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Paper‐based analytical devices as a low‐cost and point‐of‐care sensing platform have attracted widespread research interest. However, the device fabrication and signal readout remain a challenge for their real‐world applications. Herein, a technically simple paper‐based sensor is developed by taking advantage of the easily accessible paper and the plasmonic property of gold nanomaterials. The sensing mechanism relies on the iodide‐mediated surface etching of gold nanostars that induces a color change from blue to red of the paper strip. The versatility of the paper substrate in size, shape, and materials allows for the facile immobilization of gold nanostars by a simple immersing method, which is easy to operate and free from specialized skills and equipment. In addition, the readout of the paper strip can be conveniently visualized by the naked eye or through a smartphone. This paper‐based sensor advantages in low cost, light weight, easy handling, and disposability that holds great promise as a point‐of‐care detection platform in resource‐constrained settings. [ABSTRACT FROM AUTHOR]

Two imidazole‐based color‐changing fluorescent probes 4‐(4,5‐bis(4‐chlorophenyl)‐1H‐imidazol‐2‐yl)‐N, N‐diphenylaniline (CIN) and 4‐(4,5‐di(furan‐2‐yl)‐1H‐imidazol‐2‐yl)‐N, N‐diphenylaniline (FIN) were synthesized and characterized. The new probes CIN and FIN exhibit excellent selectivity and sensitivity towards Fe3+ with relatively low detection limits (0.26 μM and 0.10 μM) and strong anti‐interference properties. Both the probes CIN and FIN complex 1 : 1 with Fe3+ ion, and the complexation constants were 1.165×105 M−1 (CIN) and 1.899×105 M−1 (FIN), respectively. Moreover, CIN and FIN could be recycled by EDTA and could effectively monitor Fe3+ ions at pH 4–10, which ensures the sensor's potential for detecting Fe3+ in actual aqueous solutions. The probes were further applied to the detection of Fe3+ in the actual reaction of Fe2+ oxidation, and the filter paper and the probe solution are combined to make an indicator to detect Fe3+ more conveniently and quickly. [ABSTRACT FROM AUTHOR]

Food is necessary for survival, and contamination can shorten humans' lives on Earth in all dimensions. Real‐time screening of food pollutants, such as toxins, infectious agents, and chemical contaminants, is in high demand today. Thus, a cost‐effective and ecologically benign technology must be developed to detect food contamination in a rapid fashion. Nanoparticle (NP)‐based paper sensors are one of the most important alternatives to traditional methods because these are simple, inexpensive, highly selective, and sensitive tools. This article provides an overview of NP‐based paper sensor techniques for detecting toxic food contaminants. [ABSTRACT FROM AUTHOR]

Miniaturized paper‐based electrochemical sensors were fabricated using kraft paper and CO2 laser, dispensing the need for chemical reagents and controlled atmospheric conditions. This study initially evaluated the paper type and laser processing parameters, enhancing the electrodes′ robustness, electrochemical response, and electrical resistance. The sensors were also treated by applying −1 V for 60 s in 1.0 mol L−1 KCl, which is a simple and rapid procedure. The electrochemical treatment increased the electroactive area and roughness, confirmed by scanning electron microscopy. These aspects helped modulate the sensors′ electrochemical response for nitrite determination, improving selectivity and sensitivity for this compound. The sensors also showed repeatability and batch‐to‐batch reproducibility, with 2.2 and 10 % RSD, respectively. Therefore, this work brings a protocol to fabricating competitive electrochemical sensors through a sustainable strategy, opening possibilities for designing new analytical systems. [ABSTRACT FROM AUTHOR]

Real‐time and continuous monitoring of ultraviolet (UV) radiation in daily activity is critical in diverse fields ranging from personal fitness, cosmetics, to medical aspects. Here, a wearable UV monitoring patch that can be easily fixed/removed at desired locations and provide real‐time and continuous UVA levels in daily life is developed. The wearable patch consists of a highly sensitive, flexible graphene sensor for UVA measurement and a multifunctional fabric patch integrated with commercial electronic components for signal processing, wireless transmission. To achieve a high sensitive UVA sensor with high flexibility and long‐term stability, porous reduced graphene oxide (pRGO) papers are fabricated by simple solvent evaporation followed by thermochemical reduction. The flexible UVA sensors based on pRGO papers feature a high UVA photoresponsivity of 125 mA W−1, which is comparable to that of a commercial silicon‐based UV sensor. Furthermore, the polydimethylsiloxane‐encapsulated pRGO (PDMS‐pRGO) sensors exhibit stable UVA photoresponse characteristics that is maintained under severe conditions, such as a large number of bending cycles, thermal heating, and high humidity. The use of wearable patches that enable real‐time, wireless monitoring of personal UVA levels in various practical applications are demonstrated. [ABSTRACT FROM AUTHOR]

The separation efficiency of charge carriers determines the analytical sensitivity of the paper-based photoelectrochemical sensor. Herein, the Lewis base modification strategy is proposed to promote the carrier separation through an in-situ ion exchange method. Firstly, three-dimensional paper-based hierarchically TiO2 (PHT) arrays are prepared with the one-step hydrothermal method. With the aid of Lewis base, the photoinduced charge separation efficiency and the photocurrent signal are obviously increased. Ultimately, sensitive sensing of prostate specific antigen (PSA) is achieved and the linear range is 1 pg/mL-100 ng/mL with the detection limitation of 0.3 pg/mL. [ABSTRACT FROM AUTHOR]

2D palladium nanostructures enable sensitive room‐temperature detection of H2. However, they can be limited by stability and fabrication costs. Stability may be improved by alloying Pd with other metals, while cost could be reduced by using paper as a substrate. An ultra‐low‐cost sensor using Pd alloy (PdMoY) nanosheets (NS) on paper is reported. The 2D Pd alloy nanosheets are prepared by a solution‐phase route, drop cast onto paper (≈1 × 1 cm) with silver contacts drawn on it, and dried. The same material is deposited on an interdigitated electrode (IDE). Both sensors are tested for response to hydrogen in air. The resistance of the paper‐based sensor decreased by ≈18.7% in 1% H2, which is about 40 times the response of the IDE‐based sensor. Its H2 limit of detection (1 ppm) is also lower than that of the IDE‐based sensor (5 ppm). Compared to pristine Pd NS, PdMoY NS are more stable to repeated H2 pulses without any signs of buckling or cracks. The nanosheets are also deposited by inkjet printing to produce functional sensors, providing a simple route to manufacturing of ultra‐low‐cost gas sensors for use in fuel‐cell vehicles and related infrastructure. [ABSTRACT FROM AUTHOR]

How to monitor the freshness of packaged food, the safety of sealed medicine, or the other substances in sealed space wirelessly and environment‐friendly has become an urgent problem in recent years. After summarizing the theory of the LC sensor, a design of a paper‐based resonator (30 mm × 30 mm × 0.15 mm) consisting of a finger capacitor is proposed in this paper. The sensor is embedded inside the package by adhering it to the package's inner wall. Its response is remotely detected through a readout coil. This paper establishes a circuit simulation model and an electromagnetic simulation model to verify the feasibility of the design. Compared with the real object and the theoretical simulation model, the difference between the results only within 1 MHz, which verifies the correctness of the theory. Additionally, the measured results indicate that the resonant frequency of the resonator shifted from 102.441 MHz to 88.195 MHz, after dropping water on the sensor. Besides, the simple fabrication technology and inexpensive sensor material ensure a low cost, thus making this technology economically viable. [ABSTRACT FROM AUTHOR]

Different on‐chip antennas in Complementary Metal‐Oxide‐Semiconductor (CMOS) technology for THz detector and source are proposed. Firstly, the size of these antennas is estimated with an equivalent CMOS substrate model. Finally, through electromagnetic simulation, the structure optimised and slotted the on‐chip antenna to realise multi‐band detection, miniaturised detection, and miniaturised source. For the THz detector, multi‐band antennas with a dual‐ring structure and miniaturised antennas with circular and diamond structures are designed. At the frequency of 300, 600, and 800 GHz, the gain of the ring antennas is 5.7, 7.2, and 7.2 dBi, respectively. The gain of the circular and diamond antenna is 5.3 and 5.96 dBi at 300 GHz. For the THz source, rectangular‐slot and T‐slot antennas are designed at the frequency of 300 GHz and the gain of the rectangular‐slot and T‐slot antennas is 2.92 and 3.87 dBi, respectively. Multi‐band antennas and miniaturised antennas effectively save the occupation area and improve the performance of the THz system. The effectiveness of antennas is verified by the measurement of the detector and the source, which indicates that the proposed on‐chip antennas have potential prospects for CMOS THz applications. [ABSTRACT FROM AUTHOR]

Nanocomposite enzymes are attracting intensive attention worldwide. In the present study, a novel colorimetric H2O2 paper sensor was developed based on a new type of nanocomposites composed of Pd−Pt nanoparticles, hemin functionalized reduced graphene oxide (hemin‐rGO) and carboxylated carbon nanotubes (CNTs‐COOH). The proposed nanocomposites show a high peroxidase‐like activity. It provides a sensitive platform showing a linear response toward H2O2 in the range of 0.05–500 μM with a determination limit of 0.01 μM. Based on this, the composites were applied to construct a paper sensor for H2O2 detection in real samples. The cost‐effectiveness, simplicity and efficiency of this paper sensor could be developed for "point‐of‐care" analysis and other related areas. [ABSTRACT FROM AUTHOR]

As a self‐emissive technology, microLED displays retain all benefits of OLEDs and should be able to improve on many aspects, but will it be enough to guaranty success? In February 2024, leading proponent Apple canceled its microLED smartwatch project. More generally, as microLED keeps getting delayed and OLED keeps improving, the value proposition of microLED is shrinking. This paper looks at how the technology could deliver stronger differentiation. [ABSTRACT FROM AUTHOR]

There is a growing interest in developing displays with additional functions. We propose new microLED display architectures embedding Vis/NIR/SWIR emission/sensing. In the first, addressing full‐screen fingerprint application, there is no tradeoff between sensor performance and display brightness. In the second, related to near‐field touchless display application, the proposed solution reduced significantly the complexity. [ABSTRACT FROM AUTHOR]

We developed a flexible imager comprising low‐temperature polycrystalline silicon thin‐film transistors and organic photodiodes. The developed flexible imager has high‐resolution and high‐speed readout characteristics. Owing to these characteristics, pulse wave signals can be measured, and the images of fingerprints and veins can be obtained. Furthermore, we developed three‐axis tactile pressure sensors by integrating flexible optical components. The sensors can detect both normal and tangential pressures. [ABSTRACT FROM AUTHOR]

The paper presents the smart FRP composite bridge panel called „OptiDeck" with integrated distributed fibre optic sensors (DFOS), to monitor the panel's behavior. The panel is intended for use in newly build and refurbished road bridges. From structure point of view the uniqueness of the presented solution results from innovative technological production process to create a honeycomb core in thick sandwich panel. In order for the monitoring system to cover the entire surface of the panel and to detect local damage, it was necessary to use a modern solution based on geometrically continuous DFOS system. The DFOS system serves as the structure health monitoring (SHM) system, which has been tested during the production and laboratory testing of a prototypes in natural scale. The advantages of DFOS measurements are well known and applied in many civil engineering applications. However, the potential benefits are still not fully utilized. Finally the experimental verification of the DFOS system integrated with the FRP deck panel is presented. [ABSTRACT FROM AUTHOR]

In some previous research studies, quite successful results have been obtained in using online tools to increase students' academic achievement. In many fields; the benefits of online formative quizzes have been widely recognized by educators. However, there is little research determining whether weekly formative online exams affect students' academic achievement, especially in engineering courses. In this quasi‐experimental study, it was investigated whether the weekly quiz application method had an effect on students' academic achievement in an engineering course. One hundred and ninety sophomores participated in the study. Although the experimental group (n = 81) used the quizzes prepared on the Course Portal online to learn the Sensors and Transducers Unit, the control group (n = 109) solved the quizzes in the textbook on a paper‐pencil basis. After the online quizzes were solved, the experimental group was given which questions they answered incorrectly and the related video link of these incorrectly answered questions, and the relevant section of the book was given by the Course Portal as feedback. The pretest and posttest data of the students were obtained, and analysis of covariance was utilized as the analysis method to reveal the answer to the study question. The statistical analysis of the students' average achievement scores in the posttest (midterm exam) showed that the experimental group's average achievement score was significantly better than the control group. Results show that online weekly exams have significant effects on students' academic achievement. Weekly online quizzes are recommended to engineering lecturers as they offer students to improve their students' academic success. [ABSTRACT FROM AUTHOR]

This study investigates the use of 10‐(4‐butoxyphenyl)‐10H‐phenothiazine (PTZ), a phenothiazine‐based molecule, for detecting chloroform and other chlorinated hydrocarbons (CHCs). Upon exposure to these compounds to the phenothiazine‐dervitive in presence light, a significant change in emission occurs, enabling naked‐eye detection. The visual detection range of this phenothiazine derivative extends down to concentrations as low as 5 ppm. We demonstrate the one‐time use of thin‐layer chromatography paper (TLC) sensors and glass‐based sensors for on‐site detection of chlorinated hydrocarbons using a light source such as sunlight, UV‐lamp, or a solar box. Our findings suggest that this phenothiazine‐derivative has potential as a simple, low‐cost, and effective sensing platform for chlorinated solvents, with practical applications in environmental monitoring and industrial safety. Furthermore, our results provide insights into the development of molecular sensors for detecting chlorinated hydrocarbons. [ABSTRACT FROM AUTHOR]

With the advent of µLED displays, multiple paradigm shifts in the overall system architecture will offer new opportunities and dramatically change the requirements of display management and general sensing. This work focuses on the required system architecture of a microLED display with embedded sensing functionality. [ABSTRACT FROM AUTHOR]

We evaluate and compare the performance of a 15.6‐inch mini‐LED backlit LCD (mLCD) with a commercial OLED panel. Results show that the mLCD exhibits advantages over the OLED panel in peak brightness, gamma curve, color volume, power consumption, and ambient contrast ratio. The LMK imaging photometer with a high‐resolution CMOS sensor is employed to characterize the halo effect and reconstruct the real luminance profiles based on the non‐ideal profile of the OLED display. We have also proposed a novel strategy to measure the backlight's point spread function. [ABSTRACT FROM AUTHOR]

This paper firstly introduces a flexible hybrid integration (FHI) architecture based on organic thin‐film transistors (OTFTs) for ubiquitous sensor systems, followed by description of the low power OTFT technologies. Then, progresses on sensor integration based on the OTFTs for FHI are discussed, proving the versatility of the technology. [ABSTRACT FROM AUTHOR]

A novel emissive Schiff‐base (3)has been synthesized through single‐step condensation of sulfanilamide and fluorogenic 3‐formylchromone. Compound (3) senses Fe3+ ion in semi‐aqueous media. Both fluorogenic and colorimetrical changes were observed in the presence of Fe3+ ions. Interestingly, on introduction of EDTA into the putative complex, [(3)+Fe3+], the spectroscopic changes were reversed. The ligand detects Fe3+ ions sensitively as the limit of detection for Fe3+ ion was 9.3×10−7 M. The probe performs molecular logic operation (INHIBIT) as well as function of a three‐input keypad lock. Further, the ligand (3)was successfully incorporated into Whatman filter paper as the test strips and aluminium coated silica gel plates, which showed a great selectivity for Fe3+ ions. [ABSTRACT FROM AUTHOR]

Since OLED was first mass‐produced by Samsung Display, various researches related to OLEDs have been actively conducted and now days, People are using OLED displays every single day. As a next generation organic‐optoelectronic display, we suggest the All‐in‐one Sensor Display which can be used for fingerprint recognition, proximity sensor, illuminance sensing and photoplethysmogram which is an area of rapid interest in recent years. To demonstrate the All‐in‐one Sensor Display in entire display area, in this research, we successfully fabricated organic photodetectors (OPDs) in the OLED panels with our own materials, D‐01 and A‐01. Since designing a donor material and an acceptor material is key issue for high Signal to Noise ratio (SNR), we designed and synthesized the D‐01 and A‐01. With our own material based OPDs, All‐in‐one Sensor Display showed good characteristics and successfully recognized fingerprints. This research shows the possibility of the mass production of next organic diode and we believe that All‐in‐one Sensor Display will be the next display application beyond the OLEDs. [ABSTRACT FROM AUTHOR]

A solution for ambient light sensor (ALS) integration in a‐Si LCD with cost advantage and nearly the same performance as external ALS solution. In this work we provide practical solution for the most challenged smartphone [ABSTRACT FROM AUTHOR]

The wide range of pressure detection and the exceptional linearity are essential performance parameters for flexible pressure sensors, enabling them to adapt to diverse scenarios and acquire information accurately. However, currently available "ultra‐wide range" piezoresistive sensors lack an optimal solution that effectively balances sensing properties, device thickness, and process cost. This study proposes a distinctive approach by introducing a Janus conductive structure assembled with dual resistive sensitive layers. The design allows for a pressure‐induced staged transformation of the current transport path, effectively mitigating variations and saturation in sensor resistance over a wide pressure range. The resulting piezoresistive sensor demonstrates an unprecedented detection range of 0–3800 kPa, showcasing remarkable sensitivity of 4.11 kPa−1 and outstanding linearity of 99.9% within the range of 0–1000 kPa. Additionally, the sensor boasts a thickness of only ≈200 µm, made possible through the utilization of a cellulose nanofibers material matrix. These performance achievements stand at the forefront when compared to existing reports. This research explores the potential applications of these sensors and extended arrays in the domains of human health and motion monitoring. It investigates their utility in gait analysis for assisted posture correction, as well as in the assessment and rehabilitation of gait instability. [ABSTRACT FROM AUTHOR]

Keywords: electrochemical treatment; laser-pyrolyzed; paper-based devices; paper-based electrodes; nitrite EN electrochemical treatment laser-pyrolyzed paper-based devices paper-based electrodes nitrite 1 1 1 01/06/23 20230102 NES 230102 B The Cover Feature b illustrates eco-friendly laser-pyrolyzed paper sensors used for nitrite determination in environmental and biological samples. Cover Feature: Modulating the Electrochemical Response of Eco-Friendly Laser-Pyrolyzed Paper Sensors Applied to Nitrite Determination (ChemElectroChem 1/2023) Electrochemical treatment, laser-pyrolyzed, paper-based devices, paper-based electrodes, nitrite. [Extracted from the article]

This paper proposes a predictive power control strategy for the three‐phase, six‐switch Vienna rectifier without grid voltage sensors to reduce the hardware cost and complexity of a high‐power PWM rectifier system. Firstly, an algorithm for calculating the AC‐side voltage in the αβ coordinate system is derived according to the operating principle of the Vienna rectifier, and a voltage observer is constructed by combining a second‐order low‐pass filter to estimate the grid voltage. Secondly, a soft start method is designed to solve the problem that the rectifier is prone to inrush current when it is started. Furthermore, the control method of grid voltage sensorless is combined with predictive power control with good dynamic characteristics and simple parameter settings to form the control strategy proposed in this paper. Finally, simulation analysis and experimental verification are carried out on the proposed control strategy. Simulation and experimental results show that the grid voltage estimation has high accuracy, a good surge current suppression effect, unit power factor operation, low input current harmonic content, and good dynamic and steady‐state performance. Therefore, the correctness and effectiveness of the strategy proposed in this paper are verified. [ABSTRACT FROM AUTHOR]

The rapid and accurate detection of ammonia is very important for manufacture and environmental monitoring, which needs to be developed urgently. Herein, a thin film‐based fluorescence sensor is fabricated by using a ternary europium (III) complex probe for ammonia. The new complex Eu(TPM)3(2‐PBO) (1) was designed and synthesized by utilizing a trifluoromethyl substituted β‐diketone ligand TPM and a diimine ligand 2‐PBO (TPM = 1,1,1‐trifluoro‐5,5‐dimethyl‐2,4‐hexanedione, 2‐PBO = 2‐(2′‐pyridyl)‐benzoxazole). This complex probe was synthetically characterized by elemental analysis, crystallographic and spectroscopic analysis, and photoluminescence (PL) study. The crystallographic analysis revealed complex 1 as a neutral complex structure with the Eu(III) center in a distorted square antiprism EuO6N2 coordination polyhedron. Based on this complex probe, a thin film fluorescence sensor with highly sensitive and selective response to ammonia was developed by polymethyl methacrylate (PMMA): complex composite and cellulose paper support. When the paper‐based sensor was exposed to ammonia, its PL emission showed a sensing behavior of rapid quenching. Surprisingly, this new method can achieve excellent limit of detection as low as 2.740 × 10−6 ppm. [ABSTRACT FROM AUTHOR]

TEMPUS is a new detector system being developed for photon science. It is based on the Timepix4 chip and, thus, it can be operated in two distinct modes: a photon‐counting mode, which allows for conventional full‐frame readout at rates up to 40 kfps; and an event‐driven time‐stamping mode, which allows excellent time resolution in the nanosecond regime in measurements with moderate X‐ray flux. In this paper, the initial prototype, a single‐chip device, is introduced, and the readout system described. Moreover, and in order to evaluate its capabilities, some tests were performed at PETRA III and ESRF for which results are also presented. [ABSTRACT FROM AUTHOR]

A facile and digital do‐it‐yourself technique is proposed to fabricate inexpensive sensors on flexible substrates (paper, cloth, and plastic film). A set of office‐grade equipment (i.e., laserjet printer, thermal laminator, computer‐aided paper cutter), and commercially available supplies (i.e., baking wax paper, furniture restoration metal‐leaf) are used. Forming electrodes through traditional printing and defining a fluidic confinement region through crafting practice enable fabrication of a wide range of devices without requiring customized specialty instruments, costly infrastructure, and complicated fabrication steps, unlike previously introduced methods. Three different levels of experiments are designed to assess the comprehensiveness and responsiveness of the proposed method to the needs of existing research fields. The performances of the fabricated features at each level are evaluated to cover various application domains in environmental monitoring and biomedical diagnostics utilizing conductometric, colorimetric, biochemical, and chemoresistive detection principles. Devices with varying size of features, from nanometers to centimeters, are fabricated and characterized. This method provides an alternative route to decentralized production of low‐cost flexible sensors and other devices, with a minimal step, time, and facilities. The operation of such devices is simple and can be further empowered by smartphones for data analysis and transmission. [ABSTRACT FROM AUTHOR]

Increasing concerns about global food safety and security demands innovative solutions, particularly in food packaging technologies. This review paper investigates the advanced integration of natural colourimetric sensors with biopolymer‐based packaging materials, with a focus on developments over the past 5 years. These sensors change colour in response to environmental stimuli such as oxygen, temperature, pH and relative humidity, intuitively indicating food freshness and safety. The paper emphasizes the recent advancements in using natural colourants, such as alizarin, anthocyanins, betacyanins, chlorophyll, curcumin and shikonin. When combined with either natural or synthetic biopolymers, these colourants contribute to a sustainable and eco‐friendly approach to food packaging. Such technological advances could notably decrease the incidence of foodborne illnesses by signaling potential spoilage or contamination, while also addressing food wastage by providing clear indications of edibility. Although challenges remain in sensor longevity and widespread adoption, the prospects for biopolymer‐based food packaging with embedded natural colourimetric sensors are promising. [ABSTRACT FROM AUTHOR]

Increasing environmental concerns raised by the accumulation of electronic waste draws attention to the development of sustainable materials for short‐lived electronics. In this framework, printed capacitive humidity sensors and temperature resistive detectors composed exclusively of biodegradable materials: shellac, carbon‐derived particles, and egg‐albumin are reported. The sensor platform comprises interdigitated electrodes serving as a capacitive transducer for humidity sensing, and a serpentine used as a resistive temperature detector. Both the interdigitated and serpentine electrodes are manufactured by screen‐printing carbon ink on a shellac substrate. The humidity sensors are constructed by drop‐coating egg albumin on the interdigitated carbon electrodes and the temperature detector is prepared by encapsulating the serpentine design with shellac. Shellac is shown to be a biodegradable alternative to hydrophilic cellulose‐derived substrates, with the capacitive humidity sensors demonstrating a sensitivity of 0.011% RH−1. The response and recovery times on shellac are 12 and 20 times faster than on cellulose‐based substrate, and the serpentine resistive temperature detectors have a temperature coefficient of 5300 ppm K−1. At the end of their service‐life, the sensors produced are home compostable and can be environmentally friendly disposed, potentially enabling their future use for sustainable and environmentally friendly smart‐packaging, agricultural sensing, or point‐of‐care testing. [ABSTRACT FROM AUTHOR]

Bolt looseness may occur on wind turbine (WT) blades exposed to operational and environmental variability conditions, which sometimes can cause catastrophic consequences. Therefore, it is necessary to monitor the loosening state of WT blade root bolts. In order to solve this problem, this paper proposes a method to monitor the looseness of blade root bolts using the sensors installed on the WT blade. An experimental platform was first built by installing acceleration and strain sensors for monitoring bolt looseness. Through the physical experiment of blade root bolts' looseness, the response data of blade sensors is then obtained under different bolt looseness numbers and degrees. Afterwards, the sensor signal of the blade root bolts is analyzed in time domain, frequency domain, and time‐frequency domain, and the sensitivity features of various signals are extracted. So the eigenvalue category as the input of the state discrimination model was determined. The LightGBM (light gradient boosting machine) classification algorithm was applied to identify different bolt looseness states for the multi‐domain features. The impact of different combinations of sensor categories and quantities as the data source on the identification results is discussed, and a reference for the selection of sensors is provided. The proposed method can discriminate four bolt states at an accuracy of around 99.8% using 5‐fold cross‐validation. [ABSTRACT FROM AUTHOR]

Capacitive sensors show promising applications for human–computer interface due to their potential capabilities of both pressure and proximity sensing. However, the sensitivity loss at large strain and the complicated process of fabrication technology limit related applications. Herein, inspired by gradient and hierarchical structures in biological systems and using porous materials with different stiffness, a capacitive flexible sensor with both proximity and pressure sensing abilities is proposed. Such hierarchical structures effectively reduce the attenuation of sensitivity as the pressure increases, realizing an ultrawide detection range with high sensitivity. A theoretical mathematical model is developed and the corresponding capacitive sensor is fabricated by using the high‐performance porous impregnated dust‐free paper as the electrode and expandable polyethylene (EPE)/loofah‐like polyurethane sponge (LPS) as double‐layer porous dielectric. This sensor has an ultrawide detection range up to 3000 kPa with a significantly low sensitivity loss of 0.0195% kPa−1 and the noncontact sensing mode reaches a sensing range up to 28 cm (0.122 cm−1). Notably, a strategy is provided to design the high sensitivity sensor over an ultrawide detection range from approaching to pressuring, and eventually its promising application is presented as human–computer interaction. [ABSTRACT FROM AUTHOR]

This paper investigates the changes in the waveform of a sinusoidal carrier resulting from amplitude modulation (AM) process. Based on this analysis, a novel method for extracting amplitude information is proposed. The proposed method uses the behaviour of the amplitude limitation which does not significantly affect the slope of the sinusoidal signal near zero crossing points. A simple comparator is used to convert the changes in sinusoidal slope near zero crossing points into pulse width changes. A simple circuit is proposed which keeps the output pulse width of the comparator constant by a simple control loop. The accuracy of the method is evaluated through simulation and is experimentally tested. If the modulation index is high and the amplitude of the input signal to the detector is limited, the proposed method can yield up at least 9 dB improvement in relative error power. However, if the modulation index is small, the improvement in relative error power can be at least 35 dB compared to other conventional types of AM demodulators. [ABSTRACT FROM AUTHOR]

In this paper, we examine three important issues in the practical use of state‐of‐the‐art facial landmark detectors and show how a combination of specific architectural modifications can directly improve their accuracy and temporal stability. First, many facial landmark detectors require a face normalization step as a pre‐process, often accomplished by a separately trained neural network that crops and resizes the face in the input image. There is no guarantee that this pre‐trained network performs optimal face normalization for the task of landmark detection. Thus, we instead analyse the use of a spatial transformer network that is trained alongside the landmark detector in an unsupervised manner, jointly learning an optimal face normalization and landmark detection by a single neural network. Second, we show that modifying the output head of the landmark predictor to infer landmarks in a canonical 3D space rather than directly in 2D can further improve accuracy. To convert the predicted 3D landmarks into screen‐space, we additionally predict the camera intrinsics and head pose from the input image. As a side benefit, this allows to predict the 3D face shape from a given image only using 2D landmarks as supervision, which is useful in determining landmark visibility among other things. Third, when training a landmark detector on multiple datasets at the same time, annotation inconsistencies across datasets forces the network to produce a sub‐optimal average. We propose to add a semantic correction network to address this issue. This additional lightweight neural network is trained alongside the landmark detector, without requiring any additional supervision. While the insights of this paper can be applied to most common landmark detectors, we specifically target a recently proposed continuous 2D landmark detector to demonstrate how each of our additions leads to meaningful improvements over the state‐of‐the‐art on standard benchmarks. [ABSTRACT FROM AUTHOR]

Heavy metals and metalloid pollution poses a severe threat to the environment and human health. Various anthropogenic sources are responsible for the release of these contaminants into the water and food chain of humans and animals. To protect the environment and human health, the detection of heavy metals in various environmental matrices becomes vital. Sophisticated lab‐based instruments require more time, effort, and huge investments which warrants the requirement of field‐based disposable sensors. Various optical and electrochemical sensors are reported to demonstrate good sensitivity, selectivity, and detection limits (LOD). The disposable electrodes comprised of glass, paper, plastic, and fabric are gaining importance owing to the ease of application in field analysis, reproducibility, and low cost. The majority of these sensors are based on noble/precious metals namely gold, silver, and platinum. However, limited availability and high cost of these receptors restrict wide spread applicability of these sensors. Numerous earth‐abundant materials and non‐noble metal‐based sensors are also evolving recently due to several advantages namely large‐scale availability, ease of modifications, stability, and shelf life which overcomes the limitations of noble/precious metals‐based sensors. The present review provides a review of recent advances in various non‐noble and earth‐abundant micro and nanomaterials used as receptors in optical and electrochemical biosensors for the detection of metals/metalloids in various matrices. The review also highlights the strategies for the design and fabrication of disposable electrodes, their modification methods, detection strategy, and mechanism involved in the detection of heavy metals. Various gaps existing in the reported sensor systems and future perspectives are also delineated in the present manuscript. [ABSTRACT FROM AUTHOR]

Background: In x‐ray computed tomography (CT), the gain inconsistency of detector units leads to ring artifacts in the reconstructed images, seriously destroys the image structure, and is not conducive to image recognition. In addition, to reduce radiation dose and scanning time, especially photon counting CT, low‐dose CT is required, so it is important to reduce the noise and suppress ring artifacts in low‐dose CT images simultaneously. Purpose: Deep learning is an effective method to suppress ring artifacts, but there are still residual artifacts in corrected images. And the feature recognition ability of the network for ring artifacts decreases due to the effect of noise in the low‐dose CT images. In this paper, a method is proposed to achieve noise reduction and ring artifact removal simultaneously. Methods: To solve these problems, we propose a ring artifact correction method for low‐dose CT based on detector shifting and deep learning in this paper. Firstly, at the CT scanning stage, the detector horizontally shifts randomly at each projection to alleviate the ring artifacts as front processing. Thus, the ring artifacts are transformed into dispersed noise in front processed images. Secondly, deep learning is used for dispersed noise and statistical noise reduction. Results: Both simulation and real data experiments are conducted to evaluate the proposed method. Compared to other methods, the results show that the proposed method in this paper has better effect on removing ring artifacts in the low‐dose CT images. Specifically, the RMSEs and SSIMs of the two sets of simulated and experiment data are better compared to the raw images significantly. Conclusions: The method proposed in this paper combines detector shifting and deep learning to remove ring artifacts and statistical noise simultaneously. The results show that the proposed method is able to get better performance. [ABSTRACT FROM AUTHOR]

In this paper, we proposed ambient light sensor (ALS) and color temperature sensor (CTS) circuit integrated in the edge of LCD display panel. The designed circuit is based on the thin film transistor (TFT) technology, the photo TFT can produce high photo current under light for sensor realizing ambient light from 0~50000Lux. Also, CTS circuit are based on ALS circuit but covered with color filter. The result shows that CTS can discriminate different color temperature in ambient light. The biggest advantage of this sensor is that it is compatible with TFT process in manufacturing, and it is small in size and high in efficiency. It has the potential to replace photodiode sensors. [ABSTRACT FROM AUTHOR]

Detection of trace magnesium ion (Mg2+) is important in environmental and health monitoring. In this work, high‐performance Mg2+ sensor was developed from label‐free carbon dots. The novel carbon dots were prepared for the first time from natural rubber through the two‐step pyrolysis and hydrothermal method. They showed selectivity towards Mg2+ against a range of metal ions in solution and yielded a detection limit of 4.3 μM. The Mg2+ detection in real water samples showed an excellent recovery of 97.21 to 99.21 %. A paper‐based sensor was also fabricated as a portable device, showing a detection limit of 8.0 μM. UV‐vis and X‐ray absorption studies provided some evidences of the unique dynamic interactions between carbon dots and Mg2+ ions. In summary, the novelty of this work lies upon (i) developing a methodology of converting abundant, low‐cost natural rubber into carbon dots and (ii) fabricating sensitive and selective sensors from the label‐free carbon dots for the detection of Mg2+ both in solution and as paper‐based devices. The findings in this work will therefore have potential for environmental and health monitoring applications. [ABSTRACT FROM AUTHOR]

Calibration is the backbone of any sensor and measurement philosophy. The conventional calibration techniques for electrical parameter measurement using nonlinear sensors are affected by the repeating analogue signals and lead to errors in measurement. This research paper investigates different regression‐based mathematical models to calibrate the Hall sensor for measuring RMS and the fundamental frequency. The novelty of this research work lies in the feature‐based input modelling to measure RMS current and frequency with an error of 3.37e‐12% and 7.61e‐9%, respectively. The conventional Fourier transform method is compared with six different bio‐inspired metaheuristic algorithms to estimate the frequency components of the analogue signal received from the measurement setup. Apart from the conventional sine waveforms, this paper investigates sawtooth and square waveforms as the periodic signals for determining the frequency components. The results from the comparison study show that the Whale Optimization Algorithm exhibits 1.25% lesser error whilst predicting the features in measured frequency components. Apart from this, the paper identifies a unique combination of features that effectively measures the instantaneous electrical parameter with RMSE, NRMSE, and R2 value of 158.8, 0.51, and 0.44, respectively. Experimentally it is found that the decision tree and random forest regression models calibrate the Hall sensor with 93% less error than their linear and polynomial counterparts. [ABSTRACT FROM AUTHOR]

Summary: This paper studies the problem of sensor fault estimation for linear systems in the presence of unknown inputs in both input and output channels. Relying on matrix equation theory, the unknown inputs are first removed from the output channel. Second, an augmented descriptor system is constructed by treating both system state and sensor fault as (pseudo)‐state variables. Third, the augmented descriptor system is transformed into a regular one, followed by the elimination of the unknown input from the state equation. Finally, a reduced‐order prescribed‐time sensor fault estimator is obtained by using periodic delayed observers. This matrix equation based approach is then complemented by an alternative one, which relies on successive transformations of state, input and outputs. This approach sheds light on the adopted solvability conditions throughout the paper and on the role of different directions in the output space in handling unknown inputs, sensor faults and the core state estimation problem. Finally, two numerical examples are presented to illustrate the effectiveness of the proposed methodologies. [ABSTRACT FROM AUTHOR]

In order to improve the recognition accuracy of construction machinery and equipment and materials in low contrast scenes, a construction machinery material recognition algorithm based on multisource sensor information fusion is proposed. In the paper, the millimeter wave radar is fused with the camera considering its strong penetration ability in rainy and foggy days and dim environments. Firstly, the spatial coordinates of radar and camera are unified by establishing a spatial fusion model of millimeter wave and camera; then the target acquired by millimeter wave is projected onto the image and the detection frame intersection and ratio model is used to generate the region of interest of the camera; finally, the improved YOLOv2 algorithm is used to identify the region of interest, and in the improved idea, the low‐level information is first connected with the high‐level information in multilayer depth. At the same time, a multiscale feature pyramid network structure is used to achieve recognition of objects of different scales. This model effectively reduces interference from other feature categories while improving the recognition efficiency of the system. The algorithm can effectively improve the recognition accuracy of mechanical materials in low‐contrast scenes, as demonstrated by the validation of different scenes. [ABSTRACT FROM AUTHOR]

Summary: This paper investigates optimizing the collaborative energy power consumption between nodes with energy harvesting (EH) capability at the fusion center (FC) and multi‐antenna sensors using game theory. Using multi‐antennas at FC on sensor networks (SNs), we can benefit from the spatial diversity in receiving the data and using multi‐antenna sensors and energy to transfer the data and optimize the SN, respectively. Also, in this paper, the data transmission in the network is formulated by considering the limitations of storage resources of each sensor, minimum data receiving, minimum EH, and maximum collaboration among sensors. In this paper, some modes are suggested to minimize the collaborative energy among sensors for transmitting the data and energy among sensors in the collaboration of sensors to optimize the power control and allocation power policy. Suggestions have been studied based on the number of antennae to transmit, using the cooperative games in sharing the data and the energy and auction game in transmitting to FC. The simulation results of the proposed problem using MATLAB software show optimization in participation function, EH, allocation in cooperation time, and transferring to FC to improve the detection of the transmitted data based on the increasing number of antennas in FC. [ABSTRACT FROM AUTHOR]

The low‐light environment is integral to everyday activities but poses significant challenges in object detection. Due to the low brightness, noise, and insufficient illumination of the acquired image, the model's object detection performance is reduced. Opposing recent studies mainly developing using supervised learning models, this paper suggests LIDA‐YOLO, an approach for unsupervised adaptation of low‐illumination object detectors. The model improves the YOLOv3 by using normal illumination images as the source domain and low‐illumination images as the target domain and achieves object detection in low‐illumination images through an unsupervised learning strategy. Specifically, a multi‐scale local feature alignment and global feature alignment module are proposed to align the overall attributes of the image and feature biases such as background, scene, and target layout are thus reduced. The experimental results of LIDA‐YOLO on the ExDark dataset achieved the highest performance mAP score of 56.65% compared to several current state‐of‐the‐art unsupervised domain adaptation object detection methods. Compared to I3Net, the performance improvement is 4.04%, and compared to OSHOT, the performance improvement is 6.5%. LIDA‐YOLO achieves a performance improvement of 2.7% compared to the supervised baseline method YOLOv3. Overall, the suggested LIDA‐YOLO model requires fewer samples and presents a stronger generalization ability than previous works. [ABSTRACT FROM AUTHOR]

Aircraft coating process has been an important part in manufacturing process of modern aviation products. For coating defect detection, the manual observation with naked eyes is usually utilized, which leads to low production efficiency. In this paper, the authors propose the improved YOLOv5‐OBB with the channel‐spatial attention block (CSAB), feature pyramid non‐local module (FPNM) and structured sparsity slimming criterion (SSSC). The CSAB can pay more attention to effective channel information features from the channel dimension and the target information area from the spatial dimension. The effective non‐local module called FPNM is proposed to further improve the detection accuracy. The authors utilize the oriented bounding boxes (OBB) to reduce redundant background information for coating defect detection. In addition, the SSSC is proposed to achieve network slimming and trade‐off between the efficiency and accuracy. The experimental results on several datasets demonstrate the effectiveness of the authors' scheme, which achieves superior performance. [ABSTRACT FROM AUTHOR]

Waterborne bacteria cause many dangerous diseases as well as several health‐related issues hence detection of them is a global challenge today. A plus‐shaped graphene sensor to detect waterborne bacteria is presented in this paper. The detection mechanism is based upon the refractive index difference between waterborne bacteria sample and pure water which causes a change in resonance peak in the transmittance graph. The use of graphene material increases the sensitivity and also gives the tuning behavior by changing its potential. The effect of various parameters such as sensitivity (S), Q factor, figure of merit (FOM), and detection limit are discussed in the paper. The maximum values Q factor and FOM are 13.46 and 4.03 RIU−1 respectively. The minimum detection limit is 0.277 RIU. The proposed sensor exhibits the highest sensitivity of 255 GHz/RIU at the optimum condition which is comparably higher than previously published papers on biosensors. The proposed design with its highest sensitivity and good detection parameters can be helpful in detecting waterborne bacteria. [ABSTRACT FROM AUTHOR]

Abnormal glucose level can cause irreversible damage, including diabetes. In this work, a sensor was designed that mimics the peroxidase property of the natural horseradish peroxidase (HRP). The proposed sensor detects the presence of glucose through the reduction of hydrogen peroxide (H2O2) and the oxidation of tetramethylbenzidine (TMB). This sensor shows linear behaviour in the range of 0.001–50 μM with a limit of detection down to 0.8 nM. In addition, a paper‐based format of this sensing platform was performed which enables fast and sensitive detection and further reduces the expenses. In this method the linear behaviour of the sensor is between 0.005–40 μM and the detection limit is as low as 2.4 nM. The glucose detection in human saliva was also performed, showing an acceptable accuracy. Thus the sensor is practically suitable for the non‐invasive detection of glucose. [ABSTRACT FROM AUTHOR]

The ability to utilize a hybrid-photon-counting detector to its full potential can significantly influence data quality, data collection speed, as well as development of elaborate data acquisition schemes. This paper facilitates the optimal use of EIGER2 detectors by providing theory and practical advice on (i) the relation between detector design, technical specifications and operating modes, (ii) the use of corrections and calibrations, and (iii) new acquisition features: a doublegating mode, 8-bit readout mode for increasing temporal resolution, and lines region-of-interest readout mode for frame rates up to 98 kHz. Examples of the implementation and application of EIGER2 at several synchrotron sources (ESRF, PETRA III/DESY, ELETTRA, AS/ANSTO) are presented: high accuracy of high-throughput data in serial crystallography using hard X-rays; suppressing higher harmonics of undulator radiation, improving peak shapes, increasing data collection speed in powder X-ray diffraction; faster ptychography scans; and cleaner and faster pump-and-probe experiments. [ABSTRACT FROM AUTHOR]

This paper theoretically and experimentally analyzes the influence of different sensor array schemes and optical collimation structures on fingerprint recognition. Considering the process yield, cost and the quality of fingerprint image, we find the appropriate size ranges of microlenses and sensors are 20~30 μm and 35~50 μm respectively, and the bonding process between the optical collimating film and the sensor substrate has little damage to the sensor, which is conducive to mass production. [ABSTRACT FROM AUTHOR]

An improved filtering algorithm, called the EttAF adaptive filtering, is proposed in this paper. Compared with the available algorithm, the equivalent observation error in the fusion centre from the external sensor is considered, which makes the observation noise matrix of the filter dynamically adjust according to the relative relationship between the fusion centre and the external sensor. The strong manoeuvring target is modelled based on the CS‐jerk model, and the error adaptive variation equation is derived for the external data. Simulation results show that compared to traditional algorithm the EttAF algorithm can effectively improve the accuracy of position and velocity by 10.8% and 22.3% respectively. [ABSTRACT FROM AUTHOR]