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Developing real‐time, dynamic, and in situ analytical methods with high spatial and temporal resolutions is crucial for exploring biochemical processes in the brain. Although in vivo electrochemical methods based on carbon fiber (CF) microelectrodes are effective in monitoring neurochemical dynamics during physiological and pathological processes, complex post modification hinders large‐scale productions and widespread neuroscience applications. Herein, we develop a general strategy for the in situ engineering of carbon‐based materials to mass‐produce functional CFs by introducing polydopamine to anchor zeolitic imidazolate frameworks as precursors, followed by one‐step pyrolysis. This strategy demonstrates exceptional universality and design flexibility, overcoming complex post‐modification procedures and avoiding the delamination of the modification layer. This simplifies the fabrication and integration of functional CF‐based microelectrodes. Moreover, we design highly stable and selective H+, O2, and ascorbate microsensors and monitor the influence of CO2 exposure on the O2 content of the cerebral tissue during physiological and ischemia‐reperfusion pathological processes. [ABSTRACT FROM AUTHOR]

Dynamic and vibrational behavior of nonlinear resonant pressure micro sensors is studied in this paper using a proposed dynamic model. The basic part of the device is a microplate deflects due to external pressure in presence of electrostatic actuation. The frequency changes because of the microplate deformation is used to estimate the external pressure. For modeling of the micro sensor, the nonlinear governing equation of size dependent microplate in polar coordinate system and based on the modified couple stress theory is presented. Assuming specified number of Taylor expansion terms for electrostatic force, the linear and nonlinear ODE is obtained and nonlinear equation is solved both with multiple time scales method (MTS) and finite difference numerical method. Results indicate that considering finite terms of Taylor expansion (1 term for linear and three terms for MTS method) is the source of error in estimation of pressure or system stability. Using sufficient terms of Taylor Expansion, the error in linear and MTS solutions is vanished. Therefore, the limited values of microplate vibrational amplitude is extracted to increase the accuracy of the sensor in linear action. The effect of size dependency, applied voltage on nonlinear behavior and linearization error is also studied. [ABSTRACT FROM AUTHOR]

The rapid and simple detection methods of hydrogen peroxide (H2O2) residues is highly required for food safety. Herein, an electrochemical H2O2 sensor is developed with cerium oxide nanocubes as highly active non‐enzymatic catalyst. Combined with carbon black to improve conductivity, the disposable sensor can determine H2O2 in the range from 100 to 100 μM with a limit of detection (LOD) of 100 nM. This sensor also shows good selectivity and reproducibility, which is enabled to detect H2O2 in real food samples without any pretreatment in 100 s, providing a new solution for the direct quantitative measurement of H2O2 residues for food safety. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The rapid and simple detection methods of hydrogen peroxide (H2O2) residues is highly required for food safety. Herein, an electrochemical H2O2 sensor is developed with cerium oxide nanocubes as highly active non‐enzymatic catalyst. Combined with carbon black to improve conductivity, the disposable sensor can determine H2O2 in the range from 100 to 100 μM with a limit of detection (LOD) of 100 nM. This sensor also shows good selectivity and reproducibility, which is enabled to detect H2O2 in real food samples without any pretreatment in 100 s, providing a new solution for the direct quantitative measurement of H2O2 residues for food safety. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal "Lab on a Chip," published by the Royal Society of Chemistry. It includes a range of papers on topics such as microfluidics, nanotechnology, and biomedical research. Some of the specific papers mentioned include a programmable and automated optical electrowetting-on-dielectric (oEWOD) driven platform for single cell assay operations, an on-chip phytofluidic device for studying nutrient flow in plant roots, and optimized microfluidic formulation for improved lipid nanoparticle mediated genome editing. The journal covers a variety of scientific disciplines and offers valuable research for those interested in these fields. [Extracted from the article]

Oocyte selection is a crucial step of assisted reproductive treatment. The most common approach relies on the embryologist experience which is inevitably prone to human error. One potential approach could be the use of an electrical-based approach as an ameliorative alternative. Here, we developed a simple electrical microsensor to characterize mouse oocytes. The sensor is designed similarly to embryo culture dishes and is familiar to embryologists. Different microelectrode models were simulated for oocyte cells and a more sensitive model was determined. The final microsensor was fabricated. A differential measuring technique was proposed based on the cell presence/absence. We predicted oocyte quality by using three electrical characteristics, oocyte radii, and zona thicknesses, and also these predictions were compared with an embryologist evaluation. The evaluation of the oocyte membrane capacitance, as an electrophysiological characteristic, was found to be a more reliable method for predicting oocytes with fertilization and blastocyst formation success competence. It achieved 94% and 58% prediction accuracies, respectively, surpassing other methods and yielding lower errors. This groundbreaking research represents the first of its kind in this field and we hope that this will be a step towards improving the accuracy of the treatment. [ABSTRACT FROM AUTHOR]

Interdigital electrodes were prepared using nanoimprint lithography and piezoelectric inkjet printing. These processes are simpler and more cost‐effective than the industrially used electron beam lithography because of their purely mechanical process step. For the investigation of material dependence, platinum as well as carbon electrodes were fabricated. Afterwards electrodes with various line widths and spacings were tested for the application as a chemiresistive sensor for ferrocenyl‐methanol and the influence of the gap‐width and conductor cross‐section on the sensitivity was investigated. The general suitability of the systems for the production of such structures could be confirmed. Structures with a limit of detection (LOD) down to 1.2 μM and 35.9 μM could be produced for carbon and platinum, respectively, as well as a response time of 3.6 s was achieved. [ABSTRACT FROM AUTHOR]

Droplet transmission is the primary infection route for respiratory diseases like COVID‐19 and influenza, but small and low‐cost wearable droplet detection devices are a significant challenge. Herein, a respiratory droplet micro‐sensor based on graphene oxide quantum dots (GOQDs) assembled onto SiO2 microspheres by the nebulized natural deposition is presented. Benefiting from the energy dissipation of the microsphere to droplets, the sensor can detect droplets as far as 2 m from coughing. With this sensor, droplet signal variations caused by some factors like distance, speech, angles, and wind directions are explored, and the effectiveness of different protective measures in preventing droplet transmission is evaluated. This droplet detection technology is expected to be utilized for the development of personal detection and protection devices against infectious respiratory diseases. [ABSTRACT FROM AUTHOR]

Quantitative assessment of biotribological properties requires expensive specialized equipment. The aim was to: i) adapt an open-source load cell-based platform (PASTA) for biotribometric analysis; ii) study the effects of oxidation on the water-based lubricant using PASTA. Water-based lubricant was treated with 2,2'-azobis(2-amidinopropane) dihydrochloride and/or glutathione. The samples were analyzed with the ORP-146S redox microsensor and PASTA using a modified HX711 integrated circuit bord, NodeMCU ESP-32S, and an open-source Python script. PASTA can be adapted for affordable and reliable quantitative biotribometric assessment. Glutathione can prevent the loss of lubrication capacity of a water-based lubricant upon exposure to air. [ABSTRACT FROM AUTHOR]

This study analysed the volume, intensity and distribution of tennis serving between (1) training and tournament mesocycles, and (2) within-mesocycle based on session-type, drill-type and week. Seven elite females wore a GPS device, with in-built accelerometer and gyroscope, during training and tournament mesocycles. Sessions were classified as "practice sessions" or "official matches" and drills as "serve-focused drills" or "point-play". Training weeks were classified according to their timing prior to tournaments ("Week −3", "Week −2" and "Week −1"). Machine learning algorithms detected serves from the raw accelerometer and gyroscope data to report serve count, load and rotation magnitude in absolute and relative (.min−1 or serve) values. Cohen's d with 95% confidence intervals compared serve volume (count), intensity (serve load, rotation magnitude) and distribution (n.min−1) between session- and drill-type during mesocycles. Cumulative serve counts were compared between training weeks. Increased absolute serve load was observed during official matches compared to practice sessions (d = 0.97–1.07[0.69–1.30]). Serve-focused drills in training mesocycles have lower absolute counts and serve load (d = 0.82[0.54–1.34]), though greater relative count and load (d = 1.10–1.87[0.59–2.19]). Trivial-small ES existed between training weeks for cumulative serve count (d = 0.12–0.25[−0.83–1.27]). Session- and drill-level analyses highlight greater mechanical demands in official matches, though lower serve density in point-play. [ABSTRACT FROM AUTHOR]

The tumor microenvironment is increasingly acknowledged as a critical contributor to cancer progression, mediating genetic and epigenetic alterations. Beyond diverse cellular interactions from the microenvironment, physicochemical factors such as tumor acidosis also significantly affect cancer dynamics. Recent research has highlighted that tumor acidosis facilitates invasion, immune escape, metastasis, and resistance to therapies. Thus, noninvasive measurement of tumor acidity and the development of targeted interventions represent promising strategies in oncology. Techniques like contrast-enhanced ultrasound (CEUS) can effectively assess blood perfusion, while ultrasound-stimulated microbubble cavitation (USMC) has proven to enhance tumor blood perfusion. We therefore aimed to determine whether CEUS assesses tumor acidity and whether USMC treatment can modulate tumor acidity. Firstly, we tracked CEUS perfusion parameters in MCF7 tumor models and compared them with in vivo tumor pH recorded by pH microsensors. We found that the peak intensity and area under curve of tumor contrast-enhanced ultrasound correlated well with tumor pH. We further conducted USMC treatment on MCF7 tumor-bearing mice, tracked changes of tumor blood perfusion and tumor pH in different perfusion regions before and after the USMC treatment to assess its impact on tumor acidity and optimize therapeutic ultrasound pressure. We discovered that USMC with 1.0 Mpa significantly improved tumor blood perfusion and tumor pH. Furthermore, tumor vascular pathology and PGI2 assays indicated that improved tumor perfusion was mainly due to vasodilation rather than angiogenesis. More importantly, analysis of glycolysis-related metabolites and enzymes demonstrated USMC treatment can reduce tumor acidity by reducing tumor glycolysis. These findings support that CEUS may serve as a potential biomarker to assess tumor acidity and USMC is a promising therapeutic modality for reducing tumor acidosis. [ABSTRACT FROM AUTHOR]

Modern wireless communications advancements and miniaturization components in the field of electronics have led to the development of lower-cost, multi-functional microsensors. A very new useful type of network, called Wireless Sensor Networks (WSNs), has emerged in recent decades, acting as generators and relay data by controlling interesting physical phenomenon. However, some problems need to be improved in their mastery, particularly that of energy conservation. This valuable energy has to be sufficiently available until a WSN reaches its mission. In order to increase WSN lifetime, numerous protocols have been designed to address this problem of power consumption. The pioneer of these protocols was Low Energy Adaptive Clustering Hierarchy (LEACH) protocol and other enhancement variants were subsequently created in this context. In this paper, a new protocol named Area Splitting for Clustering (ASC) that reduces energy consumption and increases network lifetime is proposed. The performance evaluation of ASC has been carried out and showed that it outperforms those of Leach and its variant protocols. [ABSTRACT FROM AUTHOR]

The rapid development of organ‐on‐chip (OOC) technology has been propelled by advancements in micro‐nanofabrication processes and cell culture technologies. Researchers envision OOCs as models capable of simulating the functionality and structure of specific organs, aiming to develop microenvironmental models that encapsulate key physiological parameters. The gut has long been one of the most important organs in the human body, crucial for ensuring the digestion and absorption of nutrients and maintaining interconnected functions with other organs. Consequently, the development of gut‐on‐chip (GOC) has garnered significant attention. Integrating sensors into GOCs capable of monitoring relevant physical and chemical parameters within the chip is imperative for evaluating the functionality of the internal environment. This review summarizes and outlines integrated sensor technologies for GOCs, introduces manufacturing processes for OOCs, reviews relevant technologies for integrating microsensors with OOCs, and examines works combining sensors and GOCs to monitor simulated physiological parameters such as trans‐epithelial resistance, oxygen levels, and other parameters. Additionally, attention is given to relevant technologies from other OOCs that could be applicable for monitoring in GOCs, providing insights for GOC detection technologies. [ABSTRACT FROM AUTHOR]

Mussel byssus offers bio‐inspired designs for advanced adhesives, coatings, and supramolecular hydrogels. Solidification of secreted proteins into mechanically robust fibers is triggered by a pH jump from acidic fluid condensates to basic seawater conditions driving protein crosslinking by metal coordination with 3,4‐dihydroxyphenylalanine (DOPA). Knowledge of the dynamic and localized pH changes during secretion is currently lacking. Yet, this information is crucial for controlling the gelation and properties of mussel‐inspired DOPA‐modified materials. Here, an iridium oxide‐based pH microsensor combining high mechanical stability and spatial resolution is used to measure the acidic pH during byssus secretion and to map mussel‐inspired hydrogels revealing compositional heterogeneity resulting in mechanically distinct regions. Within the hydrogel, high pH values >12 are measured which are detrimental to DOPA due to its strong propensity for oxidation, which adversely alters gel properties. This demonstrates the need to improve preparation methods of mussel‐inspired adhesive materials to more closely mimic native processes. [ABSTRACT FROM AUTHOR]

Summary: Woody plants display some photosynthetic activity in stems, but the biological role of stem photosynthesis and the specific contributions of bark and wood to carbon uptake and oxygen evolution remain poorly understood.We aimed to elucidate the functional characteristics of chloroplasts in stems of different ages in Fraxinus ornus. Our investigation employed diverse experimental approaches, including microsensor technology to assess oxygen production rates in whole stem, bark, and wood separately. Additionally, we utilized fluorescence lifetime imaging microscopy (FLIM) to characterize the relative abundance of photosystems I and II (PSI : PSII chlorophyll ratio) in bark and wood.Our findings revealed light‐induced increases in O2 production in whole stem, bark, and wood. We present the radial profile of O2 production in F. ornus stems, demonstrating the capability of stem chloroplasts to perform light‐dependent electron transport. Younger stems exhibited higher light‐induced O2 production and dark respiration rates than older ones.While bark emerged as the primary contributor to net O2 production under light conditions, our data underscored that wood chloroplasts are also photosynthetically active. The FLIM analysis unveiled a lower PSI abundance in wood than in bark, suggesting stem chloroplasts are not only active but also acclimate to the spectral composition of light reaching inner compartments. [ABSTRACT FROM AUTHOR]

Functionalized optical fiber tips featuring miniature sizes and diverse functions have broken the limitations of traditional optical fiber with fixed shapes and single materials, significantly enriching the application scenarios in communication, sensing, imaging, and other fields. However, the unconventional shape presents challenges in manufacturing arbitrarily sophisticated 3D micro/nano structures on optical fiber tips. Femtosecond laser 3D nano‐printing (FL‐3DNp) technology injects new vitality into the functionalization of fiber tips due to its high‐precision, customizable structure, and real 3D processing abilities, as well as advantages of non‐vacuum, maskless, and plentiful materials. This paper extensively compares the key performance parameters of various micro‐nano manufacturing technologies for functionalizing optical fiber probes and focuses on the FL‐3DNp technology. In addition, the latest research progresses are systematically presented from the perspective of structure and application. Finally, the current research challenges and future development directions in this emerging field are discussed, aiming at providing scientific and industrial guidance for FL‐3DNp in functionalizing optical fibers. [ABSTRACT FROM AUTHOR]

Capillary force self‐assembly (CFSA) technology unfolds great potential in the fabrication of functional micro/nanostructures. To date, most self‐assembly methods focus on monolithic microstructure manipulation yet it remains a challenge to achieve precise localized control over the CFSA process of micro/nanostructures. Herein, a light‐regulated CFSA is proposed to realize the localized precise control of microstructures, leveraging on the synergistic effect of photothermally‐responsive hydrogel and self‐assembly technique. The micropillars with asymmetric cross‐linking densities can readily prepare by applying a rationally designed laser and laser‐exposing dosage, thereby realizing the on‐demand steering of their bending directions. Significantly, owing to the giant capillary force deriving from the evaporating water, above micropillars can successfully assemble into highly‐ordered chiral structures. Simulation coupling with fundamental hydrodynamics enables to shed light on the light steering principle over pillar's actuations. Last, on the basis of vortical dichroism spectra analysis, the chiral characteristics of light‐regulated self‐assembly including the chiral as well as the achiral self‐assembled microstructures are successfully deployed. This strategy provides an avenue for fabricating the localized controllable self‐assembly at the microscale and will bloom the field over metamaterials, microsensors, chiral optics, and so on. [ABSTRACT FROM AUTHOR]

Miniaturized silicon thermal probes for plant's sap flow measurement, or micro sap flow sensors, have advantages in minimum invasiveness, low power consumption, and fast responses. Practical applications in sap flow measurement has been demonstrated with the single-probe silicon micro sensors. However, the sensors could not detect flow directions and require estimating zero sap flow output that leads to significant source of uncertainty. Furthermore, silicon-needles would break easily during the insertion into plants. We present the first three-element micro thermal sap flow sensor packaged on a durable printed circuit board needle that can measure bidirectional flows with improved dynamics and precision. The performance of the newly designed calorimetric flow sensor was confirmed through precision calibration and field test on tomato stems. A calibration curve for a tomato stem was obtained with a sensitivity of 0.299 K/(µL mm−2 s−1) under the maximum temperature increase of 4.61 K. Results from the field test for one month revealed a correlation between the measured sap flux density and related conditions such as solar radiation, vapor pressure deficit, sunshade and irrigation. The developed sensor will contribute to practical long-term sap flow monitoring for small and delicate plants with minimal physical invasion. [ABSTRACT FROM AUTHOR]

An electrochemical microsensor for mesothelin (MSLN) based on an acupuncture needle (AN) was constructed in this work. To prepare the microsensor, MSLN was self-assembled on 4-mercaptophenylboronic acid (4-MPBA) by an interaction force between the external cis-diol and phenylboronic acid. This was followed by the gradual electropolymerization of thionine (TH) and eriochrome black T (EBT) around the anchored protein. The thickness of the surface imprinted layers influenced the sensing performance and needed to be smaller than the height of the anchored protein. The polymerized EBT was not electrically active, but the polymerized TH provided a significant electrochemical signal. Therefore, electron transfer smoothly proceeded through the eluted nanocavities. The imprinted nanocavities were highly selective toward MSLN, and the rebinding of insulating proteins reduced the electrochemical signal of the embedded pTH. The functionalized interface was characterized by SEM and electrochemical methods, and the preparation conditions were studied. After optimization, the sensor showed a linear response in the range of 0.1 to 1000 ng mL−1 with a detection limit of 10 pg mL−1, indicating good performance compared with other reported methods. This microsensor also showed high sensitivity and stability, which can be attributed to the fine complementation of the imprinted organic nanocavities. The sensitivity of this sensor was related to the nanocavities used for electron transport around the AuNPs. In the future, microsensors that can directly provide electrochemical signals are expected to play important roles especially on AN matrices. [ABSTRACT FROM AUTHOR]

Magnetic sensors with high sensitivity are critical for various technological applications. This paper presents a highly sensitive magnetic sensor based on magnetic torque. The sensor comprises a silicon cantilever with a micro-pillared soft magnet at its end. A piezoresistive strain sensing element is integrated into the silicon cantilever for detecting vibration signals. The prototype of the resonant magnetic sensor is designed, fabricated, and evaluated. When an alternating magnetic field, generated by a coil, is applied to the cantilever, the micro-pillared magnet undergoes pendulum-like vibrations due to magnetic torque. Additionally, the application of the alternating magnetic field, which causes the external magnetic field to change the effective spring constant of the silicon cantilever, results in a change in resonant frequency. The evaluation results demonstrate that the fabricated magnetic sensor achieves a maximum sensitivity of 114.02 Hz/mT and a minimum detectable magnetic field of 35.7 nT. These findings suggest the sensor's potential for high-sensitivity magnetic field measurements in various applications. [ABSTRACT FROM AUTHOR]

The levels of the MMPs in the biological samples of confirmed patients with gastric cancer are significantly elevated compared to those found in healthy people. Therefore, a novel 3D stochastic microsensor based on graphene oxide, modified with gold nanoparticles and (Z)-N-(pyridin-4-yl-methyl) octadec-9-enamide (namely N2-AuNP/GO), was designed for the determination of MMP-2 in biological samples, and validated for the screening tests of biological samples in order to be used for the early diagnosis of gastric cancer. The proposed sensor presents a low limit of quantification (1.00 × 10−22 g mL−1), high sensitivity (1.84 × 107 s−1 g−1 mL), and a wide working concentration range (1.00 × 10−22–1.00 × 10−7 g mL−1). Recovery values higher than 99.15% were recorded for the assay of MMP-2 in whole blood, gastric tissue tumors, saliva, and urine samples. [ABSTRACT FROM AUTHOR]

We report on the piezoresistive method for detecting stability loss events in microelectromechanical sensors based on bifurcation. The method involves measuring the resistivity changes of an entire beam to detect snap-through transitions in an electrostatically actuated, bistable double-clamped crystalline silicon (Si) microbeam. The applicability of the suggested approach in two types of sensors—an ambient air temperature sensor or a mean air velocity sensor, is demonstrated. In both cases, the bistable beam, serving as the sensing element, is affected by the electrothermal Joule's heating and air cooling. The measured signal is obtained by monitoring the critical voltages of the snap-through transitions. Piezoresistive sensing is especially suitable for the response monitoring of the exposed to the environment, free-standing heated microbeam sensors, where optical, piezoelectric, or electrostatic interrogation methods are not applicable. The approach can be implemented in various bifurcation microsensors and for response monitoring of bistable actuators. [ABSTRACT FROM AUTHOR]

Metal-oxide-based gas sensors are extensively utilized across various domains due to their cost-effectiveness, facile fabrication, and compatibility with microelectronic technologies. The copper (Cu)-based multifunctional polymer-enhanced sensor (CuMPES) represents a notably tailored design for non-invasive environmental monitoring, particularly for detecting diverse gases with a low concentration. In this investigation, the Cu-CuO/PEDOT nanocomposite was synthesized via a straightforward chemical oxidation and vapor-phase polymerization. Comprehensive characterizations employing X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and micro Raman elucidated the composition, morphology, and crystal structure of this nanocomposite. Gas-sensing assessments of this CuMPES based on Cu-CuO/PEDOT revealed that the response current of the microneedle-type CuMPES surpassed that of the pure Cu microsensor by nearly threefold. The electrical conductivity and surface reactivity are enhanced by poly (3,4-ethylenedioxythiophene) (PEDOT) polymerized on the CuO-coated surface, resulting in an enhanced sensor performance with an ultra-fast response/recovery of 0.3/0.5 s. [ABSTRACT FROM AUTHOR]

In this article, we successfully developed and simulated a wearable pressure sensor for monitoring blood pressure. This sensor utilizes MEMS technology and is based on LC wireless, eliminating the need for a battery system. The sensor is constructed with a metal-insulator-metal capacitive design, featuring a diaphragm measuring 1.1 mm × 1.1 mm and with a thickness of 22 µm. Furthermore, we devised a unique C-shaped circular slot diaphragm to enhance sensitivity by reducing the mechanical rigidity of the membrane. Our design and simulation were conducted using COMSOL Multiphysics. From our findings, we observed that the frequency response to varying pressure ranged from 285 to 445 MHz. Additionally, our results yielded a mechanical sensitivity of 125.7 nm/mmHg, along with a sensor sensitivity of 1.49 fF/mmHg. Notably, the sensor with the novel C-shaped circular slot diaphragm exhibited high-pressure sensitivity, surpassing that of a clamped diaphragm by 15.5%. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive study focusing on the detection and characterization of droplets with volumes in the nanoliter range. Leveraging the precise control of minute liquid volumes, we introduced a novel spectroscopic on-chip microsensor equipped with integrated microfluidic channels for droplet generation, characterization, and sensing simultaneously. The microsensor, designed with interdigitated ring-shaped electrodes (IRSE) and seamlessly integrated with microfluidic channels, offers enhanced capacitance and impedance signal amplitudes, reproducibility, and reliability in droplet analysis. We were able to make analyses of droplet length in the range of 1.0–6.0 mm, velocity of 0.66–2.51 mm/s, and volume of 1.07 nL–113.46 nL. Experimental results demonstrated that the microsensor's performance is great in terms of droplet size, velocity, and length, with a significant signal amplitude of capacitance and impedance and real-time detection capabilities, thereby highlighting its potential for facilitating microcapsule reactions and enabling on-site real-time detection for chemical and biosensor analyses on-chip. This droplet-based microfluidics platform has great potential to be directly employed to promote advances in biomedical research, pharmaceuticals, drug discovery, food engineering, flow chemistry, and cosmetics. [ABSTRACT FROM AUTHOR]

Knowledge of the ecological mechanisms governing N2O cycling in marine sediments lags that of water columns and terrestrial soils, leaving much to be learned about how microbial community dynamics relate to variability in sediment N2O fluxes. The present study assesses these relationships across two distinct environments by focusing on the community structure and activity of N2O reducing microorganisms. The N2O sink capacity of minimally impacted Bermudian mangrove sediments was first estimated using trace‐level microsensors and profile interpretation modeling. Molecular data obtained from these sediments were then compared with those from the Northeast Subarctic Pacific (NESAP) outer continental margin, where previous measurements suggest considerable N2O effluxes. Net N2O uptake was observed for mangrove sediments under ambient and elevated dissolved inorganic nitrogen concentrations (−0.22 ± 0.15 to −0.30 ± 0.26 μmol N2O m−2 d−1), suggesting the microbial potential for N2O consumption exceeded the potential for production via combined nitrification and denitrification. Targeting of bacterial nosZI and nosII gene clusters for quantification using qPCR indicated higher abundance and expression of non‐denitrifier nosZII genes in mangrove sediments demonstrating net N2O uptake. Net N2O production in NESAP sediments was associated with higher abundance and expression of nosZI genes associated with canonical denitrifiers. These results suggest that organisms possessing atypical nosZII genes may act as important N2O scavengers in low‐nitrogen coastal sediments. Plain Language Summary: Nitrous oxide (N2O) is potent greenhouse gas that contributes to ozone depletion in the stratosphere, and atmospheric concentrations a rising as a result of human activities. The production and consumption of N2O in the environment is mediated by microorganisms, and the balance between the two processes is governed by environmental factors such as concentrations of dissolved oxygen and fixed nitrogen. However, little is known about the relationships between microbial community dynamics and rates of N2O production and consumption, especially in sediment environments. We found that minimally impacted mangrove sediments of Bermuda are net consumers of N2O, and continue to consume N2O following short term nitrogen enrichments. This N2O sink capacity was linked to higher abundances and activity levels of atypical N2O reductase genes when compared to sediments that produce N2O. These genes facilitate the consumption of N2O, and frequently occur in microbes that do not have the capacity to produce N2O via denitrification. This study provides further insight into the role of microbial community structure in regulating sediment N2O cycling, and argues for targeted conservation and restoration of coastal systems where sediment environments are in close proximity to the atmosphere. Key Points: The N2O sink capacity of minimally impacted Bermudian mangrove sediments is resilient against modest, short‐term nutrient enrichmentHigh prevalence of non‐denitrifier nosZII genes in mangrove sediments implies a crucial role as N2O scavengers in low‐nitrogen systemsNet N2O production in NESAP sediments is associated with higher expression of nosZI genes associated with canonical denitrifiers [ABSTRACT FROM AUTHOR]

Heart disease is one of the leading causes of death in the United States and throughout the world. While there are different techniques for reducing or preventing the impact of heart disease, nitric oxide (NO) is administered as nitroglycerin for reversing angina or chest pain. Unfortunately, due to its gaseous and short-lived half-life, NO can be difficult to study or even administer. Therefore, controlled delivery of NO is desirable for therapeutic use. In the current study, the goal was to fabricate NO-releasing microspheres (MSs) using a donor molecule, S-Nitroso-N-Acetyl penicillamine, (SNAP), and encapsulating it in poly(ε-caprolactone) (PCL) using a single-emulsion technique that can provide sustained delivery of NO to cells over time without posing any toxicity risks. Optimization of the fabrication process was performed by varying the duration of homogenization (5, 10, and 20 min) and its effect on entrapment efficiency and size. The optimized SNAP-MS had an entrapment efficiency of ˃50%. Furthermore, we developed a modified method for NO detection by using NO microsensors to detect the NO release from SNAP-MSs in real time, showing sustained release behavior. The fabricated SNAP-MSs were tested for biocompatibility with HUVECs (human umbilical vein endothelial cells), which were found to be biocompatible. Lastly, we tested the effect of controlled NO delivery to human induced pluripotent stem-derived cardiomyocytes (hiPSC-CMs) via SNAP-MSs, which showed a significant improvement in the electrophysiological parameters and alleviated anoxic stress. [ABSTRACT FROM AUTHOR]

Micro-LEDs (μLEDs) have advantages in terms of brightness, power consumption, and response speed. In addition, they can also be used as micro-sensors implanted in the body via flexible electronic skin. One of the key techniques involved in the fabrication of μLED-based devices is transfer printing. Although numerous methods have been proposed for transfer printing, improving the yield of μLED arrays is still a formidable task. In this paper, we propose a novel method for improving the yield of μLED arrays transferred by the stamping method, using an innovative design of piezoelectrically driven asymmetric micro-gripper. Traditional grippers are too large to manipulate μLEDs, and therefore two micro-sized cantilevers are added at the gripper tips. A μLED manipulation system is constructed based on the micro-gripper together with a three-dimensional positioning system. Experimental results using this system show that it can be used successfully to manipulate μLED arrays. ARTICLE HIGHLIGHTS: HIGHLIGHTS • A piezoelectrically driven asymmetric micro-gripper is proposed. • A μLED manipulation system is constructed based on the micro-gripper together with a three-dimensional positioning system. • A single μLED array is manipulated by the proposed micro-gripper-based system. [ABSTRACT FROM AUTHOR]

In this study, we fabricated limiting current‐type oxygen microsensors capable of sensing a wide range of oxygen concentrations. The oxygen microsensors consist of yttria‐stabilized zirconia thin films on spiral Ta2O5 diffusion layers and high‐temperature micro‐hotplates. At temperatures above 575 °C, we observed a clear limiting current that increased proportionally with oxygen concentration between 0.4% and 94%. This wide‐range linearity is attributed to the Knudsen diffusion of the oxygen gas passing through the small gap in the spiral Ta2O5 diffusion layer. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This article describes the design, calibration, and testing of new calorimetric microsensors for the measurement of wall shear stress in low-speed aerodynamic flows. The sensors are made of three beams of platinum-plated silicon nitride suspended over a small cavity. Their range of operation and their bandwidth are of the order of ± 10 Pa and 1 kHz, respectively. Results from experimental campaigns in a laminar separation bubble, a turbulent separation bubble, and on a NACA 0015 airfoil at low Reynolds number indicate a high sensitivity and an inherent capacity to measure instantaneous backflow. This demonstrates the capability of the new sensors to accurately determine the mean and fluctuating wall shear stress in laminar, transitional, and turbulent separating and reattaching flows. [ABSTRACT FROM AUTHOR]

Improving measurement accuracy is the core issue with surface acoustic wave (SAW) micro-force sensors. An electrode transducer can stimulate not only the SAW but also the bulk acoustic wave (BAW). A portion of the BAW can be picked up by the receiving transducer, leading to an unwanted or spurious signal. This can harm the device's frequency response characteristics, thereby potentially reducing the precision of the micro-force sensor's measurements. This paper examines the influence of anisotropy on wave propagation, and it also performs a phase-matching analysis between interdigital transducers (IDTs) and bulk waves. Two solutions are shown to reduce the influence of BAW for SAW micro sensors, which are arranged with acoustic absorbers at the ends of the substrate and in grooving in the piezoelectric substrate. Three different types of sensors were manufactured, and the test results showed that the sidelobes of the SAW micro-force sensor could be effectively inhibited (3.32 dB), thereby enhancing the sensitivity and performance of sensor detection. The SAW micro-force sensor manufactured using the new process was tested and the following results were obtained: the center frequency was 59.83 MHz, the fractional bandwidth was 1.33%, the range was 0–1000 mN, the linearity was 1.02%, the hysteresis was 0.59%, the repeatability was 1.11%, and the accuracy was 1.34%. [ABSTRACT FROM AUTHOR]

This document is an editorial from the journal Applied Sciences, discussing the advancements and applications of sensor technologies in the field of marine engineering. It highlights various examples of sensor technologies being used in marine environments, such as wireless sensor networks for real-time monitoring, optical-fiber-based sensors for measuring seawater salinity, and piezoelectric sensors for determining ocean wave height. The editorial also provides an overview of nine research papers included in a special issue of the journal, covering topics such as energy-harvesting solutions, engine monitoring systems, and hydrocarbon exploration. The document emphasizes the transformative impact of sensor technologies in enhancing safety, efficiency, and sustainability in the maritime industry, and suggests that future research will continue to explore novel sensors and measurement systems to meet evolving needs. [Extracted from the article]

Selective sensing of trace hydrogen gas is highly desirable in leak detection applications, and it has recently come to the fore to an even larger degree due to the great potential of hydrogen in the current energy transition. One difficulty of room-temperature hydrogen sensing in an open environment is the potential interference from multiple other analytes, including water vapor, especially in high-humidity environments. To develop a high-responsivity, selective hydrogen gas sensor, ultrathin palladium nanosheets (PdNS) were synthesized using a hydrothermal method. Then, the PdNS were utilized as the chemical recognition layers in gravimetric resonant gas sensors for the real-time detection of hydrogen at room temperature. The nanoscale structure of the PdNS provides the material with a high amount of functional surface area; in turn, this allowed for significant surface-analyte interactions and high-performance sensing. Importantly, the PdNS active layer can selectively sense hydrogen gas in the presence of multiple interfering gases (e.g., acetone, alcohols, and water vapor) in the concentration range of 1–5% in both nitrogen and air environments. Therefore, this sensor system may potentially be of interest for future industrial applications regarding the safe handling of hydrogen gas. [ABSTRACT FROM AUTHOR]

The current research is an attempt to analyze on-site selenium(IV) ions in environmental water samples using an eco-friendly miniaturized sensor developed by deposition of a very thin amount of metallic bismuth in a solid Bi electrode tightly closed in miniaturized housing. Numerous experimental variables are optimized, including the composition of the supporting electrolyte and its pH, as well as activation and accumulation conditions. Under optimized measurement conditions, the method shows high sensitivity, permitting a very low limit of detection equal to 7 × 10−10 mol L−1 to be achieved in a short accumulation time of 50 s. The performance of this microsensor was investigated against numerous interference factors and its good anti-interference capability was demonstrated. A series of voltammetric experiments by differential pulse cathodic stripping voltammetry (DPCSV) were carried out and they proved that the miniaturized sensor is characterized by very good accuracy and precision as well as long-term stability. The solid bismuth microelectrode displays a good voltammetric response in the analysis of diverse samples with a complex matrix and demonstrates a good recovery rate. [ABSTRACT FROM AUTHOR]

Sparse grid imputation (SGI) is a challenging problem, as its goal is to infer the values of the entire grid from a limited number of cells with values. Traditionally, the problem is solved using regression methods such as KNN and kriging, whereas in the real world, there is often extra information—usually imprecise—that can aid inference and yield better performance. In the SGI problem, in addition to the limited number of fixed grid cells with precise target domain values, there are contextual data and imprecise observations over the whole grid. To solve this problem, we propose a distribution estimation theory for the whole grid and realize the theory via the composition architecture of the Target-Embedding and the Contextual CycleGAN trained with contextual information and imprecise observations. Contextual CycleGAN is structured as two generator–discriminator pairs and uses different types of contextual loss to guide the training. We consider the real-world problem of fine-grained PM2.5 inference with realistic settings: a few (less than 1%) grid cells with precise PM2.5 data and all grid cells with contextual information concerning weather and imprecise observations from satellites and microsensors. The task is to infer reasonable values for all grid cells. As there is no ground truth for empty cells, out-of-sample mean squared error and Jensen–Shannon divergence measurements are used in the empirical study. The results show that Contextual CycleGAN supports the proposed theory and outperforms the methods used for comparison. [ABSTRACT FROM AUTHOR]

Spreading depolarization (SD) is one of the most common neuropathologic phenomena in the nervous system, relating to numerous diseases. However, real‐time monitoring the rapid chemical changes during SD to probe the molecular mechanism remains a great challenge. We develop a potentiometric dual‐channel microsensor for simultaneous monitoring of H2S and pH featuring excellent selectivity and spatiotemporal resolution. Using this microsensor we first observe real time changes of H2S and pH in the rat brain induced by SD. This changes of H2S are completely suppressed when the rat pre‐treats with aminooxyacetic acid (AOAA), a blocker to inhibit the H2S‐producing enzyme, indicating H2S fluctuation might be related to enzyme‐dependent pathway during SD and less pH‐dependent. This study provides a new perspective for studying the function of H2S and the molecular basis of SD‐associated diseases. [ABSTRACT FROM AUTHOR]

In this paper, a composite pressure-sensitive mechanism combining diaphragm bending and volume compression was developed for resonant pressure microsensors to achieve high-pressure measurements with excellent accuracy. The composite mechanism was explained, and the sensor structure was designed based on theoretical analysis and finite element simulation. An all-silicon resonant high-pressure microsensor with multiple miniaturized cavities and dual resonators was developed, where dual resonators positioned in two resonant cavities with suitably different widths are used to perform opposite characteristics in pressure and the same characteristics at different temperatures, which can improve pressure sensitivities and realize temperature self-compensation by differential frequency output. The microsensor was fabricated by microfabrication, and the experimental results showed that the sensor had an accuracy of ±0.015% full scale (FS) in a pressure range of 0.1~100 MPa and a temperature range of −10~50 °C. The pressure sensitivity of the differential frequency was 261.10 Hz/MPa (~2523 ppm/MPa) at a temperature of 20 °C, and the temperature sensitivities of the dual resonators were −1.54 Hz/°C (~−14.5 ppm/°C) and −1.57 Hz/°C (~−15.6 ppm/°C) at a pressure of 2 MPa. The differential output had an outstanding stability within ±0.02 Hz under constant temperature and pressure. Thus, this research provides a convenient solution for high-pressure measurements because of its advantages, namely, large range, excellent accuracy and stability. [ABSTRACT FROM AUTHOR]

The main goal of this study was to evaluate the concentration and release dynamics of molecular hydrogen (H2, dihydrogen) in dietary evaluate supplements and identify products that provide a biologically significant amount of dihydrogen suitable for human consumption. We examined ten commercial supplements marketed for their dihydrogen content, including slow-release capsules and tablets (4 products), effervescent powders and tablets (5 products), and canned ready-to-drink beverage (1 product). These products were acquired either through online purchases, from retail stores, or obtained free of charge directly from the manufacturers upon request. Dihydrogen concentration was measured using a highly sensitive Clark-type hydrogen microsensor with a detection limit 0.05 µmol·L-1. Out of the ten products examined, only three (30.0%) exhibited dihydrogen levels surpassing the levels marketed as biologically relevant (500 µmol·L-1), and one of these products (a canned ready-to-drink beverage) approached this level with a concentration of 439.2 µmol·L-1. Interestingly, all slow-release capsules yielded negligible amounts of hydrogen (< 2 µmol·L-1), while a slow-release tablet delivered 43.6 µmol·L-1 of dihydrogen per single dose. The substantial variance in dihydrogen content among the assessed supplements holds significant implications for the general public, as high-potency products have the potential to provide up to 7 000 times more dihydrogen per single dosage compared to their low-potency counterparts. [ABSTRACT FROM AUTHOR]

For microelectronic devices, the on‐chip microsupercapacitors with facile construction and high performance, are attracting researchers' prior consideration due to their high compatibility with modern microsystems. Herein, we proposed interchanging interdigital Au‐/MnO2/polyethylene dioxythiophene stacked microsupercapacitor based on a microfabrication process followed by successive electrochemical deposition. The stacked configuration of two pseudocapacitive active microelectrodes meritoriously leads to an enhanced contact area between MnO2 and the conductive and electroactive layer of polyethylene dioxythiophene, hence providing excellent electron transport and diffusion pathways of electrolyte ions, resulting in increased pseudocapacitance of MnO2 and polyethylene dioxythiophene. The stacked quasi‐solid‐state microsupercapacitors delivered the maximum specific capacitance of 43 mF cm−2 (211.9 F cm−3), an energy density of 3.8 μWh cm−2 (at a voltage window of 0.8 V) and 5.1 μWh cm−2 (at a voltage window of 1.0 V) with excellent rate capability (96.6% at 2 mA cm−2) and cycling performance of 85.3% retention of initial capacitance after 10 000 consecutive cycles at a current density of 5 mA cm−2, higher than those of ever reported polyethylene dioxythiophene and MnO2‐based planar microsupercapacitors. Benefiting from the favorable morphology, bilayer microsupercapacitor is utilized as a flexible humidity sensor with a response/relaxation time superior to those of some commercially available integrated microsensors. This strategy will be of significance in developing high‐performance on‐chip integrated microsupercapacitors/microsensors at low cost and environment‐friendly routes. [ABSTRACT FROM AUTHOR]

In order to enhance the sensitivity of wafer-level vacuum-packaged electric field sensors, this paper proposed a vertical-resonant MEMS electric field sensor based on TGV (Through Glass Via) technology. The microsensor is composed of the electric field sensing cover, the drive cover, and the SOI-based microstructures between them. TGV technology is innovatively used to fabricate the electric field sensing cover and the vertically-driven cover. The external electric field is concentrated and transmitted to the area below the silicon plate in the center of the electric field sensing cover through a metal plate and a metal pillar, reducing the coupling capacitance between the silicon plate and the packaging structure, thereby achieving the enhanced transmission of the electric field. The sensitivity-enhanced mechanism of the sensor is analyzed, and the key parameters of the sensor are optimized through finite element simulation. The fabrication process is designed and realized. A prototype is tested to characterize its performance. The experimental results indicate that the sensitivity of the sensor is 0.82 mV/(kV/m) within the electrostatic electric field ranging from 0–50 kV/m. The linearity of the sensor is 0.65%. [ABSTRACT FROM AUTHOR]

Coral reefs, the largest bioconstruction on Earth, are formed by calcium carbonate skeletons of corals. Coral skeleton formation commonly referred to as calcification occurs in a specific compartment, the extracellular calcifying medium (ECM), located between the aboral ectoderm and the skeleton. Calcification models often assume a direct link between the surrounding seawater and the ECM. However, the ECM is separated from the seawater by several tissue layers and the cœlenteron, which contains the cœlenteric fluid found in both polyps and cœnosarc (tissue connecting the polyps). Symbiotic dinoflagellate-containing cells line the cœlenteron and their photosynthetic activity contributes to changes in the chemistry of the cœlenteric fluid, particularly with respect to pH. The aim of our study is to compare cœlenteron pH between the cœnosarc and polyps and to compare areas of high or low dinoflagellate density based on tissue coloration. To achieve this, we use liquid ion exchange (LIX) pH microsensors to profile pH in the cœlenteron of polyps and the cœnosarc in different regions of the coral colony in light and darkness. We interpret our results in terms of what light and dark exposure means for proton gradients between the ECM and the coelenteron, and how this could affect calcification. A microsensor study on a reef coral suggests that the photosynthetic activity of symbiotic dinoflagellates, lining the cœlenteron, contributes to changes in the cœlenteric fluid chemistry in response to light and spatial variability. [ABSTRACT FROM AUTHOR]

Various energy conversion devices have attracted much attention due to the rapid development of wearable microsensors and the increasing demand for continuous power supply. Among them, improving the performance of evaporation-based hydrovoltaic devices remains a meaningful endeavor. Here, we developed a conductive polymer modified flexible hydrovoltaic power generation device. By arranging the conducting polymer between the flexible substrate and the nanopore channel, the device can voltage output of 1 V and deliver more than 12 μA of current. Due to the durable attachment of the nanomaterials to the substrate, the device maintained over 60% of its electrical output capacity even after being immersed in water for 2 weeks. Improved substrate conductivity leads to an increase in over three times the current output. Furthermore, this device's output is influenced by changes in humidity, making it a viable respiratory monitoring sensor. The integration of polymer conductive materials has led to improved electrical output performance of hydrovoltaic devices, expanding their potential for applications. [ABSTRACT FROM AUTHOR]

Laser direct writing is a promising technology for flexible electronics, microsensors, and microfluidic chips. In this study, we propose a low-cost micro and nano lithography process using near-field laser direct writing. Our platform achieves a high print resolution of 3.96 µm for photosensitive resin, which is better than that of common commercial 3D printing devices. We adjust the laser power and scanning speed to precisely control the print resolution from 3.96 µm to 55.94 µm. The lithography system demonstrates repeatability and stability in repeated experiments, and wide format printing (20×20 mm) shows its ability to print across scales. Our approach employs an inexpensive photohead picker OPU, which costs less than ten dollars, to meet the demand for smallvolume, low-cost, multi-scale micro and nano device manufacturing. [ABSTRACT FROM AUTHOR]

Human-induced climate change is causing ocean warming that triggers the breakdown of the coral–algal symbiosis. The proximate cause of this phenomenon, known as coral bleaching, is commonly attributed to the overproduction of reactive oxygen species (ROS) by the thermally stressed photosynthetic algal symbionts. However, direct evidence that algal ROS production (e.g., in the form of H2O2) and coral physiological stress are the ultimate cause of bleaching remains ambiguous. Here, we investigated the temporal dynamics of H2O2 and oxygen (O2) concentrations during thermally induced coral bleaching to disentangle cause from consequence. Microsensors at the tissue interface of Pocillopora damicornis measured H2O2 and O2 concentrations while exposing single nubbins to baseline temperatures (30 °C) and to minor (33 °C), moderate (36 °C), and high (39 °C) levels of acute heat stress using the Coral Bleaching Automated Stress System (CBASS). We show that a temporary decline in O2 concentration, accompanied by a declining photosynthetic efficiency and loss of Symbiodiniaceae and pigmentation, is the initial response to moderate thermal stress. This response was neither provoked nor followed by an increased H2O2 concentration at the coral tissue interface. A steady light-independent increase of H2O2 was only detected during high heat stress, resulting in the complete and permanent loss of photosynthetic activity. Our findings do not support a direct connection between algal photodamage and an increase in H2O2 concentration during thermally induced bleaching and suggest that more research on the function of H2O2 is warranted. This notion is further substantiated by the observation of an additional source of H2O2, likely oxidative bursts, that were common at the baseline temperature and under minor heat stress, while their occurrence decreased at moderate and high heat stress. Resolving the multifaceted and dynamic roles of H2O2 in coral bleaching is critical to better understand the response of the coral holobiont to thermal stress and identifying the processes underlying the breakdown of the coral–algal symbiosis. [ABSTRACT FROM AUTHOR]

Measuring the distribution and dynamics of H2 in microbial electrochemical reactors is valuable to gain insights into the processes behind novel bioelectrochemical technologies, such as microbial electrosynthesis. Here, a microsensor method to measure and profile dissolved H2 concentrations in standard H-cell reactors is described. Graphite cathodes were oriented horizontally to enable the use of a motorized microprofiling system and a stereomicroscope was used to place the H2 microsensor precisely on the cathode surface. Profiling was performed towards the gas-liquid interface, while preserving the electric connections and flushing the headspace (to maintain anoxic conditions) and under strict temperature control (to overcome the temperature sensitivity of the microsensors). This method was tested by profiling six reactors, with and without inoculation of the acetogen Sporomusa ovata, at three different time points. H2 accumulated over time in the abiotic controls, while S. ovata maintained low H2 concentrations throughout the liquid phase (< 4 μM) during the whole experimental period. These results demonstrate that this setup generated insightful H2 profiles. However, various limitations of this microsensor method were identified, as headspace flushing lowered the dissolved H2 concentrations over time. Moreover, microsensors can likely not accurately measure H2 in the immediate vicinity of the solid cathode, because the solids cathode surface obstructs H2 diffusion into the microsensor. Finally, the reactors had to be discarded after microsensor profiling. Interested users should bear these considerations in mind when applying microsensors to characterize microbial electrochemical reactors. [ABSTRACT FROM AUTHOR]

Neurotransmitter analysis plays a pivotal role in diagnosing and managing neurodegenerative diseases, often characterized by disturbances in neurotransmitter systems. However, prevailing methods for quantifying neurotransmitters involve invasive procedures or require bulky imaging equipment, therefore restricting accessibility and posing potential risks to patients. The innovation of compact, in vivo instruments for neurotransmission analysis holds the potential to reshape disease management. This innovation can facilitate non-invasive and uninterrupted monitoring of neurotransmitter levels and their activity. Recent strides in microfabrication have led to the emergence of diminutive instruments that also find applicability in in vitro investigations. By harnessing the synergistic potential of microfluidics, micro-optics, and microelectronics, this nascent realm of research holds substantial promise. This review offers an overarching view of the current neurotransmitter sensing techniques, the advances towards in vitro microsensors tailored for monitoring neurotransmission, and the state-of-the-art fabrication techniques that can be used to fabricate those microsensors. [ABSTRACT FROM AUTHOR]

Inserting the Industry 4.0 universe into companies is necessary to guarantee their competitiveness and continuity in the market. And, one of the areas in which industry 4.0 and its technologies are most prominent is maintenance, as the use of intelligent mechanisms are capable of promoting the reliability of systems functioning, predicting failures and anticipating problems and breakdowns in equipment., thus contributing to increased performance and reduced aggregate costs. The present study then starts from the idea of using Lab-on-chip technology for the hydraulic fluid and lubricant monitoring system and aims to verify the application of Microelectromechanical Systems (MEMS) in maintenance. From the literary review, it was possible to verify that studies relating the use of microsensors for monitoring lubricants are still scarce and from this, applied research was suggested for this purpose, developing a lab-on-chip that be capable of replacing complex and high-cost laboratory analyses. [ABSTRACT FROM AUTHOR]

Background and aims: The root barrier to radial O2 loss is a trait induced during soil flooding restricting oxygen loss from the roots to the anoxic soil. It can also restrict radial water loss, potentially providing tolerance towards drought during conditions of water deficit. Several root traits (aerenchyma and xylem vessels area) respond in a similar way to soil flooding and low soil water potentials. Therefore, we hypothesised that root acclimations to soil flooding prime plants to withstand conditions of water deficit. Methods: We raised plants in hydroponics mimicking contrasting soil water conditions (aerated controls for well-watered soils; stagnant, deoxygenated solutions for flooded soils, and aerated solutions with different PEG6000 concentrations to mimic conditions of water deficit). We used O2 microsensors and gravimetric measurements to characterize the formation of a barrier to radial O2 loss during conditions of water deficit, and measured key anatomical root traits using light microscopy. Results: Several root traits were induced in stagnant conditions as well as in conditions of water deficit, including the barrier to radial O2 loss. The tightness of the barrier to water loss was similar in both stagnant and PEG6000 treatments. Moreover, plants growing in stagnant conditions tolerated a following severe condition of water deficit, whereas those growing in mimicked well-watered conditions did not. Conclusions: We demonstrated that plants growing in stagnant conditions can withstand following severe conditions of water deficit. We propose that key root traits, such as the barrier to radial O2 loss, which are induced in stagnant conditions as well as mild conditions of water deficit, prime the plants for a following severe condition of water deficit. [ABSTRACT FROM AUTHOR]

In this post-Moore era, on-chip components have transitioned into the "more Moore" and "more than Moore" technology routes. Serving as the foundational point and data source for all intelligent devices, sensors are undergoing development for multifunctionality, systematization, and integration. However, the current micro/nano multifunctional sensor fabrication technology is not sufficiently advanced to meet the requirements of practical applications. In this study, we prepared high-precision microwire arrays as multifunctional microsensors. This microsensor exhibited a highly sensitive response to humidity and bending strain. It has a sensitivity of up to 8520% and response time as low as 0.9/3.5 s (response/recovery) over a wide range of humidity variations from 23% to 97%. In the bending strain range of −0.4–0.4%, the microsensor exhibits a gauge factor of up to 267. This multifunctional microsensor has the potential for use in integrated intelligent devices. [ABSTRACT FROM AUTHOR]