Structural Adhesives Research Articles

Force-bearing phagocytic adhesion rings mediate the phagocytosis of surface-bound particles

Many micro-particles including pathogens strongly adhere to hosts. It remains elusive how macrophages detach these surface-bound particles during phagocytosis. We show that, rather than binding directly to these particles, macrophages form unique β2 integrin-mediated adhesion structures at the cell-substrate interfaces, specifically encircling the surface-bound particles. These circular adhesion structures that we named phagocytic adhesion rings (PARs) serve as strongholds to support local ring-shaped actin structures constricting into the particle-substrate cleavages, thereby pinching off the particles from the substrate. During this process, integrins in PARs sustain tensions due to the reaction force of actin polymerization against the particles. Such tensions are critical for phagocytic efficiency of surface-bound particles. PARs were formed in all tested macrophages (mouse, human and fish) and micron-sized particles (microbeads and E. coli), demonstrating their conserved role in the phagocytosis. This study reveals a mechanism of PAR-mediated phagocytosis, specialized for the detachment and internalization of surface-bound particles.

Structural Aspects and Adhesion of Polyurethane Composite Coatings for Surface Acoustic Wave Sensors

Surface acoustic wave-based (SAW) sensors are of great interest due to their high sensibility and fast and stable responses. They can be obtained at an overall low cost and with an intuitive and easy-to-use method. The chemical sensitization of a piezoelectric transducer plays a key role in defining the properties of SAW sensors. In this study, we investigate the structural and adhesion properties of a new class of coating material based on polyurethane polymeric composites. We used dark-field microscopy (DFM) and scanning electron microscopy (SEM) to observe the microstructure of polyurethane composite coatings on piezoelectric sensor elements and to analyze the effects of the chemical resistance and adhesion test (CAT) on the coating layers obtained with the polyurethane polymeric composites. The results of the microscopy showed that all polyurethane composite coatings exhibited excellent uniformity and stability after chemical adherence testing (CAT). All of the observations were correlated with the results of the ultrasonic analysis, which demonstrated the role of polyurethane as a binder to form the stable structure of the composites and, at the same time, as an adhesion promoter, increasing the chemical resistance and the adherence of the coating layer to the complex surface of the piezoelectric sensor element.

(P)ppGpp synthetase Rel facilitates cellulose formation of biofilm by regulating glycosyltransferase in Brucella abortus.

Biofilms are complex adhesive structures that establish chronic infection and allow robust protection from external stressors such as antibiotics. Cellulose as one of the compositions of bacteria biofilm which protect bacteria from stress, host immune responses and resistance to antibiotics. Bacterial stress responses are regulated via guanosine pentaphosphate and tetraphosphate (p)ppGpp. This molecule has been a target of research efforts to counteract biofilm formation in pathogenic bacteria. However, a role for (p)ppGpp synthetase Rel influencing in biofilms and its cellulose formation has not been identified in Brucella. Firstly, rel mutant significantly decreased biofilm biomass and rendered biofilms more susceptible to most antibiotics. The rel mutant also showed greatly decreased biofilm architectures including exopolysaccharide, extracellular DNA, and lipid. Remarkably, we found rel mutant significantly decreased biofilm cellulose formation. We further combined proteomic analysis to explore the key proteins involved in cellulose regulation of Rel in Brucella biofilm formation. 287 differentially expressed proteins (DEPs) were identified and enriched in diverse metabolic pathway between WT and Δrel strains including purine and sulfur metabolism, transcription factors and glycosyltransferases which may be related to cellulose formation. The Q-PCR showed that mRNA levels of only glycosyltransferase (WP_006161578.1) of the 12 down-DFPs had significantly upregulated in rel mutant contrast to WT strain and β-galactosidase assay showed a negative regulatory in rel mutant. Furthermore, Rel-dependent biofilms cellulose was also restored and accompanied by an increase in glycosyltransferase (WP_006161578.1) when glucose was added in TSB medium. Overall, this work expands the role of (p)ppGpp synthetase Rel as an important regulator in biofilm and cellulose formation that is tightly linked with pathogenicity and chronic persistent infections in Brucella.

Study of the modification mechanism and reinforcement performance of functionalized graphene-based structural adhesives

ABSTRACT This study investigates the effectiveness of modified graphene (MGE) for developing novel structural adhesives and their application in concrete beam reinforcement. The research aims to reveal the mechanism of MGE and evaluate the effect of different reinforcement methods on the flexural performance of concrete beams. Two adhesive formulations – original structural adhesive (OSA) and functionalized graphene-based structural adhesive (FGSA) – were examined alongside two reinforcement methods: the grouting reinforcement method and the adhesive fiber-reinforced polymer (FRP) method. The results show that the increased spacing of the functionalized MGE flakes improved their dispersion in epoxy resin, enhancing cohesive forces through bonding interactions and leading to the enhancement of the basic mechanical properties of FGSA by 6% to 12%. Compared to OSA, the application of FGSA improved the flexural properties of concrete beams, with the degree of improvement depending on the reinforcement method, while the failure mode of the beams remained unchanged. In addition, the FGSA/FRP combination showed the most significant improvement in the fracture parameters (220% to 480%) compared to the unreinforced control, highlighting its efficiency and cost-effectiveness as a reinforcement method. These findings offer valuable insights into reinforcement strategies for concrete beams, addressing the limitations of structural adhesive bond strength and optimizing reinforcement techniques.

The IQGAP-related RasGAP IqgC regulates cell–substratum adhesion in Dictyostelium discoideum

Proper adhesion of cells to their environment is essential for the normal functioning of single cells and multicellular organisms. To attach to the extracellular matrix (ECM), mammalian cells form integrin adhesion complexes consisting of many proteins that together link the ECM and the actin cytoskeleton. Similar to mammalian cells, the amoeboid cells of the protist Dictyostelium discoideum also use multiprotein adhesion complexes to control their attachment to the underlying surface. However, the exact composition of the multiprotein complexes and the signaling pathways involved in the regulation of adhesion in D. discoideum have not yet been elucidated. Here, we show that the IQGAP-related protein IqgC is important for normal attachment of D. discoideum cells to the substratum. Mutant iqgC-null cells have impaired adhesion, whereas overexpression of IqgC promotes directional migration. A RasGAP C-terminal (RGCt) domain of IqgC is sufficient for its localization in the ventral adhesion focal complexes, while RasGAP activity of a GAP-related domain (GRD) is additionally required for the proper function of IqgC in adhesion. We identify the small GTPase RapA as a novel direct IqgC interactor and show that IqgC participates in a RapA-regulated signaling pathway targeting the adhesion complexes that include talin A, myosin VII, and paxillin B. On the basis of our results, we propose that IqgC is a positive regulator of adhesion, responsible for the strengthening of ventral adhesion structures and for the temporal control of their subsequent degradation.

Air pollution modifies colonisation factors in beneficial symbiont Snodgrassella and disrupts the bumblebee gut microbiome

Particulate air pollutants, a major air pollution component, are detrimental to human health and a significant risk to wildlife and ecosystems globally. Here we report the effects of particulate pollutant black carbon on the beneficial gut microbiome of important global insect pollinator, the buff-tailed bumblebee (Bombus terrestris). Our data shows that exposure to black carbon particulates alters biofilm structure, gene expression and initial adhesion of beneficial bee gut coloniser, Snodgrassella alvi. Exposure of adult Bombus terrestris to non-toxic black carbon particulates significantly increased viable bacteria on MRS agar and 16S absolute abundance of beneficial bacteria Bombilactobacillus in Post-treated bumblebees compared to Pre-treated, demonstrating disruption of the bumblebee gut microbiome. These findings show that black carbon exposure has direct, measurable effects on bees’ beneficial commensal bacteria and microbiome. Together these data highlight that black carbon, a single type of particulate pollution, is an underexplored risk to insect pollinator health.

Plasma-aided direct printing of silver nanoparticle conductive structures on polydimethylsiloxane (PDMS) surfaces

We report a controlled deposition process using atmospheric plasma to fabricate silver nanoparticle (AgNP) structures on polydimethylsiloxane (PDMS) substrates, essential for stretchable electronic circuits in wearable devices. This technique ensures precise printing of conductive structures using nanoparticles as precursors, while the relationship between crystallinity and plasma treatment is established through X-ray diffraction (XRD) analysis. The XRD studies provide insights into the effects of plasma parameters on the structural integrity and adhesion of AgNP patterns, enhancing our understanding of substrate stretchability and bendability. Our findings indicate that atmospheric plasma-aided printing not only avoids the need for high-temperature sintering but also significantly enhances the electrical and mechanical properties of the conductive structures, advancing the production of robust and adaptable electronic devices for wearable technology.

Formation of Wrinkled Nanostructures via Surface-Bulk Curing Disparity in Ethyl Cyanoacrylate: Toward Superhydrophobic Surface Applications.

Superhydrophobic surfaces, known for their exceptional water-repellent properties with contact angles exceeding 150°, are highly regarded for their effectiveness in applications including self-cleaning, antifouling, and ice prevention. However, the structural fragility and weak durability of conventional coating limit their long-term use. In this research, a new approach is proposed for the fabrication of long-lasting superhydrophobic surfaces using ethyl cyanoacrylate (ECA) and a primer. The application of the primer creates a curing rate disparity between the surface and bulk of the ECA layer, resulting in the formation of wrinkled microstructures essential for achieving superhydrophobicity. The fabricated surfaces were further functionalized through plasma treatment and hydrophobic silane (OTS) coating, enhancing their water-repellent properties. This straightforward and scalable method produced surfaces with excellent superhydrophobicity and robust adhesion to substrates. Durability tests, including roller abrasion and microscratch evaluations, indicated that the wrinkled structure and strong substrate adhesion contributed to sustained performance even under mechanical stress. Additionally, mechanical properties were assessed through nanoindentation, demonstrating enhanced resistance to physical damage compared to conventional superhydrophobic coatings. This study highlights the potential of ECA-based superhydrophobic surfaces for applications requiring durability and mechanical stability, such as architectural coatings, automotive exteriors, and medical devices. The approach offers a promising solution to the limitations of existing superhydrophobic technologies and opens new avenues for further research into wear-resistant and environmentally resilient coatings.

The survival grip-how cell adhesion promotes tumor maintenance within the microenvironment.

Cell adhesion is warranted by proteins that are crucial for the maintenance of tissue integrity and homeostasis. Most of these proteins behave as receptors to link adhesion to the control of cell survival and their expression or regulation are often altered in cancers. B-cell malignancies do not evade this principle as they are sustained in relapsed niches by interacting with the microenvironment that includes cells and their secreted factors. Focusing on chronic lymphocytic leukemia and mantle cell lymphoma, this Review delves with the molecules involved in the dialog between the adhesion platforms and signaling pathways known to regulate both cell adhesion and survival. Current therapeutic strategies disrupt adhesive structures and compromise the microenvironment support to tumor cells, rendering them sensitive to immune recognition. The development of organ-on-chip and 3D culture systems, such as spheroids, have revealed the importance of mechanical cues in regulating signaling pathways to organize cell adhesion and survival. All these elements contribute to the elaboration of the crosstalk of lymphoma cells with the microenvironment and the education processes that allow the establishment of the supportive niche.

Focal adhesions, reticular adhesions, flat clathrin lattices: what divides them, what unites them?

The majority of cells within multicellular organisms requires anchorage to their surroundings in the form of cell-cell or cell-matrix adhesions. In regards to cell-matrix adhesions, the transmembrane receptors of the integrin family have long been recognized as the central scaffold around which these adhesion complexes are built. Via their extracellular domains integrins bind extracellular matrix ligands while their intracellular tails interact with a plethora of proteins that link integrin-based adhesions to the cytoskeleton and turn them also into important signaling platforms. Depending on the specific intracellular interactome of the integrins, different types of integrin adhesion complexes have been classified. The best-studied ones are the focal adhesions, in which integrins become firmly linked to contractile actomyosin fibers, allowing force transduction. But integrins also form an integral part of adhesion structures that lack the strong actomyosin link and are enriched in endocytic proteins. These have been named reticular adhesions, flat clathrin lattices, or clathrin plaques. Initially, the different types of integrin adhesion complexes have been viewed as discrete entities with their own separate life cycles. However, in the past years it has become more and more apparent how closely intertwined they are. In fact, it was shown that they can trigger each other's biogenesis or can even directly convert into each other. Here, we describe similarities as well as differences between integrin adhesion complexes, focusing on the versatile αvβ5 integrins, and discuss the recently discovered close links and interconversion modes between the different αvβ5 integrin adhesion types.

Mechanics analysis and experimental study of ultra-thin chip peeling from pre-stretching substrates

Successful chip peeling from a substrate facilitates the transfer process for obtaining the final functional chips, but remains a challenge in the practical production of ultra-thin chips. Flexible ultra-thin chips are prone to fragmentation during the peeling process, due to their fragility. In this study, a substrate pre-stretching process is introduced to the picking process to achieve a high yield of chip peeling, and this process is explored via modelling and experiments. The chip–adhesive pre-stretched substrate structure is modelled, involving both multi-needle ejection and vacuum suctioning, within the framework of Timoshenko’s beam theory. The theoretical analysis is validated using finite element analysis to compare the surface stress distribution on the chip and tip stress within the adhesive layer. During the peeling process, the competitive fracture behaviour of the chip between cracking and peeling is analysed using a dimensionless peeling health index as a metric to assess the health status of the chip. The effects of substrate pre-stretching on the adhesive layer stress, chip layer stress, and peeling health index are analysed. As substrate pre-stretching is found to improve the peeling health index only in the case of needle ejection, but impairs the peeling health index in the case of vacuum suctioning, needle ejection is considered the sole effective peeling method when a substrate pre-stretching process is introduced. Furthermore, through meticulous experimental verification, it is confirmed that pre-stretching of the substrate can significantly improve the success rate of chip peeling.

Multi-Mechanism Collaborative Bionic Fixation Technique Between a Wide Range of Solid Interfaces.

For rough surfaces, stable, fast, and repeatable fixation has wide applicability in transportation, fire protection, and other fields. Different rough surfaces present technical challenges for achieving convenient and reliable fixation. Based on the highly adhesive attachment structures of typical organisms, a multi-mechanism (negative pressure adsorption, mechanical locking, and chemical bonding) cooperative bionic fixation device is proposed. The device is equipped with a suction disc with gradient guide channels, a microneedles friction-enhancing unit, and fast-curable UV glue. These components work together to complete the fixation. The detachment work (max. 5.7 and 5.5 J) and pull-off force (max. 377 and 175 N) are evaluated on sandpaper of different roughness under vertical and horizontal pulling respectively. By analyzing the detachment process and experimental curves, the cooperative principle of the multi-mechanism is identified. In addition, the microneedles with soft backing at the bionic fixation device bottom improve its adaptability to rough surfaces. The gradient guide channels of the suction disc create Laplace pressure to speed up the UV glue flow and shorten fixation time. Furthermore, its applicability is demonstrated by combining it with monitoring equipment and an adult to attach to rough surfaces.

Enhanced recognition of bonding interface defects within CFRP-steel adhesive structures via thermal signals in low-power vibrothermography

Carbon fiber reinforced polymers (CFRP) have been used as one of the options to strengthen steel structures through adhesive bonding, particularly in specific applications where traditional strengthening methods may not be suitable. Therefore, it becomes crucial to perform inspections on the resulting CFRP-steel adhesive structures (CSAS) to ensure their structural integrity and safety. However, the distinct physical properties of CFRP, epoxy resin, and steel pose significant challenges to accurately inspecting bonding interface defects of such special hybrid engineering structures. To address these challenges, a new approach, streamlined one-dimensional convolutional denoising autoencoder-low-power vibrothermography (SOCDAE-LVT), is proposed in this study to enhance the recognition of bonding interface defects within CSAS. This approach utilizes thermal signals from low-power vibrothermography (LVT) to enhance the recognizability of CSAS bonding interface defects. A low-power vibrothermography inspection system was developed to acquire thermal signals on the surface of CSAS samples. A streamlined one-dimensional convolutional denoising autoencoder (SOCDAE) model was designed for robust representation extraction of the thermal signal at each pixel point. The study further investigated the impact of different types of added noise and signal pre-processing approaches on the performance of the SOCDAE-LVT, aiming to optimize its effectiveness. By comparing qualitatively and quantitatively with the state-of-the-art approaches, the results show that the proposed approach can better improve the recognizability of defects. The enhanced recognizability of bonding interface defects enables accurate assessment of the quality of CSAS, thereby contributing to the safety of such structures.

Analysis of the Influence of Adhesive, Geometry, and Manufacturing Processes on Mixed Mode Stress Ratio in Single Lap Shear Adhesive Joint Structures of Aluminum and Composite Plates

In aircraft structures, composite plate joints often present significant challenges. Mechanical fastenings such as pins, bolts, or rivets require holes to be drilled in the plates, which reduces the strength of the laminate due to stress concentrations around the hole edges. These joints frequently become sources of structural failure in aircraft. Therefore, the design of composite plate joints is crucial to maintain structural integrity. Adhesive joints offer several advantages over mechanical joints, including the ability to join two different materials, more uniform stress distribution along the joint, and reduced weight since no bolts or rivets are needed. The most common adhesive joint design is the Single Lap Joint (SLJ), which is popular due to its simple geometry and high structural efficiency. However, the main drawback of the SLJ is load eccentricity, which leads to secondary bending and undesirable normal stresses along the adhesive edges. The hypothesis of this study is that SLJ conditions with optimal shear strength can be achieved through the right combination of adhesive type, bond surface preparation, and joint configuration. This study analyzes the influence of various adhesive materials, joint designs, and manufacturing methods using numerical modeling methods, validated with analytical approaches and ASTM standard testing. Numerical modeling is conducted using the finite element method with a cohesive zone model (CZM) approach to examine stress distribution in various cases, such as the impact of geometry, adhesive thickness, and joint length. The normal and shear stress distribution along the joint is found to significantly affect the strength of the SLJ, highlighting the importance of careful design and material selection in these applications.

Regulating Cross-Linking Structure and Dispersion of Core-Shell-Rubber Particles in Polyurethane Composite to Achieve Excellent Mechanical Properties for Structural Adhesive Application.

Structural adhesives are bonding materials that can quickly join structures with components and repair cracks. However, thermosetting polyurethane structural adhesives suffer from disadvantages such as insufficient toughness, poor aging resistance, and long curing time, which greatly limit their practical application. Herein, a polyurethane (PU) composite with excellent mechanical properties was prepared successfully via regulating the cross-linking structure and the dispersion of core-shell-rubber (CSR) particles. Various polyols were selected to improve the cross-linking density of the PU and to enhance the intermolecular forces, which can achieve the high strength and stability of the polyurethane composites. Solvent displacement was used to improve the dispersion of CSR in PU. The cured composite has ultra-high toughness and impact resistance due to the well-dispersed CSR particles. The impact strength was increased from 52.0 to 90.4 kJ/m2, and the elongation at break was increased from 6.1% to 14.9%. Due to the addition of catalyst T120, this composite can be cured quickly at room temperature, reaching high strength after 30 min. In addition, these composites can resist extreme environments, such as high and low temperature changes, UV aging, high humidity and heat environment, and salt spray aging, which has potential and value for practical application. The prepared PU structural adhesive can meet the requirements of structural bonding transit and improve the production efficiency. This work proposed a novel strategy to prepare polyurethane composites with excellent mechanical properties for structural adhesive application.

Custom-shaped malleable, recyclable and reversible structural adhesives based on vanillin polyimine vitrimers

A series of polyimine vitrimers were prepared from a synthesized dialdehyde derivative of vanillin. This derivative was then crosslinked with two different ratios of amines (Jeffamine T403 and m-xylylenediamine), forming imine bonds responsible for the exchange reactions. This process resulted in three distinct materials which exhibited glass transition temperatures (Tgs) ranging from 20 to 60 °C, along with good thermal stability, and strong mechanical and thermomechanical properties.Their dynamicity resulted in a fast relaxation rate achieving a complete relaxation in less than 15 min at 140 °C. Additionally, the polyimines could be mechanically recycled up to three times without significant loss in their final properties, demonstrating the possible enhancement of their lifespan. Moreover, they could be chemically recycled under mild conditions through acid hydrolysis or transamination, which significantly contributes towards a better circular economy. Furthermore, these vitrimers were tested as reversible structural adhesives, achieving initial lap-shear strength values of 12.4 MPa and up to 97 % of efficiency after re-bonding, highlighting their huge potential for industrial applications. Due to their pre-cured state, these adhesives were malleable, which allow them to be custom-shaped into different complex shapes. Finally, these imine materials showed outstanding self-welding capabilities with the repaired versions showing comparable performance to the original.

A double-layered optically clear adhesive with enhanced resistance to waviness and impact, designed for use in high-end mobile display

In high-tech display industries, excellent impact resistance and surface waviness implementation technologies have gained much attention as the products are being lightweight and thinned. In particular, as a black pixel defining layer is adopted instead of a polarizer used to prevent external light reflection, impact resistance performance and surface quality characteristics are problematic. Herein, we proposed the double-layered optically clear adhesive (OCA) structure consisting of urethane-acrylate type OCA and UV-curable acrylic OCA for simultaneously achieving impact resistance and surface quality performances. Urethane simultaneously contains the soft segment and the hard segment based on hydrogen bonding between urethane functional groups, indicating high shock absorption performance. In addition, due to this unique structure, it exhibited a high modulus in the compression direction, thereby realizing excellent surface waviness. The UV-curable acrylate OCA can implement basic properties of adhesives such as tacky, adhesion, and inkstep cover capability, while at the same time securing indentation resistance with high modulus after UV curing. Optimization of impact resistance performance and surface waviness according to the thickness and laminating order of the proposed double-layered OCA was performed, and as a result, the double-layered OCA in panel/urethane-acrylate type OCA 100 μm/UV-curable acrylic OCA 25 μm/window structure showed the improved surface quality of 0.22 Kc value improved by 56.8 % and impact resistance of 5.1 cm improved by 100 % compared to the conventional OCA.

Suction-forced triboelectricity escalation by incorporating biomimetic 3-dimensional surface architectures

Triboelectric nanogenerators (TENGs), which operate on the principles of electrostatic induction and triboelectrification, have emerged as highly promising devices for energy harvesting, offering vast potential to address the challenges of energy depletion. In this study, we present a hierarchical bio-inspired architecture designed to enhance the triboelectric effect through a physically adhesive mechanism, achieved by creating a highly deformable 3D microstructure. This three-dimensional (3D) architecture, inspired by the male diving beetle, features properties that increase the contact area and compressibility of the interface by forming conformal contact with the electrode surface in both dry and wet environments. The architecture enhances van der Waals forces and generates multiple physical adhesion forces at the interface, leading to significant charge transfer. Compared to flat surfaces as well as various 3D bio-inspired architectures such as linear-shaped pillars and mushroom-like architectures, diving beetle inspired architecture demonstrated the highest triboelectric performance, generating voltage (∼42 V) and current (∼1008 nA) in dry conditions at 16 N of force. The results of this study offer a new perspective, demonstrating that triboelectricity can be efficiently generated through the strategic design of physically adhesive structures, as opposed to conventional TENGs that rely on structureless designs or chemical adhesives.

Effects of Loading Type and Loading Rate on Glulam Sipo Timber Beams for Flexural Loading

Glulam wood elements are a high-performance structural material created by bonding layers of wood with structural adhesives. This study investigates the behavior of glulam beams made from the tropical timber species Sipo, which has limited representation in existing literature, under different loading types and rates in bending tests. Six Sipo glulam beams were tested: three under four-point bending and three under three-point bending. To assess the behavior at various loading rates, loads were applied at rates of 10 mm/min, 20 mm/min, and 30 mm/min. The results included load-displacement curves, ultimate load capacities, initial stiffness, and energy absorption capacities. The study revealed differences between values obtained from three-point and four-point bending tests. Generally, beams subjected to three-point bending yielded higher values than those tested under four-point bending at the same loading rates. Notably, a significant reduction in values was observed for both testing methods at the loading rate of 20 mm/min.

Convolutional Neural Network for Interface Defect Detection in Adhesively Bonded Dissimilar Structures

This study presents an ultrasonic non-destructive method with convolutional neural networks (CNN) used for the detection of interface defects in adhesively bonded dissimilar structures. Adhesive bonding, as the weakest part of such structures, is prone to defects, making their detection challenging due to various factors, including surface curvature, which causes amplitude variations. Conventional non-destructive methods and processing algorithms may be insufficient to enhance detectability, as some influential factors cannot be fully eliminated. Even after aligning signals reflected from the sample surface and interface, in some cases, due to non-parallel interfaces, persistent amplitude variations remain, significantly affecting defect detectability. To address this problem, a proposed method that integrates ultrasonic NDT and CNN, and which is able to recognize complex patterns and non-linear relationships, is developed in this work. Traditional ultrasonic pulse-echo testing was performed on adhesive structures to collect experimental data and generate C-scan images, covering the time gate from the first interface reflection to the time point where the reflections were attenuated. Two classes of datasets, representing defective and defect-free areas, were fed into the neural network. One subset of the dataset was used for model training, while another subset was used for model validation. Additionally, data collected from a different sample during an independent experiment were used to evaluate the generalization and performance of the neural network. The results demonstrated that the integration of a CNN enabled high prediction accuracy and automation of the analysis process, enhancing efficiency and reliability in detecting interface defects.