Changes In Resistance Research Articles

The Effect of Durio Zibethinus L. Seed Extract on Fasting Blood Glucose and Insulin Resistance in Metabolic Syndrome Model Rats

Metabolic syndrome is known as insulin resistance syndrome, characterized by chronic hyperglycemia. Management of metabolic syndrome involves several combinations, including lifestyle modifications and pharmacological interventions. Durian seeds are one source of antioxidants that have the potential to improve blood glucose homeostasis and insulin sensitivity. This study aims to analyze the effect of durian seed extract on changes in fasting blood glucose levels and insulin resistance. The extraction process utilized the maceration method with a 70% ethanol solution. This study consisted of 30 rats divided into six treatment groups: KN (normal group), K- (negative control), K+ (positive control metformin 9 mg/kgBW), P1, P2, and P3, which were given durian seed extract at doses of 100 mg/kgBW, 200 mg/kgBW, and 300 mg/kgBW, respectively. Metabolic syndrome rats were induced with a high-fat, high-fructose diet for 14 days, then induced with streptozocin (STZ) and nicotinamide (NA). Fasting blood glucose levels were determined using the GOD-PAP method. The HOMA-IR index was used to measure insulin resistance. The data results were evaluated using a paired T-test and one-way ANOVA. The analysis showed a significant variance in fasting blood glucose and HOMA-IR index following a 21-day treatment (p<0.05). The highest decrease was found in the 300 mg/kgBW dose group with fasting blood glucose and HOMA-IR index of 90.00 ± 2.70 mg/dl and 3.55 ± 0.11. The P2 and P3 treatments did not show different results with metformin treatment (p>0.05). The findings of this study suggest that consumption of durian seed extract for 21 days can effectively improve the condition of mice with metabolic syndrome. In addition, the drug metformin has the same effect as the intervention of durian seed extract doses of 200 and 300 mg/kgBW.

Polydopamine-modified MXene-integrated photothermal responsive hydrogel for constructing rapid photothermal and self-sensing gradient hydrogel actuators

Abstract PNIPAm-based stimuli-responsive hydrogel actuators have made significant progress. By introducing responsive modules such as photothermal nanoparticles, the hydrogel can respond to environmental changes and construct anisotropic structures, allowing the hydrogel actuators to quickly bend and realize complex shape deformation. How-ever, there remains a need to enhance the mechanical properties of these hydrogels to accommodate multiple deformation actions and different application scenarios, and enhance the compatibility between nanoparticles and the hydrogels to improve the comprehensive performance of materials are still issues that need to be solved. In this study, we modified two-dimensional MXene nanosheets with polydopamine (PDA) to obtain P-MXene, which served as a photothermal agent and can be stably dispersed within the hydrogel system. We copolymerized thermosensitive N-isopropylacrylamide (NIPAm) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) in situ and used a direct current (DC) electric field to induce a concentration gradient distribution of P-MXene nanosheets within the hydrogel, resulting in the preparation of anisotropic gradient hydrogel actuators with good stretchability and conductivity. The hydrogel structure was characterized using scanning electron microscopy (SEM) and the Fourier transform infrared (FTIR) spectra. The swelling properties, mechani-cal properties and conductivity of the hydrogel were studied. The actuation behavior of P(NIPAm-DMAEMA)/P-MXene gradient hydrogel actuators under different thickness and electric field intensity was investigated. Additionally, the sensitivity and stability of the conductive hydrogel actuators were tested. and the functions of monitoring human health and information transmission were realized. It integrated with rapid photo responsiveness and self-sensing capabilities to monitor the defor-mation process of the actuators through real-time relative resistance changes during the actuations. This work is expected to expand the application field of soft hydrogel actuators and provide new insights into the design of a new generation of soft robots.

Development and Verification of Microclimate Control System for Enhanced Driver Comfort and Safety Based on Skin Resistance Measurements

Abstract This study deals with the design and construction of a device that enhances driver comfort and safety by automatically adjusting the microclimate in the vehicle cabin based on real-time skin resistance measurements. Using electrodes attached to driver‘s skin and an Arduino microcontroller, the system monitors and evaluates skin conductivity and adjusts heating, ventilation, and air conditioning (HVAC) settings accordingly. Experimental verification in laboratory conditions demonstrated device‘s functionality in changing microclimate parameters. Preliminary results suggest a potential correlation between baseline skin resistance values and the magnitude of observed changes in response to ambient conditions. Subjects with lower baseline skin resistance (≤100,000 Ω) showed smaller changes compared to those with higher baseline resistance (≥100,000 Ω). The current results are graphically processed as the course of skin resistance changes depending on the changing parameters of microclimate.

Assessment of Platelet Response to Aspirin Therapy and Hemocompatibility-Related Adverse Events in HeartMate 3 Left Ventricular Assist Device Recipients.

Background: Patients with a HeartMate 3 (HM3) left ventricular assist device (LVAD) typically receive anticoagulation and antiplatelet therapy. The HM3 has shown a marked reduction in hemocompatibility-related adverse events (HRAEs) like stroke, bleeding, and pump thrombosis. This study evaluated whether aspirin (ASA) response influences HRAE incidence and if ASA sensitivity changes over time in HM3 recipients. Methods: This single-center, cross-sectional study included 32 HM3 patients (age: 59.0 ± 10.0 years, 15.6% female). ASA sensitivity was assessed twice using the VerifyNow assay, with ASA resistance defined by ASA reactivity units (ARU) > 550. The primary endpoint was HRAE incidence in ASA responders vs. non-responders over two consecutive follow-ups; the secondary endpoint was temporal changes in ASA resistance. Results: At the first follow-up, 13 (40.6%) patients were ASA-resistant, and 8 (28.6%) were resistant at the second follow-up, without significant change (p = 0.22). ASA non-responders and responders had similar ASA doses and baseline characteristics. No significant difference in HRAE incidence was found between ASA non-responders and responders (0.0% vs. 15.8%, p = 0.14), and no additional HRAEs occurred during follow-up. Conclusions: ASA resistance varied considerably among HM3 patients without significant temporal changes, and the demonstrated excellent hemocompatibility supports recent evidence that ASA may have a limited role in the antithrombotic regimen for HM3 recipients.

The Effect of a Zeolite Addition to Modified Bitumen on the Properties of Stone Matrix Asphalt Lärmarmer Mixtures Produced as Warm Mix Asphalt.

This paper presents the properties of an SMA LA (stone matrix asphalt Lärmarmer) mixture based on the polymer-modified binder PMB 45/80-55, formed by the addition of zeolites (synthetic zeolite type Na-P1 and natural zeolite-clinoptilolite). The compositions of the SMA 11, SMA 8 LA and SMA 11 LA mixtures based on modified bitumen with PMB 45/80-55 (reference mixture) or PMB 45/80-55 with Na-P1 or clinoptilolite were determined. Their resistance to permanent deformation, water sensitivity, water permeability and susceptibility to changes in texture and skid resistance during the period of use were verified. Adding zeolites reduced the production temperature by as much as 15 °C for the SMA 11 LA mixtures and 20 °C for SMA 8 LA. The addition of zeolites did not significantly affect the resistance to permanent deformation, the water permeability or the mass loss. The mixtures with clinoptilolite were resistant to the harmful effects of water, while the mixtures with Na-P1 proved more sensitive to water. Water permeability tests showed a higher permeability for SMA 11 LA compared to SMA 8 LA due to the higher nominal aggregate size. The Cantabro test showed greater particle loss for SMA 11 LA than for SMA 8 LA. A skid resistance and macrotexture analysis indicated that the SMA LA layers required special maintenance on the road due to the clogging of pores in the mix structure.

Evaluation of Electrical Characteristics of Weft-Knitted Strain Sensors for Joint Motion Monitoring: Focus on Plating Stitch Structure.

We developed a sensor optimized for joint motion monitoring by exploring the effects of the stitch pattern, yarn thickness, and NP number on the performance of knitted strain sensors. We conducted stretching experiments with basic weft-knit patterns to select the optimal stitch pattern and analyze its sensitivity and reproducibility. The plain stitch with a conductive yarn located on the reverse side exhibited the highest gauge factor value (143.68) and achieved excellent performance, with a stable change in resistance even after repeated sensing. For an in-depth analysis, we developed six sensors using the aforementioned pattern with different combinations of yarn thickness (1-ply, 2-ply) and NP numbers (12, 13, 14). Based on bending experiments, the GF across all sensors was 60.2-1092, indicating noticeable differences in sensitivity. However, no significant differences were observed in reproducibility, reliability, and responsiveness, confirming that all the sensors are capable of joint motion monitoring. Therefore, the plain-patterned plating stitch structure with conductive yarn on the reverse side is optimal for joint motion monitoring, and the yarn thickness and NP numbers can be adjusted to suit different purposes. This study provides basic data for developing knitted strain sensors and offers insights into how knitting methods impact sensor performance.

Silicon Enhanced Italian Ryegrass (Lolium multiflorum) Production and Induced Defense Responses Against Fall Armyworm (Spodoptera frugiperda)

The spread of invasive pests exacerbates the direct damage to host plants and the potential threat to the environment. Silicon has the potential to enhance host plant resistance to insects while also increasing plant yield. This study evaluated changes in Italian ryegrass biological yield and resistance to fall armyworm (Spodoptera frugiperda) larvae after silicon supplementation (sodium silicate and potassium silicate at 6 mmol·L−1 were denoted as groups T1 and T2, respectively). Silicon supplementation significantly increased the shoot biological yield (T1 by 30.26%, T2 by 23.05%) and silicon content (T1 by 22.61% and T2 by 12.43%) of Italian ryegrass. At the same time, silicon supplementation increased the protein, soluble sugar, and vitamin contents of Italian ryegrass, while also stimulating the improvement of its physical and chemical defenses. Therefore, even though the nutrient intake of fall armyworm increased, the synergistic physical-chemical defense formed by silica deposition, flavonoid content, and increased protease inhibitor activity in the Italian ryegrass still weakened the antioxidant capacity of the larvae and inhibited larval feeding and protein accumulation. The larval body weight of the T1 and T2 groups decreased by 20.32% and 15.16%, respectively. The comprehensive scores showed that sodium silicate and potassium silicate of the same concentration had similar effects on the growth and insect resistance of Italian ryegrass. These findings suggest that both sodium and potassium silicate are effective silicon supplements for host plants. Therefore, reasonable supplementation of silicon fertilizer may become an important alternative plan for optimizing the comprehensive pest control strategy in agricultural production areas in the future, but this still needs further field research verification.

Ultrasensitive and Breathable Hydrogel Fiber‐Based Strain Sensors Enabled by Customized Crack Design for Wireless Sign Language Recognition

AbstractWearable strain sensors, capable of continuously detecting human movements, hold great application prospects in sign language gesture recognition to alleviate the daily communication barriers of the deaf and mute community. However, the unsatisfactory strain sensing performance (such as low sensitivity, narrow detection range, etc.) and wearing discomfort severely hinder their practical application. Here, high‐performance breathable hydrogel strain sensors are proposed by introducing an adjustable localized crack in a closed‐loop connected hydrogel fiber encapsulated by porous elastomer films. Upon loading/unloading of external strain, the dynamic opening/closing of the pre‐cut crack causes a rapid switching in the hydrogel conductive path, resulting in sharp changes in resistance and a high sensitivity. Consequently, the hydrogel‐based crack‐effect strain sensor exhibits a superb sensitivity (GF up to 3930), a broad detection range (from 0.02% to 80%), fast response/recovery time (78/52 ms), repeatability, and structural stability. Based on the capability to accurately detect various strains across the full range of human movements, a wireless sign language recognition system is developed to achieve a high recognition accuracy of 98.1% by encoding and decoding various sign language gestures with the assistance of machine learning, providing a robust platform for efficient sign language intelligibility and barrier‐free communication.

Negative temperature coefficient effect of TPU/SWCNT/PEDOT:PSS polymer matrices for wearable temperature sensors

Composite-based temperature sensors utilizing the negative temperature coefficient (NTC) effect have gained significant attention across various fields, particularly in healthcare. However, the development of innovative, highly linear, and high-performance NTC-based temperature sensors remains a challenge. In this study, we developed a composite temperature sensor comprising thermoplastic polyurethane (TPU), single-walled carbon nanotubes (SWCNTs), and poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). A series of performance tests demonstrated that the TPU/SWCNT/PEDOT:PSS (TSP) composite effectively monitors temperature variations with both linearity and superior performance, attributed to the synergistic NTC effects of SWCNTs and PEDOT:PSS. This flexible temperature sensor retained its sensing functionality after repeated cycles of temperature fluctuations and multiple bending tests. Moreover, due to the unique properties of CNTs, the TSP sensor exhibited photothermal responses, showing highly sensitive resistance changes upon exposure to infrared radiation. The TSP sensor proved to be effective for various practical applications, including biosignal monitoring through thermal detection, temperature tracking during phone charging, and accurate temperature sensing on curved surfaces. Additionally, non-contact heat detection can be reliably performed regardless of whether tensile stress is applied. These findings underscore the immense potential of TSP sensors for future use in wearable healthcare technologies.

High-performance flexible sensor with rapidly adjustable sensitivity for wearable electronics

Despite numerous advances in sensor structural design, existing sensors still struggle to achieve rapidly adjustable sensitivity. Here, we utilized a structural design with alternating hard and soft sensor connections, and a lockout device to construct a sensitivity-adjustable sensor (AHS-L). Silicone rubber foams (SF) served as the flexible matrix for fabricating sensors with different hardnesses. Among them, the soft sensor (SRC-ACPF) retained the foam structure, and constructed dual conductive networks both within and on the pore walls, enhancing its resistance sensitivity with a gauge factor (GF) of up to 561.9. In contrast, the SF used in the hard sensor (ASR-PPS) featured a fingerprint-like structure. A conductive network was introduced on the pores and backfilled with liquid silicone rubber to achieve a “soft and hard” distinction from SRC-ACPF. The fingerprint-like structure induced stress concentration during stretching, resulting in high resistance sensitivity for ASR-PPS (GF up to 711.5). This microstructure also amplified contact signals, enabling ASR-PPS to realize intelligent material recognition. Notably, the alternating soft and hard structure of the AHS-L allowed the tensile deformation to be concentrated in the SRC-ACPF. Meanwhile, due to the initial resistance difference, the resistance change in SRC-ACPF has less effect on the overall resistance fluctuation of AHS-L than ASR-PPS. Therefore, a lockout device was introduced to limit the deformation of the SRC-ACPF, allowing the deformation pattern of the AHS-L to be tuned and enabling the sensitivity to be quickly adjusted from low (GF of 3.7 within 0–22% strain, 63.8 within 22–38% strain) to ultra-high (GF of 444.7 within 0–20% strain, 821.2 within 20–46% strain).

Evaluating changes in slip-resistance performance of select IceFX® winter boots in real-world use over a winter season

Winter boots with specialized outsoles (composite footwear) may be able to reduce the risk of falls on ice by 78%. However, a pilot study has also found that the slip resistance of this composite footwear can diminish relatively quickly with simulated use. The objective of this study was to evaluate the change in slip resistance of popular composite footwear (with IceFX outsoles) over a winter season of real-world use. Eighteen participants were given composite footwear to use over 4 winter months. Changes in slip resistance were measured monthly using the Maximum Achievable Angle (MAA) test while a pedometer was used to track step counts. Over 150,000 steps, MAA scores dropped from 13.86±1.35 (SD) to 8.81 ± 1.32 (SD), with a significant decrease after just 75,000 steps. This drop in slip resistance suggests that the risk of slip-related falls on ice may increase during even the first season of use.

Determination of the Rate Change of Electrical Resistance of Aluminium Oxide Film By White Light-Optical Interferometry

A white light, i.e., Fabry-Perot, interferometry was utilized for the first time to determine the rate change of the electrical resistance of aluminum samples during the initial stage of anodization processes in aqueous solution. In fact, because the resistance values in this investigation were obtained by Fabry-Perot interferometry, an electromagnetic method rather than an electronic method, the abrupt rate change of the resistance was called electrical resistance–emission spectroscopy. The anodization process of the aluminum samples was carried out by the DC method in different sulphuric acid concentrations (0.0,2,4,6,8,10% H2SO4) at room temperature. In the meantime, the Fabry-Perot interferometry was used to determine the difference between the electrical resistance of two subsequent values, dR, as a function of the elapsed time of the DC experiment for the aluminum samples in 0.0,2,4,6,8,10% H2SO4 solutions. The Fabry-Perot interferometry was based on a fiber-optic sensor in order to make real time-white light interferometry possible at the aluminum surfaces in the sulphuric acid solutions. The electrical resistance-emission spectra represent a detailed picture of not only the rate change of the electrical resistance throughout the anodization processes but also the spectra represent the rate change of the growth of the oxide films on the aluminum samples in different solutions. As a result, a new spectrometer was developed based on the combination of the Fabry-Perot, i.e., white light, interferometry and DC method for studying in situ the electrochemical behavior of metals in aqueous solutions. In addition, the obtained values of the resistance of the combination of the Fabry-Perot interferometry and DC method were compared with resistance values of the aluminum samples in 0.0,2,4,6,8,10% H2SO4 solutions by the electrochemical impedance spectroscopy (EIS). Keywords: Fabry-Perot interferometry, White light interferometry, Electrical resistance, Anodization, Fiber-optics sensor, DC method & EIS. Figure 1

Significant Changes in Electrical Resistance of Conductive Porous Silicon Films Produced from Thiol-Modified Silicon Nanoparticle Inks

Materials that reversibly modify their electrical resistance in response to external stimuli have attracted the interest of many researchers due to their potential applications in low-energy consumption memories and memristive devices for constructing electrical neural networks. For example, various chalcogenide glasses, such as Ge2Sb2Te5 [1] and Ag- or In-incorporated Sb2Te [2], can change resistances by 3–6 orders of magnitude, originating from the phase changes between amorphous (high resistance) and crystal (low resistance) states due to rapid and gradual Joule heating. Similar dynamic ranges of resistance changes have been observed in metal-doped glasses [3], such as Ta:Ta2O5, Cu:Ta2O5, Ag:SiO2, Ni:NiO, and nanocomposite Sb-SiO2, using the conductive filament growth/rupture in glasses. Furthermore, devices containing ferroelectric materials, such as Pt/BaTiO3/Nb:SrTiO3 tunnel junctions and Sc-doped AlN/MoS2 ferroelectric field-effect transistors, exhibit similar dynamic ranges by ferroelectric polarization switching.Among these, nanometer-sized Si is a unique material whose resistance can be controlled by near-infrared optical and electrical stimulations [4]. This is the advantage of incorporating resistance change materials into optical communication systems, resulting in the construction of optoelectronic neural networks. However, the following shortcomings of nanometer-sized Si hinder its applications: (1) serious conductivity degradation that proceeds in air and (2) insufficient dynamic ranges of the resistance changes.Recently, we produced sulfur (S)-terminated Si nanoparticles, whose surface is difficult to oxidize even in the air [5]. Because S atoms, which are known to act as donors in Si, are located at the outermost surface of nanoparticles, the electron doping from S atoms can be considerably influenced by the surface-adsorbed molecules. Considering the large surface-to-volume ratio in nanoparticles, the electrical resistances of Si nanoparticle films can potentially be largely changeable through adsorption/desorption of electron-withdrawing molecules, such as O2 and halogens.In this study, we demonstrated that surface S termination considerably reduces resistances in Si nanoparticles, and that S-terminated nanoparticles can reversibly change resistances similar to hitherto reported resistance change materials. Figure 1 shows current–voltage characteristics of the S-terminated Si nanoparticles measured under N2 and O2 atmospheres. As shown in the figure, changing the atmospheric gas significantly altered the current. For example, by changing the atmospheric gas from N2 to O2, the resistance at 2 V changed from 5×106 Ω to greater than 1012 Ω and vice versa. This reversible resistance change is due to O2 adsorption/desorption on the film surface. The electron-withdrawing nature of O2 may induce band bending at the nanoparticle surface as depicted in the figure, and the induced energy barrier may prevent the interparticle transport of electrons, which agrees with the small energy barrier found in our conductive atomic force microscopy measurements. The dynamic range of the resistance change was remarkably comparable to the ranges of the conventional phase change materials, indicating that by terminating the surface with S atoms, Si nanomaterials can be used not only in sensors but also photo-stimulated synaptic devices by controlling the amount of the adsorbed O2, for example, through light irradiation [4].

Study on Catalyst and Binder Degradation Analysis during Electrode Degradation Using EIS in PEMFC

Research is underway to reduce the cost of PEMFCs by decreasing the loading amount of Pt catalyst, which necessitates research on catalyst structures and binders to compensate for the resulting decrease in performance and durability. Recent studies have focused on improving performance using binders such as high oxygen permeation ionomer (HOPI), but research on the durability of such binders is lacking. The primary challenge in studying binder durability lies in the difficulty of binder degradation analysis. Since the binder in the catalyst layer exists in small quantities within the catalyst layer, and degradation is difficult to distinguish from membrane degradation, it is crucial to develop analysis methods to identify binder degradation. Distribution relaxation time (DRT) analysis is a method that utilizes Electrochemical Impedance Spectroscopy (EIS) to analyze resistance in detail by representing it as distribution relaxation time peaks. By using DRT analysis, the resistance in EIS can be subdivided into ORR charge transfer resistance, oxygen transfer resistance, and proton transfer resistance and changes in the ion transfer resistance of the catalyst layer can be analyzed in situ to observe binder degradation. In this study, we aim to analyze the degradation of catalyst and binder ionomer during electrode degradation using EIS in situ. In addition, we compare the electrochemical analysis results and post-analysis results with the EIS analysis results to examine the suitability for EIS analysis. Electrode degradation was carried out using the DOE catalyst degradation protocol. Characterization during electrode degradation included I-V, EIS, mass activity, CV, LSV, while post-degradation analysis involved AFM, XRD, XRF analysis to analyze electrode catalyst and binder degradation. As catalyst degradation progressed, the cell's performance decreased, leading to increased charge transfer resistance (CTR), decreased electrochemical surface area (ECSA), and decreased mass activity. Catalyst degradation was observed through changes in ORR charge transfer resistance in DRT analysis, while binder degradation was confirmed through changes in proton transfer resistance in DRT results and Warburg-like response impedance. The results obtained from the postmortem of degraded MEAs matched well with the results obtained from DRT analysis.

The Effect of Doping Conditions on Amorphous IGZO Electrical Conductivity

In recent years, there has been a noticeable increase in interest in thin-film transistors (TFTs) employing oxide semiconductors in the display industry. Among various oxide semiconductors, amorphous indium gallium zinc oxide (a-IGZO) has emerged as a particularly promising material and being used for the backplane of the OLED (organic light emitting diode) TV. It offers several advantages over conventional materials such as amorphous silicon (a-Si) and organic semiconductors, including higher electron mobility, lower leakage current, and wide area process applicability.For the top-gate self-aligned structure offers distinct advantages over the bottom-gate structure, reducing parasitic capacitance between source/drain and gate electrodes. For low contact resistance between the source/drain electrodes and a-IGZO, the doping process on the IGZO layer is necessary to enhance conductivity at the source and drain region. Various doping techniques are employed for a-IGZO, including ultraviolet (UV) irradiation [1], ion implantation, and plasma treatment [2]. Ion implantation is a widely used method in semiconductor manufacturing, where ions are injected into the semiconductor using high-energy ion beams. UV irradiation, on the other hand, utilizes ultraviolet light to shift the Fermi level below the conduction band, thereby making the semiconductor conductive. Plasma doping, the focus of this study, typically involves using equipment such as PECVD (Plasma Enhanced Chemical Vapor Deposition) or RIE (Reactive Ion Etching) to dope a-IGZO within a low-pressure chamber using plasma generated. Reactive gases are introduced, and plasma ions with high energy disrupt the metal-oxygen bonds within a-IGZO, enhancing conductivity and reducing sheet resistance.In this study, plasma doping was employed and the changes in sheet resistance was investigated under different plasma conditions, particularly focusing on various reaction gases. Doping experiments were conducted for various gases, while the effects of plasma treatment were evaluated through the sheet resistance measurements and comprehensive composition analysis. The results of this study provide insights into the relationship between plasma doping through controlled reaction gases and changes in sheet resistance in a-IGZO.Our experimental results reveal that plasma treatment leads to a decrease in the electrical conductivity of the IGZO layer. Moreover, we explore how varying plasma treatment time and power levels influence this conductivity reduction. Furthermore, we examine the effect of post-annealing on the electrical conductivity of plasma treated IGZO layers. Our findings demonstrate that post-annealing conditions play a crucial role in determining the final electrical conductivity of IGZO layers after plasma treatment.[1] H. Seo, et al. "Permanent optical doping of amorphous metal oxide semiconductors by deep ultraviolet irradiation at room temperature," Appl. Phys. Lett. 96, 222101 (2010).[2] W. -S. Liu, C. -H. Hsu, Y. Jiang, Y. -C. Lai, and H. _C. Kuo, “Improving device characteristics of dual-gate IGZO thin-film transistors with Ar-O2 mixed plasma treatment and rapid thermal annealing,” Membranes 12, 49 (2022).

Comparative Study on Hydrodynamic Characteristics of Under-Water Vehicles Near Free Surface and Near Ice Surface

In this paper, the commercial computational fluid dynamics software STAR-CCM+ (18.04.008-R8) is utilized to analyze the hydrodynamic performance of BB2 underwater vehicles under various navigation conditions, as well as the flow field disturbances caused by the free surface and ice surface during navigation. After dividing the computational domains based on different navigation scenarios, numerical simulations are conducted for BB2 underwater vehicles (without a propeller) at infinite depth, near the free surface, and near the ice surface under various operating conditions. The analysis focuses on changes in resistance, velocity fields, and pressure fields of the BB2 at different velocities and navigation depths, followed by a comparison of the navigation differences of BB2 vehicles under varying operating conditions. Furthermore, to simulate realistic navigation conditions for underwater vehicles, numerical simulations are performed for BB2 underwater vehicles equipped with a propeller under different operating conditions. The results indicate that both the free surface and ice surface significantly influence the resistance, velocity field, and pressure field of the BB2. When the navigation depth exceeds 2D, the impact of ice on the vehicle can be nearly disregarded, and when the navigation depth exceeds 3D, the influence of the free surface on the vehicle can also be considered negligible.

Extraction of Performance Factors for Clay-Type-Solid-State Batteries Based on Electrochemical Evaluation

Extraction of performance factors for clay-type-solid-state batteries based on electrochemical evaluation. Keigo Suzuki, Takaaki Ichikawa, Kento Okanishi, Rintaro Mogi, and Shiro Seki (Kogakuin Univ.) Introduction Performance development of Li-ion batteries (LIBs) has been desired due to high energy density, and is also expected to the engineering issues, such as huge mass loading of electrode sheet. To realize high-performance LIB with high energy density, clay-type solid-state batteries (CSSBs) with the composite electrode included electrolyte are attracting attention. CSSBs are easily prepared thick electrodes without adding a binder, and therefore, expected to increase energy density. In this study, we applied AC impedance measurements for clay into CSSBs to evaluate the factors for high-performance in the conduction pathways of electrode clay of high-performance with variations in electrolyte composition using the highly concentrated electrolyte with a wide potential window and a high Li-ion transference number1. Experimental method The clay electrode was prepared by using LiFePO4 (LFP) as the positive active material, acetylene black (AB) as the conductive additive, and (LiTFSA+4EC) as the electrolyte. LFP: AB was weighed to a weight ratio of 94.25:5.75, mixed in a mortar for 20 min, and then the electrolyte was added to the weight ratio of (100-x)(LFP+AB):x (LiTFSA+4EC) (x=0~100). Positive electrode clay was prepared after mixing for 10 min using a paste mixer. After that, the positive electrode clay was filled into the cell with [SUS | Positive electrode clay | SUS] and the AC impedance spectrum of the positive electrode clay was measured. The AC impedance measurements were conducted under constant temperature conditions of 30 ℃ with an amplitude of 100 mV and a frequency range of 200 kHz to 50 mHz. Temperature under temperature dependences were also evaluated for conditions of between -10 ℃ and 80 ℃ with an amplitude of 100 mV and a frequency range of 500 kHz to 50 mHz2. Result and Discussion Fig. 1 shows typical Nyquist plots of [SUS | Positive electrode clay | SUS] cells positive electrode clay for each electrolyte composition at 30 wt%. At 10 wt% electrolyte composition, resistance component (R E) attributed to the electronic conduction was only observed at low frequencies. In contrast, the resistance component (R I) attributed to the ionic conduction was observed at high frequencies at 80 wt% electrolyte composition. At 50 wt% electrolyte composition, two resistance components were observed on both the high and low frequencies, and considered to be resistance components desired to the electric composite electrode and ionic electrolyte components.Fig. 2 shows the temperature dependence of resistance changes for the 30 wt% electrolyte composition of the positive electrode clay. Electric conduction generally involves electrons being scattered by lattice vibrations and increases resistance with temperature. On the other hand, for ionic conduction, the mobility of ions always increases with temperature. On the low-frequency side, the increasing trend of resistance with temperature was observed, while on the high-frequency side, the opposite trend was also confirmed. In these results, we defined that R I corresponds to the high-frequency side and R E corresponds to the low-frequency side, respectively.Fig. 3 shows the Nyquist plots of [SUS | Positive electrode clay | SUS] cells (A) is an overview of Nyquist plots of [SUS | Positive electrode clay | SUS] cells, (B) and (C) are enlarged figures of (A). To analyze resistance components for electrode clay, obtained R E and R I were calculated and plotted against the percentage of the electrolyte composition.Fig. 4 shows the relationship between R E and R I of positive electrode clay for electrolyte composition. Only R E was observed in the region of (a) (electrolyte composition 0 ~ 20 wt%), and also only R I was observed in the composition region of (c) (electrolyte composition 70 ~ 100 wt%). In contrast, both R E and R I were observed in the region of (b) (electrolyte composition 30 ~ 60 wt%). In the composition region (a), only continuous electron conduction paths in the clay electrode should be formed. Also, in the composition region (c), only ionic conduction paths should be formed. On the other hand, in the composition region (b) was considered that both continuous electric and ionic conduction paths into the clay electrodes are provided by AB and LiTFSA+4EC electrolyte. In addition, in the composition region (b) was confirmed both electron conduction and ionic conduction coexist conditions, the smallest values of R E and R I at 30 wt%, suggesting that the optimal composition condition of positive electrode clay.(1) Y. Yamada, A. Yamada, J.Electrochem.Soc.,162, A2406-A2423 (2015).(2) R. Motoyoshi, et al., ACS Appl. Mater. Interfaces, 14, 45403−45413 (2022). Figure 1

Dcir for in-Situ Analysis of Li-NMC Batteries

This research delves into the qualitative analysis of internal processes in lithium nickel manganese cobalt oxide (Li-NMC) batteries by utilizing direct current (DC) techniques throughout the battery's lifecycle. Expanding on the comparative approach between electrochemical impedance spectroscopy (EIS) and DC techniques highlighted by Martin Winter1, this study emphasizes the exclusive application of DC techniques for an in-situ understanding of battery behavior without the potentially performance-impacting application of EIS. By systematically measuring resistance changes, this work uncovers the effects of lithium coatings, electrode thickness variations, and the operation of anode-free batteries on the internal resistance profiles. The methodology provides a non-invasive insight into the electrochemical dynamics, enabling a deeper understanding of the material and design factors that influence battery efficiency and longevity. Utilizing the information imbedded within the electrochemical data the plating overpotential which translates into the ohmic resistance, a pattern is seen connect the ohmic resistance to that of cycle stability. Understanding the resistance helps to identify characteristics that have been previously hidden without intrusive testing. L. Stolz, M. Gaberšček, M. Winter and J. Kasnatscheew, Chemistry of Materials, 2022, 34, 10272-10278.

Understanding Degradation Behavior in All-Solid-State Batteries through Scanning Spreading Resistance Microscopy

All-solid-state lithium-ion batteries (ASSLIBs) are promising candidates as the next generation battery because of inherently high safety and high energy density. The practical application of high-performance ASSLIBs is to be achieved by the development of solid electrolytes (SEs) with high ionic conductivity. So far, many SEs with high ionic conductivity over 10−3 S cm−1 have been discovered. However, ASSLIBs still face challenges arising from solid/solid interfaces. ASSLIBs using sulfide SEs involve chemical and mechanical degradations at the interface between cathode materials and solid electrolytes in cathode composites during the charge/discharge process. These degradations increase total resistance in ASSLIBs, leading to cycle deterioration. Therefore, understanding the degradation behavior is important for realizing long-life ASSLIBs. Scanning spreading resistance microscopy (SSRM) is a type of atomic force microscopy technique, which provides current distribution with high spatial resolution at the sample surface. An SSRM study by Otoyama et al. reported that a part of the cathode materials in the electrode shows insufficient electron conduction paths after the charging and involves high local resistance in the domains of the cathode materials.1 The local resistance analysis using SSRM is a useful technique for unveiling the degradation behavior in ASSLIBs.Herein, we investigate the local resistance of cathode composites with LiNbO3-coated LiNi0.5Co0.2Mn0.3O2 (NCM) and argyrodite-type SEs for ASSLIBs after charging and elucidate the degradation behaviors through ex-situ SSRM. The local resistance analysis reveals the intrinsic resistance changes of NCM particles involving lithium deintercalation. Topography and local resistance mapping obtained by ex-situ SSRM study show that a part of NCM particles in cathode composites is electrically isolated after the charging to a high potential.2 Our work demonstrates that the ASSLIBs after the charging to a high potential cause mechanical degradation due to the volume change of NCM particles. Acknowledgments This study is based on the results obtained in the ‘Evaluation of All-Solid-State Battery Material and Foundational Technology Development for Next Generation (SOLiD-Next, JPNP23005)’ project, commissioned by the New Energy and Industrial Technology Development Organization (NEDO). References M. Otoyama et al., J. Phys. Chem. C, 125, 2841 (2021).H. Gamo et al., J. Mater. Chem. A, submitted.

Enabling in-Line Silicon Wafer Porosification: An Experimental and Simulation Study

Silicon is the dominant material of microelectronic and solar cell devices but also a very promising material for Li-ion battery anodes. For many of these applications thin silicon layers are needed for which a layer transfer is a very efficient way to produce them. In this paper, results of large-scale etched porous silicon wafers using an in-line pilot production tool will be presented. The tool uses a wet chemical front-side contact that periodically changes polarity and thus just needs one side of the wafer in contact to the electrolyte. However, the proportion of the wafer that is exposed to each polarity is a function of its current location, leading to large current density fluctuations. Therefore, multiple electrodes have been positioned within the half-cells of the setup. Voltage and current data were recorded as a function of time, and the respective position of wafer, for all electrodes. A finite element simulation using COMSOL allowed for a very good reproduction of these in-operando measured data. A clear correlation to lateral and vertical porosity variations within the porous layers has been found.All etching inhomogeneities in the porous layer can be clearly explained by changes in the series resistance and the corresponding voltage losses as the wafer is moving through the setup. These series resistance changes are almost exclusively related to the geometrical shape of the half cells and the positions of the counter electrodes. This means that the passive series resistance network is the reason for non-perfect etching of the porous layers rather than non-linear electrochemical processes. This network also includes the anode and the cathode that are used for contacting the electrochemical half cells. The smart contacting scheme of the in-line etching tool showed up to be fully reliable. The COMSOL studies displayed, that changes of the half-cell geometries can drastically decrease the current fluctuations. Adjustments have shown that a decrease from an initial 40% fluctuation to less than 6% fluctuation are achievable. This allows for the etching of laterally homogeneous porous layers suitable for a layer transfer.