Resistive Research Articles

Modulation of the Respiratory Epithelium Physiology by Flavonoids—Insights from 16HBEσcell Model

Extensive evidence indicates that the compromise of airway epithelial barrier function is closely linked to the development of various diseases, posing a significant concern for global mortality and morbidity. Flavonoids, natural bioactive compounds, renowned for their antioxidant and anti-inflammatory properties, have been used for centuries to prevent and treat numerous ailments. Lately, a growing body of evidence suggests that flavonoids can enhance the integrity of the airway epithelial barrier. The objective of this study was to investigate the impact of selected flavonoids representing different subclasses, such as kaempferol (flavonol), luteolin (flavone), and naringenin (flavanone), on transepithelial electrical resistance (TEER), ionic currents, cells migration, and proliferation of a human bronchial epithelial cell line (16HBE14σ). To investigate the effect of selected flavonoids, MTT assay, trypan blue staining, and wound healing were assessed. Additionally, transepithelial resistance and Ussing chamber measurements were applied to investigate the impact of the flavonoids on the electrical properties of the epithelial barrier. This study showed that kaempferol, luteolin, and naringenin at micromolar concentrations were not cytotoxic to 16HBE14σ cells. Indeed, in MTT tests, a statistically significant change in cell metabolic activity for luteolin and naringenin was observed. However, our experiments showed that naringenin did not affect the proliferation of 16HBE14σ cells, while the effect of kaempferol and luteolin was inhibitory. Moreover, transepithelial electrical resistance measurements have shown that all of the flavonoids used in this study improved the epithelial integrity with the slightest effect of kaempferol and the significant impact of naringenin and luteolin. Finally, our observations suggest that luteolin increases the Cl- transport through cystic fibrosis transmembrane conductance regulator (CFTR) channel. Our findings reveal that flavonoids representing different subclasses exert distinct effects in the employed cellular model despite their similar chemical structures. In summary, our study sheds new light on the diverse effects of selected flavonoids on airway epithelial barrier function, underscoring the importance of further exploration into their potential therapeutic applications in respiratory health.

Development of significantly hard hypereutectoid plain carbon steel through incomplete austenitization based cyclic quenching treatment

AbstractIn this investigation hot rolled steel bars of 1.24 weight % carbon steel are subjected to incomplete austenitization based cyclic quenching treatment. Each cycle consists of inserting the specimen in an electric resistance furnace at a temperature of 894 °C and holding for a short duration (6 minutes), followed by oil quenching to the room temperature. Such a typical thermal cycling results in the evolution of a novel microstructure that comprises of large clusters and blocks of cementite in a matrix of martensite after 3 and 4 cycles. Accordingly, a significantly high hardness (7.13 GPa) is achieved on execution of 3 cycles which envisages a new pathway of incomplete austenitization based cyclic quenching treatment for development of new‐generation plain carbon hypereutectoid tool steel.

Surface-Reconstructed CdNNi3 Antiperovskite Electrocatalyst: Unlocking Ampere-Level Current Density for Hydrogen Evolution.

Developing conductive electrocatalysts is crucial for decreasing the ohmic loss induced by electric resistance of the catalyst layer in the large-current-density hydrogen evolution reaction (HER), which has been overlooked previously. In this study, we screen a highly conductive antiperovskite CdNNi3 with negligible ohmic loss, as a highly active and durable HER electrocatalyst capable of unlocking ampere-scale current densities. CdNNi3 exhibits an impressive activity (an overpotential of 235 mV) at 1 A cm-2 and maintains its performance steadily at an ampere-scale current density (at 1 A cm-2 over 400 h). Besides, the CdNNi3-enabled anion-exchange membrane water electrolyzer outperforms that of the benchmark Pt/C, evidenced by a reduced cell voltage of 160 mV at 1 A cm-2, and presents a favorable stability at 1 A cm-2. Importantly, this study experimentally discovers the dynamic surface reconstruction phenomena of antiperovskite nitrides during alkaline HER. Theoretical analysis suggests that the presence of Cd in the reconstructed surface effectively adjusts the local electronic configuration of active sites, which promotes the adsorption of OH and reduces the binding strength to H, thereby facilitating the water dissociation step and reducing the energy barrier of the potential-determining step in the HER process.

Impact of Tetrakis(dimethylamido)tin(IV) Degradation on Atomic Layer Deposition of Tin Oxide Films and Perovskite Solar Cells.

Tin oxide (SnOx) films synthesized by atomic layer deposition (ALD) are widely explored in a range of optoelectronic devices including electrochemical sensors, transistors, and photovoltaics. However, the integrity of the key ALD-SnOx precursor, namely tetrakis(dimethylamido)tin (IV) (TDMASn), and its influence on the properties of ultimate films remain unexplored. Here a significant degradation of TDMASn into bis(dimethylamido)tin(II) via the Sn-imine complex is reported, and its impact on the corresponding films and devices is examined. It is found, surprisingly, that this degradation does not affect the growth kinetics and morphology of ALD-SnOx films. But it notably deteriorates their electronic properties, resulting in films with twice the electrical resistance due to different oxidation mechanisms of the degradation products. Perovskite solar cells employing such films exhibit a significant loss in power conversion efficiency, primarily due to charge transport and transfer losses. These findings urge strategies to stabilize TDMASn, a critical precursor for ALD-SnOx films, or to identify alternative materials to achieve efficient and reliable devices.

Postbiotic Metabolite Derived from Lactiplantibacillus plantarum PD18 Maintains the Integrity of Cell Barriers and Affects Biomarkers Associated with Periodontal Disease

Background/Objectives: Periodontal disease is caused by oral infections, biofilms, persistent inflammation, and degeneration of cell barrier integrity, allowing pathogens to invade host cells. Probiotics have been extensively studied for the treatment of periodontal disease. However, research on the involvement of beneficial substances produced by probiotics, called “postbiotics,” in periodontal diseases remains in its early stages. The present study aimed to evaluate the effect of a postbiotic metabolite (PM) from Lactiplantibacillus plantarum PD18 on immunomodulation and maintenance of cell barrier integrity related to periodontal disease. Method: The main substance in PM PD18 was analyzed by GC-MS. The cytotoxic effect of PM PD18 was performed using the MTT assay, wound healing through the scratch assay, cell permeability through TEER value, modulation of inflammatory cytokines through ELISA, and gene expression of inflammatory cytokines and tight junction protein was determined using qRT-PCR. Results: The main substance found in PM PD18 is 2,3,5,6-tetramethylpyrazine. PM PD18 did not exhibit cytotoxic effects on RAW 264.7 cells but promoted wound healing and had an antiadhesion effect on Porphyromonas gingivalis concerning SF-TY cells. This postbiotic could maintain cell barrier integrity by balancing transepithelial electrical resistance (TEER) and alkaline phosphatase (ALP) activity. In addition, the gene and protein expression levels of zonula occludens-1 (ZO-1) increased. PM PD18 was found to have immunomodulatory properties, as demonstrated by regulated anti- and pro-inflammatory cytokines. Interleukin-10 (IL-10) increased, while IL-6 and IL-8 were reduced. Conclusions: This study demonstrated that PM PD18 is efficient as a natural treatment for maintaining cell barrier integrity and balancing inflammatory responses associated with periodontal disease.

Crack Development and Electrical Degradation in Chromium Thin Films Under Tensile Stress on PET Substrates

The mechanical and electrical deterioration of chromium (Cr) thin films sputtered onto polyethylene terephthalate (PET) substrates under tensile strain was studied. Understanding mechanical and electrical stability due to imposed strain is particularly important for device reliability, as the demand for flexible electronic devices increases. Cr thin films, widely spread across the field of electronic and sensor applications, face crack propagation with electrical degradation with tensile stress that can seriously compromise the performance. Accordingly, this study offers new findings on how Cr film thickness might influence crack formation and electrical resistance differently and also the general guidelines for flexible electronic component design with respect to long-term durability. Electrical resistances were measured while mechanically stretching 100- and 200 nm thin sheets. The study focused on crack development and propagation mechanisms in both film thicknesses and their effects on percentage change in electrical resistance (PCER). Scanning electronic microscopy (SEM) was used to characterize surface morphology and observe cracks as the strain rose. Early crack formation in 100 nm Cr films led to rapid PCER increases due to quick crack propagation and fast electrical degradation. Thicker 200 nm films, however, showed a more gradual PCER rise with fewer but deeper cracks, indicating a regulated strain response. Unlike the sharp PCER spike in 100 nm films, 200 nm samples were more variable, with three out of four showing a slight PCER decrease at the end, hinting at partial crack repair or conductive realignment before full failure. These results underscore the role of layer thickness in managing crack propagation and electrical stability, relevant for flexible electronics and strain sensors. This paper is aligned with the ninth goal of the United Nations Sustainable Development Goals, specifically Target 9.5: Enhance Research and Upgrade Industrial Technologies.

Rubber-based piezoresistive sensing: a new approach based on hydrodynamic flow of material deformation describing nonlinear signals in stretchable sensors

AbstractThe nonlinearity of piezoresistive response is critical in developing strain sensors, various self-monitoring applications and wearable electronics based on filled rubbers. This parameter could change dramatically when scaling up from small-size prototypes to full-scale production. The present work focuses on the nonlinear signals in stretchable rubber-based sensors, their origin and dependence on size of samples. Thus, a set of rectangular, piezoresistive samples differing in width was prepared from natural rubber reinforced with carbon black filler. Their electric resistance was tested under planar strain/recovery conditions at 25 and 50% strain amplitudes. It was found that piezoresistance and the related nonlinear phenomena significantly depended on the size of the samples. For the first time, hydrodynamic flow of deformed material was used to explain the nonlinearities of the piezoresistive signal. The trajectory, velocity, and magnitude of this flow were accounted for by a newly developed empirical equation describing the evolution of local resistivity under the strain/recovery process.

Effect of nickel catalyst thickness on growth of carbon nanotubes on glass nonwoven mat using thermal chemical vapor deposition method

This study aimed to explore how varying the thickness of nickel catalyst affects the synthesis of carbon nanotubes on glass mats using the thermal chemical vapor deposition (TCVD) method. Nickel served as the catalyst, with acetylene as the hydrocarbon source and argon as the carrier gas. Initially, different thicknesses of nickel catalyst were applied to the glass mat via plasma-enhanced chemical vapor deposition (PECVD). Subsequently, these samples underwent TCVD plasma treatment. Electrical resistance measurements were conducted, and scanning electron microscopy (SEM), Raman spectroscopy, and transmission electron microscopy (TEM) were employed to analyze the presence, surface morphology, and quality of the nanotubes. The research revealed that the thickness of the nickel catalyst significantly influences the nanotube synthesis process on glass mat substrates. An optimal thickness of nickel catalyst yielded a glass mat with an electrical resistance of 2 Ω per unit area post-TCVD treatment.

Fractional extraction phenolics from C. oleifera seed kernels exhibited anti-inflammatory effect via PI3K/Akt/NF-κB signaling pathway under Caco-2/RAW264.7 co-culture cell model

Camellia oleifera Abel (C. oleifera) is a multifunctional oilseed, which is rich in many biological active substances with health-promoting properties, especially polyphenols. Previous research revealed that camellia oil phenolics exhibited anti-inflammatory effect, which originated from seed. Thus, we aimed to explore the components of camellia seed phenolics and its potential mechanism of anti-inflammation. Initially, fractional extraction was processed to prepare the phenolics from camellia seed kernels, and we compare four different fractions of phenolics under the LPS-induced Caco-2/RAW264.7 coculturing model. Results showed that free phenolics (FP) had best effect on alleviating pro-inflammatory cytokines (IL-1β, IL-6, IL-8 and TNF-α) compared to esterified-bound phenolics (EP), glycosylated-bound phenolics (GP) and insoluble-bound phenolics (IP). Furthermore, FP reduced inflammation by suppressing the PI3K/Akt/NF-κB signaling pathway and effectively inhibited LPS-induced intestinal permeability increase, tight junction related proteins loss (ZO-1, claudin-1). Same results obtained, as the transepithelial electrical resistance (TEER) and alkaline phosphatase (AKP) activity of high-dose FP treated group was high than model group. Finally, molecular docking was used for evaluating the anti-inflammatory effect for phenolic monomer. KGRG (kaempferol −3-O-(2-O-glucopyranosyl-6-O-rhamnopyranosyl)-glucopyranoside), KXR (kaempferol 3-O-(2′’-xylopyranosyl)-rutinoside) and leucoside (kaempferol 3-O-sambubioside) show lower binding energy docking with NF-κB, PI3K and Akt protein, indicating better interactions, which might be effective constituents against inflammation. Subsequently, five major polyphenols were obtained to validate the docking results, especially, indicating the best anti-inflammatory activities of KGRG. Overall, this research sheds insights on the therapy of phenolics from C. oleifera seed towards LPS-induced intestinal inflammation model in vitro and its related mechanism.

Comparing Feature and Trajectory-Based Remaining Useful Life Modeling of Electrical Resistance Heating Wires

Industrial heating significantly contributes to global greenhouse gas emissions, accounting for a substantial portion of annual emissions. The transition to fossil-free operations in the heating industry is closely linked to advancements in industrial electrical heating systems, especially those using resistance heating wires. In this context, Prognostics and Health Management is crucial for enhancing system reliability and sustainability through predictive maintenance strategies. The integration of machine learning technologies into Prognostics and Health Management has significantly improved the precision and applicability of Remaining Useful Life modeling. This improvement enables more accurate predictions of component lifespans, optimizes maintenance schedules, and enhances operational efficiency in industrial heating applications. These developments are essential for reducing greenhouse gas emissions in the sector. This paper serves as a guide for conducting Remaining Useful Life modeling for industrial batch processes. It evaluates and compares two methodologies: deep learning-based approaches using full time-series data, such as recurrent neural networks and their variants, and feature-engineering-based methods, including random forest regression and support vector machines. Our results show that the feature-oriented approach performs better overall in terms of predictive accuracy and computational efficiency. The study includes a detailed sensitivity analysis and hyperparameter estimation for each method, providing valuable insights into developing robust and transparent Prognostics and Health Management systems. These systems are crucial in supporting the heating industry’s move towards more sustainable and emission-free operations. The findings reveal that feature-oriented methods are both performant and robust, particularly excelling in handling outliers. The random forest regression model, in particular, demonstrated the highest performance on the test dataset according to the chosen evaluation metrics. Conversely, trajectory-oriented methods exhibited less bias across varying levels of degradation, a helpful characteristic for Prognostics and Health Management systems. While feature-oriented methods tend to systematically underestimate Remaining Useful Life at high true values and overestimate it at low actual values, this issue is less pronounced in trajectory-oriented models. Overall, these insights highlight the strengths and limitations of each approach, guiding the development of more effective and reliable predictive maintenance strategies.

Quantized Seebeck coefficient of quasi-ballistic gold nanowires

The behavior of the Seebeck coefficient in the intermediate regime between atomic scale ballistic conduction and bulk-like diffusive conduction remains unclear. To address this, we have developed a microscale device capable of simultaneously measuring the Seebeck coefficient and electrical conductance of gold nanowires in an adiabatic environment. The nanowires were made in situ by electromigration from lithographically prepared bow-tie electrodes, yielding a wide range of wire thicknesses down to a few hundred atoms. We observed quantization of the Seebeck coefficient, a phenomenon previously observed only at the Ångstrom scale, in relatively thick wires with a thickness of several tens of nanometers. The quantized Seebeck coefficient was proportional to the reciprocal of the electrical conductance with a slope of −47.8 μV/K, indicating that electrons are spatially confined due to the electronic shell structure of the nanowire, similar to the quantization of electrical conductance.

Investigation on piezoresistive properties of reduced graphene oxide treated glass textiles based multifunctional sensors

AbstractGlass fabric‐reinforced composites (GFRC) and other revolutionary engineered materials find extensive application in the aerospace, construction, and automobile sectors. It is challenging to predict damage under real‐time stresses due to the anisotropic behavior of composite materials. This study presents the development of a glass textile‐based multifunctional composite sensor and demonstrates its application as a change in resistance or gauge factor in structural health monitoring (SHM) systems. This sensor is coated with reduced graphene oxide (rGO) nanomaterial. Its electrical resistance is evaluated by examining the concentration of nanoparticles and varying geometrical parameters. A three‐point bending method assessed the piezoresistive behavior of the integrated sensor in the GFRC. The impact of sensor width and relative placements in the material's thickness direction within the composite samples is evaluated. Cyclic flexural testing was also performed to demonstrate real‐world applications. The research concludes that it can be utilized as a damage assessment technique for GFRC. The developed sensor can be used to provide an electrically conductive path or as a resistor in the field of E‐textiles. The developed piezoresistive sensor has the flexibility to be used as a multifunctional sensor for multiple purposes, such as force, torque, weight, pressure, flow, acceleration sensors, etc.Highlights Glass textile‐based multifunctional materials are reported as strain‐monitoring sensors. Tailored sensor resistance could be achieved through rGO current conduction paths. Glass textile‐based sensors could potentially be used in the field of E‐textile.

Features of the change in the thermal coefficient of electrical resistance upon heating electrically conductive composites of crystallizable polyolefins with carbon black

Objectives. To investigate electrically conductive polymer composite materials (EPCMs) based on crystallizable polyolefins and electrically conductive carbon black for the production of self-regulating heaters; to study the mechanism of the occurrence of positive and negative temperature coefficients (PTC and NTC) upon heating such composites.Methods. A comprehensive study of the structure and properties of crystallizable EPCMs with electrically conductive technical carbon was carried out. In order to measure the electrical characteristics of the composites, they were compacted into plates to model polymer heaters. Contact electrodes made of an ungreased brass mesh were embedded in their ends. The temperature dependencies of the electrical characteristics of the samples were investigated in a modified thermal chamber of an FWV 633.10 Vicat softening temperature meter. The change in the degree of crystallinity was analyzed by means of differential scanning calorimetry with a NETZSCH DSC 204 F1 Phoenix calorimeter. The dilatometric and rheological characteristics of the samples were studied using an IIRT-AM melt flow index tester.Results. It was determined that the self-regulation ability (an abnormally high positive thermal coefficient of electrical resistance) of selfregulating heaters made of composites of crystallizable polyolefins with electrically conductive technical carbon cannot be explained by the thermal expansion of EPCMs alone. It was shown that in crystallizable polyolefin-based EPCMs, the inversion of the thermal coefficients of electrical resistance (transition from PTC to NTC) is associated with a change in the aggregate state of EPCMs and the beginning of its transition to a viscous-flow state. A mechanism involving a sharp increase in the electrical resistance of self-regulating crystallizable polyolefin-based composite with electrically conductive technical carbon was proposed and substantiated. This mechanism takes into account the additional shear deformation effect produced on the crystalline phase of the EPCM by numerous expanding melt microvolumes formed at the early stages of the melting process with a minimum change in the degree of crystallinity.

Kindlin-2 Phase Separation in Response to Flow Controls Vascular Stability.

Atheroprotective shear stress preserves endothelial barrier function, while atheroprone shear stress enhances endothelial permeability. Yet, the underlying mechanisms through which distinct flow patterns regulate EC integrity remain to be clarified. This study aimed to investigate the involvement of Kindlin-2, a key component of focal adhesion and endothelial adherens junctions crucial for regulating endothelial cell (EC) integrity and vascular stability. Mouse models of atherosclerosis in EC-specific Kindlin-2 knockout mice (Kindlin-2iΔEC) were used to study the role of Kindlin-2 in atherogenesis. Pulsatile shear (2±4 dynes/cm2) or oscillatory shear (0.5±4 dynes/cm2) were applied to culture ECs. Live-cell imaging, fluorescence recovery after photobleaching assay, and optoDroplet assay were used to study the liquid-liquid phase separation (LLPS) of Kindlin-2. Co-immunoprecipitation, mutagenesis, proximity ligation assay, and transendothelial electrical resistance assay were used to explore the underlying mechanism of flow-regulated Kindlin-2 function. We found that Kindlin-2 localization is altered under different flow patterns. Kindlin-2iΔEC mice showed heightened vascular permeability. Kindlin-2iΔEC were bred onto ApoE-/- mice to generate Kindlin-2iΔEC; ApoE-/- mice, which displayed a significant increase in atherosclerosis lesions. In vitro data showed that in ECs, Kindlin-2 underwent LLPS, a critical process for proper focal adhesion assembly, maturation, and junction formation. Mass spectrometry analysis revealed that oscillatory shear increased arginine methylation of Kindlin-2, catalyzed by PRMT5 (protein arginine methyltransferase 5). Functionally, arginine hypermethylation inhibits Kindlin-2 LLPS, impairing focal adhesion assembly and junction maturation. Notably, we identified R290 of Kindlin-2 as a crucial residue for LLPS and a key site for arginine methylation. Finally, pharmacologically inhibiting arginine methylation reduces EC activation and plaque formation. Collectively, our study elucidates that mechanical force induces arginine methylation of Kindlin-2, thereby regulating vascular stability through its impact on Kindlin-2 LLPS. Targeting Kindlin-2 arginine methylation emerges as a promising hemodynamic-based strategy for treating vascular disorders and atherosclerosis. URL: https://www.clinicaltrials.gov; Unique identifier: NCT02783300.

Cysteine Leukotriene Receptor Antagonist-Montelukast Effects on Diabetic Retinal Microvascular Endothelial Cells Curtail Autophagy.

Diabetic macular edema (DME) is the primary cause of vision impairment in diabetic retinopathy (DR) patients. A previous study has shown the efficacy of montelukast, a cysteinyl leukotriene receptor (CysLTR)1 antagonist, in a diabetic mouse model. This study aims to understand the CysLTR1 signaling in retinal endothelial cells and the impact of montelukast. Primary human retinal microvascular endothelial cells (HRECs) challenged with 20 ng/mL TNF-α and 30mM D-glucose (D-glu) for six to 24 hours served as a model of endothelial activation. HRECs were incubated with L-glucose (L-glu) as an osmotic control. CysLTR1 knockdown and montelukast pretreatment assessed CysLTR1 antagonism. Gene expression, protein expression, and cell-permeable dyes were utilized to measure autophagy and inflammation. Transendothelial electrical resistance (TER) and transendothelial migration of mononuclear leukocytes across HRECs monolayer were measured as a functional assessment of vascular permeability. Endothelial activation induced by hyperglycemia and inflammation increased CysLTR1 expression, triggering autophagy within two to six hours, IL-1β production, loss of junction integrity, decreased TER, and increased leukocyte migration within six to 24 hours. Pretreatment with montelukast effectively alleviated these effects, demonstrating its dependence on CysLTR1. Dysfunctional retinal endothelium initiates a self-reinforcing loop of inflammation, autophagy, and compromised integrity associated with heightened CysLTR1 levels. The antagonistic effect of montelukast against CysLTR1 effectively mitigates these detrimental changes. This study reveals CysLTR1 as a potential therapeutic target in treating DME and offers a novel strategy to mitigate detrimental changes in DR.

Simultaneous Primer Coating for Fast Drying of Battery Electrodes

Primers are used to promote adhesion and reduce electrical interface resistance. Normally, the process of applying primer and electrode coating happens in two separate, sequential steps. Herein, primer and electrode are applied simultaneously, wet‐in‐wet. For fast drying of electrode coatings, a binder‐redistribution by binder migration happens. A normally unwanted binder migration is tried to be utilized. The goal is to use less binder in the electrode coating and dry it faster without losses in adhesion and performance. By using simultaneous primer coatings incorporating LAPONITE, the adhesion can be promoted by over 200%. This allows to eliminate the styrene‐butadiene‐rubber‐binder in the electrode slurry, saving in total of 70% of the binder. For eight times faster drying up to 30% improved specific capacity at 2C can be shown. This promising approach shows potential for any materials that lack adhesion, extending it, e.g., to porous, nanostructured particles and materials used in sodium‐ion batteries.

Three-Dimensional Printed Nanocomposites with Tunable Piezoresistive Response.

This study explores a novel approach to obtaining 3D printed strain sensors, focusing on how changing the printing conditions can produce a different piezoresistive response. Acrylonitrile butadiene styrene (ABS) filled with different weight concentrations of carbon nanotubes (CNTs) was printed in the form of dog bones via fused filament fabrication (FFF) using two different raster angles (0-90°). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) in TUNA mode (TUNA-AFM) were used to study the morphological features and the electrical properties of the 3D printed samples. Tensile tests revealed that sensitivity, measured by the gauge factor (G.F.), decreased with increasing filler content for both raster angles. Notably, the 90° orientation consistently showed higher sensitivity than the 0° orientation for the same filler concentration. Creep and fatigue tests identified permanent damage through residual electrical resistance values. Additionally, a cross-shaped sensor was designed to measure two-dimensional deformations simultaneously, which is applicable in the robotic field. This sensor can monitor small and large deformations in perpendicular directions by tracking electrical resistance variations in its arms, significantly expanding its measuring range.

First Principles Investigation of thermoelectric properties of naphyne

Designing a thermoelectric device to efficiently convert waste heat into electricity involves simultaneous adjustment of its electrical and thermal conductance. Herein, we have investigated the thermoelectric property of a two-dimensional naphyne sheet under various bias voltages and temperatures. Naphyne possesses a superior Seebeck coefficient under zero bias voltage at room temperature in comparison to other conventional thermoelectric materials, affirming its potential as a promising candidate for thermoelectric devices. Increase in temperature, tend to decrease various thermoelectric properties like Seebeck coefficient, conductance and figure of merit. However, an exception is found for the electronic part of thermal conductance which rises with the rise in temperature for naphyne. Interestingly, at a bias voltage of 0.2V, the highest value of electronic part of thermoelectric figure of merit ZTe=30.11 is found at 200K, while at 0.6V the highest value of ZTe=4.21 is observed at a temperature of 300K, indicating that naphyne could play a beneficial role in the design of thermoelectric materials.

Numerical Investigation of G–V Measurements of metal – A Nitride GaAs junction

In this study, a Schottky diode consisting of Au/GaN/GaAs was fabricated using a radiofrequency nitrogen plasma source. The voltage-conductance characteristics (G/ω-V) of this diode structure were investigated at room temperature. To interpret the changes in the electrical properties of the nitrided GaAs-based Schottky structure, we developed a simulation program. This program employs a numerical model to calculate the G-V characteristics, allowing us to validate the experimental measurements conducted on the Schottky diodes. The geometric model used in our simulation considers not only the GaN layer formed between the metal and GaAs substrate but also the density and distribution of trapped states within the band gap. The program utilizes the numerical resolution of the Poisson and continuity equations to calculate the electrostatic potential and the concentrations of both n and p mobile carriers. These parameters are then used to determine the electric charge, current, capacitance, and conductance. The simulation results were subsequently compared to the experimental measurements to ensure their accuracy.

Bacterial film-based degradable triboelectric nanogenerator for both contact and non-contact sensing

As an emerging environmentally friendly energy conversion device, degradable triboelectric nanogenerators (TENGs) play an important role in self-powered sensing, health care and human–machine interaction. However, traditional degradable materials used in TENGs often suffer from limited material sources and complex preparation processes, restricting large-scale production for widespread applications. Here, we propose a simple and efficient way to prepare degradable TENGs with inactivated bacterial film, taking advantage of wide source, self-proliferation and easy culture properties of bacteria. The prepared bacterial film-based TENG (BF-TENG) has stable electrical output, good durability and fatigue resistance, along with superior capabilities in both contact and non-contact sensing. In contact mode, the BF-TENG can generate a peak voltage of up to 83.3 V, which is employed for accurate Morse code transmission. In non-contact mode, the BF-TENG is capable of effectively perceiving the target polymer at a distance of 150 cm. The non-contact LED control circuit and a sensing array based on BF-TENG further demonstrate its practical potential for gesture recognition and spatial position perception. Furthermore, the fully degradable nature of BF-TENG ensures effortless disposal after use without environmental impact, serving as a promising solution for the new generation of eco-friendly and sustainable sensing devices.