COMSOL Multiphysics Simulation Research Articles

Stable Millivolt Range Resistive Switching in Percolating Molybdenum Nanoparticle Networks.

To overcome the limitations of the conventional Von Neumann architecture, inspiration from the mammalian brain has led to the development of nanoscale neuromorphic networks. In the present research, molybdenum nanoparticles (NPs), which were produced by means of gas phase condensation based on magnetron sputtering, are shown to be the constituents of electrically percolating networks that exhibit stable, complex, neuron-like spiking behavior at low potentials in the millivolt range, satisfying well the requirement of low energy consumption. Characterization of the NPs using both scanning electron microscopy and scanning transmission electron microscopy revealed not only pristine shape, size, and density control of Mo NPs but also a preliminary proof of the working mechanism behind the spiking behavior due to filament formations. Furthermore, electrostatics COMSOL Multiphysics simulations of the morphology of the NPs provided evidence that the stable switching is due to the as-deposited stellate Mo NPs creating high electric field strengths, while keeping them separated, not seen before in other percolating networks based on spherical NPs. Hence, our results show the working mechanism behind switching in percolating Mo NP networks and show that they are very promising for realistic neuromorphic systems.

Achieving Dendrite-Free Lithium Metal Batteries by Constructing a Dense Lithiophilic Cu1.8Se/CuO Heterojunction Tip.

Lithium (Li)metal batteries (LMBs) have garnered widespread attention due to their high specific capacity. However, the growth of lithium dendrite severely limits their practical applications. Herein, a novel strategy is proposed to regulate the overall potential strength and lithium ions (Li+) concentration on the surface of the current collector by utilizing densely distributed tip effects. This concept is exemplified through the construction of lithiophilic Cu1.8Se/CuO heterojunction needle array on the Cu foil, ultimately achieving dendrite-free lithium deposition. Based on the simulation in COMSOL multiphysics and experimental research, this design is demonstrated to enrich Li+ on the current collector surface, delay the formation of space charge regions, and mitigate the growth of lithium dendrites. Additionally, a built-in electric field (BIEF) triggered by the heterointerface between Cu1.8Se and CuO further alleviates the Li+ concentration gradient on the electrode surface, achieving uniform bottom-up deposition of Li within the array structure. Consequently, the symmetrical cell exhibits an ultra-long cycle life of 2400h (1mAcm-2, 1mAhcm-2) with an extremely low overpotential of 13mV. Furthermore, full batteries using LiFePO4 as the cathode exhibit superior cycle stability and rate performance. This study presents a promising approach for designing dendrite-free current collectors in LMBs.

Cu2SnS3/rGO nanocomposites with optimized pore structure for high-performance lithium-ion batteries

Developing advanced anode materials is essential for enhancing the rate performance and stability of lithium-ion batteries (LIBs), which is critical for meeting the demands for next-generation energy storage solutions. In this research, Cu2SnS3/rGO nanocomposites were synthesized via a rapid microwave-assisted one-step method, followed by post-synthetic annealing. The incorporation of reduced graphene oxide (rGO) not only significantly improves its electrical conductivity, but also effectively inhibits the agglomeration of CTS nanoparticles. The nanocrystal size in the CTS/rGO nanocomposites has been dramatically downsized, transitioning from the pristine CTS dimensions of 0.9–1.5 μm to a mere 100 nm. This downsizing is a critical advancement in the electrode, as it enhances the surface area and reactivity of the composite. The subsequent high-temperature annealing process shrinks the pore size in the CTS/rGO nanocomposite, decreasing from an average of 42.13 nm to a more confined range of 7.81 to 8.77 nm, depending on the annealing temperatures. Electrochemical testing reveals that the CTS/rGO-A nanocomposite annealed at 300 °C exhibits superior electrochemical performance to the unmodified CTS and non-annealed CTS/rGO composite. The performance is evidenced by an initial capacity of 1856.97 mAh g−1 at a current density of 1 A g−1 and retains a capacity of 1250.32 mAh g−1 after 500 cycles. To elucidate the underlying mechanisms governing the lithium ion diffusion kinetics, capacitance and diffusion behavior of the CTS/rGO-A electrode, advanced techniques such as galvanostatic intermittent titration technique (GITT) and rate cyclic voltammetry (CV) were utilized. These analyses revealed that the synergistic effect of an increased Li+ diffusion coefficient (DLi+), coupled with a notable capacitive contribution, is demonstrated to the enhanced electrochemical performance observed. Furthermore, the COMSOL Multiphysics simulation also indicates improved structural stability of CTS/rGO-A, attributed to minimized stress from volume expansion during discharge. The CTS/rGO-A nanocomposites, featuring enhanced electrochemical performance, coupled with a straightforward and efficient fabrication method, emerge as a promising material for scalable and practical energy storage solutions.

Development of Bamboo Based Nylon 66 Composite through Friction Stir Processing-An Attempt

The concept of developing a bamboo-based Nylon 66 polymer matrix composite is a relatively novel and very new technical attempt through friction stir processing (FSP). This innovative approach can create a composite material that strengthen the mechanical properties of bamboo and the versatility of Nylon 66. However, successful implementation requires careful consideration of FSP process parameters such us tool rpm, traverse speed, tilt angle and tool design. Among the processing parameters, the tool rpm shows the significant role for severe plastic deformation and temperature generation which leads to the achieving excellent bond. Therefore, in this present study attempt has made to develop the polymer matrix composite (nylon 66 and bamboo powder) using FSW process at a variant rotational speed of 300,400 and 500 rpm with the constant traverse speed of 25 mm min-1. The deformation behavior and the peak temperature evolved under the tool shoulder during the stirring motion is studied using COMSOL Multiphysics simulation. It is found that, the specimen processed with higher rpm (500rpm) shows the higher volumetric strain and the peak temperature and it is evident that with increasing rpm the higher amount of severe plastic deformation occurred. Initially the process parameters are optimized without bamboo powder on the nylon 66 plate of 6 mm thickness and found that the 500 rpm processed specimen shows the defect free. Prior to the actual FSP, the small keyways taken on the center of the nylon 66 plate in order to add the bamboo powders in it. Actual processing was done with bamboo powder after adding natural bamboo powder of size 50µm. The result reveals that, the bamboo powder has partially expelled out during the period of FSP. This complete study concedes that the processing parameters needs to be optimized and also bamboo added method need to be studied for the successful development of bamboo-based polymer matrix composite.

Light-harvesting properties of photocatalyst supports—no photon left behind

AbstractIn this work, we set out to elucidate the light-harvesting properties of various random and ordered photocatalyst supports (PSs) with different macropore sizes. To accomplish this, we propose two studies of increasing relevance, enabled by computed tomography (CT) reconstructions and ray-tracing COMSOL Multiphysics simulations: (a) a 360-degree light release study approximating a PS situated within a compound parabolic concentrator (CPC) or cylindrical LED reactor with open ends; and (b) the same system as before but with closed ends. The ordered geometry is of interest, as it can be 3D printed at scale with a tailored morphology and porosity, and it can potentially be refined using machine learning models to optimize its light-harvesting properties. As will be shown, the local volumetric light absorption (LVLA) data suggests that an ordered PS with a more open pore interior and a smaller pore exterior would begin to approach the more isophotonic light-harvesting properties of random PSs.

Cleanroom-free fabrication of flexible capacitive pressure sensors using paintable silver electrodes on stationery paper and random microstructured polydimethylsiloxane dielectric layer

Abstract In this work, we propose a facile, low-cost, and cleanroom-free approach for fabricating flexible capacitive pressure sensors based on paintable Ag electrodes on stationery paper substrates (Ag–paper electrodes) and a random microstructured polydimethylsiloxane (PDMS) dielectric layer transferred from emery paper. COMSOL Multiphysics simulations and experimental investigations suggest that the pressure sensor with random microstructured PDMS dielectric layer performs better than the sensor with ordered micropyramidal dielectric layer. The developed Ag–paper electrode and random microstructured PDMS dielectric layer-based pressure sensors are workable in a wide pressure range (up to 630 kPa) and exhibit a high sensitivity of 0.132 kPa−1 up to 1 kPa, low hysteresis (6.6%) with loading–unloading of ∼500 kPa pressure, high stability during a ∼5250 cyclic test, and the ability to sense a low pressure of ∼27 Pa. The developed sensor also successfully transduces arterial pulse wave forms when it is properly attached to the wrist. Using the proposed process, a flexible capacitive pressure sensor matrix of 4 × 4 array is also successfully developed for single- and multiple-point pressure mapping with minimal cross-talk. The proposed sensor process is simple and inexpensive to implement, and offers spatial pressure mapping for e-skin applications.

Study on the suppression of parasitic resonance of film bulk acoustic wave resonators

To suppress the parasitic resonance of a film bulk acoustic resonator (FBAR) and meet the high-frequency requirements of 5G communication, an FBAR model was established based on COMSOL Multiphysics simulation software. The effects of the piezoelectric materials, electrode lateral size, electrode shape (rectangle, circle, trapezoid, and regular pentagon), and apodization angle (30°, 36°, 40°, and 45°) on parasitic resonance were studied, and the suppression effect of the step-load structure on lateral acoustic wave leakage was discussed. The simulation results show that the best suppression effect on parasitic resonance is achieved when the piezoelectric material is AlN, the electrode shape is a non-regular pentagon, and the apodization angle is 40°; when the resonant area is 3600μm2, its non-circularity is 6.45 %, which is equivalent to the rectangular electrode when the resonant area is 10000μm2. The designed electrode step-load structure improved the quality factor at the parallel resonance point. When the electrode lateral size is 60 μm, the quality factor of the second-order electrode load structure is 1378, which is 10.07 % higher than the quality factor of the electrode-free load structure.

Computational and experimental study of AC measurements performed by a double-nanohole plasmonic nanopore sensor on 20 nm silica nanoparticles

A novel method of AC sensing is presented that uses a double nanohole (DNH) nanoaperture atop a solid-state nanopore (ssNP) to trap analytes and measure their optical and electrical properties. In this method analytes are propelled by an external applied voltage towards the sensor until they are trapped at the DNH-ssNP interface via a self-induced back action (SIBA) plasmonic force. We have previously named this method SIBA Actuated Nanopore Electrophoresis (SANE) sensing and have shown its ability to perform concurrent optical and DC electrical measurements. Here, we extend this method to AC sensing of 20 nm SiO2 (silica) nanoparticles, using voltage modulation over a wide range of frequencies applied on top of a baseline DC bias. The sensor was constructed using two-beam GFIS Focused Ion Beam (FIB) lithography, incorporating Ne FIB to mill the DNH and He FIB to drill a central 30 nm ssNP. We utilized COMSOL Multiphysics simulations to explore the multi-frequency AC current conductance properties of the silica nanoparticles trapped at the SANE sensor. These simulations computed conductance changes and phase shifts induced by the presence of the nanoparticle over an AC frequency range of 20 Hz to 100 kHz. Experimental measurements confirmed the trends seen in the computational data. Additional computational studies were then performed to dissect the underlying mechanisms driving the observed AC measurements. Looking forward, we aim to adapt this technology for probing therapeutic nanoparticles non-invasively, offering a promising tool for enhancing quality control of nanoparticle-mediated drug and gene delivery systems.

Low-voltage organic field-effect transistors by using solution-processable high-κ inorganic-polymer hybrid dielectrics

Organic field-effect transistors (OFETs) incorporating hybrid high-κ inorganic Al2O3 and polymer dielectrics, including polyvinyl alcohol (PVA), polystyrene (PS), or polymethyl methacrylate (PMMA), through solution-processing techniques were fabricated. The analyses revealed that the high surface energy and hydrophilicity property of Al2O3 and PVA, and the relatively hydrophobic property of PS surface, hindered the performance of corresponding OFETs. The Al2O3/PMMA-based OFET achieved the optimized performance, with a threshold voltage of −2.7 V, a hole carrier mobility of 0.056 cm2/Vs, and a current on/off ratio of 1.0 × 104 at a low operating voltage of −5 V. Through analyzing the characteristics of leakage current, capacitance, contact resistance, and trap density of OFETs, we found that the PMMA-engaged films possessed the optimized electrical properties. The introduction of PMMA eliminated the interfacial trapping, thereby lowering the threshold voltage and enhancing the performance of the device. The COMSOL Multiphysics simulation was conducted to confirm the physical mechanism. The strategy of utilizing Al2O3/PMMA hybrid dielectric could simultaneously ensure the low operating voltage and good performance of OFET, while guaranteeing the low leakage current by the thick PMMA.

The preparation technology and catalytic mechanism of PVDF/PVP/a-MoSx porous membrane for water flow driven piezoelectric PMS activation

Piezoelectric catalysis couples with peroxymonosulfate (PMS) activation technology can efficiently increase the yield of reactive oxygen species (ROS). Herein, a novel flexible polyvinylidene difluoride/polyvinyl pyrrolidone/amorphous molybdenum sulfide (PVDF/PVP/a-MoSx) membrane with finger-like pore structure was prepared by non-solvent induced phase separation (NIPS) method. As a result, a-MoSx nanosheets can be exposed out of the pores to provide multiple active sites. The PVDF/PVP/a-MoSx with large dipole moment can form enhanced polarization field under water flow to accelerate the charges separation and transfer, thereby promoting the breakage of the OO bond of PMS. The mechanism of piezo-photocatalytic activated PMS was confirmed by COMSOL multiphysics simulations, electrochemical experiments, contribution of active species and DFT calculations. Moreover, a self-cycling degradation reactor was proved more effective in generating piezoelectric potential and improving the degradation efficiency, supporting the practical potential of this strategy. This study provides a new platform to develop piezoelectric porous membrane for enhanced PMS activation under low density flow water energy.

Biomimetic bilayer phase change hydrogels with enhanced water adsorption and desorption for evaporative cooling

Hygroscopic hydrogels, reliable carriers for water-based evaporative materials, undergo shrinkage after evaporative cooling, and the consequent reduction in hygroscopic sites can significantly impair their recyclability in cooling period. To realize cyclic evaporative cooling for rapid regeneration and evaporation, bilayer phase change hydrogel (BPH) concept combining an upper layer of hygroscopic polymer film (CaCl2@ carboxymethyl cellulose/konjac glucomannan films, CaCl2@CMC/KGM, MAF) with a lower layer of hygroscopic hydrogel (CaCl2@poly(vinyl alcohol)/sodium tetraborate decahydrate hydrogel, CaCl2@PVA/Borax, PCH), is presented in this paper. The high liquid–vapor phase change enthalpy of BPH (1274 J/g) enables it to continuously and rapidly remove heat. Benefiting from the MAF hygroscopic porous skeleton, the saturated BPH exhibited a faster water evaporation rate (2.15 kg m−2 h−1) and comparable water vapor transmission rate (1.61 kg m−2 h−1) at 50 °C. After being heated at 50 °C for 1 h, BPH requires 9h to regain its initial mass at 25 °C, 90 % RH. Fifteen moisture adsorption–desorption cycles demonstrate the excellent cyclic regeneration capability of BPH. COMSOL Multiphysics simulation results indicate that evaporative cooling in BPH provides excellent heat dissipation (reduced by about 27 °C). BPH reduces the peak temperatures of a mobile phone by 7.8 °C while charging and 6.5 °C while gaming. This design will contribute to the future cooling of heat-related devices and global sustainability.

Enhanced coalbed methane recovery by microwave-induced thermal fracture

Abstract The investigation on microwave-induced permeabilization and response of coal under microwave heating is of great significance for the industrial application of microwave heating technology instead of traditional heating in coalbed methane mining. Santanghu coal is used as a sample to measure the permeability and porosity of coal samples before and after microwave heating. The fracture changes of coal samples before and after heating are compared to observe the penetration effect of microwaves on coal samples. Based on the technology of directional drilling and continuous tubing technology in petroleum engineering, a technology of increasing the production of coalbed methane by microwave heating in a wide range of coal seams is proposed. The feasibility of this enhanced production method is validated through COMSOL Multiphysics simulations, which model the temperature field distribution within coal seams under various microwave parameters. This approach highlights the potential of microwave technology in coalbed methane recovery. The results show that: (1) the thermal field of coal samples under microwave heating is inhomogeneous. The average length and area of the cracks of the coal samples increased under microwave radiation, and the cracking of the coal samples confirmed the cracking effect of microwaves on the coal samples. (2) With prolonged microwave heating, coal samples exhibit an initial decrease followed by an increase in porosity and permeability, a trend attributed to the expansion of solid particles that occupy and reduce pore spaces. (3) The in-situ microwave heating technique for coalbed methane extraction overcomes the challenges of long-distance microwave transmission loss and methane backflow in transmission pipelines, utilizing continuous pipelines for extensive microwave heating of coal seams. (4) The microwave power and intermittent heating duration have a significant effect on the temperature field distribution of the coal seam, and when the heating duration is 60 days, 1600 W is used to have an effective temperature field distribution while avoiding the waste of heat. When the power is constant at 1600 W, the effective temperature range is wider when the intermittent heating duration is 60 days.

A study of XLPE insulation failure in power cables under electromagnetic stress

Underground cables with cross-linked polyethylene (XLPE) insulation are integral to medium voltage (MV) power transmission systems, ensuring continuous electricity supply amidst operational challenges and environmental conditions. However, the reliability of these cables can be compromised over time due to aging and installation-related factors, particularly at joints and terminations. This study offers a comprehensive analysis of how various defects, including spherical air voids, pinholes, and irregularities in semiconducting layers, affect electric field and potential distributions within cable end terminations using COMSOL Multiphysics software. Through detailed simulations, the study identifies significant variations in electric field strength caused by these defects, highlighting critical stress concentration areas. In this study, it assumed that the cable and termination have the same cross-section. By analyzing these simulations, the study provides insights into optimizing cable design and installation practices to enhance the reliability and lifespan of underground power transmission systems. This study introduces a novel approach by combining advanced COMSOL Multiphysics simulations with a detailed analysis of defect impacts on electric field distributions, offering new insights into stress concentrations and degradation at cable terminations. Simulation outcomes reveal significant variations in electric field strengths due to air voids and pinholes in cables and terminations: for 2 mm voids, up to 2.45×106 V mm−1 near the conductor and 56.5 V mm−1 at termination. These findings enhance the understanding of XLPE-insulated cable behavior under electromagnetic stress, providing a basis for mitigating failures and improving overall system performance.

Synergistic effects of kinetics and lyophilicity stimulated by Mg2+/Li+ co-insertion in Bi2-xSbxS3 toward reversible hybrid batteries

Co-intercalation type hybrid magnesium-lithium-ion batteries (MLIBs) have received widespread attention in recent years for higher electrolyte utilization and conspicuous insertion kinetics. However, the co-intercalation strategy is rarely explored in replaceable anode host structures. We propose a cation exchange strategy to optimize metal sulfide, endowing MLIBs with high specific capacity, prominent cycle stability and rate performance. Kinetics analyses combined with density functional theory (DFT) calculations demonstrate the preferential absorption of Mg2+/Li+ in Bi-Sb sites and fast migration kinetics induced by Mg2+/Li+ co-insertion. COMSOL Multiphysics simulations further prove the prominent lyophilic effect of the bimetallic sulfide in facilitate ion diffusion. In addition, the multi-step reaction mechanisms and structural evolutions are profoundly revealed by a series of ex-situ investigations. Our findings provide inspirations on exploring novel electrode materials with outstanding electrochemical performance toward large-scale energy storage applications.

Label-Free Biosensor Based on Particle Plasmon Resonance Coupled with Diffraction Grating Waveguide.

Particle plasmon resonance (PPR), or localized surface plasmon resonance (LSPR), utilizes intrinsic resonance in metal nanoparticles for sensor fabrication. While diffraction grating waveguides monitor bioaffinity adsorption with out-of-plane illumination, integrating them with PPR for biomolecular detection schemes remains underexplored. This study introduces a label-free biosensing platform integrating PPR with a diffraction grating waveguide. Gold nanoparticles are immobilized on a glass slide in contact with a sample, while a UV-assisted embossed diffraction grating is positioned opposite. The setup utilizes diffraction in reflection to detect changes in the environment's refractive index, indicating biomolecular binding at the gold nanoparticle surface. The positional shift of the diffracted beam, measured with varying refractive indices of sucrose solutions, shows a sensitivity of 0.97 mm/RIU at 8 cm from a position-sensitive detector, highlighting enhanced sensitivity due to PPR-diffraction coupling near the gold nanoparticle surface. Furthermore, the sensor achieved a resolution of 3.1 × 10-4 refractive index unit and a detection limit of 4.4 pM for detection of anti-DNP. The sensitivity of the diffracted spot was confirmed using finite element method (FEM) simulations in COMSOL Multiphysics. This study presents a significant advancement in biosensing technology, offering practical solutions for sensitive, rapid, and label-free biomolecule detection.

Enhanced photothermal conversion properties of graphene aerogel surface and its application in oil spill treatment

As an environmentally friendly material, graphene aerogel has been widely studied. The photothermal conversion performance is an important property of graphene aerogel. Graphene aerogels were prepared by hydrothermal reduction method. The factors affecting its surface photothermal conversion properties were explored and graphene aerogels with ideal photothermal conversion properties were obtained. In addition, COMSOL Multiphysics simulation was carried out to further analyze the intrinsic factors affecting the photothermal properties of the materials. The prepared materials were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectrometry (Raman) to obtain their physicochemical properties. UV–visible-near infrared spectrophotometer and microcomputer-controlled electronic universal testing machine were used to evaluate the light-absorbing capacity and mechanical properties of the materials. The obtained graphene aerogel can be rapidly heated up to higher than 110 °C in 8 s on its surface under simulated sunlight (1000 W·m−2) irradiation. When used for the treatment of oil spill at sea, the prepared graphene aerogel with good photothermal conversion ability can adsorb 105.61 times of its own weight of crude oil and the adsorption rate is as high as 10.56 g·g−1·min−1, which shows a broad application prospect.

Ventilated low-frequency sound absorber based on Helmholtz acoustic metamaterial

In this work, we present a novel Helmholtz acoustic metamaterial (HAM) designed for ventilated low-frequency sound absorption. Based on COMSOL Multiphysics simulation results, a double-layer HAM achieves near-perfect sound absorption at approximately 687 Hz. Transmission loss within the range of 661 to 1074 Hz exceeds 10 dB. Both experimental measurements and theoretical calculations using the transfer matrix method validate the simulation results. A four-layer HAM enables effective broadband sound absorption across the range of 454 to 698 Hz. Consequently, our study presents a potential breakthrough in achieving effective low-frequency sound absorption across a broad spectrum in ventilated environments.

Microelectrode-Based Diffusivity Measurements of Hydrogen in Molten 2LiF-BeF2

Detailed knowledge of the mass transport behavior of hydrogen isotopes in molten 2LiF-BeF2 salt (FLiBe) is essential to the design of new nuclear fusion technologies that make use of this molten salt to breed tritium to fuel the fusion reaction. However, typical studies of hydrogen transport using macroelectrodes are limited to solely measuring the permeability of an analyte—a property defined as the product of concentration squared and diffusivity. This challenge necessitates the development of microelectrodes capable of dynamically measuring diffusion coefficients when concentrations are variable. Unlike macroelectrodes, microelectrodes can measure diffusivity and concentration independently due to a steady-state current proportional to the product of diffusivity and concentration captured in addition to the Cottrellian current response.This steady-state current is established due to a continuously expanding diffusion layer from the electrode that cannot expand indefinitely within finite experimental setups. Therefore, COMSOL Multiphysics simulations mirroring experimental conditions were performed to validate the analytical mass transport model based on the solution of Fick’s Second Law in radial coordinates. These simulations employed a 2D axisymmetric model to examine the conditions under which the infinite bulk solution approximation is valid, confirming that our electrode design would yield true steady-state current responses indicative of radial diffusion.Platinum microelectrodes developed in this study served a dual purpose: they not only addressed previous limitations in high-temperature molten salt experimentation but also enabled dynamic measurements of both the diffusion coefficient and concentration of hydrogen in molten FLiBe introduced by lithium hydride. Square wave voltammetry and chronoamperometry were performed on a three-electrode cell using a platinum working microelectrode, a tungsten counter electrode, and a Ni/Ni2+ thermodynamic reference electrode. The successful measurement of hydrogen diffusivity in these experiments not only offers essential insights into molten FLiBe behavior but also sets the stage for future investigations into the effects of redox conditions, impurities, and equilibration time on tritium within nuclear fusion reactors.

Numerical Analysis of Highly Sensitive D-Shaped PCF SPR Temperature Sensor

This numerical study presents an investigation of an optical fiber D-shaped PCF SPR sensor for temperature sensing, via the finite element method-based COMSOL Multiphysics simulation software. In the proposed PCF configuration, the sensor consists of two different-sized air holes and a gold layer. Between 10°C and 60°C, pure ethanol and an ethanol-chloroform mixture are selected to be used as analytes and their temperature sensitivities are compared. The effect of sensor parameters on sensor sensitivity is studied, and the optimum value is set for each parameter. The maximum sensitivity is calculated as 2008 pm/℃ for the pure ethanol, while it has reached 7750 pm/℃ for the ethanol-chloroform mixture, showing that chloroform improves the performance. The sensor proposed in this study has a higher temperature sensitivity compared to other studies and therefore has significant potential for applications requiring precise measurement

Shape memory behavior of polyethylene-foam-based nanocomposite for sustainable triboelectric nanogenerators

Durable self-powering electronic devices need high-performance triboelectric nanogenerators (TENGs) with shape memory capabilities. A novel porous shape memory polymer nanocomposite that includes polyethylene foam (PEF) with switching molecules and graphitic carbon nitride nanosheets is designed to create a robust, high-performance TENG. This nanocomposite shows outstanding thermal-actuated shape recovery capabilities by heating at 70 °C. Although the TENG initially excels in output performance (1840 V voltage, 79.66 mW.cm‐2 power density), prolonged harsh conditions cause nanocomposite deformation and performance decline. However, heating the nanocomposite to 70 °C fully restores the TENG’s original performance. Besides, the COMSOL Multiphysics simulation of TENG aligns with the experimental results. Furthermore, two TENG application scenarios are demonstrated: self-charging humidity sensing (where TENG’s output performance is humidity-sensitive and decreases as humidity rises) and powering electronic devices (where TENG turns on commercial LEDs, powers a smartwatch, and charges capacitors). Therefore, this TENG may open new possibilities for future self-powered electrical devices and sensors.