Reliable Sensor Research Articles

Gas Phase Aldehydes Detection in Exhaled Breath in Screening of Barrett's Esophagus

Aldehydes, e.g., acetaldehyde, have been classified as toxic and carcinogenic volatile organic compounds (VOCs) and are recognized as one determinant of upper aerodigestive tract cancer like Barrett's esophagus. Measuring aldehyde levels in breath provides information about the aldehydes released by abnormal cells, the level of aldehyde dehydrogenase (ALDH2) activity, and risks and diseases associated with high levels of acetaldehyde, which include liver disease and lung and upper digestive cancers. Devices currently available for breath analysis are state-of-the-art, high-resolution mass spectrometry instruments. These instruments have some drawbacks such as size, initial cost, and operational expense. Electrochemical sensors are capable of miniaturization and are available as portable and handheld breathalyzers. The non-invasive nature of breath analysis and its easy sampling makes smaller devices a more attractive alternative, particularly for continuous monitoring and point-of-care (POC) testing.1 However, the lack of an exchangeable/disposable sensing element, the resulting memory effect, and the need for frequent recalibration is the main drawback of currently available electrochemical breathalyzers.Herein we examine the feasibility of a POC testing device for aldehyde in exhaled breath to assess the medical application of such a device in noninvasive diagnostic testing for Barrett’s esophagus. To improve the selectivity of the method we harness the unique catalytic activity of the aminoxyl radical/oxoammonium redox couple toward aldehyde oxidation. The highly selective/sensitive device offers the capability for use in the detection of Barrett's esophagus, ideally at early stages, without the need for a high-cost screening test. Our functional sensing element consists of a screen-printed electrode (SPE) in which the graphene oxide-based is the working electrode. Exposing this electrode to simulated breath that contains aldehyde, while applying the required potential for oxidation of the aminoxyl radical (4-acetamido-TEMPO known as ACT), generates an electrocatalytic current proportional to the aldehyde concentration in the breath. These simple, sensitive, durable, and inexpensive electrodes may contribute to the development of a single-use reliable aldehyde sensor for personal or law enforcement applications.1. M. Mayer, M. Rafiee, Electrocatalytic Detection of Ethanol and Acetaldehyde by Aminoxyl Radicals: Utilizing Molecular Catalysis for Breath Analysis. Analyst 147, 2022, 3420 – 3423.

Biofluid Fouling Effects on 3D Printed Ion-Selective Electrodes for Diagnostic Sensing

Research for more reliable and cost-effective sensors in healthcare applications is a global priority. This is one of the main reasons that the scientific community is pushed in development of diagnostic tools for use in point-of-care (POC) applications. The combination of electrochemistry and 3D-printing techniques in terms of POC sensor development has many advantages. Utilization of ion selective electrodes (ISEs) in potentiometric techniques has provided fast and reliable analysis as well as high selectivity for analytes in many biofluids. 3D printing, as an additive manufacturing technique, has been used in a variety of applications since it has been shown to be a low-cost and rapid fabrication technique for many sensors that can be applied in diverse POC applications. As a result, 3D-printed electrochemical sensors are used for detection of a wide range of biomarkers associated with many diseases. Several 3D printed ISEs have already been shown to selectively detect analytes in biofluids, however a comprehensive study of the effects of biofluid fouling has yet to be established. Herein, we discuss the fabrication of a novel 3D printed sodium ISE to investigate the effect of biofouling on 3D printed ISEs in comparison to conventional PVC-based ISEs. Using a custom 3D printed microfluidic device, various biofluids were introduced to understand the effects of potential ISE deterioration after prolonged use in biofluids.

Recent Developments in Fe-Based Electrodeposited Thin Films

Electrodeposition is a commonly employed technique for synthesizing magnetic thin films, serving both fundamental research and practical applications. Of particular interest are Fe-based alloys like NixFe1-x and Fe1-xGax, as fundamental properties of ferromagnets as saturation magnetization (Msat), Curie temperature (TC), magnetic anisotropy (K) and magnetostriction constant (λ) strongly depend on the composition [1-2]. This work presents our latest findings on Fe-based thin films and multilayers, exploring diverse phenomena ranging from controlling magnetization switching in magnetoelastic structures to fine-tuning the out-of-plane (OOP) component of magnetization [3-4].Materials exhibiting moderate perpendicular magnetic anisotropy can develop stripe domains above a critical thickness (tcr). In addition to the interest in the basic understanding of this magnetic texture, nowadays, there is an increasing attention in this type of domains since they can be used for example for spin waves generation. The Ni80Fe20 alloy known as permalloy has been widely investigated because of its low coercivity and null magnetostriction. Sputtered Ni80Fe20 layers has been reported to have tcr around 300 nm [5], and its formation is generally believed to be due to columnar growth. However, for applications like magnetoimpedance, these stripes can be undesirable, hindering the growth of sufficiently thick layers to fabricate reliable sensors. Therefore, it is of interest the control of stripe domains in NixFe1-x films and whether the electrodeposition technique can also be used to tailor the appearance of this magnetic texture. Initially, we have examined the formation of stripe domains in the Ni90Fe10 alloy that is also of great interest because of its low coercivity and negative magnetrostriction (λ ~ -20 ppm). Subsequently, we have analyzed the magnetic behavior of electrodeposited NixFe1-x films in which the Fe content has been increased up to 30 at. %. Experimental results show that for Ni90Fe10 films magnetic stirring during growth suppresses the presence of stripes even for a thickness exceeding 1 µm. On the other hand, when growing with unstirred electrolyte, tcr can be reduced if a perpendicular magnetic field of 100 Oe is applied during samples growth. Eventually, it has been observed that tcr depends on the Fe content in the NixFe1-x and no stripes are observed for a content above 13 at.% when no perpendicular magnetic field is applied during growth.We have also investigated a bilayer structure comprised of two magnetic layers with opposite signs for the magnetostriction constant, Ni90Fe10 (λ ~ -20 ppm) and Fe70Ga30 (λ~ 70 ppm) to analyze the effect of magnetoelasticity on the magnetization reversal process. The exchange correlation length is a key parameter that determines the transition region between two opposite directions of the magnetization that depends on characteristics such as the magnetic anisotropy and the exchange stiffness constant. It is also used to quantify the domain wall thickness (δ) that can be considered as the distance over which the magnetic moments are correlated by exchange interactions, and that plays a fundamental role on magnetic systems relying on interfacial interactions as spring magnets or exchange-biased systems. Since the thickness of the layers cannot be higher than δ to avoid the magnetic switching of uncoupled regions, this implies that the thickness of layers is intrinsically limited in systems with interfacial coupling. We have studied Ni90Fe10/Fe70Ga30 bilayers with thicknesses exceeding δ to analyze the magnetic switching in these new magnetoelastic bilayer structures. 500 nm-thick Ni90Fe10 and Fe70Ga30 single layers have coercive fields of 22 Oe and 42 Oe, respectively, which guarantees that independent magnetic switchings from each layer can be experimentally observed.This has been confirmed by micromagnetic simulations performed by OOMF in which magnetoelasticity has not been included. However, when measuring the hysteresis loops of different NiFe/FeGa samples with thicknesses exceeding δ it is observed an in-unison magnetization reversal in all cases. Since magnetoelasticity is not an interfacial effect, it enables to control the magnetization reversal process of the whole bilayer regardless of the thickness being possible to promote this simultaneous reversal process regardless of the layer thickness (Fig.1).In conclusion, these results highlight the capability of electrodeposition to achieve new magnetic systems with enhanced functionalities.[1] J. M. D. Coey. Magnetism and Magnetic Materials. Cambridge University Press (2010)[2] Q. Xing, Y. Du, R. J. McQueeney, T. A. Lograsso. Acta Mater. 56 (2008) 4536−4546.[3] N. Coton, J. P. Andres, A. Cabrera, M. Maicas, R. Ranchal. J. Appl. Phys. 134 (2023) 103904.[4] N. Coton, J.P. Andres, E. Molina, M. Jaafar, R. Ranchal. J. Magn. Magn. Mater. 565 (2023) 170246.[5] M. Romera, R. Ranchal, D. Ciudad, M. Maicas, C. Aroca, J. Appl. Phys. 110 (2011) 083910 Figure 1

Efficient nitrite determination by electrochemical approach in liquid phase with ultrasonically prepared gold-nanoparticle-conjugated conducting polymer nanocomposites.

An electrochemical nitrite sensor probe is introduced herein using a modified flat glassy carbon electrode (GCE) and SrTiO3 material doped with spherical-shaped gold nanoparticles (Au-NPs) and polypyrrole carbon (PPyC) at a pH of 7.0 in a phosphate buffer solution. The nanocomposites (NCs) containing Au-NPs, PPyC, and SrTiO3 were synthesized by ultrasonication, and their properties were thoroughly characterized through structural, elemental, optical, and morphological analyses with various conventional spectroscopic methods, such as field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, and Brunauer-Emmett-Teller method. The peak currents due to nitrite oxidation were characterized in detail and analyzed using conventional cyclic voltammetry (CV) as well as differential pulse voltammetry (DPV) under ambient conditions. The sensor response increased significantly from 0.15 to 1.5mM of nitrite ions, and the sensor was fabricated by coating a conducting agent (PEDOT:PSS) on the GCE to obtain the Au-NPs/PPyC/SrTiO3 NCs/PEDOT:PSS/GCE probe. The sensor's sensitivity was determined as 0.5μA/μM∙cm2 from the ratio of the slope of the linear detection range by considering the active surface area (0.0316cm2) of the flat GCE. In addition, the limit of detection was determined as 20.00 ± 1.00 µM, which was found to be satisfactory. The sensor's stability, pH optimization, and reliability were also evaluated in these analyses. Overall, the sensor results were found to be satisfactory. Real environmental samples were then analyzed to evaluate the sensor's reliability through DPV, and the results showed that the proposed novel electrochemical sensor holds great promise for mitigating water contamination in the real samples with the lab-made Au-NPs/PPyC/SrTiO3 NC. Thus, this study provides valuable insights for improving sensors for broad environmental monitoring applications using the electrochemical approach.

Measurement System for the Calibration of Accelerometer Arrays

This paper addresses accelerometer array calibration, focusing on determining the errors between multiple sensors. Micro-electromechanical system (MEMS) based triaxial accelerometers, key components of Inertial Measurement Units (IMUs), are used in localization, robotics, and navigation systems. The requirements of these applications necessitate low-cost sensors, which makes MEMS IMUs a reasonable choice. However, these low-cost IMUs are significantly affected by systematic (i.e., bias, misalignment, scale-factor) and random errors. Achieving reliable sensor output depends on the precision of the executed calibration method. While traditional laboratory-based sensor calibration using specialized equipment (i.e., three-axis turntable) is accurate, it is time-consuming and costly. In contrast, in-field calibration techniques, which can be performed using a mechatronic actuator or a robotic arm, have gained popularity. These techniques involve comparing sensor measurements to established reference values. The MEMS sensors are increasingly being used in multi-sensor applications, which demands not only individual sensor error calibration but also important to determine the axis misalignment between the used sensors. During calibration process, various optimization algorithms (e.g., GA, PSO) can also be used to find the error parameters. The proposed measurement system allows for individual calibration of misalignment, bias, and scale factor of the sensor array, and eliminates between-sensor misalignment errors.

CsPbBr3 NCs Confined and In Situ Grown in ZIF-8: A Stable, Sensitive, Reliable Fluorescent Sensor for Evaluating the Acid Value of Edible Oils.

Rapidly and sensitively evaluating the acid value (AV) of edible oils is significant to ensuring food quality and safety. Cesium lead bromide perovskite nanocrystals (CsPbBr3 NCs) are an effective candidate for AV detection; however, their instability restricts wide applications. Herein, CsPbBr3@ZIF-8 was prepared by confining and growing CsPbBr3 NCs in situ into zeolitic imidazolate framework-8 (ZIF-8) to improve the stability, and a fluorescence sensor was established to evaluate the AV of edible oils. The results present that CsPbBr3 NCs (below 5 nm) with excellent optical properties were confined and grown in situ in micropores and mesopores of ZIF-8. Meanwhile, CsPbBr3@ZIF-8 had better long-term storage, ultraviolet-irradiation, and water-exposure stabilities, compared with CsPbBr3 NCs. Given the fact that free fatty acids (the major contributor of AV) decrease the fluorescence of CsPbBr3 NCs, the fluorescence intensities of CsPbBr3@ZIF-8 were negative-linearly related to oil AV (R2 = 0.9902) in 0.04-6.00 mg of KOH/g with a 0.06 mg of KOH/g limit of detection. Besides, the practical AV recovery was 92-101% with an average relative standard deviation of 2%. Furthermore, the detection time was 20 min. The response mechanism revealed that free fatty acids could remove surface ligands and increase surface defects to prompt the aggregation of CsPbBr3 NCs and the formation of lattice fringe dislocations, inducing a decrease in the fluorescence. Thus, a stable, sensitive, reliable sensor was established to evaluate the AV of edible oils.

Pengaruh Jenis Sensor terhadap Persentase Eror Sensor Parkir Berbasis STM32

This study evaluates the impact of sensor type on the percentage error in an STM32-based parking sensor system by comparing the HY-SRF05 and JSN-SR04T ultrasonic sensors. The aim of this research is to determine the accuracy of each sensor in distance measurement and identify the more reliable sensor for parking sensor applications. The methodology includes installing both sensors on the STM32 system, measuring distances at various intervals, and analyzing the percentage error. The results indicate that the HY-SRF05 sensor exhibits a lower percentage error compared to the JSN-SR04T across all tested distances, from 50 cm to 300 cm. The average percentage error for the HY-SRF05 is 1.78%, while for the JSN-SR04T it is 2.6%. The conclusion of this research is that the HY-SRF05 sensor is more accurate and reliable than the JSN-SR04T for STM32-based parking sensor applications.

Integrated MUSIC array for high-precision damage diagnosis in complex composite structures

Guided Wave (GW)-based Multiple Signal Classification (MUSIC) damage imaging presents several advantages, such as high resolution, which makes it a promising technique for localizing damage in composite structures. However, the application of this technology in aircraft is confronted with various challenges. The variability in performance of MUSIC array sensors is attributed to material and manufacturing process dispersion. Additionally, the conventional wiring of MUSIC array sensors adds considerable weight and is not compatible with complex structural configurations. Furthermore, within intricate configurations, the attenuation of scattering signals induced by structural damage impacts the accuracy of imaging. Moreover, the manual and individual placement of sensors on structures, along with structural anisotropy, may introduce phase errors in the signals detected by MUSIC array sensors. This can lead to a reduction in the accuracy of MUSIC imaging and result in compromised long-term sensor reliability. This paper proposes a high-precision integrated MUSIC array for the diagnosis of complex composite damage. This approach aims to address the challenges related to damage imaging in materials with complex structures. Impedance curve screening and surface-mount co-curing technology are utilized to manage the performance variation of MUSIC array sensors, enhance layout uniformity, and improve long-term stability. Subsequently, a focus compensation algorithm is proposed within the integrated MUSIC design to enhance precision, reduce weight, and adapt to complex structures. The effectiveness of the proposed method is confirmed through experimental validation on an actual complex composite wing box segment, demonstrating a maximum error of 2 cm in locating impact damage.

A review on development of enzymatic biosensors for industrial applications

Enzymatic biosensors are vital tools across various industries due to their high specificity, sensitivity, and rapid response times. They are extensively used in medical diagnostics for monitoring biomarkers like glucose and lactate, environmental monitoring to detect pollutants, food safety and quality assurance, bioprocess control in industrial fermentation, pharmaceutical drug development and quality control, soil health and agrochemical detection in agriculture, and for identifying biological warfare agents. However, several challenges limit their broader adoption and effectiveness in industrial settings. Key challenges include enzyme stability, as enzymes can denature under extreme environmental conditions, reducing sensor lifespan and performance. Variability in enzyme activity and immobilization techniques also leads to inconsistencies, affecting sensor reproducibility and reliability. Complex sample matrices, such as those in environmental and food samples, introduce interference that can affect sensor accuracy. Integrating biosensors into existing industrial processes is another significant challenge, requiring compatibility with automated systems and real-time data processing capabilities. Additionally, high production costs and scalability issues hinder widespread adoption. Regulatory and standardization barriers further complicate the development and deployment of enzymatic biosensors. Despite these limitations, advancements in materials science, nanotechnology, and bioengineering are paving the way for more robust and reliable biosensors. Innovations such as nanomaterial-based enzyme immobilization, synthetic biology for enzyme engineering, and advanced data analytics integration hold promise for overcoming current limitations. Collaborative efforts among researchers, industry stakeholders, and regulatory bodies are essential to accelerate the development and application of enzymatic biosensors in industrial settings. While enzymatic biosensors offer significant potential, addressing these challenges through ongoing research and technological advancements is crucial for their widespread implementation and optimization.

A Multielectrode Layout for High Reliability of Flexible Piezoresistive Sensor: One Stimulus Signal to Three Sensing Signals.

Flexible sensors have developed rapidly due to their great application potential in the intelligent era. However, the frequent bending work requirements pose a serious challenge to the mechanical reliability of flexible sensors. Herein, a strategy of using a new multielectrode layout to achieve multiple sensing signals based on one external signal is proposed for the first time to improve the reliability of flexible piezoresistive sensors. The multielectrode layout consists of a pair of interdigital electrodes and a bottom electrode. The interdigitated electrodes are used to sense the change in the surface resistance of the sensor, and the interdigital electrodes and the bottom electrode are used to sense the change in the bulk resistance of the sensor. As a result, without increasing the sensing unit area, the electrode layout allows the sensor to generate three response electrical signals when sensing an external pressure, thus improving the reliability of the sensor. Based on the electrode layout, a highly reliable flexible piezoresistive sensor with a multilevel porous structure is obtained by a microwave foaming method with a template. In the working state of sensing surface resistance, the sensor has a 22.12 kPa-1 sensitivity. Meanwhile, in the working state of sensing bulk resistance, the sensor shows a 55.17 kPa-1 sensitivity. Furthermore, the sensor is applied to monitor human pulse and speech signals, demonstrating its multisignal output characteristics and potential applications in flexible electronics. In conclusion, the new strategy of using the proposed electrode layout to improve the reliability of flexible sensors is expected to greatly promote the practical application of flexible electronics.

Synergistic Etching and Hydrogen Bonding-Induced Self-Assembly of MXene/MOF Hybrid Aerogel for Flexible Room-Temperature Gas Sensing.

Limited by insufficient active sites and restricted mechanical strength, designing reliable and wearable gas sensors with high activity and ductility remains a challenge for detecting hazardous gases. In this work, a thermally induced and solvent-assisted oxyanion etching strategy was implemented for selective pore opening in a rigid microporous Cu-based metal-organic framework (referred to as CuM). A conductive CuM/MXene aerogel was then self-assembled through cooperative hydrogen bonding interactions between the carbonyl oxygen atom in PVP grafted on the surface of defect-rich Cu-BTC and the surface functional hydroxyl group on MXene. A flexible NO2 sensing performance using the CuM/MXene aerogel hybridized sodium alginate hydrogel is finally achieved, demonstrating extraordinary sensitivity (S = 52.47 toward 50 ppm of NO2), good selectivity, and rapid response/recovery time (0.9/4.5 s) at room temperature. Compared with commercial sensors, the relative error is less than 7.7%, thereby exhibiting significant potential for application in monitoring toxic and harmful gases. This work not only provides insights for guiding rational synthesis of ideal structure models from MOF composites but also inspires the development of high-performance flexible gas sensors for potential multiscenario applications.

Smart wearable flexible sensor based on laser-induced graphene/gold nanoparticles/black phosphorus nanosheets for in situ quercetin detection

In situ detection of metabolic substances in plants is necessary for the development of smart agriculture. However, there is a mechanical mismatch between the traditional rigid sensing interfaces and the softness surface of plant leaves, which can reduce the reliability and accuracy of sensor. Stretchable and flexible sensors provide new solutions to this problem. Herein, using quercetin (Que) as a model, we developed a flexible electrochemical sensor for in situ monitoring of metabolite in plants. A light and thin laser-induced graphene (LIG) electrodes with good flexibility were obtained after polydimethylsiloxane (PDMS) transfer. Gold nanoparticles (AuNPs) and two-dimensional black phosphorus (BP) nanosheets were fabricated on the electrode to further improve the electrochemical performance. The sensor can detect Que concentrations in the range of 1–100 μM with a detection limit of 0.65 μM (S/N=3). The sensor can adapt well to the soft plant leaf surfaces, thus realizing the application of in situ and in vivo detection in the field. This innovative plant wearable biosensor is expected to be a next-generation electronic candidate for intelligent agriculture, paving the way for in-situ and in vivo detection, and facilitating the intelligentsias of modern agriculture.

Microchannel pressure sensor for continuous and real-time wearable gait monitoring

A highly sensitive and multi-functional pressure sensor capable of continuous pressure readings is greatly needed, particularly for precise gait pattern analysis. Here, we fabricate a sensitive and reliable pressure sensor by employing eutectic gallium indium (EGaIn) liquid metal as the sensing material and EcoFlex 00-30 silicone as the substrate, via a low-cost process. The device architecture features a microchannel, creating two independent sensing devices, and the mechanical properties of the substrate and sensing material contribute to high stretchability and flexibility, resulting in a sensitivity of 66.07 MPa−1 and a low measurement resolution of 0.056 kPa. The sensor detects applied pressure accurately and can distinguish pressure distribution across a wide area. We demonstrate high efficiency for monitoring human walking gait at various speeds when a single sensor is attached to the foot, and can differentiate between walking postures. This device has strong potential for clinical and rehabilitation applications in gait analysis.

Boosting Electrochemical Sensing Performances Using Molecularly Imprinted Nanoparticles.

Nanoparticles of molecularly imprinted polymers (nanoMIPs) combine the excellent recognition ability of imprinted polymers with specific properties related to the nanosize, such as a high surface-to-volume ratio, resulting in highly performing recognition elements with surface-exposed binding sites that promote the interaction with the target and, in turn, binding kinetics. Different synthetic strategies are currently available to produce nanoMIPs, with the possibility to select specific conditions in relation to the nature of monomers/templates and, importantly, to tune the nanoparticle size. The excellent sensing properties, combined with the size, tunability, and flexibility of synthetic protocols applicable to different targets, have enabled the widespread use of nanoMIPs in several applications, including sensors, imaging, and drug delivery. The present review summarizes nanoMIPs applications in sensors, specifically focusing on electrochemical detection, for which nanoMIPs have been mostly applied. After a general survey of the most widely adopted nanoMIP synthetic approaches, the integration of imprinted nanoparticles with electrochemical transducers will be discussed, representing a key step for enabling a reliable and stable sensor response. The mechanisms for electrochemical signal generation will also be compared, followed by an illustration of nanoMIP-based electrochemical sensor employment in several application fields. The high potentialities of nanoMIP-based electrochemical sensors are presented, and possible reasons that still limit their commercialization and issues to be resolved for coupling electrochemical sensing and nanoMIPs in an increasingly widespread daily-use technology are discussed.

Hollow mesoporous In2O3 derived from MIL-68 (In) for dual gas sensing of NO2 and H2

NO2 is one of the most important air pollutant gases for the environment and human health. H2 is seen as the next generation of clean energy to promote sustainable development. However, sensitive detection of NO2 at room temperature is still a major challenge, and reliable H2 sensors are also scarce. Metal oxide semiconductor (MOS) gas sensors are advantageous for detecting gas. Hence, we synthesized the unique hexahedral hollow mesoporous In2O3 (h-In2O3) derived from MIL-68 (In). The formation process and properties of h-In2O3 were analyzed. The surface of h-In2O3 is rich in hydroxyl groups, which are active sites for NO2 adsorption at room temperature. Increasing working temperature up to 160 °C enables effective sensing reaction with H2. Based on different temperature-dependent gas sensing mechanisms, the h-In2O3 sensor exhibits ultrasensitive response values of 400 towards 100 ppb NO2 at room temperature (24 °C) and of 17.99 towards 10 ppm H2 at 160 °C. In addition, the h-In2O3 sensor exhibits reliable linear response, low theoretical detection limit of 1.8 ppt and 23 ppb for NO2 and H2, excellent selectivity, repeatability and long-term stability. The synergistic effect of the unique structure, larger specific surface area, and abundant adsorbed oxygen plus oxygen vacancy contribute to the excellent gas sensing performance of the h-In2O3 sensor. This study provides a promising strategy for the development of bifunctional gas sensors.

An Algorithm for Automated Measurement of Kinetic Tremor Magnitude Using Digital Spiral Drawings

Introduction: Essential tremor is a common movement disorder. Numerous validated clinical rating scales exist to quantify essential tremor severity by employing rater-dependent visual observation but have limitations, including the need for trained human raters and the lack of precision and sensitivity compared to technology-based objective measures. Other continuous objective methods to quantify tremor amplitude have been developed, but frequently provide unitless measures (e.g., tremor power), limiting real-world interpretability. We propose a novel algorithm to measure kinetic tremor amplitude using digital spiral drawings, applying the V3 framework (sensor verification, analytical validation, and clinical validation) to establish reliability and clinical utility. Methods: Archimedes spiral drawings were recorded on a digitizing tablet from participants (n = 7) enrolled in a randomized placebo control double-blinded crossover pilot trial evaluating the efficacy of oral cannabinoids in reducing essential tremor. We developed an algorithm to calculate the mean and maximum tremor amplitude derived from the spiral tracings. We compared the digitally measured tremor amplitudes to manual measurement to evaluate sensor reliability, determined the test-retest reliability of the digital output across two short-interval repeated measures, and compared the digital measure to kinetic tremor severity graded using The Essential Tremor Rating Assessment Scale (TETRAS) score for spiral drawings. Results: This algorithm for automated assessment of kinetic tremor amplitude from digital spiral tracings demonstrated a high correlation with manual spot measures of tremor amplitude, excellent test-retest reliability, and a high correlation with human ratings of the TETRAS score for spiral drawing severity when the tremor severity was rated “slight tremor” or worse. Discussion: This digital measure provides a simple and clinically relevant evaluation of kinetic tremor amplitude that shows promise as a potential future endpoint for use in clinical trials of essential tremor.

Stretchable Piezoresistive Pressure Sensor Array with Sophisticated Sensitivity, Strain-Insensitivity, and Reproducibility.

This study delves into the development of a novel 10 by 10 sensor array featuring 100 pressure sensor pixels, achieving remarkable sensitivity up to 888.79kPa-1, through the innovative design of sensor structure. The critical challenge of strain sensitivity inherent is addressed in stretchable piezoresistive pressure sensors, a domain that has seen significant interest due to their potential for practical applications. This approach involves synthesizing and electrospinning polybutadiene-urethane (PBU), a reversible cross-linking polymer, subsequently coated with MXene nanosheets to create a conductive fabric. This fabrication technique strategically enhances sensor sensitivity by minimizing initial current values and incorporating semi-cylindrical electrodes with Ag nanowires (AgNWs) selectively coated for optimal conductivity. The application of a pre-strain method to electrode construction ensures strain immunity, preserving the sensor's electrical properties under expansion. The sensor array demonstrated remarkable sensitivity by consistently detecting even subtle airflow from an air gun in a wind sensing test, while a novel deep learning methodology significantly enhanced the long-term sensing accuracy of polymer-based stretchable mechanical sensors, marking a major advancement in sensor technology. This research presents a significant step forward in enhancing the reliability and performance of stretchable piezoresistive pressure sensors, offering a comprehensive solution to their current limitations.

Distributed clustering model for energy efficiency based topology control using game theory in wireless sensor networks

In this study, we use a topology control technique to tackle the issue of energy balance and consumption minimization in wireless sensor networks. By maintaining network connection while sensibly adjusting the transmission power level, such an algorithm may reduce and balance energy usage. This study provides an energy welfare topological control using a game-theoretic approach by calculating energy welfare as usefulness metric for energy populations using the welfare function from the social sciences. Energy balance occurs when every node works to improve its local society's energy situation to the best of its ability. We demonstrate that the consequence ant game is an intriguing game with a single Nash equilibrium that is Pareto optimum. According to economic theory, Pareto optimality is a situation in which improving one person's circumstances would always make another person's worse off. We demonstrate our suggested methodology's superiority in establishing energy balance and efficiency in wireless sensor networks by contrasting the simulation results of our algorithm with those of other approaches. Our approach surpasses existing methods by a wide margin. For reliable and long-lasting wireless sensor applications, this study offers insightful information about how to maximize network performance while preserving energy resources.

Enhancing Trace Pb2⁺ Detection via Novel Functional Materials for Improved Electrocatalytic Redox Processes on Electrochemical Sensors: A Short Review

The efficient detection of lead ions (Pb2⁺) is significant for environmental protection and public health. Electrochemical detection has emerged as one of the most promising technologies due to its low detection limits, high sensitivity, and cost-effectiveness. However, significant challenges remain, including issues related to sensitivity, selectivity, interference, and the stability of electrode materials. This review explores recent advancements in the field, focusing on integrating novel catalytic materials and innovative sensor construction methods. Particular emphasis is placed on enhancing the electrocatalytic redox processes on sensor surfaces using advanced nanomaterials such as MXenes, ferrite-based nanomaterials, carbon nanomaterials, and metal–organic frameworks (MOFs). Additionally, the role of biomaterials and enzymes in improving electrochemical sensors’ selectivity and anti-interference capabilities is discussed. Despite the impressive low detection limits achieved, real-world applications present additional challenges due to the complex composition of environmental samples. The review concludes with future perspectives on overcoming these challenges by leveraging the unique properties of catalytic materials to develop more effective and reliable electrochemical sensors for trace Pb2⁺ detection.

Hierarchical 0D/1D/2D Au/PANI/WS2 ternary nanocomposite NH3 sensor with high performance and fast response/recovery for food spoilage detection

Ammonia (NH3) gas is regarded as a biomarker for clinical diagnosis of various diseases and a potential indicator for the spoilage of protein-rich foods. The acuate detection of the ammonia gas concentration depend on reliable gas sensor. In this paper, flexible room temperature ammonia gas sensor based on hierarchical Au/PANI/WS2 ternary composite was successfully prepared by in-situ polymerization, reduction and drop-coating process. The Au/PANI/WS2-based ammonia sensor was tested for its room temperature sensing property including response value, response/recovery time, selectivity, and long-term stability. The effects of flexible state, humidity and operating temperature on the sensor response were also investigated. The 0D/1D/2D Au/PANI/WS2-based sensor showed significantly enhanced ammonia sensing property both in response and response/recovery time as compared to that of pristine WS2. Gas sensing mechanism of the prepared sensor was investigated by complex impedance spectroscopy and in-situ fourier transform infrared spectroscopy analysis. Besides, the sensor was proved for its practical usability in seafood spoilage detection and warning. The construction of multidimensional materials into hierarchical structure may provide an instructive way for the sensibilization of layered two-dimensional nanomaterial of WS2.