ObjectiveTo investigate the influence of the microstructure of nanoparticle silver wires on their mechanical and electrical properties, finite element modeling of the microstructure of silver wires was conducted. A force-electric coupling cohesive zone model was established to simulate and analyze the effect of multiscale nanoparticle size distribution on the bending fatigue resistance of silver wires.MethodsFirstly, a random circular packing algorithm was developed to perform stochastic packing modeling of nanoparticles generated based on a normal distribution, enabling finite element modeling of silver wires with different microstructures. Secondly, a force-electric coupling cohesive zone model was employed to characterize the mechanical and electrical damage behavior at particle interfaces. Finally, numerical implementation was carried out using the UEL subroutine in Abaqus software. Finite element simulations were conducted to study the effects of average particle size, particle size standard deviation, and bimodal particle size distribution on the resistance variation and service life of nanoparticle silver wires during fatigue loading.ResultsThe results indicate that the bending fatigue resistance of silver wires significantly improves with increasing particle size standard deviation, while changes in average particle size have a minor effect on performance. For silver wires with bimodal particle size distributions, small particles effectively enhance bending fatigue resistance by filling the gaps between large particles. However, as the proportion of small particles increases, the performance improvement gradually diminishes. Additionally, an increase in the size of small particles impedes effective bonding between large particles, thereby reducing the enhancement effect on the bending fatigue resistance of silver wires.

The crack-based strain sensor consisted of a metal film and a conductivity substrate, can achieve high-sensitivity and wide-range sensor performance. However, the morphology of micro-cracks in metal film is sensitive to structural and material parameters of the bilayer strain sensor, which makes the quantitative design of the sensors difficult. In this work, a mechanical-electrical damage model was proposed to develop the relationship between the degradation of electrical properties and mechanical damage of metal film, and a reversible electrical damage variable was introduced to characterize the influence of micro-cracks opening and closing behavior on the reversible variation of metal film electrical conductivity. Based on the model, the effect of film-substrate thickness ratio and conductivity ratio on the film-substrate structural strain sensor performance was investigated. The results showed that with the increase of the thickness ratio and conductivity ratio, the sensitivities of the sensors in both the high-sensitivity region and wide-range region are obviously increased. In addition, a grooved structure was introduced in the sensor substrate, and the simulation results indicated that a three-segment linear sensing curve can be obtained. In the grooved sensor, high sensitivity can be achieved in the region close to the strain limit, making the sensor suitable for accurately detecting bending movements of human joints.

The patch-type biomedical sensor attached to human skin by a soft conductive adhesive layer has a good application potential in human healthcare. However, the complex strain of human skin can cause damage to the adhesive interface which can lead to signal drift and affect the long-term service reliability of the sensors. It is imperative to predict the trend of interfacial damage and signal drift and develop compensation method to enhance the sensor service reliability. In this work, a three-dimensional cohesive zone model (CZM) coupled with electrical damage was proposed to simulate the interfacial damage and signal drift behavior of sensor electrode with soft conductive adhesive layer. The viscoelastic behavior of the soft interface was described by the Wiechert model, and electrical damage behavior was incorporated into the CZM. The different electrical damage evolution mechanisms for normal and tangential loading were introduced based on experiments. The model was tested by tensile-shear tests with various normal and tangential loading combinations, and the effectiveness of the CZM in characterizing the mechanical and electrical damage behavior of soft conductive interface in complex loading conditions was verified. Then, the model was employed to predict the signal drift of the sensor electrode in cyclic torsional loading. The simulation results are in good agreement with the experiments. This work provides a numerical strategy for predicting the electrical signal drift of sensor electrodes under complex loading cycles.

Lithium-ion batteries encounter interconnected issues of thermal management, expansion-induced mechanical degradation, and vibration threats under dynamic operating conditions. Thus, a multifunctional flexible plate (MFP), composed of a flexible phase-change composite and an embedded film heater, is evaluated through numerical thermal-fluid modelling, thermo-mechanical and random-vibration simulations, compression tests, infrared thermal imaging, and low-temperature preheating experiments. The findings indicate that incorporating a 3 mm MFP into the air-cooled battery module decreases the maximum temperature and temperature difference of the battery module by 6.37% and 49.3%, respectively, at an airflow rate of 1 m∙s−1 and a 2 C discharge rate. The MFP can preheat the battery from −10 °C to 18.9 °C, attaining a competitive preheating rate of 0.66 °C·min−1 and a temperature difference of 3.5 °C. Under thermal expansion and aging expansion conditions, the MFP can effectively adhere to batteries by altering its expansion and compression states, remaining within the permissible compression range. Under vibration excitation conditions, the power spectral density responses of the MFP-integrated battery module are diminished by 27.3% and 9.95% in the peripheral and central regions, respectively, as compared to the blank design. After considering the thermal stress, the 3-sigma directional deformation and equivalent stress of the battery module are reduced by 1.1 μm and 0.003 MPa, respectively. This study integrates the thermal and mechanical management requirements of battery systems, providing an innovative perspective for the application and design of functional materials.

Handling delicate products with high variability in shape and texture remains a key limitation of rigid industrial end-effectors. This paper evaluates three Fin Ray Effect (FRE)-inspired soft gripper geometries: Straight, Beak, and Constant Curve, manufactured by 3D printing and assessed through coupled numerical and experimental analysis. Finite element simulations were conducted in Ansys using a hyperelastic material representation of TPU, and a cylindrical object was subjected to a prescribed displacement of 50 mm under low-friction contact to quantify deformation patterns, stress/strain fields, and reaction forces. Experimental tests were performed using a dedicated fixture on a universal testing machine, replicating the gripper arrangement and measuring force–displacement response for cross-validation. Results show clear geometry-dependent trade-offs: the Straight design delivers the highest reaction force and is therefore suitable for tasks requiring firmer retention; the Beak design provides the lowest force and stress, supporting gentler interaction with delicate or fragile objects; and the Constant Curve design offers an intermediate solution with more uniform contact pressure distribution. This work serves as a foundation for optimising gripper design to improve handling capabilities across diverse applications.

Polylactic acid (PLA)/biomass polymer composite filaments are environmentally friendly 3D printing supplies with the features of natural materials. This study prepared cellulose-enriched Huangjiu (Chinese rice wine) distillers’ grains (CHG) fillers with 46.2 wt

The electrocatalytic nitrogen reduction reaction (eNRR) is a promising technology for NH3 production under ambient conditions. In this study, Fe-MnO2 layered nanoflower catalysts are prepared by an impregnation method at room temperature with an MnO2 layered nanoflower precursor, which is prepared by a hydrothermal method. The as-prepared Fe-MnO2 layered nanoflower catalysts show good performance in the eNRR. Using Fe-MnO2 layered nanoflower catalysts as eNRR catalysts, an average ammonia yield rate of 7.54 mu g h-1 mgcat-1 and a faradaic efficiency (FE) of 11.34% in 0.1 M Na2SO4 solution at -0.5 V are achieved. Moreover, the Fe-MnO2 layered nanoflower catalyst exhibited good stability and excellent selectivity in the eNRR.

In order to ensure the service reliability of flexible electronic products, flexible electronic interconnection wires need to have good conductivity and good resistance and mechanical reliability. In this study, Ag microwire samples were prepared on flexible substrates by aerosol inkjet printing. The electrical tests show that the resistivity of the Ag microwire treated by high-density pulsed electric current was reduced. At the same time, the bending resistance tests show that the resistance of Ag microwire changes less when treated by high-density pulsed electric current under the same bending angle. Thus, the electrical conductivity and flexural behavior of the samples can be simultaneously enhanced by applying high-density pulsed electric current. After pulsing under the specified electrical parameters, the microstructure of the Ag microwire was denser, and the grain distribution was more uniform owing to the decrease in grain porosity, which was caused by atomic filling. The atomic diffusion was controlled directionally by the electron wind and Joule thermal effect. Ultimately, a significant accumulation of Ag atoms occurred, healing the voids and cracks. The technique holds promise for utilization in the realm of flexible printed circuits.

In this paper, pod-like Fe7Se8/C nanocomposite catalyst materials were prepared by MIL-88 selenide annealing and the as-prepared Fe7Se8/C nanocatalyst exhibited excellent electrocatalytic performance in neutral electrolyte for the electrocatalytic nitrogen reduction reaction (eNRR). The average ammonia yield rate was 7.11 mu g h-1 mgcat-1 with a corresponding faradaic efficiency (FE) of 10.44% obtained at the optimum potential of -0.3 V. Moreover, the as-prepared Fe7Se8/C electrocatalyst shows good selectivity and stability for the eNRR.

The electrocatalytic nitrogen reduction reaction (eNRR) under ambient conditions is deemed a promising alternative for NH3 synthesis. In this paper, an FeP-Fe3O4 nanocomposite electrocatalyst was prepared by phosphating annealing using Fe2O3 as a precursor, and the resulting FeP-Fe3O4 exhibited excellent N2-to-NH3-producing activity over a wide potential window. The highest faradaic efficiency of FeP-Fe3O4 is 11.02% at -0.1 V vs. reversible hydrogen electrode (RHE), and the maximum NH3 yield reaches 12.73 μg h-1 mgcat-1, comparable to or exceeding the reported values in this field. Furthermore, the FeP-Fe3O4 nanocomposite electrocatalyst presents high electrochemical stability, selectivity, and durability.

Flexible and room-temperature (RT) ammonia gas sensors are needed for exhaled breath detection and recognition. Two-dimensional transition metal disulfides are potential materials for RT gas sensing because of their low band gap and a large number of edge-exposed sites that can provide strong binding to gas molecules. In this work, a 1D/2D heterostructured composite material of 2D tungsten disulfide (WS2) modified with 1D polyaniline (PANI) was proposed. The fibrous PANI adsorbed on the edges and inserted in the interlayers of the laminated WS2 provide more diffusion channels for the ammonia gas and act as sensing sites. The WS2@PANI-based sensor shows high selectivity for ammonia with satisfying reproducibility and long-term stability. A response of 216.3% and a short response/recovery time of 25 s/39 s were achieved for 100 ppm ammonia gas. The sensing mechanism was investigated in detail via complex impedance spectra and in situ FT-IR, which was attributed to the synergistic effect of WS2 and PANI. The excellent sensing performance coupled with its resistance to thermal and humidity interference endows the WS2@PANI-based sensor with potential for human exhaled detection and wearable electronics.

Ammonia (NH3) gas is regarded as a biomarker for clinical diagnosis of various diseases and a potential indicator for the spoilage of protein-rich foods. The acuate detection of the ammonia gas concentration depend on reliable gas sensor. In this paper, flexible room temperature ammonia gas sensor based on hierarchical Au/PANI/WS2 ternary composite was successfully prepared by in-situ polymerization, reduction and drop-coating process. The Au/PANI/WS2-based ammonia sensor was tested for its room temperature sensing property including response value, response/recovery time, selectivity, and long-term stability. The effects of flexible state, humidity and operating temperature on the sensor response were also investigated. The 0D/1D/2D Au/PANI/WS2-based sensor showed significantly enhanced ammonia sensing property both in response and response/recovery time as compared to that of pristine WS2. Gas sensing mechanism of the prepared sensor was investigated by complex impedance spectroscopy and in-situ fourier transform infrared spectroscopy analysis. Besides, the sensor was proved for its practical usability in seafood spoilage detection and warning. The construction of multidimensional materials into hierarchical structure may provide an instructive way for the sensibilization of layered two-dimensional nanomaterial of WS2.

The electrocatalytic nitrogen reduction reaction (eNRR) under ambient conditions is a promising alternative to the Haber-Bosch process, but one of the primary pending issues for the eNRR is the development of efficient and stable electrocatalysts. Herein, we propose to prepare a ZIF-67-derived nitrogen-doped porous carbon-supported Co9S8 nanocomposite achieving the maximum average of 9.80 mu g h(-1) mg(cat)(-1) NH3 yield and the highest Faradaic efficiency (FE) of 9.89% in 0.1 M Na2SO4. Moreover, Co9S8/NC shows excellent electrocatalytic stability and durability for the eNRR.

An encapsulated sandwich-structured flexible strain sensor with high sensitivity and simple repairability was prepared using a Sn-Bi alloy film as the sensitive layer. Conductive composite materials were prepared by combining graphene with Ecoflex, to completely encapsulate the sensitive layer. The resultant flexible strain sensor demonstrated a wide sensing range (50%), high sensitivity coefficient of 16323 (0 < epsilon < 3.84%) and 2125 (3.84% < epsilon < 50%), rapid response time (approximately 46 ms), and high durability (similar to 4800 stretch-release cycles before needing repair). The high sensitivity was attributed to the cracks generated in the Sn-Bi alloy film during the stretching process, and the EG (Ecoflex/graphene) layer maintained the conductive pathways under large strains, greatly expanding the sensing range. Furthermore, the EG layers on the outside surfaces provided robust protection for the Sn-Bi alloy film, endowing the sensor with water, dust, and friction resistance, which is needed in various daily life scenarios. After 6000 cycles of stretching and releasing, the accumulation of cracks in the Sn-Bi alloy film resulted in significant residual resistance. With the melting point of the Sn-Bi alloy film as low as 47 degrees C, a simple thermal pressing treatment was used to rapidly and efficiently restore the damaged Sn-Bi alloy film to its initial state. This work presents an effective approach for achieving both high sensitivity and a wide sensing range in strain sensors. The encapsulated sandwich structure design endows the sensor with repair capabilities and resistance to external environmental interference. The sensor demonstrates significant potentiality for applications in health monitoring, electronic skin, and wearable devices.

Synthetic membrane technology plays an increasingly dominant role in modern industry, boasting remarkable efficiency and low carbon attributes. The ever-growing demand for molecular-level separation necessitates precise structures at the angstrom range with a concomitant low transport resistance, but it still remains a great challenge. Here, we demonstrate an enhanced separation performance towards monovalent cations of two-dimensional (2D) conjugated polymeric carbon nitride (PCN) membranes with angstrom pores, achieved through the strategic incorporation of multivalent ions. Based on the additional ions, the energy barrier of transmembrane transport for individual alkali metal ions could be effectively manipulated. Remarkably, the presence of LaCl3 substantially improves monovalent cation selectivity ratios, improving from 7 to 22 for K+/Li+ in mixtures. More importantly, under an initial concentration gradient, the transport rate of K+ was further enhanced over 1 kmol m(-2) h(-1), primarily attributed to the low ion transfer barrier.

Glass nano/micron pipettes, owing to their easy preparation, unique confined space at the tip, and modifiable inner surface of the tip, can capture the ion current signal caused by a single entity, making them widely used in the construction of highly sensitive and highly selective electrochemical sensors for single entity analysis. Compared with other solid-state nanopores, their conical nano-tip causes less damage to cells when inserted into them, thereby becoming a powerful tool for the in situ analysis of important substances in cells. However, glass nanopipettes have some shortcomings, such as poor mechanical properties, difficulty in precise preparation (aperture less than 50 nm), and easy blockage during complex real sample detection, limiting their practicability. Therefore, in recent years, researchers have conducted a series of studies on glass micropipettes. Ionic current rectification technology is a novel electrochemical analysis technique. Compared with traditional electrochemical analysis methods, it does not generate redox products during the detection process; therefore, it can not only be used for the determination of non-electrochemically active substances, but also causes less damage to the cell/living body in situ analysis, becoming a powerful analysis technology for the in situ analysis of cells/in vivo in recent years. In this review, we summarize the preparation and functionalization of glass nano/micron pipettes and introduce the sensing mechanisms of two electrochemical sensing platforms constructed using glass nano/micron pipette-based ion current rectification sensing technology as well as their applications in single cell/in vivo analysis, existing problems, and future prospects.

打印银导线的横截面尺寸是影响导线性能和质量的一个重要参数.为了实现气溶胶打印银导线横截面尺寸的定量控制,通过实验总结分析了载气体积流量(8～14 mL/min)、气体体积流量比(环绕气体体积流量与载气体积流量的比值,2～6)、打印速度等工艺参数对打印银导线横截面尺寸的影响,并拟合得到了银导线横截面面积和横截面宽高比与打印参数的关系公式,结果显示,银导线横截面面积与载气体积流量基本呈线性关系,而银导线宽高比与载气体积流量和气体体积流量比呈近似二次关系.采用不同的参数组合对打印银导线横截面尺寸定量控制方法的有效性进行了验证,以打印横截面面积为100 μm2、宽高比为20的银导线为例,三组不同的打印工艺参数均可得到相同横截面尺寸的银导线,同时结果表明采用载气体积流量为14 mL/min,气体体积流量比为1.63时,打印的银导线质量最佳.

通过模具法制备了3 种不同功能材料的网格柔性应变传感器,对比其拉伸断裂极限和灵敏度,发现Ag-Ecoflex-Graphene网格柔性应变传感器兼具了高灵敏度和宽检测量程,同时该传感器在手腕关节运动监测方面表现良好.将该网格柔性应变传感器组合构建多通道检测系统,实现了多种手势识别,在人工智能和运动识别领域具有广阔的市场应用前景.

为了研究导电水凝胶电极贴片在疲劳载荷下因界面损伤而导致的电阻变化规律,本文提出了一种力电学内聚力模型.首先基于水凝胶的黏弹性力学行为,采用Wiechert模型构建了应变率相关的内聚力牵引力-牵引位移关系方程,并将界面电阻率定义为牵引力和损伤变量的函数,然后通过ABAQUS的UEL子程序对黏弹性力电学内聚力模型进行了数值实现.通过搭接剪切试验确定了模型的黏弹性参数和不同应变率下内聚力模型的损伤起始和界面断裂的能量释放率,以及应变率下界面电阻率随牵引力的变化规律.采用单个单元对模型的有效性进行了验证,最后将模型应用于导电水凝胶电极贴片的在疲劳载荷下的界面电阻变化规律仿真预测,结果表明随着电极贴片的电阻随着加载循环次数的增加呈波动上升趋势,且随着加载速率增大,电阻随加载次数上升的趋势逐渐减缓,电阻的波动也越小,有限元仿真结果与实验结果吻合良好.