifetime remain highly sensitive to baseline definition and data representation. In conventional approaches, the threshold voltage shift is referenced to an initial
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Bias temperature instability (BTI) degradation is commonly described using empirical power-law kinetics; however, extraction of the time exponent and projection of lifetime remain highly sensitive to baseline definition and data representation. In conventional approaches, the threshold voltage shift is referenced to an initial value that cannot be measured simultaneously with stress, introducing uncertainty that can produce apparent curvature and variability in the extracted exponent. In this work, a baseline-independent linearization method is applied to representative published datasets spanning advanced silicon, SiC MOSFETs, and GaN power devices. By analyzing the measured degradation trajectories directly in a transformed time coordinate, the method removes curvature associated with baseline ambiguity and enables consistent extraction of the effective power-law exponent. Across all material systems examined, the extracted exponent exhibits systematic dependence on applied stress once baseline effects are reduced. This behavior challenges the commonly assumed constant-exponent formulation used in conventional lifetime projections and shows that even modest variations in the exponent can produce large differences in projected time-to-failure. A transformed lifetime representation based on is introduced, in which the influence of exponent variation is separated from the intrinsic voltage and temperature acceleration of the degradation rate. In this representation, the extracted acceleration parameters become more stable and physically interpretable. This formulation is consistent with standard reliability frameworks, including JEDEC JEP122G, in which the time exponent enters directly into the lifetime expression. These results demonstrate that baseline-independent analysis provides a unified framework for interpreting BTI degradation across disparate semiconductor technologies and suggest that explicit treatment of stress-dependent exponents is required for physically consistent lifetime modeling.
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Open AccessArticle
Hydrogen Evolution Kinetics on Noble-Metal-Lean Pd/Ag Nanowire Networks Supported on Graphite
by
Martina Schwager, Niklas Käfer, Jenni Richter and Hannes Reggel
Micro 2026, 6(2), 30; https://doi.org/10.3390/micro6020030 - 30 Apr 2026
Abstract
The hydrogen evolution reaction (HER) plays a central role in electrochemical hydrogen production and requires catalysts that combine high activity with reduced noble metal usage. In this work, palladium nanoparticles (PdNPs) were deposited onto silver nanowire-modified graphite electrodes (Pd/AgNW/C) to investigate the influence
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The hydrogen evolution reaction (HER) plays a central role in electrochemical hydrogen production and requires catalysts that combine high activity with reduced noble metal usage. In this work, palladium nanoparticles (PdNPs) were deposited onto silver nanowire-modified graphite electrodes (Pd/AgNW/C) to investigate the influence of Pd loading on HER kinetics and catalytic efficiency. The electrodes were prepared by constant-current electrodeposition and characterized using polarization measurements and electrochemical impedance spectroscopy (EIS). The direct current (DC) results showed a pronounced enhancement of HER activity in the presence of Pd, while the highest mass-specific activity was observed at low Pd loadings. Increasing the Pd content further increased the overall current but reduced the catalytic efficiency when normalized to the Pd mass. EIS measurements revealed two contributions to the impedance response associated with processes occurring on different timescales. With increasing cathodic overpotential, both the charge transfer resistance and the low-frequency resistance decreased markedly, indicating accelerated reaction kinetics. The combined DC and alternating current (AC) analyses suggest that the silver nanowire network facilitates efficient electron transport and promotes a favorable dispersion of Pd nanoparticles at low loadings, enabling efficient HER catalysis with reduced noble metal usage.
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(This article belongs to the Special Issue Nanomaterials for Sustainable Waste Conversion, Energy Production, and Environmental Applications)
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Beyond the Black Box: Resin Viscosity and Tensile Strength as Fabrication Guides for VPP 3D-Printed Microfluidic Molds
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Rifat Hussain Chowdhury, Shunya Okamoto, Takayuki Shibata, Tuhin Subhra Santra and Moeto Nagai
Micro 2026, 6(2), 29; https://doi.org/10.3390/micro6020029 - 24 Apr 2026
Abstract
Resin 3D-printed molds are being increasingly favored for PDMS microfluidics across many disciplines. However, resin diversity, as well as secret manufacturer formulations, leads to a lack of standardization when using 3D printing for microscale applications. The impact of physical resin properties, both in
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Resin 3D-printed molds are being increasingly favored for PDMS microfluidics across many disciplines. However, resin diversity, as well as secret manufacturer formulations, leads to a lack of standardization when using 3D printing for microscale applications. The impact of physical resin properties, both in its monomeric concoction and polymerized lattices at 100 µm or lower scales, needs quantification. We tested the performance of locally available resin formulations, isolating the impact of resin pigments and how it impacted the resin’s properties and performance. Lower resin viscosity improved feature fidelity (edge filleting < 25 µm) and improved resolution limit for recessed features, while cured polymer mechanical strength impacted the limit for positive mold features. We combined our findings to fabricate quality negative and positive mold structures in the mold and determined the best protocols associated with limitations during the fabrication of such structures. The methodologies in this study are expected to be widely applicable across various resin types and simplify the adoption of 3D printing protocols for specific feature fabrication in microscale molds for PDMS devices.
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(This article belongs to the Special Issue Micro- and Nanosized Polymer Powders: From Design to Processing Technologies and Advanced Applications)
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Optical and Thermal Control of Pore Architecture in Collagen Hydrogels for Vascular-like Tissue Engineering Scaffolds
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Mareni Arishima, Shigehisa Aoki, Sayaka Masaike and Takayuki Narita
Micro 2026, 6(2), 28; https://doi.org/10.3390/micro6020028 - 22 Apr 2026
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Vascularization remains a central challenge in thick tissue engineering. Building on our prior demonstration that carbonate buffer concentration governs multi-channel collagen gel (MCCG) architecture and perfusion culture performance, this study aimed to establish non-contact, orthogonal control of pore size and density in riboflavin-sensitized
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Vascularization remains a central challenge in thick tissue engineering. Building on our prior demonstration that carbonate buffer concentration governs multi-channel collagen gel (MCCG) architecture and perfusion culture performance, this study aimed to establish non-contact, orthogonal control of pore size and density in riboflavin-sensitized Type I collagen hydrogels via UV irradiation intensity and preparation temperature. UV intensity was modulated by varying the source-to-sample distance (25–52 mm); preparation temperature was set at 5, 25, or 40 °C; gelation kinetics were quantified using a vial-tilt assay. Pore area fraction ranged from 0.9% to 8.6% and Young’s modulus from 16 to 49 kPa depending on UV dose. Higher preparation temperatures accelerated gelation and produced smaller, more densely distributed pores, consistent with kinetically arrested phase separation. NIH/3T3 fibroblasts cultured on intermediate- and low-intensity UV scaffolds achieved >80% confluency by Day 7, with three-dimensional tissue-like organization and directionally aligned cellular bundles within large pores; cell metabolic activity, assessed by CCK-8 assay, remained consistently high throughout the culture period. These results demonstrate that UV irradiation intensity and preparation temperature are independently tunable, non-contact parameters for reproducible fabrication of collagen scaffolds with tunable vascular-like pore networks, complementing and extending the chemical (buffer concentration) design space of MCCG-based perfusion culture systems.
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Open AccessArticle
Carbonaceous Composites of Eco-Friendly Alginic Acid–Calcium (II) Beads for Cleaning Herbicides from Water
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Sahin Demirci, Jorge H. Torres, Seneshaw Tsegaye and Nurettin Sahiner
Micro 2026, 6(2), 27; https://doi.org/10.3390/micro6020027 - 21 Apr 2026
Abstract
The widespread use of herbicides such as paraquat and glyphosate is a serious environmental and health concern due to their persistence, mobility, and toxicity in aquatic ecosystems. Composites of alginic acid (Alg) are prepared with carbonaceous materials such as graphene oxide (GO), carbon
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The widespread use of herbicides such as paraquat and glyphosate is a serious environmental and health concern due to their persistence, mobility, and toxicity in aquatic ecosystems. Composites of alginic acid (Alg) are prepared with carbonaceous materials such as graphene oxide (GO), carbon particles (CPs), porous carbon particles (PCPs), carbon black (CB), and carbon nanotubes (CNTs) were synthesized and evaluated as sorbents for the removal of cationic herbicide paraquat and the anionic herbicide glyphosate. The resulting Alg-based beads are environmentally safe because of the materials used during their preparation, such as a biopolymer, Alg, carbonaceous substances (GO, CPs, PCPs, and CB) as composite moieties, and Ca(II) ions as cross-linkers. The Alg–bead composite possessed strong swelling ability ranging from 1700% to 2500%, which led to swollen beads of spherical shape and an average diameter of 3 mm, each containing 20% of carbonaceous materials. Amongst all Alg-based beads prepared for paraquat and glyphosate removal from the aquatic environment, the highest adsorption capacity was attained for Alg–porous carbon particle (Alg-PCP) composites. The Alg-PCP beads were capable of adsorbing 85.7 ± 2.9 mg/g and 31.6 ± 2.2 mg/g from 50 mL of 250 ppm solutions of paraquat and glyphosate, respectively. In contrast, bare Alg beads adsorbed only 39.7 ± 1.8 mg/g and 12.9 ± 1.7 mg/g, respectively. A 250 mg Alg-PCP bead composite achieved a 91% removal of paraquat from a 50 mL solution containing 250 ppm of paraquat. These results show that Alg–PCP can be used to mitigate herbicide contamination in water, protecting aquatic ecosystems and addressing associated environmental and health risks.
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(This article belongs to the Section Microscale Materials Science)
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A Custom-Built SPIM Platform for Three-Dimensional Time-Lapse Imaging and Quantification of Anisotropic Tumor Spheroid Growth
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Yudai Oda, Masaki Miyamoto and Shogo Miyata
Micro 2026, 6(2), 26; https://doi.org/10.3390/micro6020026 - 18 Apr 2026
Abstract
Mechanical confinement plays an important role in regulating tumor growth and invasion; however, the quantitative, time-resolved, three-dimensional evaluation of confined tumor spheroids remains technically challenging. In this study, we developed a custom-built selective plane illumination microscopy (SPIM)-based monitoring platform for long-term volumetric imaging
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Mechanical confinement plays an important role in regulating tumor growth and invasion; however, the quantitative, time-resolved, three-dimensional evaluation of confined tumor spheroids remains technically challenging. In this study, we developed a custom-built selective plane illumination microscopy (SPIM)-based monitoring platform for long-term volumetric imaging of tumor spheroids under mechanically confined conditions. This system integrates a culture housing unit and a transparent cuvette-based spheroid culture method optimized for SPIM observation. Colorectal adenocarcinoma-derived cell spheroids were embedded in agarose gels with defined concentrations to modulate the stiffness of the surrounding matrix. Bright-field imaging and viability analyses confirmed sustained spheroid growth without necrotic core formation over a 4-day culture period, demonstrating that the SPIM-based system maintained the physiological culture conditions. Three-dimensional imaging using SPIM enabled a quantitative evaluation of spheroid growth and anisotropic invasion. Volumetric expansion was observed under all confinement conditions. Notably, increasing the matrix stiffness enhanced both the volumetric growth rate and anisotropic invasion, indicating stiffness-dependent directional growth under mechanical confinement. The developed SPIM-based platform has the potential to serve as a practical tool for the time-resolved three-dimensional analysis of tumor spheroid growth and may provide a useful approach for investigating the mechanobiological regulation of tumor progression in confined microenvironments.
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(This article belongs to the Section Microscale Biology and Medicines)
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Enhanced Antibiotic Removal Using Fe-Doped ZnS Nanoparticles
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Sonia J. Bailón-Ruiz, Yarilyn Cedeño-Mattei, Nayeli Colón-Dávila and Luis Alamo-Nole
Micro 2026, 6(2), 25; https://doi.org/10.3390/micro6020025 - 9 Apr 2026
Abstract
The environmental persistence of β-lactam antibiotics represents a growing ecological concern, requiring materials capable of combined adsorption and catalytic degradation. Herein, pure ZnS and 1% Fe-doped ZnS nanoparticles were synthesized via microwave-assisted treatment and evaluated for the removal of ceftaroline fosamil from aqueous
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The environmental persistence of β-lactam antibiotics represents a growing ecological concern, requiring materials capable of combined adsorption and catalytic degradation. Herein, pure ZnS and 1% Fe-doped ZnS nanoparticles were synthesized via microwave-assisted treatment and evaluated for the removal of ceftaroline fosamil from aqueous media. Transmission electron microscopy revealed quasi-spherical nanoparticles below 10 nm, while selected area electron diffraction confirmed a face-centered cubic structure retained after Fe incorporation. UV-Vis spectroscopy showed similar absorption edges (~316 nm), indicating negligible band-gap variation, whereas photoluminescence analysis demonstrated strong emission quenching in Fe-ZnS, indicating suppressed electron–hole recombination. Point-of-zero charge measurements (pHPZC ≈ 4.6 for ZnS; 4.5 for Fe-ZnS) indicated negatively charged surfaces under circumneutral conditions, influencing interfacial interactions with the antibiotic. Adsorption experiments followed the Langmuir isotherm model, with Fe-ZnS exhibiting a higher maximum adsorption capacity (156 mg g−1) compared to ZnS (115 mg g−1). Under UV irradiation (302 nm), Fe-ZnS achieved near-complete degradation at a catalyst loading of 500 ppm. Liquid chromatography–mass spectrometry analysis revealed the transformation of ceftaroline fosamil (m/z 685.01) into ceftaroline (m/z 605.05) via phosphate group loss, followed by the formation of intermediate fragments at m/z 492.08 and 308.03, associated with cleavage of the thiadiazol-amine moiety and subsequent opening of the cephalosporin ring. After extended irradiation, these intermediates diminished, and a fragment at m/z 356.01 was detected, suggesting further breakdown through thioether bond cleavage. These results support a degradation pathway involving sequential dephosphorylation and fragmentation of the cephalosporin core. Overall, the enhanced performance of Fe-ZnS arises from the synergistic interplay between surface charge characteristics and dopant-modulated charge carrier dynamics, highlighting its potential for antibiotic remediation in aquatic environments.
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(This article belongs to the Section Microscale Materials Science)
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Open AccessArticle
Formation of Nano-Sized Silicon Oxynitride Layers on Monocrystalline Silicon by Nitrogen Implantation
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Sashka Alexandrova, Anna Szekeres, Evgenia Valcheva, Mihai Anastasescu, Hermine Stroescu, Madalina Nicolescu and Mariuca Gartner
Micro 2026, 6(2), 24; https://doi.org/10.3390/micro6020024 - 30 Mar 2026
Abstract
Nitridation of different materials using ion implantation is of considerable interest for many applications. As electronic components, oxynitride (SiOxNy) layers exhibit beneficial properties such as precise compositional variability, refractive index tunability, oxidation resistance, and low mechanical stress. In the
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Nitridation of different materials using ion implantation is of considerable interest for many applications. As electronic components, oxynitride (SiOxNy) layers exhibit beneficial properties such as precise compositional variability, refractive index tunability, oxidation resistance, and low mechanical stress. In the present study we investigate nanoscale SiOxNy synthesized using ion implantation methods. To introduce N+ ions into a shallow Si subsurface region, both conventional ion beam implantation and plasma immersion ion implantation with subsequent high-temperature treatment in dry O2 are used. The optical and morphological properties and chemical bonding of formed SiOxNy layers were studied by applying spectroscopic ellipsometry in the range of VIS-Near IR (SE) and IR (IR-SE), Raman spectroscopy and Atomic Force Microscopy (AFM). Monte Carlo modeling of implant profiles contributed to understanding physical and chemical processes and predicted different influences of the incorporated N+ ions on the oxidation mechanism, confirmed by the thickness dependence of SiOxNy/Si layers obtained from the SE data analysis. IR-SE spectral analysis established the formation of Si-O, Si-N, Si-N-O and Si-Si chemical bonds in the grown layers. The occurrence of amorphization of the Si crystal lattice due to incorporation of high-energy N+ ions into the Si lattice is confirmed by the Raman and ellipsometry results. The free Si atoms can congregate, forming nanocrystalline clusters. AFM imaging revealed that both implantation methods left the surface of the resulting SiOxNy layers considerably smooth with similar roughness parameter values. The results of the studies imply that the technological approaches used allow the production of high-quality nanoscale silicon oxynitride films with appropriate tunable composition and properties for possible application in advanced electronic devices for nanoelectronics, optoelectronics and sensor applications.
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(This article belongs to the Topic Surface Engineering and Micro Additive Manufacturing)
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Highly Sensitive CO Sensor Based on ZnO/SnO2 and ZnO/Au Nanorods
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Victor Petrov, Timofey Grishin and Alexandra Starnikova
Micro 2026, 6(2), 23; https://doi.org/10.3390/micro6020023 - 26 Mar 2026
Abstract
This study investigates the properties of ZnO nanorod-based sensors and ZnO nanorods modified with tin dioxide (ZnO/SnO2) and gold (ZnO/Au) nanoclusters and their response to low concentrations of carbon monoxide (CO). It was demonstrated that the ZnO/SnO2(3) nanorod-based sensor
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This study investigates the properties of ZnO nanorod-based sensors and ZnO nanorods modified with tin dioxide (ZnO/SnO2) and gold (ZnO/Au) nanoclusters and their response to low concentrations of carbon monoxide (CO). It was demonstrated that the ZnO/SnO2(3) nanorod-based sensor exhibited the highest sensitivity (S = 1.64) to 10 ppm CO, while the ZnO/Au(3) sensor displayed the shortest response (69–207 s) and recovery (203–233 s) times. This behavior can be explained by ZnO/Au and ZnO/SnO2 nanostructures having low activation energies (0.23–0.25 eV) and high potential barrier values (0.37–0.43 eV). Sensors based on ZnO/Au and ZnO/SnO2 nanorods demonstrate sensitivity to 10 ppm CO at 250 °C and at 200 °C. In contrast, ZnO nanorod-based sensors are sensitive to 2 ppm CO at 250 °C.
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(This article belongs to the Special Issue Functional Micro- and Nanomaterials: Design, Modulation, and Applications in Energy and Sensing)
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Open AccessArticle
Effective Energy Harvesting in Polymer Solar Cells Using NiS/Co as Nanocomposite Doping
by
Jude N. Ike and Raymond Tichaona Taziwa
Micro 2026, 6(1), 22; https://doi.org/10.3390/micro6010022 - 21 Mar 2026
Abstract
Over the past two decades, organic semiconductors have attracted significant research interest due to their advantageous features, including low-cost fabrication, lightweight properties, and portability, for photonic device applications. In this study, nickel sulfide doped with cobalt
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Over the past two decades, organic semiconductors have attracted significant research interest due to their advantageous features, including low-cost fabrication, lightweight properties, and portability, for photonic device applications. In this study, nickel sulfide doped with cobalt nanocomposites were successfully synthesized via a wet-chemical processing technique and used as a dopant in the active layer of thin-film organic solar cells (TFOSCs). The poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) blend was used as the active layer in this investigation. The devices were fabricated with nanocomposites at 1 wt%, 2 wt%, and 3 wt% in the active layer to determine the optimal dopant concentration. However, the experimental evidence clearly showed that the solar cell’s performance depends on the concentration of the nanocomposites. As a result, the highest power conversion efficiency (PCE) recorded in this experimental work was 6.11% at a 1% doping concentration, compared with 2.48% for the pristine reference device under AM 1.5G illumination (100 mW/cm2) in ambient conditions. The optical and electrical properties of the active layers are found to be strongly influenced by the inclusion of nanocomposites in the medium. However, the device doped with 1 wt% nanocomposite exhibits the highest absorption intensity, consistent with the better performance observed in this study, which can be attributed to the localized surface plasmon resonance (LSPR) effect. The optical and morphological characteristics of the synthesized nanocomposites were comprehensively analyzed using high-resolution transmission electron microscopy (HRTEM), high-resolution scanning electron microscopy (HRSEM), and additional complementary techniques.
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(This article belongs to the Section Microscale Physics)
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Laser-Surface-Remelted Powder Metallurgy TiAl Alloys: Microstructure and Mechanical Properties
by
Warlen Monfardini, João Victor Vieira, João Batista Fogagnolo and Juliano Soyama
Micro 2026, 6(1), 21; https://doi.org/10.3390/micro6010021 - 17 Mar 2026
Abstract
Laser processing has been widely investigated as an effective approach for improving surface properties and consolidating advanced materials, particularly complex alloys such as titanium aluminides (TiAl). In this study, laser surface remelting was applied to binary (Ti-45Al) and ternary (Ti-45Al-2Co and Ti-45Al-2Ni) alloys
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Laser processing has been widely investigated as an effective approach for improving surface properties and consolidating advanced materials, particularly complex alloys such as titanium aluminides (TiAl). In this study, laser surface remelting was applied to binary (Ti-45Al) and ternary (Ti-45Al-2Co and Ti-45Al-2Ni) alloys produced by powder metallurgy via blended elemental (BE) and pre-alloyed (PA) powder routes. Laser powers of 50 and 100 W were employed, resulting in a high-energy-density surface remelting regime applied to both green compacts and sintered samples with relatively high initial porosity, under an argon-controlled atmosphere. Microstructural and phase analyses were performed using scanning electron microscopy (SEM) and X-ray diffraction (XRD), while mechanical behavior was assessed by instrumented microindentation. Laser processing promoted the formation of a dense and homogeneous surface layer, approximately 150 μm thick, accompanied by significant microstructural refinement and enhanced hardness and elastic modulus. While rapid solidification led to crack formation in laser-treated sintered samples, the green compacts exhibited defect-free modified layers. Overall, the results demonstrate that laser surface remelting is an effective strategy for enhancing the surface integrity and mechanical performance of TiAl alloys processed by powder metallurgy.
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(This article belongs to the Special Issue Microstructural Design and Control in Advanced Metallic Materials: From Powder Processing to Additive Manufacturing)
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Open AccessArticle
Effect of Order on the Spin Gapless Semiconducting Behavior of Mn2CoAl
by
Iosif Galanakis
Micro 2026, 6(1), 20; https://doi.org/10.3390/micro6010020 - 10 Mar 2026
Abstract
Employing ab initio electronic structure methods, in this study, I examine the effect of order on the spin gapless semiconducting behavior of the Mn2CoAl Heusler compound. The occurrence of atomic disorder in general destroys the spin gapless semiconductivity observed in the
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Employing ab initio electronic structure methods, in this study, I examine the effect of order on the spin gapless semiconducting behavior of the Mn2CoAl Heusler compound. The occurrence of atomic disorder in general destroys the spin gapless semiconductivity observed in the inverse XA lattice structure; however, in some cases, novel magnetic configurations emerge. In the case of structures derived from the XA structure, where only Mn-Co or Mn-Al atoms are mixed, Mn2CoAl alloy presents a half-metallic magnetic character. In the case of full disorder (A2 lattice structure), where atoms occupy all sites with the same probability, the ground state is an antiferromagnetic metallic one. The L21 and B2 lattice structures, where Mn atoms occupy both sites of a similar local environment, correspond to a ferromagnetic state of very high spin magnetic moment per formula unit. The present study encompasses a much larger variety of disordered structures in comparison with other studies in the literature. It concludes that the control and minimization of the concentration of impurities at anti-sites is imperative to achieving optimal performance in spintronic devices based on spin gapless semiconducting Mn2CoAl.
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(This article belongs to the Section Microscale Materials Science)
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Fabrication and Properties of Axially Compressed Isotropic Epoxy-Bonded NdFeB Magnets with Partial Rare-Earth Substitution
by
Evangelia Dimeli, Dimitrios I. Anyfantis, Athanasios Sigalos, Alexandros Banis and Dimitrios Niarchos
Micro 2026, 6(1), 19; https://doi.org/10.3390/micro6010019 - 9 Mar 2026
Abstract
This work investigates the fabrication and performance of axially compressed isotropic epoxy-bonded NdFeB-type magnets produced from melt-spun powders with partial substitution of (Nd,Pr) by (La,Ce). Four alloy compositions were synthesized and processed into bonded magnets using two powder-to-binder weight ratios (95:5 and 96.5:3.5).
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This work investigates the fabrication and performance of axially compressed isotropic epoxy-bonded NdFeB-type magnets produced from melt-spun powders with partial substitution of (Nd,Pr) by (La,Ce). Four alloy compositions were synthesized and processed into bonded magnets using two powder-to-binder weight ratios (95:5 and 96.5:3.5). Structural analysis confirms that all substituted alloys retain the tetragonal Nd2Fe14B phase (up to ~95 wt%) even at high substitution levels, while the lattice parameters decrease slightly with increasing (La,Ce) content. Microscopy analysis confirms a homogeneous distribution of the binder phase around the powder particles, demonstrating uniform binder–powder integration. Thermal analysis reveals composition-dependent Curie temperatures and enhanced crystallization onset in highly substituted powders. Magnetic measurements on both powders and bonded magnets show that increasing substitution leads to a gradual reduction in remanence, coercivity, and energy product, though all samples maintain strong hard-magnetic behavior. Increasing the powder fraction to 96.5 wt.% significantly improves all magnetic parameters due to higher magnetic-phase density and enhanced interparticle coupling, yielding bonded magnets with densities up to ~80% of the theoretical value. The resulting magnets achieve competitive performance, uniform field distribution and isotropic magnetization with (BH)max values about 65 kJ/m3, a coercivity around 660 kA/m, and superior thermal stability compared with commercial bonded NdFeB magnets. Overall, partial substitution with light rare-earth elements (La,Ce) provides a cost-effective route to high-density bonded NdFeB magnets that combine strong magnetic performance, enhanced thermal stability, and suitability for lightweight, complex-shaped industrial applications. Surprisingly, the coefficients of the temperature variation of coercivity and (BH)max are much better compared to the commercial NdFeB bonded magnets.
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(This article belongs to the Section Microscale Materials Science)
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