Practical Devices Research Articles

Highly efficient alkaline aqueous MXene-based asymmetric supercapacitors developed by corrugation-like MoS2 and WS2 modified CMX electrodes

The preparation of superior performance supercapacitors to achieve high energy density, fast charge-discharge speed and long cycle stability characteristics has become the focus of attention to realize their potential as practical energy storage devices. In this paper, a cross-linking CNTs@MXene (CMX) architecture is selected as the negative electrode to increase the contact area with electrolyte, and corrugation-like morphologies MoS2 and WS2 nanoparticles modified CMX (Mo/W-CMX) two-dimensional nanostructure as the positive electrode to provide multiple ion diffusion through its channels structure, which presents good electrochemical performance with high specific capacitance and high energy density in 1 M KOH alkaline electrolyte. CNTs introduced into MXene interface by bridges can effectively impede the re-stacking of MXene, meanwhile, CMX as a matrix can also alleviate the properties degradation caused by the agglomeration and volume strain for sulfides. Benefiting from the facilitate accessibility of ions and high ability of electron transfer, the prepared Mo/W-CMX electrode exhibits a dramatic specific capacitance of 1160 F g−1 at 1 A g−1 and excellent capacitance retention of 88.67% at 25 A g−1 after 10,000 cycles. Meanwhile, the assembled asymmetric supercapacitor (Mo/W-CMX // CMX) presents an ultrahigh energy density of 28.1 Wh kg−1 at the power density of 697.3 W kg−1 and maintains 81.25% cycle stability at 15 A g−1 for 10,000 charge-discharge cycles. It is essential to highlight that the superior performance fabricated asymmetric supercapacitor holds a wide application prospect and very competitive energy-storage values in the upgrading of new high-performance devices.

Recent Advances in Flexible Wearable Technology: From Textile Fibers to Devices.

Smart textile fabrics have been widely investigated and used in flexible wearable electronics because of their unique structure, flexibility and breathability, which are highly desirable with integrated multifunctionality. Recent years have witnessed the rapid development of textile fiber-based flexible wearable devices. However, the pristine textile fibers still can't meet the high standards for practical flexible wearable devices, which calls for the development of some effective modification strategies. In this review, we summarize the recent advances in the flexible wearable devices based on the textile fibers, putting special emphasis on the design and modifications of textile fibers. In addition, the applications of textile fibers in various fields and the critical role of textile fibers are also systematically discussed, which include the supercapacitors, sensors, triboelectric nanogenerators, thermoelectrics, and other self-powered electronic devices. Finally, the main challenges that should be overcome and some effective solutions are also manifested, which will guide the future development of more effective textile fiber-based flexible wearable devices.

Unleashing the potential: Multifunctionality of PVDF-HFP based ternary nanocomposite films - magnetoelectric, energy harvesting and impact sensing performance

Multifunctional materials are proving to be highly promising for advancing various technologies, including magneto-mechano-electric energy harvesting devices and flexible sensors. This study focused on synthesizing a polyvinylidene fluoride-hexafluoropropylene-metal-oxide-layered silicate nanocomposite system using a cost-effective solution casting technique. The performance of the system was evaluated in terms of magnetoelectric behaviour, energy harvesting capabilities, and impact sensing. The nanocomposite films demonstrated a peak-to-peak voltage of 12.2 V with a filler loading of 15 wt% and an applied force of 9 N, along with a magnetoelectric coupling coefficient of 20.6 mVcm−1Oe−1. The device's ability to scavenge biomechanical energy during body movements like foot stamping, arm bending, finger flexing, and wrist bending was successfully verified. Furthermore, rigorous durability testing was conducted through repeated energy harvesting studies, proving the device's practicality and resilience. Notably, the developed device powered up six LEDs and a digital clock, while the impact sensor exhibited a linear relationship between output voltage and impact force. These findings highlight the remarkable potential of the polyvinylidene fluoride-hexafluoropropylene-metal-oxide-layered silicate nanocomposite system for multifunctional applications in various technological fields.

Hydrogen Spillover Accelerates Electrocatalytic Semi-hydrogenation of Acetylene in Membrane Electrode Assembly Reactor.

Electrocatalytic acetylene semi-hydrogenation (EASH) offers a promising and environmentally friendly pathway for the production of C2H4, a widely used petrochemical feedstock. While the economic feasibility of this route has been demonstrated in three-electrode systems, its viability in practical device remains unverified. In this study, we designed a highly efficient electrocatalyst based on a PdCu alloy system utilizing the hydrogen spillover mechanism. The catalyst achieved an operational current density of 600 mA cm-2 in a zero-gap membrane electrode assembly (MEA) reactor, with the C2H4 selectivity exceeding 85%. This data confirms the economic feasibility of EASH in real-world applications. Furthermore, through in situ Raman spectroscopy and theoretical calculations, we elucidated the catalytic mechanism involving interfacial hydrogen spillover. Our findings underscore the economic viability and potential of EASH as a greener and scalable approach for C2H4 production, thus advancing the field of electrocatalysis in sustainable chemical synthesis.

Twisted van der Waals Quantum Materials: Fundamentals, Tunability, and Applications.

Twisted van der Waals (vdW) quantum materials have emerged as a rapidly developing field of two-dimensional (2D) semiconductors. These materials establish a new central research area and provide a promising platform for studying quantum phenomena and investigating the engineering of novel optoelectronic properties such as single photon emission, nonlinear optical response, magnon physics, and topological superconductivity. These captivating electronic and optical properties result from, and can be tailored by, the interlayer coupling using moiré patterns formed by vertically stacking atomic layers with controlled angle misorientation or lattice mismatch. Their outstanding properties and the high degree of tunability position them as compelling building blocks for both compact quantum-enabled devices and classical optoelectronics. This paper offers a comprehensive review of recent advancements in the understanding and manipulation of twisted van der Waals structures and presents a survey of the state-of-the-art research on moiré superlattices, encompassing interdisciplinary interests. It delves into fundamental theories, synthesis and fabrication, and visualization techniques, and the wide range of novel physical phenomena exhibited by these structures, with a focus on their potential for practical device integration in applications ranging from quantum information to biosensors, and including classical optoelectronics such as modulators, light emitting diodes, lasers, and photodetectors. It highlights the unique ability of moiré superlattices to connect multiple disciplines, covering chemistry, electronics, optics, photonics, magnetism, topological and quantum physics. This comprehensive review provides a valuable resource for researchers interested in moiré superlattices, shedding light on their fundamental characteristics and their potential for transformative applications in various fields.

Using a standalone ear-EEG device for focal-onset seizure detection

BackgroundSeizure detection is challenging outside the clinical environment due to the lack of comfortable, reliable, and practical long-term neurophysiological monitoring devices. We developed a novel, discreet, unobstructive in-ear sensing system that enables long-term electroencephalography (EEG) recording. This is the first study we are aware of that systematically compares the seizure detection utility of in-ear EEG with that of simultaneously recorded intracranial EEG. In addition, we present a similar comparison between simultaneously recorded in-ear EEG and scalp EEG.MethodsIn this foundational research, we conducted a clinical feasibility study and validated the ability of the ear-EEG system to capture focal-onset seizures against 1255 hrs of simultaneous ear-EEG data along with scalp or intracranial EEG in 20 patients with refractory focal epilepsy (11 with scalp EEG, 8 with intracranial EEG, and 1 with both).ResultsIn a blinded, independent review of the ear-EEG signals, two epileptologists were able to detect 86.4% of the seizures that were subsequently identified using the clinical gold standard EEG modalities, with a false detection rate of 0.1 per day, well below what has been reported for ambulatory monitoring. The few seizures not detected on the ear-EEG signals emanated from deep within the mesial temporal lobe or extra-temporally and remained very focal, without significant propagation. Following multiple sessions of recording for a median continuous wear time of 13 hrs, patients reported a high degree of tolerance for the device, with only minor adverse events reported by the scalp EEG cohort.ConclusionsThese preliminary results demonstrate the potential of using ear-EEG to enable routine collection of complementary, prolonged, and remote neurophysiological evidence, which may permit real-time detection of paroxysmal events such as seizures and epileptiform discharges. This study suggests that the ear-EEG device may assist clinicians in making an epilepsy diagnosis, assessing treatment efficacy, and optimizing medication titration.

Type-I antiferromagnetic Weyl semimetal InMnTi2

Topological materials have been a main focus of studies in the past decade due to their protected properties that can be exploited for the fabrication of new devices. Among them, Weyl semimetals are a class of topological semimetals with nontrivial linear band crossings close to the Fermi level. The existence of such crossings requires the breaking of either time-reversal (T) or inversion (I) symmetry and is responsible for the exotic physical properties. In this work we identify the full-Heusler compound InMnTi2, as a promising, easy to synthesize, T- and I-breaking Weyl semimetal. To correctly capture the nature of the magnetic state, we employed a novel DFT+U computational setup where all the Hubbard parameters are evaluated from first principles; thus preserving a genuinely predictive character of the theory. We demonstrate that this material exhibits several features that are comparatively more intriguing with respect to other known Weyl semimetals: the distance between two neighboring nodes is large enough to observe a wide range of linear dispersions in the bands, and only one kind of such node's pairs is present in the Brillouin zone. We also show the presence of Fermi arcs stable across a wide range of chemical potentials. Finally, the lack of contributions from trivial points to the low-energy properties makes the materials a promising candidate for practical devices. Published by the American Physical Society 2024

Performance analysis of a three-stage quadrature RC generator with operational amplifiers

This paper presents the special features of RC harmonic oscillation generators and their widespread use and in particular the quadrature generators which provide two output signals dephased at 90º or 270º. Quadrature generators can be classified as those with an aperiodic frequency-determining circuit or with a phase inverter group which are used to generate oscillations of one or more fixed frequencies. Studies of a three-stage quadrature RC generator circuit with operational amplifiers have been performed. The results obtained from the simulation and experimental studies performed are presented for the selected circuit. It can be assumed that the experimental and simulation results completely coincide to an accuracy of up to 20% for the amplitude of the generated signals and to the total accuracy for the generated frequency. Quadrature generators are very widely used in communication technology and, most importantly, in the structure of digital frequency, phase and quadrature-amplitude modulators and demodulators, in vector RLC meters and many other electronic circuits and devices in practice.

Data-Driven Distributed Grid Topology Identification Using Backtracking Jacobian Matrix Approach

The topology identification of distribution system is the foundation of state estimation and system analyses. However, the lack of sufficient measurement devices in practice makes full-scale identification of distributed grid hardly achievable. On the other hand, the high-scale distributed renewable energy grid-connected aggravates the complex associations between nodal injection power and voltage. Taking full advantage of it, this paper proposes a novel data-driven approach to identify the topology by backtracking Jacobian matrix from the voltage and power data from gird terminal units. Specifically, a data-driven power-to-voltage mapping model is proposed. It uses the adaptive online deep learning algorithm based on hedge backpropagation to model the mapping relationship of terminal active power, reactive power, and voltage. Then, Backtracking the mapping model, a Jacobian matrix consisting of the partial derivative of voltage to the active and reactive power is obtained, which reflects the connectivity between nodes. Finally, through the Jacobian matrix, a maximum connectivity screening algorithm is developed to generate the topology of medium distribution systems. The effectiveness of the proposed method is verified on IEEE 33-node, IEEE 123-node, and actual distribution systems.

Implantable hearing devices in clinical practice. Systematic review and consensus statements.

Implantable hearing devices represent a modern and innovative solution for hearing restoration. Over the years, these high-tech devices have increasingly evolved but their use in clinical practice is not universally agreed in the scientific literature. Congresses, meetings, conferences, and consensus statements to achieve international agreement have been made. This work follows this line and aims to answer unsolved questions regarding examinations, selection criteria and surgery for implantable hearing devices. A Consensus Working Group was established by the Italian Society of Otorhinolaryngology. A method group performed a systematic review for each single question to identify the current best evidence on the topic and to guide a multidisciplinary panel in developing the statements. Twenty-nine consensus statements were approved by the Italian Society of Otorhinolaryngology. These were associated with 4 key area subtopics regarding pre-operative tests, otological, audiological and surgical indications. This consensus can be considered a further step forward to establish realistic guidelines on the debated topic of implantable hearing devices.

Стабилизация характеристик регенераторов

The article relates to the field of research of the physics of the transition of the amplifier from the aggregate state of amplification to the aggregate state of generation. The aim of the study is to find the possibility of controlling the process of transition from one state of aggregation to another, to implement a stable retention of the device at a given point. The latter will make it possible to implement the construction of stable regenerators. A theoretical conclusion is obtained about the possibility of stable signal regeneration, for which the stabilization coefficient of negative feedback on a constant, zero component should be greater than the regeneration coefficient or gain in gain due to positive feedback at the maximum gain frequency, and for a resonant amplifier – at a resonant frequency. The information confirming the theoretical conclusions and conditions on the example of some technical solutions and implementations of practical devices is given. The multiple technical advantages of stable regenerators over traditional amplifying devices are demonstrated, including resistance to excitation of parasitic generation in a wide dynamic range and temperature range. This is explained by the fact that a stable regenerator cannot be excited twice, a stable excitation is a normal state of aggregation of the regeneration of the input signal. There is also a significant increase in sensitivity and, accordingly, a decrease in intrinsic noise by 9-10 orders of magnitude, an improvement in the width of the linear dynamic range by 8-9 orders of magnitude. An improvement in the amplified frequency bandwidth is demonstrated, not only in the area of minimization, but also in the region of significant expansion, more than an order of magnitude, relative to the maximum achievable for specific samples of the amplifying element, the transistor. The fact that the dependence of the regeneration coefficient and the quality factor of the LC circuit is a special case, only for LC regenerators, is shown and explained. The presented broadband regenerators use strip valves or broadband transformers without an LC circuit and have a regeneration coefficient, which does not contradict the theory and is useful in practice. Multiple improvements are predicted in the construction of systems and devices for low-power signals, as well as an improvement by several orders of magnitude of the main technical characteristics of communication and location systems, measuring systems and devices.

Inter-device agreement of sacral subepidermal oedema measurement in healthy adults during prolonged 60° head of bed elevation.

To investigate the level of agreement between the SEM 200 and Provisio® subepidermal moisture sacral delta measurements, which may indicate increased pressure injury risk, in healthy adults during 120 min of prolonged 60° head of bed elevation. This position, which requires the elevation of the patient's upper body at a 60° angle above the horizontal plane for an extended period, is used by clinicians to prevent or manage a patient's medical or surgical conditions. This prospective exploratory study recruited 20 healthy adults during October 2021 and collected sacral subepidermal moisture delta measurements using the SEM 200 and Provisio® devices. Delta measurements were taken at 20-min intervals over 120 min resulting in seven data collection timepoints. Descriptive statistics and a Bland Altman plot analysis were conducted. A total of 280 sacral subepidermal moisture delta measurements were gathered or 140 per device. There were good levels of agreement between the two devices at baseline (T0) [mean 0.025; SD 0.137] and following 60- (T3) [mean 0.025; SD 0.111], 80- (T4) [mean -0.01; SD 0.177] and 100 min (T5) [mean 0.01; SD 0.129] of prolonged 60° head of bed elevation. Head of bed elevations can increase a patient's risk of sacral pressure injuries. In some countries, nurses have access to the SEM 200 and/or the Provisio® device, so our findings may increase nurses' confidence in the interchangeability of the device measurements, although further research is needed to confirm this. The SEM 200 and Provisio® subepidermal moisture scanners show promise in gathering similar objective pressure injury risk data which could prompt clinicians to implement prevention strategies. Current pressure injury risk assessment is largely subjective in nature. This quantitative study on healthy human sacral tissue found a good level of agreement in the SEM 200 and Provisio® subepidermal moisture scanners, which may increase nurses' confidence in the interchangeability of the devices in clinical practice.

Evaluation of the practice of contraception among adult female traders at international market Orlu, Imo state, South east Nigeria

Aim: To evaluate the practice of contraception among adult female traders at Orlu International Market Background: Contraception is the use of any practice methods or devices to prevent pregnancy from occurring in sexually active women. Currently in Nigeria, there are concerns about the rise in maternal mortality rate and the increase in unwanted pregnancies. This trend is said to be on the rise among the less educated women. This necessitated our study to evaluate the practice of contraception among adult female traders in the international market Orlu Imo State of Nigeria Methodology: An observational descriptive retrospective study involving adult female traders of Orlu International Market, selected by convenience sampling, which is a non probability sampling method. Both self and interviewer administered questionnaires were used collaged data was analysed using statistical package for soual sciences (SPSS) version 20 IBM, USA. Results were presented in frequency tables, bar charts and pie charts Result: A total of 308 respondents participated in the study. Majority were within the age range of 30-39years (36%). Majority of the respondents (68%) had good knowledge of contraception, however, only 34% has used one or more forms of contraception in the past; disappointingly, majority (64%) do not use any form of contraception Conclusion: There is high level of knowledge of the practice of contraception but the usage rate is abysmally low.

Electrical 180° switching of Néel vector in spin-splitting antiferromagnet.

Antiferromagnetic spintronics have attracted wide attention due to its great potential in constructing ultradense and ultrafast antiferromagnetic memory that suits modern high-performance information technology. The electrical 180° switching of Néel vector is a long-term goal for developing electrical-controllable antiferromagnetic memory with opposite Néel vectors as binary "0" and "1." However, the state-of-art antiferromagnetic switching mechanisms have long been limited for 90° or 120° switching of Néel vector, which unavoidably require multiple writing channels that contradict ultradense integration. Here, we propose a deterministic switching mechanism based on spin-orbit torque with asymmetric energy barrier and experimentally achieve electrical 180° switching of spin-splitting antiferromagnet Mn5Si3. Such a 180° switching is read out by the Néel vector-induced anomalous Hall effect. On the basis of our writing and readout methods, we fabricate an antiferromagnet device with electrical-controllable high- and low-resistance states that accomplishes robust write and read cycles. Besides fundamental advance, our work promotes practical spin-splitting antiferromagnetic devices based on spin-splitting antiferromagnet.

Numeric simulation and experimental validation for a Novel Trapezoidal Solar Collector

In a global warming context, the diversification of the energy matrix is essential for mitigation. Technologies and solar devices have begun to play an important role in this sense, being flat-plate solar collectors the most practical device. On the other hand, numerical modeling and experimental validation are important tools for improving the performance of these technologies. In this work, a trapezoidal solar air heating collector for food drying processes was modeled by using the Simusol open-access software, and experimental validation was performed. This particular shape presents a geometrical novelty since no other similar designs were found into the available literature, even in such application as food drying. Key parameters, such as air temperature, global efficiency, air mass flow, global heat loss coefficient, and useful heat, are determined and discussed. The proposed air collector numerically behaves as expected. The output air temperature reaches about 100 °C, while the peak heat gain is about 900 W, which makes the air heating collector suitable for drying applications. Due to natural convection is the main heat transferring mechanism, low air mass flows were obtained. For the case analyzed here, this last parameter ranges in 0.012–0.016 kg/s for the optimal thermal behavior.

Sensory, Affective, and Social Experiences with Haptic Devices in Intramural Care Practice.

Previous work has shown that technology can facilitate the communication of emotions, social touch, and social presence through haptic devices, meaning devices that provide a haptic stimulation. However, for special user groups living in long-term care facilities, such as people with dementia, the applications of these haptic devices are not apparent. The aim of this study is to understand how haptic devices can be used in intramural care facilities in times of social isolation, focusing on haptic devices that utilize haptic sensation. Five haptic devices were tested at three care facilities. Insights from this study highlight the potential of haptic devices to enhance sensory, affective, and social experiences during video calling between residents and their relatives. Moreover, the importance of the tactile sensation and form factor of haptic devices in the care context is addressed, along with insights on how to create the appropriate atmosphere during video calling.

Hierarchical high K content birnessite MnO2 nanosheet arrays as high capacity cathode for asymmetric supercapacitor with broaden potential window of 2.6 V

High specific capacitance and energy density for energy storage devices are dependent on the types of electrodes selection and operational working potential windows. Birnessite MnO2 is reported as the astounding material to show strong electrochemical performances due to it's widen inter-planar spacing, capable to accommodate the alkaline ions for the better outcomes. Herein this article, high K content Birnessite MnO2 nanosheet arrays at carbon cloth substrate (K0.46MnO2 NSAs@CC) are successfully fabricated to optimize its structural, morphological and electrochemical performances as cathode for supercapacitors (SCs). K0.46MnO2 NSAs@CC is operated at broaden potential window from 0 to 1.3 V to achieve excellent specific capacitance of ∼375 F g−1. Reported broaden potential window provides the opportunity for the construction of aqueous asymmetric supercapacitors (ASC) to operate above 2.0 V. For the construction of efficient ASC, Bi2S3 nanoflakes interconnected nanosheets at carbon cloth (Bi2S3 NFNS@CC) are synthesized as anode capable to operate at negative (−1.3 to 0 V) potential window. The 2.6 V ASC is constructed by K0.46MnO2 NSAs@CC as cathode and Bi2S3 NFNS@CC as an anode (K0.46MnO2 NSAs@CC//Bi2S3 NFNS@CC). K0.46MnO2 NSAs@CC//Bi2S3 NFNS@CC as ASC is presenting excellent energy density of ∼72 Wh kg−1 on top of outstanding cycle performance and rate capability compatible with the earlier reported MnO2-based ASCs. This work is elaborating the new guidelines for novel electrode materials scheme and possibilities to achieve broaden potential windows capable to be utilized in practical devices.

Synthesis and Characterization of Type II Ge-Si Clathrate Films for Optoelectronic Applications.

Type II inorganic clathrates consist of cage-like structures with open frameworks, and they are considered promising materials due to their unique properties. However, the difficulty of synthesizing phase-pure and continuous films has hindered their application in practical devices. In this report, we demonstrate the synthesis of type II SiGe clathrate films through the thermal decomposition of a Na-deposited amorphous SiGe film on a sapphire substrate in a high vacuum. The as-prepared films of type II SiGe clathrates showed uniform growth and were evaluated for their structural and optical properties. Morphological studies conducted using a scanning electron microscope showed the presence of cracks on the film surface.

Sr4Al2O7: A New Sacrificial Layer with High Water Dissolution Rate for the Synthesis of Freestanding Oxide Membranes.

Freestanding perovskite oxide membranes have drawn great attention recently since they offer exceptional structural tunability and stacking ability, providing new opportunities in fundamental research and potential device applications in silicon-based semiconductor technology. Among different types of sacrificial layers, the (Ca, Sr, Ba)3Al2O6 compounds are most widely used since they can be dissolved in water and prepare high-quality perovskite oxide membranes with clean and sharp surfaces and interfaces; However, the typical transfer process takes a long time (up to hours) in obtaining millimeter-size freestanding membranes, let alone realize wafer-scale samples with high yield. Here, a new member of the SrO-Al2O3 family, Sr4Al2O7 is introduced, and its high dissolution rate, ≈10 times higher than that of Sr3Al2O6 is demonstrated. The high-dissolution-rate of Sr4Al2O7 is most likely related to the more discrete Al-O networks and higher concentration of water-soluble Sr-O species in this compound. This work significantly facilitates the preparation of freestanding membranes and sheds light on the integration of multifunctional perovskite oxides in practical electronic devices.

NOTICE OF DUPLICATE PUBLICATION: "Stability of meropenem in portable elastomeric infusion devices: which protocol should be implemented in clinical practice?"

The American Society for Microbiology (ASM) and Microbiology Spectrum are withdrawing the article mentioned below as it is an inadvertent duplicate publication: Esteban-Cartelle B, Serrano DR, Pérez Menéndez-Conde C, Vicente-Oliveros N, Álvarez-Díaz A, Abete JF, Martín-Dávila P. 2024. Stability of meropenem in portable elastomeric infusion devices: which protocol should be implemented in clinical practice? Microbiol Spectr 12:e02063-23. https://doi.org/10.1128/spectrum.02063-23. This article was accidentally published twice in the journal due to a technical error, and there are no ethical or integrity concerns regarding the original published article. The duplicate version of the article has been withdrawn to correct the scholarly record. The original published article and its content are not affected by this withdrawal and can be found here: https://journals.asm.org/doi/10.1128/spectrum.02064-23 The American Society for Microbiology apologizes to the authors and its readers for the technical error and the inconvenience this may have caused. The authors agreed with the publication of this notice.