Lamination Process Research Articles

Outdoor Performance Monitoring Method for Degradation Studies of Perovskite Modules

ABSTRACTThis paper presents an outdoor performance monitoring method for degradation studies of perovskite modules, focusing on a large‐area perovskite module (81.9 cm2) over a long‐term monitoring campaign. The module underwent an industrial lamination process to prevent long‐term degradation from environmental factors. The characterization procedure involved degradation correction and determining the temperature coefficients and electrical parameters of the module using initial days of measurements. The results demonstrated temperature coefficients for Isc, Voc, and Pm (α′, β′, and γ) of −0.071%·K−1, −0.119%·K−1, and −0.113%·K−1, respectively, indicating a minimal temperature influence on this technology compared with conventional ones. Using this coefficient, the STC electrical parameters were retrieved from 1‐min power output data, resolving the uncertainty of the indoor/outdoor IV curve measurements caused by the curve scan direction (JV hysteresis effect). We also highlight the initial remarkable capacity recovery effect of almost 16% during the first 2 days of operation. Additionally, a procedure that includes the IV curves analysis taken every 10 min and their translation to standard conditions has been implemented to evaluate the degradation of the module over the long‐term outdoor campaign. The results show three different trends over the period.

A piezoelectric driven amphibious microrobot capable of fast and controllable movement

Abstract Due to its excellent adaptability to the environment and flexibility in narrow spaces, amphibious microrobots have become an important research direction recently. This study proposes an amphibious microrobot driven by piezoelectric actuators with a body length of 4.5 cm and a mass of 1.4 g. The microrobot consists of two active front legs, two passive rear legs, two caudal fins, and a support frame. Each front leg and each caudal fin are designed as structures integrated with their respective piezoelectric actuators. The microrobot has a tilted body, and the ground exerts an oblique upward impact force that makes it jump forward when its front legs swing backwards. The opposite swing of the two caudal fins generates propulsion for swimming. The components of the microrobot are manufactured based on the monolithic laminate process. The monolithic front actuator-leg and monolithic actuator-fin both emerge from a multi-layer material laminate. The support frame is designed and fabricated as a monolithic structure to improve assembly accuracy and reduce redundant assembly steps. The manufactured microrobot demonstrates its flexible and fast amphibious movements. Its maximum land walking speed reaches 15.3 cm/s and its turning speed reaches 48.2 degrees per second. The microrobot has a maximum payload capacity of 5 g moving on land. When the front legs and caudal fins work simultaneously, its underwater swimming speed reaches 9.1 cm/s, and the maximum turning speed is 20.5 degrees per second. The microrobot also confirms a maximum payload of 3 g during its underwater movement.

Understanding Process-Structure Relationships during Lamination of Halide Perovskite Interfaces.

Fabrication of halide perovskite (HP) solar cells typically involves the sequential deposition of multiple layers to create a device stack, which is limited by the thermal and chemical incompatibility of top contact layers with the underlying HP semiconductor. One emerging strategy to overcome these restrictions on material selection and processing conditions is lamination, where two half-stacks are independently processed and then diffusion bonded to complete the device. Lamination reduces the processing constraints on the top side of the solar cell to allow new device designs, expanded use of deposition methods, and self-encapsulation of devices. While laminated perovskite solar cells with high efficiencies and novel interlayer combinations have been demonstrated, there is a limited understanding of how the lamination process parameters affect the diffusion-bond quality and material properties of the resulting HP layer. In this study, we systematically vary temperature, pressure, and time during lamination and quantify the resulting impacts on bonded area, grain domain size, and photoluminescence. A design of experiments is performed, and statistical analysis of the experimental results is used to quantitatively evaluate the resulting process-structure-property relationships. The lamination temperature is found to be the key parameter controlling these properties. A temperature of 150 °C enables successful bonding over 95% of the substrate area and also results in increases in apparent grain domain size and photoluminescence intensity. Based on these insights, the lamination temperature of functional perovskite solar cell devices is varied, demonstrating the importance of the resulting bond quality on device performance metrics.

Determination of Composition and Density of Sandwich Composites Produced by Vacuum Lamination

Purpose: This study aims to characterize the composition and density of bulkheads manufactured by vacuum lamination. Theoretical Framework: Sandwich composites are widely used due to their high specific strength, a critical factor in reducing energy consumption associated with weight, especially when manufactured through vacuum lamination. However, the final composition and density of these materials are important factors for decision-making in the project, but they are often not known beforehand. Method: Characterization was carried out on five samples taken from different regions of the laminated plates. The composition was determined by varying the area density, and the final composite density was obtained based on the observed composition and the density of the components. Results and conclusion: The results indicated a density of 0.21 g/cm³ for the laminated material. The analysis allowed determining the mass and volumetric fractions of the components, demonstrating the consistency of the manufacturing parameters and their adequacy to the project's requirements. Research Implications: This study contributes to improving the vacuum lamination process by providing a methodology for characterizing the density of sandwich composites, which can be applied in various projects, as well as providing reference values. Originality/Value: The research offers an innovative approach by exploring the variation of area density to characterize the composition of composites, contributing to the optimization of the sandwich composite manufacturing process, such as the vessel “Gigante Vermelho” used in the Desafio Solar Brasil 2022.

Towards More Sustainable Schiff Base Carboxylate Anodes for Sodium-Ion Batteries.

Bismine sodium salt (BSNa), a Schiff base with two sodium carboxylates, has shown promising electrochemical performance as an anode material. However, its synthesis involves toxic reagents and generates impurities, requiring significant solvent use for purification. This study introduces a novel synthetic method using sodium hydroxide as the sole reagent, which acts as both a base and Na source in the ion exchange step. With this procedure, we reduce the amounts of chemicals, diminish toxicity, improve the purity of the target compound, and use less solvent while maintaining comparable electrochemical performance. Additionally, the procedure is carried out under anhydrous conditions that avoid the undesirable hydrolysis of the imine linkages. In a previous report, the processing of the composite electrode was not established. In this article, we address this issue; the electrochemical performance, specifically the rate capability, is enhanced by processing the electrodes in laminate form rather than powder. As alternative to N-methyl-2-pyrrolidone (NMP), a common but disadvantageous solvent in laminate processing, other solvents were explored by testing acetone (DMK), methylisopropylketone (MIPK), and a DMK-NMP mixture. The remarkable electrochemical performance (specific capacity of 260-280 mAh/g, and capacity retentions higher than 84% at 1C (260 mA/g) remained consistent across these solvents. Furthermore, we investigated replacing copper with aluminum as the current collector to reduce costs and increase the energy density of the battery. While aluminum performed comparably to copper at low specific currents C/10 (26 mA/g), it showed a significant shift in the redox process potentials at higher specific currents.

Mechanical and thermal properties as a function of matrix composition of all-oxide ceramic matrix composites fabricated by a sequential infiltration process

The microstructural design of matrices for all-oxide ceramic matrix composites (Ox/Ox) with damage tolerant fracture behavior is challenging. Therefore, the potential use of different matrix materials might be limited even though they appear to offer advantageous functional properties, such as thermal insulation or corrosion resistance. In this study, we investigated the hypothesis of simultaneously adjusting mechanical and functional properties by separate matrix phases within and between the fiber bundles in Ox/Ox. A sequential infiltration process was used to manufacture Ox/Ox with an alumina-zirconia matrix phase (high damage tolerance) and a mullite-alumina matrix phase (thermal insulation). The effect on the mechanical and thermal properties was governed by the infiltration sequences. A property combination was achieved for either the mechanical or the thermal behavior. This was due to a shear-induced mixing of the matrix phases during the lamination process, which renders it difficult to achieve distinctly separated matrix phases within the composite.

Shingled design lightweight photovoltaic modules using honeycomb sandwich structures as backsheets

The expanding scale of the photovoltaic (PV) market has intensified the focus on PV module designs for diverse applications. Research actively pursues lightweight PV modules, replacing front glass with polymer films as a suitable design solution. Lightweight PV modules with front-film structures require additional structures to compensate for their inadequate mechanical rigidity. Hence, we integrated honeycomb sandwich structures into lightweight PV modules, substituting them for traditional PV backsheets. It increased the mechanical rigidity of lightweight PV modules and effectively replaced the PV backsheet through a simple one-step lamination process. Consequently, we successfully fabricated lightweight PV modules with a shingled design, achieving a conversion power of 205.80 W in an area of 1.034 m2, facilitating the integration of more solar cells in a limited space. Additionally, standard reliability tests were performed on a PV module weighing only 6.2 kg/m2.

Large-scale sub-5-nm vertical transistors by van der Waals integration

Vertical field effect transistor (VFET), in which the semiconductor is sandwiched between source/drain electrodes and the channel length is simply determined by the semiconductor thickness, has demonstrated promising potential for short channel devices. However, despite extensive efforts over the past decade, scalable methods to fabricate ultra-short channel VFETs remain challenging. Here, we demonstrate a layer-by-layer transfer process of large-scale indium gallium zinc oxide (IGZO) semiconductor arrays and metal electrodes, and realize large-scale VFETs with ultra-short channel length and high device performance. Within this process, the oxide semiconductor could be pre-deposited on a sacrificial wafer, and then physically released and sandwiched between metals, maintaining the intrinsic properties of ultra-scaled vertical channel. Based on this lamination process, we realize 2 inch-scale VFETs with channel length down to 4 nm, on-current over 800 A/cm2, and highest on-off ratio up to 2 × 105, which is over two orders of magnitude higher compared to control samples without laminating process. Our study not only represents the optimization of VFETs performance and scalability at the same time, but also offers a method of transfer large-scale oxide arrays, providing interesting implication for ultra-thin vertical devices.

Damage detection and classification of carbon fiber-reinforced polymer composite materials based on acoustic emission and convolutional recurrent neural network

Carbon fiber-reinforced polymer (CFRP) composite laminates generate acoustic emission signals during the tensile process, which can be used to identify the type of acoustic emission (AE) signal at a given moment and determine the current damage condition. However, due to the large number and complexity of AE signals generated during the tensile process of carbon fiber composite laminates, it is challenging to manually identify and annotate them. To address this issue, we propose a low-complexity classification and detection network model based on the convolutional recurrent neural network (CRNN) architecture. First, we construct a dataset of composite damage signals for a single damage category and use log-mel spectrogram features to train the model for that specific category of damage signals. Then, we utilize the trained model to recognize the AE signals of CFRP composite laminates. The proposed method achieves an accuracy of 99.02% in classifying single damage modes in the test set and effectively distinguishes the types of AE signals generated during the damage process of CFRP composite laminates. Compared with the classic classification model using AE signals, the number of parameters in our proposed low-complexity CRNN model is reduced by 94.42%. It also demonstrates that 19.4% of the AE signals during the damage process are in a superimposed state, indicating the simultaneous occurrence of multiple damage modes in CFRP composite laminates.

Fiberglass Construction Testing Simulation On Boat Hulls

As a maritime country, Indonesia relies heavily on ships as an economical means of transportation and conveyance. Boats, which were used for many years, were originally made of wood. However, because wood has properties that are easily weathered due to weather and chemical factors and requires adequate maintenance, fiberglass material in the form of FRP (Fiber Reinforced Plastics) laminates appeared as a substitute for wood. This material has many advantages over wood, so ships made from FRP began to gain a place in the shipping world, especially among ship manufacturers. However, In 2009, a survey carried out at multiple shipyards revealed that the construction design and lamination process of fiberglass ship hulls generally did not have clear standards, resulting in a significant risk of accidents. To minimize this risk, a simulation of fiberglass construction testing was held with samples taken from 6 shipyards where each sample had a different configuration and material, and the results of Carbon Fiber provided optimal results.

Simulation on lightning erosion protection performance of CFRP laminates with metal cluster structure

The tufting technology has the advantages of high flexibility and high economy. Research has found that metal tufting structures can significantly improve the mechanical and electrical properties of carbon fiber composites, and have great prospects in engineering applications. In order to investigate the damage characteristics of carbon fiber CFRP laminates with metal tufted structures during lightning strikes and the influence of structural parameters on lightning protection effectiveness, an electric thermal coupling model of CFRP laminates with metal tufted structures was established. Comparing the simulation and experimental results under the same load condition, it was found that the two were consistent in terms of damage appearance, damage area, and damage propagation trend, proving the effectiveness of the model. The transverse heat transfer process and current conduction path of CFRP laminates with metal cluster structure were discussed. The research results indicate that the ablation surface area of CFRP laminates with metal tufted structures is reduced to 8.06% of the reference component. Wire spacing had an effect on the area and shape of the area of the high potential region, and the wire spacing had the greatest impact on the ablation area of lightning strikes.

Research on ballistic properties of UHMWPE hybrid laminates impregnated with shear thickening fluid

In this paper, a technology of impregnating ultra-high molecular weight polyethylene (UHMWPE) with shear thickening fluid (STF) was proposed to prepare composite laminates, and the ballistic properties of laminates with hybrid configurations were studied. Firstly, two kinds of STFs were prepared using silica particles of 20 nm and 500 nm. Then, STF-impregnated UHMWPE composite laminates were prepared using the hot-press lamination process. Finally, a ballistic experimental study of different combinations of laminates was carried out using a two-stage light gas gun. The results of the study show that the energy absorption rate of the hybridized laminate with the 20 nm + 50 nm configuration scheme is enhanced by more than 9.3 % compared to the laminate impregnated with the single STF. The laminate’s back face deformation depth (BFD depth) after impregnation with shear thickening fluid is only 66.8 % of that of pure UHMWPE laminate. The research work can provide new ideas and references for designing and developing new protective equipment.

Assessing the Environmental Benefits of Extending the Service Lifetime of Solar Photovoltaic Modules.

Requiring no fuel for generation and negligible material/energy for operation and maintenance, photovoltaic (PV)systems have environmental impacts mostly due to the production of modules and the commissioning of power plants. Thus, extending the service lifetime of these systems from 30 to 40 years through an enhanced lamination process for module production potentially reduces environmental impacts per unit energy generated. Life cycle assessment is employed to evaluate the environmental impacts under scenarios for resource utilizations for the new lamination process, operation and maintenance requirements in the extended service lifetime, and degradation rates of the devised modules. Extending the service lifetime significantly reduces environmental impacts across categories, with a 21-27% reduction in global warming potential on the pessimistic and optimistic ends. At least 20% impact reduction is achieved in most impact categories, even under a pessimistic scenario. Considering uncertainty models in the life cycle inventories, samples are generated for scenarios via Monte Carlo simulation, and with significant improvements with large effects in most environmental impact categories, deterministic impact comparisons are supported by ANOVA and Tukey tests. Production strategies for more durable and reliable PV modules have a significant potential in contributing to global sustainability efforts.

Combination of MFC wet lamination and chromatogeny grafting processes to produce all cellulose packaging materials

Combination of MFC wet lamination and chromatogeny grafting processes to produce all cellulose packaging materials

Alignment Error Estimation of the Conductive Pattern of 3D-Printed Circuit Boards

Introduction. When manufacturing printed circuit boards (PCBs), including their prototypes, the proper alignment of PCB layers is mandatory. While the causes and preventive measures against misalignment in PCBs manufactured using conventional technologies are known, research into alignment errors in 3D-printed PCBs is still ongoing. Another task regarding 3D printing, which is related to topological accuracy (alignment errors in particular), consists in ensuring the opportunity to remove the printed part of the product in order to perform operations thereon, such as embedding components, followed by its return and continuation of the printing process.Aim. Numerical estimation and analysis of the causes of layer-to-layer alignment errors in PCBs manufactured using 3D printing.Materials and methods. The research was conducted using the following materials and equipment: Polyethyleentereftalaatglycol (PETG); an Ultimaker Cura slicer; an Ender 3 S13D printer; a brass nozzle with a diameter of 0.3 mm. The study was conducted using the facilities of the Additive Technologies Center, Bauman Moscow State Technical University. Interlayer alignment errors are estimated by microsection analysis and X-ray inspection, as well as using the misalignment decomposition method described by Yu.B. Tsvetkov for electronics.Results. The possibility of manufacturing PCB prototypes with three conductive layers is demonstrated, including a method for removing the printed part of the product and its further return in the printing process using printed pins. Large-scale distortions were found to make the largest contribution to the alignment error: on average, approximately 150 gm for each layer when compared to its 3D model and approximately 60 gm when comparing the topology of the top layer with the bottom layer. These values exceed the common misalignment value of 50 gm for the pin lamination process. This substantiates the need to control and minimize temperature effects, e.g., using 3D printers with a thermostatically-controlled chamber.Conclusion. The conducted analysis of possible causes of misalignment emergence determines the significance of temperature gradients that occur during 3D printing. The proposed manufacturing method allows the printed part of the product to be removed and further returned into the printing process, which can be used to produce PCB prototypes with three conductive layers.

A 10 × 10 cm2 protonic ceramic electrochemical hydrogen pump for efficient and durable hydrogen purification

Protonic ceramic electrochemical hydrogen pumps (PCEHPs) have garnered notice as a promising technology for the hydrogen separation. However, the practical application of PCEHPs has been limited by the insufficient performance and stability. In this work, a 10 × 10 cm2 PCEHP with the symmetrical configuration of “porous Ni-BaCe0.7Zr0.1Y0.1Yb0.1O3-δ (BCZYYb) supporting layer | porous Ni-BCZYYb functional layer | dense BCZYYb electrolyte layer | porous Ni-BCZYYb functional layer | porous Ni-BCZYYb supporting layer” is fabricated by the tape-casting, hot-pressing lamination, and co-sintering process. The PCEHP with an active area of 1.13cm2 shows an impressive hydrogen separation rate of 7.93 mL min−1 cm−2 under 0.3 V with a Faradaic efficiency of 88 % at 650 °C. Furthermore, it exhibits excellent stability for over 500 h in both the electrolysis and thermal cycling modes. Notably, a 10 × 10 cm2 PCEHP with a large active area of 81 cm2 was fabricated and demonstrated a remarkable H2 flux of 153.32 mL min−1 at 650 °C under 0.3 V. The results indicate that the developed PCEHPs have great potential for hydrogen purification.

Bending behavior and damage evolution of GLARE laminate using in‐situ AE technology and FEM

AbstractGLARE laminate experiences multiple damage modes during bending failure, including fiber fracture, matrix cracking, interlayer delamination, and fracture of aluminum alloy. In most cases, two or more failure modes occur together, which makes the damage process complex and unpredictable. This paper proposes a combination of experimental testing and numerical simulation to investigate the influence of fiber lay‐up direction and center open‐hole on the bending failure behavior of GLARE laminate. Simultaneously, Acoustic Emission (AE) technology was used to monitor the bending process of GLARE laminates in real‐time, and a numerical simulation model for the three‐point bending of GLARE laminates was established. The experimental results showed that the bending strength of intact specimens decreased significantly with the increase of the fiber off‐axis angle, whereas the strength retention of open‐hole specimens increased significantly with the increase of the fiber off‐axis angle. Based on the K‐means++ clustering algorithm, the peak frequencies corresponding to different damage modes of GLARE laminates were identified as follows: aluminum alloy damage [1–70 kHz], matrix cracking [93–210 kHz], interlaminar delamination [211–304 kHz], and fiber breakage [304–516 kHz]. The simulation results agreed well with the experimental results, showing that the damage in intact specimens initiated at the laminate edges and propagated sequentially along the thickness direction, while the damage in open‐hole specimens initiated at the hole edges and then propagated towards the laminate edges.Highlights The present study investigated the effects of fiber lay‐up direction and central open‐hole on the bending performance and failure behavior of GLARE laminate. In‐situ monitoring of the GLARE laminate during three‐point bending was conducted using AE technology. A model for simulating the progressive damage of GLARE laminate was established and its accuracy was verified.

Thermomechanical-induced cracking model for ceramic matrix composite laminates subjected to thermal gradients and transients

Regarding the potential damage and failure issues that may occur in high-temperature transient environments during the service process of ceramic matrix composite laminates, the present work proposes a multi-layer thermomechanical induced crack initiation model for ceramic matrix composite laminates subjected to thermal gradients and transients. This model can determine the history of temperature, deformation, and stress distribution within each layer of the material, as well as the steady-state energy release rate of all possible crack locations. Then the influence of bending constraints on material stress distribution and energy release rate is investigated, finding that maximum stress and energy release rate values are significantly lower without bending constraints compared to those under bending constraints. Furthermore, the study explores the impact of material structural parameters and boundary conditions on the energy release rate of ceramic matrix composite laminates, providing direct insights for designing laboratory tests and evaluating the lifespan of these materials under in-service conditions.

Highly Stable Silver Nanowire Plasmonic Electrodes for Flexible Polymer Light-Emitting Devices.

Silver nanowire (AgNW) transparent electrodes are considered as a promising candidate for applications in flexible optoelectronic devices. However, it remains a great challenge to obtain flexible AgNW electrodes with excellent optoelectrical properties and mechanical flexibility. Here, highly stable Ag nanoparticle (AgNP)-enhanced plasmonic AgNW electrodes are demonstrated via the controllable in situ growth of AgNPs at the AgNW junctions and introduction of an l-histidine (l-His) wrapping layer. The flexible transparent electrodes of AgNW-AgNP/l-His possess a low sheet resistance (Rsh) of ∼17.5 Ω sq-1, a high transmittance of ∼92.5% (550 nm), and a robust mechanical stability (100,000 bending cycles). Benefiting from plasmon-coupling effects, flexible polymer light-emitting devices (FPLEDs) with AgNW-AgNP/l-His electrodes present a current efficiency (CE) of ∼14.8 cd A-1 and an external quantum efficiency (EQE) of ∼5.6%, constituting ∼80% and ∼75% increases compared to those of the reference devices with AgNW electrodes, respectively. Additionally, the laminated flexible transparent PLEDs (FT-PLEDs) are demonstrated by integrating polydimethylsiloxane/AgNW-AgNP anodes by a soft lamination process. The FT-PLEDs present a CE of ∼7.1 cd A-1 (cathode side: ∼3.9 cd A-1; anode side: ∼3.2 cd A-1) and an EQE of ∼2.7% (cathode side: ∼1.5%; anode side: ∼1.2%). Furthermore, the FPLEDs and FT-PLEDs exhibit robust mechanical durability, maintaining ∼89% and ∼86% of their initial luminance after 1000 bending cycles at a bending radius of 2 mm, respectively. This work opens up a new avenue for the development of high performance and stable flexible optoelectronic devices.

Research on size effects in the low‐velocity impact (LVI) and compression after impact (CAI) characteristics of composite laminates

AbstractThe load‐bearing capacity and failure characteristics of composite structures are closely related to their dimensions. In this study, low‐velocity impact, ultrasonic non‐destructive testing, and compression after impact tests were conducted on composite laminates of varying widths to investigate the influence of size effects. Distinct impact response profiles and compression failure modes were characterized. The results indicate that under impact loading, the delamination threshold load (6700 N ~ 7200 N) and the knee‐point energy (40 J) are not affected by width. However, variations in width lead to differences in indentation depth, impact duration, peak load, delamination characteristics, and energy absorption. Furthermore, increasing impact energy further magnifies these differences. Under compression loading, wider laminates exhibit lower residual strength, with the influence of impact energy on residual strength decreasing as width increases. Importantly, the observed compression failure deformation mode transitions from localized buckling to widespread sub‐layer delamination‐induced compression failure. This suggests that changes in width alter the governing mechanical mechanisms of CAI failure. Consequently, the use of a single‐size laminate to represent both LVI and CAI processes is not recommended. Based on experimental results, the reliability of the equivalent damage method in predicting the residual compression strength of laminates of different widths was confirmed, providing valuable insights for practical engineering applications.Highlights Assess the variations in the low‐velocity impact process of laminates with different widths. Evaluate the delamination damage of laminates after impacts by ultrasonic C‐scan techniques. Investigate the effect of variation in widths on the compression behavior of laminates after impact. Validate the feasibility of equivalent damage modeling for calculating residual strength.