Generation Of Electrons Research Articles

Measuring and Indexing the Durability of Electrical and Electronic Equipment

Due to the large and unsustainable use of valuable natural resources and electronic waste generation worldwide, which poses risks to human health and the environment, different organizations have initiated efforts to shift from a linear economy to a circular economy. A crucial aspect of promoting a circular economy is improving product durability, which can reduce resource extraction and waste because products remain in use for a longer period. Methods for measuring and indexing durability should encourage consumers to buy more durable products and incentivize manufacturers to compete in improving durability. This paper reviews past research on measuring product durability. It proposes an overall framework based on the promise of product life as well as its readiness to perform required functions for indexing durability. Finally, it presents an example of durability assessment. The proposed framework enables manufacturers to improve the design and communication of product durability. Furthermore, it supports establishing durability standards by standard development organizations and promotes sustainability through durability initiatives.

The realization of the nanoscale bar-codes based on CdS branched nanostructure

The nanostructures with controllable emission colors have shown great attention for achieving high throughput sensing, anti-counterfeiting, and information security. Here, a branched CdS nanostructure with Sn nanoparticles implanted in the junctions is proposed to construct lateral photonic barcodes in a two dimensional domain. Due to the encapsulated Sn nanoparticles, the plasmon enhanced photoluminescence is practically observed. However, with the generation of the high-energy electrons under illumination of the electron beam, the transfer process occurring between the CdS and Sn nanoparticles, result in cathodoluminescence quenching at the junctions. In addition, both temperature coefficients and Debye temperatures of the CdS branched nanostructures are determined to be 5.56 × 10−4 eV/K and 97 K, respectively, based on the temperature dependent photoluminescence spectrum. Also, the emission intensity of the band edge and the defect related emission can be well tuned by the excitation power. As the laser power increases, the emission color changes from red to the green. Therefore, the coding capacity of the CdS branched barcodes can be well modulated by the temperature and pump laser power. Our studies demonstrate the possibility of using these branched nanostructures in multifunctional optical devices.

Plasmonic hot electron-induced WO3 films for a highly responsive visible photodetector

Visible photodetectors have found significant applications in various fields that require rapid and precise detection of visible light. These fields encompass optical communication, high-speed imaging, LIDAR systems, biomedical imaging, and industrial process monitoring. Semiconductors play a crucial role in photodetection applications by efficiently converting light into electrical signals, offering high sensitivity and rapid response time. Among various semiconductor metal oxides, WO3 is commonly used as a visible photodetector due to its unique properties like high chemical & thermal stability, and it possesses a direct bandgap making it suitable for efficient detection of visible light. Here we report the surface plasmon resonance induced visible light detection using Au NPs on WO3 film. The WO3 film was grown on SiO2 substrate by DC magnetron sputtering while monodispersed (⁓20 nm) Au NPs were chemically synthesised. MSM based Au NPs functionalized WO3 film was tested under 455 nm wavelength with changing optical power and applied bias. The interaction of Au NPs and visible light lead to generation of hot electrons leading to enhancement in the photocurrent. The fabricated device exhibits large bias-dependent responsivity, low NEP, and high EQE of 23.45 A/W, 2.6 × 10−13 WHz−1/2, and 126%, respectively. The study not only provides understanding of plasmon-enhanced visible light detection but also underscores the significance of Au NPs as a powerful tool for enhancing the performance of WO3-based visible photodetectors. The implications of this study extend beyond fundamental research, paving the way for novel applications in the field of optoelectronics appliances.

Parametric instabilities and hot electron generation in the interactions of broadband lasers with inhomogeneous plasmas

The development of parametric instabilities in the interaction of a large-scale inhomogeneous plasma with either a monochromatic or a broadband laser pulse is investigated theoretically and numerically. For a monochromatic laser at an intensity of W cm−2, the development of Stimulated Brillouin Scattering (SBS) in the relatively low density region will obviously dissipate pump laser and hence inhibit the development of Two-Plasmon Decay (TPD) and absolute Stimulated Raman Scattering (SRS) near the quarter-critical density. By using a laser with a moderate fractional bandwidth (∼1.0%) at the same averged intensity, it is found that the laser reflectivity will be greatly reduced since the SBS can be suppressed effectively due to its low linear growth rate. On the contrary, the TPD and absolute SRS are obviously enhanced since the in situ laser intensity near the quarter-critical density becomes stronger in this case. As a result, the hot electron generation due to the TPD and absolute SRS is dramatically enhanced as well. This indicates that the competition between various parametric instabilities in a large-scale inhomogeneous plasma makes it more challenging to simultaneously suppress all kinds of parametric instabilities by using broadband lasers. Particular attention should be paid to the TPD, which not only has a relatively large linear growth rate but also is efficient in generating harmful hot electrons. Increasing the laser bandwidth further, the hot electron generation will be finally reduced as long as the TPD and SRS are also suppressed with a sufficient bandwidth (3%) at the intensity of W cm−2 that may be encountered in some novel ignition schemes such as shock ignition. However, it is worth noting that the laser bandwidth required to mitigate parametric instabilities and hot electron production strongly depends on laser intensity. A moderate laser bandwidth (∼1%) may be sufficient to mitigate both the laser reflectivity and hot electron production for typical ICF target designs operated with laser intensities lower than 1015 W cm−2.

Responses of soil bacterial and fungal denitrification and associated N2O emissions to organochloride pesticide

The extensive application of organochloride pesticides in agriculture has raised concerns about their potential negative impacts on soil microbial denitrification and associated N2O emissions. However, most studies have primarily focused on bacteria, and the contribution of fungi to N2O emissions and their response to organochloride pesticides have often been overlooked. In this study, 15N tracing combined with the respiration inhibition method was applied to examine the impacts of chlorothalonil on both fungal and bacterial denitrification. The results demonstrated that fungal N2O emissions dominated in the absence of chlorothalonil, accounting for 73 % of total N2O emissions. Chlorothalonil inhibited fungal and bacterial denitrification via different mechanisms and altered the main pathways of soil N2O emissions. Amplicon sequencing analyses indicated that chlorothalonil significantly reduced the abundances of N2O-producing fungi owing to its fungicidal effect and fungal N2O emissions significantly dropped. Molecular biological analyses revealed that chlorothalonil induced lower electron generation, transport, and consumption efficiencies, which led to the inhibition of denitrifying enzymes in bacteria. Bacterial N2O emissions dramatically increased and became the dominant source. These findings provide insights into the mechanisms by which N2O emissions from fungal and bacterial denitrification are influenced by chlorothalonil.

Two-Dimensional Van Der Waals Thin Film and Device.

In the rapidly evolving field of thin-film electronics, the emergence of large-area flexible and wearable devices has been a significant milestone. Although organic semiconductor thin films, which can be manufactured through solution processing, have been identified, their utility is often undermined by their poor stability and low carrier mobility under ambient conditions. However, inorganic nanomaterials can be solution-processed and demonstrate outstanding intrinsic properties and structural stability. In particular, a series of two-dimensional (2D) nanosheet/nanoparticle materials have been shown to form stable colloids in their respective solvents. However, the integration of these 2D nanomaterials into continuous large-area thin with precise control of layer thickness and lattice orientation still remains a significant challenge. This review paper undertakes a detailed analysis of van der Waals thin films, derived from 2D materials, in the advancement of thin-film electronics and optoelectronic devices. The superior intrinsic properties and structural stability of inorganic nanomaterials are highlighted, which can be solution-processed and underscor the importance of solution-based processing, establishing it as a cornerstone strategy for scalable electronic and optoelectronic applications. A comprehensive exploration of the challenges and opportunities associated with the utilization of 2D materials for the next generation of thin-film electronics and optoelectronic devices is presented.

Scalable, solution-based dye-sensitized photovoltaic fibers with an electrolytic solid-state ion conductor

We have created a textile with solid-state dye-sensitized photovoltaic fibers (DSPFs) fabricated using a unique combination of inexpensive, commercial-off-the-shelf materials and solution-based processing deposition techniques. DSPFs were made possible by macroscopic support of liquid state components in both the electrolyte and photoanode of the DSPFs. A plastic crystal system of succinonitrile was doped with iodide salts to achieve a solid-state ion-conducting electrolyte. Similarly, utilization of a mesoporous TiO2 photoanode created an adsorptive scaffold for photoactive dyes in a liquid solution. An inexpensive pairing of coated carbon and stainless steel, replacing the traditional and expensive platinum-based counter electrode, was used as a catalytic counter electrode. A solid-state DSPF including both electrodes aligned in comparative orientations provided peak power of up to 0.4 µW/mm with open-circuit voltage (VOC) of 0.7 V. A module of solid-state DSPFs was then incorporated into a simple weave in a mini-loom to demonstrate textile capability. Solid-state DSPFs woven and connected in series in the loom produced peak power of over 50 µW and VOC of 4.5 V. Creation of the flexible DSPFs was achieved through a series of simple and scalable solution-based coating processes, and to the best of our knowledge, has not been previously reported in literature to produce fully encapsulated solid-state dye-sensitized photovoltaic cells with a fiber form factor. Low cost, high throughput processing of this technology can potentially support the manufactural transition for the next generation of commercial energy harvesting wearable electronics.

Photoelectrocatalytic modification of nanofiltration membranes with SrF2/Ti3C2Tx to simultaneously enhance heavy metal ions rejection and permeability

Heavy metal pollution can significantly harm water systems and human health. Combining photoelectrocatalytic (PEC) and nanofiltration (NF) membrane separation technologies can effectively remove heavy metal ions from wastewater. In this study, a water bath method was used to form SrF2/Ti3C2Tx (ST) nanoparticles on the surface of polyvinylidene fluoride (PVDF) membranes and an additional polyamide (PA) functional layer was formed at the interface by crosslinking. ST@PA composite NF membranes (STPP) with good photocatalytic performance were obtained. The separation and catalytic properties of the STPP membranes were controlled by the ST content, which modifies the surface structure and properties of the membranes. The membrane with optimal ST crosslinking exhibited a water contact angle of 50.8°, pure water flux of 24.6 L·m−2·h−1·bar−1, and rejection rates of Mn2+, Ni2+, Cu2+, and Zn2+ of 98.8%, 95.3%, 95.7%, and 97.3%, respectively, under PEC-assisted separation with visible light illumination from a Xe lamp (300 W) and an applied voltage (2 V). The STPP membranes showed improved rejection rates of heavy metal ions under PEC-assisted operation. The mechanism for the improved membrane performance under PEC conditions was preliminarily clarified considering the relationship between the photocatalytic and filtration properties of STPP membranes along with the influence of light irradiation and an external voltage on the heavy metal ions. The generation of electrons, holes, superoxide radicals, and hydroxyl radicals during membrane operation enhances the rejection rates of heavy metal ions. Based on these results, STPP membranes are considered a promising technology for industrial applications in heavy metal removal.

Study on Cs2AgIn(Cl1−xBrx)6 perovskite based on the balance of stability and optical absorption properties

The Cs2AgIn(Cl1−xBrx)6 (x = 0, 1/6, 1/3, 1/2, 2/3, 5/6, 1) lead-free perovskites show great advantages as a stable and non-toxic alternative to lead halide perovskite. In this study, Cs2AgIn(Cl1−xBrx)6 are treated by replacing Cl with Br in a stepwise manner to balance its stability and optical properties. Density functional theory is used to investigate the structural, electronic, and optical properties of Cs2AgIn(Cl1−xBrx)6. The results show that the doping of Br make the average bond length of metal-halides longer, resulting in an increase in volume. The value of the bandgap decreases from 3.168 eV to 2.095 eV. The decomposition energy (−92.3365 to −70.4435 meV/atom) of the material gradually increases, the stability decreases gently (−92.3365 to −90.934 meV/atom, Δ0–1/2 = 0.4675) when the amount of Br doping is less than 1/2, and it decreases significantly (−90.934 to −70.4435 meV/atom, Δ1/2–1 = 6.83) when it exceeds 1/2. The partial density of states reveal that the electronic contribution is mainly related to the [AgX6]5- (X = Cl, Br) octahedral. The analysis of charge density indicates that partially or completely replacing Cl with Br is beneficial for the generation of free electrons, which may improve its photoelectric performance. The analysis of the complex dielectric function and the optical absorption coefficient shows a more significant increase in the absorption coefficient when half of the Br is incorporated compared to full substitution. According to our results, adjusting x in Cs2AgIn(Cl1−xBrx)6 can expand the material's range of spectroscopic applications. Based on the trade-off between stability and light absorbance, Cs2AgInCl3Br3 exhibits the best overall performance.

Well-designed α-Fe2O3/ZnFe2O4 heterojunction for photocatalytic CO2 reduction to fuels

Spinel ZnFe2O4 photocatalyst has been widely applied in CO2 reduction due to its negative enough conduction band edge and relatively narrow band gap, which enable the generation of strong reduction electrons in the presence of light irradiation. Unfortunately, the catalytic performance of pure ZnFe2O4 was seriously hindered because of inefficient charge transfer. Here, Z-scheme α-Fe2O3/ZnFe2O4 heterojunctions were synthesized by coupling α-Fe2O3 nanosheets with spinel ZnFe2O4 nanoparticles and applied to the photoreduction of CO2. The α-Fe2O3/ZnFe2O4 heterojunctions realized high charge separation efficiency and strong redox ability. As a result, the CH4 generation rate of α-Fe2O3/ZnFe2O4 heterojunctions was 2.6 times higher than that of ZnFe2O4. This work exhibits a new strategy to design ZnFe2O4-based Z-scheme heterojunction for converting CO2 to hydrocarbon fuels.

New electronic implementation of the timestamps method intended for high resolution comparison of laser wavelengths.

This article describes a new measurement system for the comparison of two electronic signals of different frequencies with application to high resolution comparison of laser wavelengths using a Michelson interferometer. It was built within the framework of research projects made by the University of Vigo and the Laboratorio Oficial de Metroloxía de Galicia (LOMG) in cooperation with Escolas Proval High School. The new hardware is based on a cheap high-speed module for the acquisition of data and a microcontroller module for processing, which can also be used for practical lessons in vocational training. The system has been tested with electronic signal generators. The novel measurement method reduces the uncertainty using multiple consecutive measurements and the fractional part of the fringes and could achieve precisions in the range 10-12 of the wavelength ratios.

Evolution and hot electron generation of laser–plasma instabilities in direct-drive inertial confinement fusion

A series of 2D in-plane plane wave particle-in-cell simulations find distinctive paths of laser-plasma instability evolution in OMEGA-scale implosions, depending on the initial electron temperature. At low temperatures, two-plasmon decay (TPD) dominates in both initial growth and the steady state. At high temperatures, the initial dominant modes switch to stimulated Raman scattering, but TPD still dominates a steady state characterized by cavitation and Langmuir turbulence. A hot electron scaling is also obtained from the simulations that, when combined with laser/plasma conditions from hydro simulations, can predict hot electron generation in implosions that do not employ smoothing-by-spectral-dispersion (SSD). It also shows that under the same laser/plasma conditions, SSD can reduce hot electron generation.

A swarm of helical photocatalysts with controlled catalytic inhibition and acceleration by magneto-optical stimuli

Highly persistent and toxic organic pollutants increasingly accumulate in freshwater resources, exacerbating the human water scarcity crisis. Developing novel microrobots with high catalytic performance, high mobility, and recycling capability integrated to harness energy from the surrounding environment to degrade pollutants effectively remains a challenge. Here, we report a kind of Spirulina (SP)-based magnetic photocatalytic microrobots with a substantially decreased band gap than that of pure photocatalysts, facilitating the generation of stable holes and electrons. Under sunlight irradiation, the degradation rate of rhodamine B (RhB) by the microrobots could be increased by 7.85 times compared with that of pure BiOCl, indicating its excellent photocatalytic performance. In addition, the microrobots can swarm in a highly controllable manner to the targeted regions and perform selective catalytic degradation of organic pollutants in specific areas by coupling effect of light and magnetic field. Importantly, the catalytic capability of the swarming microrobots can be activated by light stimulus whereas inhibited by magneto-optical stimuli, with a rate constant 2.15 times lower than that of pure light stimulation. The biohybrid and magneto-optical responsive microrobots offer a potential platform for selective pollutants catalysis at assigned regions in wastewater treatment plants.

Polymer Electrolytes for Printed 2-D Microcapacitors with Silver Electrodes

The next generations of wearable electronics require high-performance, low-cost, thin, and flexible 2-D electronic components, e.g. capacitors and transistors. The commercial feasibility of these technologies relies on printable, high throughput, highly electronically-conductive, and inexpensive silver electrodes/current collectors to replace gold counterparts. However, silver-based devices are prone to failure due to corrosion forming resistive oxides or dendrites in aqueous environments (as shown in Figure 1a). Polymer electrolytes, possessing high ionic conductivity and enabled double layer capacitance at electrode interface, are highly tunable to minimize the dendritic growth and can be a promising technology for these 2-D devices.In this study, some high-performance aqueous polymer electrolytes that have previously been demonstrated for supercapacitors were compared and modified for better integration into printed interdigitated devices with silver electrodes. The polymer electrolytes were evaluated for their apparent ionic conductivities, capacitance, and corrosion properties using cyclic voltammetry and electrochemical impedance spectroscopy. Polymer electrolytes can effectively inhibit dendritic formation as shown via optical microscope in Fig. 1b. The optimized electrolytes possessed (i) high ionic conductivity (>1 mS cm-1) at ambient, (ii) good ability to maintain well-dissociated ions enabling double layer capacitance formation (Fig. 1c), with capacitance >100 μF cm-2 and (iii) good compatibility with silver electrodes. Overall, the optimized polymer electrolytes can be a low-cost, viable alternative in printed electronics requiring high dielectric materials, such as microcapacitors and low-powered field-effect transistors. Figure 1

Techno-Economic Analysis of Reversible and Paired Solid Oxide Cell Systems for Hydrogen Production

The United States (U.S.) Department of Energy (DOE) National Energy Technology Laboratory (NETL) has been pursuing the development of solid oxide cell (SOC) technology to enable future power generation systems with high efficiencies and low emissions. Government and industry net-zero goals are driving interest in approaches to decarbonize challenging sectors of the economy, such as industrial applications. Hydrogen (H2) – including that produced by SOC technology-based high-temperature electrolysis – is one promising route. At present, low prices for low-greenhouse gas intensity electrical power (i.e., renewable sources such as wind and solar) are available intermittently (at low-capacity factors), complicating the economics of clean hydrogen produced by electrolysis. Reversible solid-oxide cell (r-SOC) based power to gas systems have the potential to address this challenge by producing power when electricity prices are high and hydrogen when they are low. Plants with the ability to co-generate power from solid oxide fuel cells (SOFC) and hydrogen from solid oxide electrolysis cells (SOEC) are of particular interest for their dual revenue streams and the flexibility they can provide to the grid.This study investigates the cost and performance of two configurations of co-generating SOC plants. The first includes an r-SOC stack that alternates between power and hydrogen production. The second plant contains paired SOFC and SOEC stacks that are each dedicated to generating a single product when operated. For the purposes of this study, the plants are primarily intended to generate hydrogen, only switching to power production mode when market conditions are favorable. The study aims to elucidate expected tradeoffs between the higher capital cost of the paired SOFC/SOEC plant and the higher degradation rate of the r-SOC.The anticipated tradeoff of a reversible system is an increased degradation rate for lower capital costs. This is due to the paired systems being optimized for either fuel cell or electrolysis operation while the reversible system is not optimized for either. To quantify the impact of this, a base case where the SOFC, SOEC, and r-SOC all degrade performance-wise at the same rate (0.2% per 1000 h). The degradation rate of the r-SOC is then allowed to float to where the levelized cost of hydrogen (LCOH) of the two systems is at parity, which does not occur at the base case assumptions. Additional sensitivity analyses are performed on natural gas price and cost of imported power to determine which system is more favorable under different assumptions.In summary, the results show that the total plant cost of the paired SOFC/SOEC system is about 5% higher than the reversible system. The additional cost of having two separate SOC modules is largely diluted by the balance of plant costs. The LCOH of the r-SOC and paired SOFC/SOEC are ≈$3.60/kg and ≈$3.30/kg H2, respectively as shown in Figure 1. Despite the higher capital cost, the paired SOFC/SOEC has a more favorable LCOH. This is due to the SOFC’s ability to generate electricity cheaper than the assumed $60/MWh grid purchase price. Sensitivity analyses show how the assumed cost of grid power and natural gas price affects the disposition of hydrogen versus electron generation. As an example, the LCOH of the r-SOC becomes more favorable than the paired SOFC/SOEC at natural gas prices above $12/MMBtu and at electricity purchase prices below $27/MWh.In conclusion, this investigation shows that depending on the market situation and final application, reversible SOC units warrant consideration for inclusion in advanced integrated energy systems as grid electricity prices continue to decrease over time.For the purposes of this study, natural gas is used as the fuel for power generation operation, and the systems are equipped with high rate (≈98%) carbon capture. In future work, stored hydrogen may be examined as the fuel for power generation. Future analyses may also examine the use of industrial or other waste heat sources, as well as perform life cycle analyses for the cradle-to-gate greenhouse gas intensity for select system configurations and applications. Figure 1

(Invited) Probing and Utilizing Hot Carriers for Plasmonic Photoelectrochemical Processes

The detection of hot electrons and understanding the correlation between hot electron generation and surface phenomena are challenging questions in the surface science and catalysis community. Hot electron flow generated on a gold thin film by photon absorption (or internal photoemission) appears to be correlated with localized surface plasmon resonance. It has been found that the hot electron flux generated under photon absorption and exothermic chemical reaction is the major mediator of energy conversion process [1-3]. In this talk, I introduce the research direction to attempt to detect the surface plasmon driven hot carrier at the nanometer scale by using scanning probe microscopy. To detect and utilize the hot electron flows at the macroscale level, the metal-semiconductor nanodiodes were constructed. At the nanometer scale, we utilized photoconductive atomic force microscopy to observe photoinduced hot electrons on a triangular Au nanoprism on n-type TiO2 under incident light. This is the direct proof of the intrinsic relation between hot electrons and localized surface plasmon resonance. We observed surface plasmon induced hot hole by using the system of Au nanoprism on p-type GaN [4]. I will discuss the impact of hot carriers in the photocatalytic activity under photoelectrochemical water splitting by using Au-based plasmonic nanostructures [5].

Biomass and domestic waste: a potential resource combination for bioenergy generation and water treatment via benthic microbial fuel cell.

The benthic microbial fuel cell (BMFC) is one of the most efficient types of bioelectrochemical fuel cell systems. Modern bioelectrochemical fuel cells have several drawbacks, including an unstable organic substrate and a microorganism-unfriendly atmosphere. The recent literature to encounter such issues is one of the emerging talks. Researchers are focusing on the utilization of biomass and waste to encounter such challenges and make the technique more feasible at the pilot scale. This study investigated the combination of local bakery waste as an organic substrate with lignocellulosic biomass material. The whole experiment was conducted for 45days. At an external resistance of 1000 ῼ and an internal resistance of 677 ῼ, the power density was found to be 3.51 mW/m2. Similarly, for Pb2+, Cd2+, Cr3+, Ni2+, and Co2+, the degradation efficiency was 84.40%, 81.21%, 80%, 89.50%, and 86.0%, respectively. The bacterial identification results showed that Liquorilactobacillus nagelii, Proteus mirabilis, Pectobacterium punjabense, and Xenorhabdus thuongxuanensis are the most prominent species found on anode biofilm. The method of electron generation in this study, which includes the degradation of metal ions, is also well described. Lastly, optimising the parameters showed that pH 7 provides a feasible environment for operation. A few future suggestions for practical steps are enclosed for the research community.

From “100%” Utilization of MAX/MXene to Direct Engineering of Wearable, Multifunctional E‐Textiles in Extreme Environments

AbstractTransition metal carbides/nitrides (MXenes) show great potential for preparing wearable, flexible multifunctional e‐textiles due to the exceptional electrical and mechanical properties and easy processing in aqueous medium. At present, MXene‐based e‐textiles face challenges including high production costs, low utilization of precursor titanium aluminum carbide (MAX), poor durability in extreme environments, and the inability to achieve a balance between large‐scale fabrication and high performance. Here, this work proposes a “100%” utilization of MAX/MXene strategy to produce additive‐free conductive inks with controllable viscosity, subsequently enabling an accessible, scalable direct‐blade‐coating followed by chemical cross‐linking approach for creating wearable, high‐performance, multifunctional MXene‐based e‐textiles that perform in extreme conditions. The structural design provides integrated multifunctionality involving controllable and exceptional electromagnetic interference (EMI) shielding within an ultrabroadband frequency range, visual electrothermal conversion, electrothermal deicing, remarkable visual photothermal, and antibacterial performance. This work employs a fabrication process that is simple, cost‐effective, and scalable, presenting a novel “100% efficiency” and “waste‐to‐wealth” strategy to manufacture robust, durable, multifunctional e‐textiles. This approach provides exciting potential for the next generation of wearable electronics, EMI compatibility, visual heating, thermotherapy, antibacterial treatments, deicing, defense, and aerospace applications.

In-situ twisted spiral fiber with tree-ring like structure for joule heating, photothermal and humidity sensing

Smart fibers are increasingly becoming an optimal material for producing the next generation of flexible wearable electronics. However, balancing practical functionality and comfort remains a major challenge at this stage. Herein, we have prepared a bacterial cellulose (BC)/MXene-30% composite fiber using an in-situ twisting method, as this fiber possessed excellent conductivity (4050 S/m) and mechanical strength (108 Mpa). In addition, this BC/MXene spiral fiber has excellent joule heating and photothermal performance, which can be rapidly heated up to 70 °C within 25 s under a low voltage of only 9 V. They also have a stable and repeatable light-induced heating capability under 250 W infrared light. This new fiber material has a simple preparation process and versatile functional characteristics, which broadens its application in the fields of intelligent hyperthermia, respiratory monitoring, water level warnings and so on. The BC/MXene spiral fiber exhibited in this work is expected to provide a powerful database and theoretical reference for the next generation of flexible wearable electronic products.

3D Nanocomposite Thin Film Cathodes for Micro‐Batteries with Enhanced High‐Rate Electrochemical Performance over Planar Films

AbstractHigh energy and high power density rechargeable micro‐batteries are a necessity for powering the next generation of flexible electronics, internet of things, and medical technology devices. In theory, significant improvements in the capacity, current and power densities of micro‐batteries would result if 3D architectures with enhanced interdigitated component interface areas and shortened ion diffusion path‐lengths were used. Further gains are achievable if the materials utilized have high crystalline quality and are preferentially oriented for fast lithium intercalation. In this work, this is achieved by creating epitaxial thin film cathodes comprised of nanopillars of LiMn2O4 (LMO) embedded in a supporting matrix of electronically conducting SrRuO3 (SRO). The first electrochemical study of such a 3D vertically aligned nanocomposite (VAN) that displays clear cathode redox signatures is provided, and demonstrates remarkable capacity retention under high‐rate regimes. The electrochemical performance is shown to be dependent on the nanopillar topography, namely the crystallographic orientation, nanopillar dimensions, and electrode/electrolyte interfacial surface area. This work offers a pathway to realizing 3D architectured micro‐batteries with high‐capacity retention under high‐rate conditions enabling fast charge capabilities.