Electron Field Research Articles

Strong, tough and environment-tolerant organohydrogels for flaw-insensitive strain sensing.

Conductive organohydrogels are promising for strain sensing, while their weak mechanical properties, poor crack propagation resistance and unstable sensing signals during long-term use have seriously limited their applications as high-performance strain sensors. Here, we propose a facile method, i.e., solvent exchange assisted hot-pressing, to prepare strong yet tough, transparent and anti-fatigue ionically conductive organohydrogels (ICOHs). The densified polymeric network and improved crystallinity endow ICOHs with excellent mechanical properties. The tensile strength, toughness, fracture energy and fatigue threshold of ICOHs can reach 36.12 ± 4.15 MPa, 54.57 ± 2.89 MJ m-3, 43.44 ± 8.54 kJ m-2 and 1212.86 ± 57.20 J m-2, respectively, with a satisfactory fracture strain of 266 ± 33%. In addition, ICOH strain sensors with freezing and drying resistance exhibit excellent cycling stability (10 000 cycles). More importantly, the fatigue resistance allows the notched strain sensor to work normally with no crack propagation and output stable and reliable sensing signals. Overall, the unique flaw-insensitive strain sensing makes ICOHs promising in the field of wearable and durable electronics.

Insight into the Impact of Electron Drift Trajectory on Charge Collection in Silicon Drift Detector

The internal electric field distribution is one key design consideration, which affects the charge collection efficiency in silicon drift detectors (SDDs). The internal electrostatic potential distributions along SDD front and back surfaces, which are determined by the applied voltages at cathode electrodes, define the final internal field distribution. Front-back bias coupling leads to the complexity of electrode structure design and voltage tuning. Device simulation is performed to investigate the performance of SDDs with varied bias voltages. When the cathode bias is −40 V with the first ring bias of −15 V and the outermost ring bias of −80 V, the detector is biased with a uniform electric field distribution, favorable electron drift trajectories. The simulation results provide new insight into the influence of internal electric field and electron drift trajectories on the charge collection efficiency. According to the analysis of simulation results, a 2000 × 2000 μm area concentric silicon drift detector was designed and fabricated. The electrical characteristics of the designed detectors were studied to show the validity of the proposed device design methodology. The internal electric field distribution and electron drift trajectories can be tuned to improve the charge collection efficiency.

The adsorption of amantadine antiparkinsonian drug on the B24N24 and Al24N24 nanoclusters: An investigation using the density functional theory

By employing the density functional theory (DFT), the present investigation studied the adsorption of an anti-Parkinson drug called Amantadine (AM) onto the nanoclusters of B24N24 and Al24N24. Through their –NH2 group, the molecules of Amantadine interacted with the B or Al head of the AlN(BN) nanoclusters, and it was found that the change in the free Gibbs energy was –32.3 (−27.2) kcal/mol. The increased dosage of Amantadine led to weaker AM/cluster interactions, which is attributable to the steric effect. The molecule of Amantadine was subjected to electrostatic adsorption onto the nanoclusters of AlN and charge transfer adsorption onto the nanoclusters of BN. The Amantadine adsorption led to a dramatic decrease from 4.47 eV to 3.63 eV in the work function of the AlN nanoclusters. As a result, the electron field emission improved. Thus, one may use AlN nanoclusters as an Φ-type chemical sensor for the detection of Amantadine molecules. The AM adsorption onto the BN nanoclusters resulted in noticeable HOMO destabilization and decreased HOMO-LUMO energy gap from 6.84 eV to 5.67 eV. Consequently, a great increase was observed in the electrical conductivity of the BN nanoclusters. As a result, one may use BN nanoclusters as a suitable candidate for manufacturing electronic sensors with the capability of detecting Amantadine.

Study of dot size effect on electron emission from Si-QDs multiple-stacked structures

We have fabricated diodes with different sized Si quantum dots (QDs) by precisely controlled low-pressure chemical vapor deposition using a pure SiH4 gas and studied the effect of dot size on field electron emission properties of their multiple‒stacked structures. At an applied bias of ∼9 V, the emission current of ∼4.0 nm height dot‒stacks is two orders of magnitude higher than that of ∼5.9 nm height dot‒stacks. These results can be interpreted in terms of an increase in the number of electrons with higher kinetic energy due to the increase in discrete energy levels associated with the reduction in the dot size, which suppresses electron scattering within the dot, and the electric field concentration resulting from the decrease in the curvature of the dot.

Sandwich-Structured Carbon Nanotube Composite Films for Multifunctional Sensing and Electrothermal Application.

Electro-conductive films with excellent flexibility and thermal behavior have great potential in the fields of wearable electronics, artificial muscle, and soft robotics. Herein, we report a super-elastic and electro-conductive composite film with a sandwich structure. The composite film was constructed by spraying Polyvinyl alcohol (PVA) polymers onto a buckled conductive carbon nanotube-polydimethylsiloxane (CNTs-PDMS) composite film. In this system, the PVA and PDMS provide water sensing and stretchability, while the coiled CNT film offers sufficient conductivity. Notably, the composite film possesses high stretchability (205%), exceptional compression sensing ability, humility sensing ability, and remarkable electrical stability under various deformations. The produced CNT composite film exhibited deformation (bending/twisting) and high electro-heating performance (108 °C) at a low driving voltage of 2 V. The developed CNT composite film, together with its exceptional sensing and electrothermal performance, provides the material with promising prospects for practical applications in wearable electronics.

Stimulus-dependent spiking and bursting behavior in memsensor circuits: experiment and wave digital modeling

Biological information processing pathways in neuron assemblies rely on spike activity, encoding information in the time domain, and operating the highly parallel network at an outstanding robustness and efficiency. One particularly important aspect is the distributed, local pre-processing effectively converting stimulus-induced signals to action potentials, temporally encoding analog information. The field of brain-inspired electronics strives to adapt concepts of information processing in neural networks, e.g., stimulus detection and processing being intertwined. As such, stimulus-modulated resistive switching in memristive devices attracts an increasing attention. This work reports on a three-component memsensor circuit, featuring a UV-sensor, a memristive device with diffusive switching characteristics and a capacitor. Upon application of a DC bias, complex, stimulus-dependent spiking and brain-inspired bursting can be observed, as experimentally showcased using combination of a microstructured, tetrapodal ZnO sensor and a Au/SiOxNy/Ag cross-point memristive device. The experimental findings are corroborated by a wave digital model, which successfully replicates both types of behavior and outlines the relation of temporal variation of switching thresholds to the occurrence of bursting activity.Graphical abstract

Stretchable Ag2Se Thermoelectric Fabric with Simple and Nonthermal Fabrication for Wearable Electronics

As the field of wearable electronics continues to expand, the integration of inorganic thermoelectric (TE) materials into fabrics has emerged as a promising development due to their excellent TE properties. However, conventional thermal methods for fabricating TE fabrics are unsuitable for wearable applications because of their high temperatures, resulting in rigid TE materials. Herein, a nonthermally fabricated silver selenide (Ag2Se) TE fabric is developed that can be effectively integrated into wearable applications. Ag2Se nanoparticles are densely formed within the fabric through a simple in situ chemical reduction process, resulting in remarkable electrical stability even after 10 000 cycles of mechanical deformation, such as stretching and compression. Notably, the fabricated Ag2Se TE fabric exhibits superior stretchability, stretching ≈1.36 times more than the thermally treated Ag2Se TE fabrics, while retaining its excellent electrical conductivity. Moreover, the TE unit exhibits 9.80 μW m−1 K−2 power factor, 134.45 S cm−1 electrical conductivity, and −26.98 μV K−1 Seebeck coefficient at 370 K. A haptic sensing glove based on the Ag2Se TE fabric as a sensor for detecting potential hazards is demonstrated. The glove effectively distinguishes between simple touch, physical pain, and high‐temperature hazards, ensuring user safety and prompt response.

Proportional scintillation in liquid xenon: demonstration in a single-phase liquid-only time projection chamber

The largest direct dark matter search experiments to date employ dual-phase time projection chambers (TPCs) with liquid noble gas targets. These detect both the primary photons generated by particle interactions in the liquid target, as well as proportional secondary scintillation light created by the ionization electrons in a strong electric field in the gas phase between the liquid-gas interface and the anode. In this work, we describe the detection of charge signals in a small-scale single-phase liquid-xenon-only TPC, that features the well-established TPC geometry with light readout above and below a cylindrical target. In the single-phase TPC, the proportional scintillation light (S2) is generated in liquid xenon in close proximity to 10 μm diameter anode wires. The detector was characterized and the proportional scintillation process was studied using the 32.1 keV and 9.4 keV signals from 83mKr decays. A charge gain factor g 2 of up to (1.9 ± 0.3) PE/electron was reached at an anode voltage 4.4 kV higher than the gate electrode 5 mm below it, corresponding to (29 ± 6) photons emitted per ionization electron. The duration of S2 signals is dominated by electron diffusion and approaches the xenon de-excitation timescale for very short electron drift times. The electron drift velocity and the longitudinal diffusion constant were measured at a drift field of 470 V/cm. The results agree with the literature and demonstrate that a single-phase TPC can be operated successfully.

The impact of LSM pretreatment on the growth behavior, electrical insulation and corrosion resistance properties of PEO coating on 6061 aluminum alloy

This work reported the influence of laser surface melting (LSM) pretreatment on the growth behavior, electrical insulation and corrosion resistance of plasma electrolytic oxidation (PEO) film on 6061 aluminum alloy. It is found that the LSM pretreatment refines the surface structure of original Al metal, generating defects that store excessive energy, thereby enhancing reaction kinetics and phase transition during the PEO process. By LSM pretreatment, uniform electrical discharge and film growth can be obtained, resulting in fewer defects and lower porosity in PEO layers. Additionally, a large amount of columnar crystals comprising of SiO2 phase are observed, which transformed from the SiO32− deposited on the surface, and the LSM pretreatment significantly improves the electrical insulation, corrosion resistance, and substrate adhesion of following PEO layer. Under the same PEO treatment duration, the breakdown voltage of coating increased by 100 V, and icorr decreased from 3.26 × 10−4 to 9.13 × 10−6 A cm−2. It is expected that the combination of LSM and PEO processes can not only enhance the surface properties of Al metal, but also expand the practical application of aluminum alloy in high-power electronic devices and related fields.

A versatile ionic liquid enables epoxy resin with excellent fire safety and mechanical properties but ultra-low loading

The emergence of ionic liquids provides an effective way to construct new advanced multifunctional epoxy resin (EP) composites with excellent fire retardancy and mechanical properties. In this study, 1-butyl-3-methylimidazolium dibutyl phosphate (BDBP) was synthesized via a facile strategy and then incorporated into the EP matrix. The results showed that ultra-low loading of BDBP (1 wt%) enabled EP composite to achieve a V-0 rating (3.2 mm) in the UL-94 test. When increasing the loading to 4 wt%, the limiting oxygen index (LOI) of EP/BDBP4 composites was improved to 31.9 %. Meanwhile, the peak heat release rate (PHRR), total heat release (THR), and total smoke production (TSP) significantly decreased by 48.1 %, 21.9 %, and 13.5 %, respectively, compared to neat EP. Moreover, the presence of BDBP increased the tensile strength of EP/BDBP2 by more than 7 %, while all EP/BDBP composites maintained high transparency. In summary, this work provides a feasible and low-cost idea for constructing multifunctional EP composites, paving the way for their applications in aerospace, wind turbines, and electronic and electrical fields.

FeSiBCCr bulk metallic glasses with excellent soft magnetic properties prepared using spark plasma sintering technology

Fe-based amorphous alloys have received much attention in the fields of electronics and electrical due to their excellent soft magnetic properties at high frequency. However, the controllable preparation of large-sized Fe-based bulk metallic glasses (BMGs) still faces numerous challenges. In this study, FeSiBCCr amorphous powders prepared by gas-water combined atomization were used as raw materials, and FeSiBCCr BMGs were prepared through spark plasma sintering (SPS) at different pressures. The microstructure, phase and magnetic properties of the compacts were systematically characterized using SEM, XRD, TEM, DSC, and VSM. The results showed that when the sintering pressure was 50 MPa, the slow densification process dominated by particle rearrangement at the initial densification process made the internal contact resistance of the compacts larger. This led to macroscopic inhomogeneous physical fields and severe local overheating during the later stages of sintering, causing the precipitation of α-(Fe, Si) and Fe3B phases. Although the material exhibited a relatively high saturation magnetization (Bs) of 1.08 ± 0.01 T, the low density and amorphous fraction resulted in a high coercivity (Hc) of 1060.8 ± 37.8 A·m-1. When the sintering pressure was increased to 250 MPa, the degree of particle densification significantly improved, and the temperature inhomogeneity was markedly suppressed due to reduced internal resistance. Thus, the prepared FeSiBCCr BMGs exhibited an extremely high density of 6.66 ± 0.06 g·cm-3 and excellent soft magnetic properties with Bs of 1.23 ± 0.01 T and Hc of 18.8 ± 1.8 A·m-1. This indicated that the FeSiBCCr BMGs prepared in this study exhibited broad application prospects in efficient electromagnetic conversion and advanced electronic devices.

Efficient broadband near-infrared emission based on copper-alloyed metal halides

Recently, metal halides have shown broad application prospects due to excellent electronic and optical properties. Although significant developments have been realized, the spectra range of their photoluminescence (PL) emission is mainly limited to the visible region. Near-infrared (NIR) emitting materials are widely used in the fields of night vision, biomedical imaging, non-destructive food inspection, etc. On this occasion, extending the luminescence scope of metal halides to NIR region is of great significance. Generally, NIR-emitted metal halides are realized through rare earth (RE) ions doping. However, RE luminescence usually have narrow-band characteristics, which makes it difficult to realize broadband NIR emission. In this study, we present an efficient broadband NIR-emitted metal halide CsAgBr2 through copper ions alloying, its emission locates at 830 nm with a large FWHM (full width at half maximum) of 332 nm. Theoretical calculations suggest that the incorporation of Cu+ could effectively modulate the density of states and enhance the localized characterization, which is beneficial to boost the PL efficiency. Furthermore, this material displays favorable structure stability under ambient conditions. This study demonstrates the great application potential of Cu+-alloyed CsAgBr2 in the field of NIR optical electronics.

Tuning (Photo)Electronic Properties of an Electron Deficient Porous Polymer via n-Doping with Tetrathiafulvalene.

Charge-transfer complex formation within the pores of porous polymers is an efficient way to tune their electronical properties. Introduction of electron accepting guests to the electron donating hosts to conduct their p-doping is intensively studied in this context. However, the vice versa scenario, n-doping by treating the electron deficient (i.e., n-type) porous polymers with electron donating dopants, is rare. In this work, synthesis of an n-type phenazine based conjugated microporous polymer and its exposure to strong electron donating tetrathiafulvalene (TTF) dopants are presented. The fundamental physical characterizations (e.g., elemental analysis, gas sorption) showed that the vacuum impregnation technique is a good approach to load the guest molecules inside the pores. Moreover, the formation of charge-transfer complexes between the phenazine building blocks of the polymeric network and TTF dopants are confirmed via spectral techniques such Fourier transform infra-red, UV-vis, steady-state/time-resolved photoluminescence, and transient absorbance spectroscopies. Effect of the doping to the electronical properties is monitored by employing photoelectrochemical measurements, which showed lower charge-transfer resistivity and nearly doubled photocurrents after the doping. The study is, therefore, an important advancement for the applicability of (n-type) porous polymeric materials in the field of photo(electro)catalysis and organic electronics.

Theoretical Investigation on the Initial Reaction Mechanism of Hexaethynylbenzene on Au(111) Surface.

Graphyne has attracted considerable interest and attention since its successful synthesis, due to its enormous potential for applications in the fields of electronics, energy, catalysis, information technology, etc. Although various methods for synthesizing graphyne have been explored, single-layer graphynes have not been successfully developed. Hexaethynylbenzene (HEB) is considered an ideal precursor molecule because it can undergo Glaser coupling reactions between molecules to synthesize single layer graphdiyne on single crystal metal surfaces via on-surface reactions. Unfortunately, this method fails to achieve the expected results, and the underlying mechanism is not clear. In this work, we employed a combination of ab initio molecular dynamics (AIMD) and quantum mechanics (QM) methods to investigate the initial reaction mechanism of HEB molecules on a Au(111) surface. We revealed that HEB molecules undergo both intermolecular coupling and intramolecular cyclization on the Au(111) surface. The favorable pathways of these two types of reactions were then distinguished, confirming that the distance between the terminal carbon atoms of the ethynyl groups plays an important role in C-C coupling. The insights revealed from this work could facilitate the rational design of precursor molecules and deepen the understanding of the reaction processes.

Effect of temperature and relative humidity on the moisture recovery and specific resistance of yak hair fiber

This study measured the moisture regain and specific resistance values of yak hair fiber in a humidified environment to provide a theoretical basis for the development and utilization of yak hair fiber in the fields of textile, electronics and manufacturing. The effects of temperature and relative humidity on moisture absorption and electrical resistance of yak hair fiber were measured, and the effects of ambient temperature and humidity on the moisture regain and specific resistance of yak hair fiber were evaluated when using a new type of water-cooled textile air conditioner as a humidifying device, and the amino acid structure and crystallinity were compared between yak hair fiber and wool fiber. The experimental results show that temperature and relative humidity have a greater effect on the moisture regain rate and specific resistance value of the fiber, and the higher the temperature and relative humidity, the higher the moisture regain rate of yak hair fiber and the lower the specific resistance. When the temperature was 30 °C and the relative humidity was 85%, the fiber had the lowest specific resistance value and the highest moisture return rate. In terms of amino acid species, there is not much difference in chemical structure between yak hair fiber and wool fiber. The crystallinity of yak hair fiber is lower than that of wool fiber.

Electronic Force Density Fields: Insights into Partial Bonds, Transition States, and Chemical Structure Evolution.

This paper presents the quantum-topological binding approach, in which the electrostatic and total static force density fields, Fes(r) and , together with the electron density gradient field ∇ρ(r), are simultaneously analyzed to elucidate the chemical structure of transition states and the nature of interatomic interactions for semibroken semiformed partial chemical bonds. The approach attributes the discrepancies between the force fields and Fes(r) to the nonclassical electron-electron interaction effects. The internuclear gap between the zero-flux boundaries of Fes(r) and ∇ρ(r) indicates the interatomic charge transfer phenomenon (ICT) that occurs upon the formation of a system from free atoms. Concomitantly, the mismatch of the zero-flux surfaces defined in and ∇ρ(r) can be interpreted as a phenomenon of the electron-transfer-induced quantum chemical response (QCR), which originates from the electron exchange correlation. Our study permits the assertion of parallels between partial bonds and noncovalent interactions, as both typically exhibit incomplete QCRs, indicating the partial electron sharing of the transferred density. The changes in atomic and pseudoatomic charges are employed to describe the evolution of the chemical structure upon the substitution reaction. It is observed that the acquired difference in the actual atomic electronegativity causes polarization upon the heterolytic breaking of virtually nonpolar bonds. It is further proposed that the proximity of closely related stationary states along the reaction path on a potential energy hypersurface implies their similarity in the manifestation of the ICT and sympathetic QCR. Furthermore, the involvement of an electron pair in a partial bond facilitates its delocalization through the attraction by the static forces and Fes(r) to a neighboring nucleus and through the smearing by the Pauli kinetic force FP(r).

A one-step fabrication method of flexible magnetostrictive fiber ribbon based on Fe50Co50 alloy and its characteristics study

Magnetostrictive materials are widely used in sensors, actuators and micro-nano electronics because of their excellent performance. However, traditional rigid magnetostrictive materials are difficult to adapt to the flexible and deformable structure of flexible electronic devices. In order to solve the deformation, sensing and control problems in the field of flexible electronics, a one-step new method of is proposed to deposit Fe50Co50 fiber ribbons with reciprocated and loop structures on flexible substrate. Helmholtz coil is designed to test the magnetostrictive positive effect ability of Fe50Co50 ribbon, and its magnetostrictive strain curve is analyzed. Furthermore, frequency domain characteristics of Fe50Co50 ribbon are tested, and the influence of externally driving magnetic field on elastic layer materials and resonance output characteristics is analyzed. The experimental results show that Fe50Co50 ribbon exhibits good low-frequency magnetic field characteristics. And free end displacement of Fe50Co50 ribbon based on loop structure, under 12 mT alternating magnetic field and 134 mT bias magnetic field, reaches a peak-to-peak value of 870 μm for first-order resonance, and 320 μm for second-order resonance. This verifies that Fe50Co50 ribbon possesses the expected properties that magnetostrictive materials should have, and innovatively breaks through the technical bottleneck of manufacturing flexible micro-nano magnetostrictive energy exchange components.

Understanding of Job Insecurity, Quality of Work Environment, and its Implications for Employee Turnover Intention: A Study of Indonesian State-Owned Companies (SOEs) in the Field of Electronics for Facilities and Infrastructure

The phenomenon of employee turnover is triggered by high turnover intention in employees caused by internal or external factors. This study aims to determine how job insecurity and work environment can contribute to the phenomenon of turnover intention in Indonesia State-Owned Companies (SOE’s) in the field of electronics for industry and infrastructure. By using descriptive causality analysis and quantitative approach. Data from 250 samples were collected through questionnaires and tested with multiple linear regression analysis with the help of SPSS version 29 software to determine the magnitude of variable contributions. The results showed that job insecurity partially influenced turnover intention positively but insignificantly, while workers' surrounding conditions significantly influenced turnover intention negatively. The influence of job insecurity and work environment together affect 8.1% of employee turnover intention in the state-owned company.

The robustness waterproof ionogel based on the phase separation to form soft hard heterostructures and the interaction of cation-π realizes underwater adhesion and sensing

Flexible ionic conductors hold significant promise for advancing the field of soft ion electronics in the future. However, the creation of flexible conductors that possess mechanical robustness, underwater adhesion and underwater motion monitoring remains a challenge. Drawing inspiration from the multiphase hetero structure found in biological connective tissues, such as high modulus fibers and low modulus water-rich matrices, this article proposes a one-pot polymerization in-situ design strategy to create a hydrophobic ionogel with a hetero structure of soft and hard domains. The mechanical robustness, elasticity, and toughness of the ionogel are achieved through a synergistic combination of a strong skeleton in the hard domain and an elastic matrix in the soft domain. Additionally,hydrophobic aromatic rings and quaternary ammonium cation simulated cation-π interactions in mussel foot silk protein. Upon contact with water, the hydrophobic clusters quickly aggregate, facilitating the expulsion of interfacial water and exposing salicylic acid groups and quaternary ammonium cationic groups, leading to outstanding underwater adhesion between the ionogel and various substrates. The resulting hydrophobic ionogel can be utilized in underwater wearable electronic devices for monitoring human movement and physiological information, underwater repair monitoring, and intelligent soft robotics, demonstrating its vast potential in the field of underwater sensors.

High-strength conductive hydrogels based on the Hofmeister effect for friction nanogenerators

Hydrogels have received much attention in the field of flexible electronics as materials with flexibility and multifunctionality. The mechanical strength of conventional hydrogels is usually difficult to meet the requirements of practical applications in electronic devices. How to fabricate a high-strength hydrogel should remain a challenge. Here, a strategy to enhance the mechanical properties of conductive hydrogels based on the Hofmeister effect is reported. The mechanical properties of hydrogels were enhanced by increasing the polymer chain density, enhancing the hydrophobicity and increasing the crystallinity, the high-strength and high-toughness polyvinyl alcohol/carbon nanotubes/polyethyleneimine (PVA/MWCNTs/PEI) conductive hydrogel was successfully produced. The ultimate stress of the hydrogel was as high as 3.5–6.3 MPa, the elongation at break was between 500 and 1200 %, and the toughness was up to 23.62 MJ/m3. The conductivity of high-strength, high-toughness hydrogel is 0.05–0.45 S/m. Hydrogel was manufactured into a single-electrode friction nanogenerator (TENG), and it can easily light up to 100 LEDs. Therefore, this high-strength and high-toughness conductive hydrogel has great potential for TENG applications, offering the possibility of extending the working life of TENG in harsh environments.