Adhesion Area Research Articles

Artificial intelligence-based analysis of time-lapse images of sphere formation and process of plate adhesion and spread of pancreatic cancer cells.

Background: Most pancreatic cancers are pancreatic ductal adenocarcinomas (PDAC). Spherical morphology formed in three-dimensional (3D) cultures and the effects of anticancer drugs differ between epithelial and mesenchymal PDAC cell lines. In the human pancreas, cancer cells form 3D tumors, migrate to adjacent tissues, and metastasize to other organs. However, no effective methods exist to examine the ability of the tumor mass to migrate to surrounding tissues in vitro. We used spheres formed in 3D culture to investigate whether the migratory ability of tumors of PDAC cell lines, including epithelial and mesenchymal cell lines, varies. Methods: Sphere formation and adhesion and spread on culture plates were examined by artificial intelligence-based analysis of time-lapse imaging using five epithelial and three mesenchymal PDAC cell lines. Fused and non-fused areas of the sphere surface during sphere formation on low-attachment plates, the adhesion area to normal culture plates, and the sphere area maintaining its original form during adhesion to plates were measured. Results: Immunocytochemical staining confirmed that E-cadherin was highly expressed in epithelial PDAC spheres, as was vimentin in mesenchymal PDAC spheres, in 2D culture. When forming spheres using low-attachment plates, most epithelial PDAC cell lines initially showed decreased sphere area, and then the covering cells fused to form a smooth surface on the sphere. Mesenchymal PANC-1 and MIA PaCa-2 cells showed little reduction in sphere area and few areas of sphere surface fusion. When formed PDAC spheres were seeded onto normal culture plates, spheres of epithelial PK-8 cells-which have the highest E-cadherin expression, form numerous cysts, and have smooth sphere surfaces-did not adhere to normal plates even after 60h, and epithelial PK45-P and T3M-4 spheres hardly adhered. Conversely, the area of adhesion and spread of mesenchymal PANC-1 and KP4 cell spheres on normal plates markedly increased from early on, forming large areas of attachment to plates. Conclusion: Seeding spheres formed in 3D culture onto culture plates can clarify differences in tumor migration potential to surrounding areas. The masses formed by each PDAC cell line varied in migratory ability, with mesenchymal PDAC masses being more migratory than epithelial PDAC masses.

Biomechanical Behavior of Lithium-Disilicate-Modified Endocrown Restorations: A Three-Dimensional Finite Element Analysis

This study aimed to assess the biomechanical behavior of endocrown-restored mandibular molars according to “margin design” and “coverage extent” using finite element analysis (FEA). Six 3D solid models were fabricated, namely, those with complete occlusal coverage: A (butt joint), B (anatomic margin); partial coverage (two mesial cusps): C (butt joint), D (anatomic margin); and partial coverage with mesial class II cavity: E (butt joint), F (anatomic margin). All models received lithium disilicate endocrowns (2.0 mm thickness and 4.0 mm central retainer cavity depth). A 300 N vertical load was applied to the occlusal surface, while a 250 N oblique load was applied at 45° to the lingual inclined planes of the buccal cusps. The maximum von Mises stress (VMS) distribution patterns were calculated for the endocrown, tooth structure, and cement layer. The VMS on the prepared teeth and cement layer showed subtle differences between the tested models under vertical loads. The anatomic margin (partial and complete coverage) exhibited a more homogeneous stress distribution and offered a more adhesive area of the tooth structure. Under oblique loading, the anatomic margin (complete and partial), except Model D, exhibited the lowest VMS in the cement layer. An anatomically based endocrown could be a promising alternative to the butt joint design, providing better-devised endocrown restorations, which could potentially yield a more benign stress dissipation.

Efficacy and safety of purified starch for adhesion prevention in colorectal surgery

BackgroundAdhesions within the abdominal cavity develop in as many as 90 % of individuals following abdominal surgery. However, the true adhesive condition of patients can only be ascertained during the second surgery. MethodsWe conducted a prospective, non-randomized study to assess the anti-adhesion properties of purified starch in patients who had undergone colorectal surgery in the past and then needed a subsequent surgical intervention. Adhesion scores have been prospectively recorded in operation notes since January 2020 when patients underwent a second surgery. Patients who had received purified starch during their initial surgery constituted the purified starch group, while those who had not received anti-adhesion medical materials were the control group. The main objectives of the study were to evaluate the extent and severity of adhesions as primary outcomes, while secondary outcomes included measuring blood loss, operation time, and postoperative complications. ResultsWe analyzed the data of 101 patients, with 61 in the purified starch group and 40 in the control group. In multivariate analysis, adhesion severity (Odds ratio, 0.20, 95 % confidence interval 0.08–0.54, P < 0.01) and adhesion area scores (Odds ratio, 0.13, 95 % confidence interval 0.04–0.45, P < 0.01) were significantly lower in the purified starch group than in the control group. There was no significant difference in operation times, blood loss, and postoperative complications between the two groups. ConclusionPurified starch is a safe and effective anti-adhesion material that can significantly reduce the severity and extent of adhesion after colorectal surgery.

Composite Microfluidic Petri Dish-Chip (MPD-Chip) without Protein Coating for 2D Cell Culture.

Hydrophilicity is a requisite attribute for the 2D cell culture substrate's surface, facilitating cell adhesion and spreading. Conventional poly(dimethylsiloxane) (PDMS) microfluidic chips necessitate protein coatings to enhance hydrophilicity; however, this approach is afflicted by issues of transient efficacy, interference with cell analysis, and high costs. This paper presents a protein-free microfluidic chip, termed a "microfluidic Petri dish-chip (MPD-chip)", integrating PDMS as the cover and a tissue culture-treated (TC-treated) Petri dish as the substrate. Microstructures are hot-embossed onto the Petri dish substrate using a silicon mold. This meticulous replication process serves to establish stable flow field dynamics within the chip. A simplified method for irreversible bonding, utilizing plasma activation and silylation, is proposed for affixing the PDMS cover onto the microstructured Petri dish substrate. The prepared composite chip exhibits remarkable tightness, boasting a notable bond strength of 2825 kPa. Furthermore, the composite microfluidic chip demonstrates the capability to withstand flow velocities of at least 200 μL/min, effectively meeting the required injection standards for both cell suspension and culture medium. SH-SY5Y and HeLa cells are cultured dynamically in the MPD-chip and control groups. Outcomes encompassing normalized cell density, cell adhesion area, and cell viability metrics unequivocally highlight the superiority of the MPD-chip in facilitating long-term two-dimensional (2D) cell cultures.

Stem Cell Self‐Triggered Regulation and Differentiation on Polyvinylidene Fluoride Electrospun Nanofibers

AbstractSmart electroactive materials that can dynamically regulate stem cell fate without external stimuli have fascinated increasing attention. Meanwhile, noninvasive electrical stimulation has emerged as a less restrictive approach, generating considerable interest in its potential biomedical applications. The intricate interplay between cells and materials within complex microenvironments includes encompassing substrate response, ion exchange, and membrane potential alterations. However, the mechanisms by which smart materials influence stem cells have yet to be fully elucidated. Herein, electrospinning technology is utilized to fabricate bone‐mimicking microenvironments comprising disordered and highly oriented polyvinylidene fluoride (PVDF) nanofibers. The aligned annealed PVDF (AA) and random annealed PVDF (RA) membranes present high fractions of β‐phase. By comparing the osteogenic ability, calcium activity, and F‐actin distribution of bone marrow‐derived mesenchymal stem cells (BMSCs) cultured with these PVDF nanofibers, it is proposed that the stem cells autonomously regulate their differentiation by remodeling the cytoskeleton on the electrospun membranes. Electrical stimulation, more adhesion area, and active calcium influx support the greater osteogenesis of BMSCs on RA than AA. This mechanism can provide a basic theory for the design and preparation of bone tissue engineering scaffolds and contribute to the further study of cells and microenvironments.

Determination of the optimal shape of permanent magnets of a given volume providing maximum strength of their magnetic coupling

The ponderomotive force of the adhesion of two permanent magnets depends on their shape. We present the results of determining the optimal shape of ellipsoidal magnets providing maximum magnetic adhesion between them. The interaction of two halves of a magnet, which is an ellipsoid of revolution, and a magnet in the form of a long rod with an elliptical cross section, is analyzed. Analytical formulas for the cohesion forces in these cases are obtained. For a fixed mass or volume of magnets, the problem of optimizing the adhesion force is solved and a geometric shape which provide the maximum adhesion force is determined. It is shown that in the case of a magnet in the form of an ellipsoid of revolution, the maximum adhesion force of its halves (ignoring the magnetic tension on the side surfaces) is achieved at an eccentricity of 0.625958. The magnitude of the maximum adhesion force exceeds the adhesion force of the halves of a uniformly magnetized spherical magnet of the same volume by 1.7%. In this case, the adhesion area of the ellipsoidal magnet will be less than the adhesion area of the spherical magnet by 28%. The optimal form of a bar magnet with an elliptical section with the maximum force of adhesion of its halves at a fixed volume of the magnet is determined. A formula is derived for the ponderomotive magnetostatic force of the interaction between the halves of a bar magnet with an elliptical section and the maximum force of interaction. Numerical estimates for a sintered NdFeB bar magnet showed that the ponderomotive force of interaction with a cross-sectional radius of 5 cm can reach 2 tons per 1 m of length. The results obtained can be used to improve the efficiency of devices based on permanent magnets.

Bilayer nonwovens using natural rubber, poly(lactic acid) and bactericidal nanoparticles for wound dressings

Wound healing poses a significant challenge in healthcare, impacting not only on patients' quality of life but also placing a substantial financial burden on healthcare systems. Bilayer nonwovens have emerged as a promising solution for wound dressings due to their porous morphology, providing a high surface area for cellular adhesion and growth, and their permeability, allowing proper oxygen and fluid exchange to promote wound healing. When bactericide materials are added to the formulation, they can decrease or prevent infection caused by microorganisms, further aiding the healing process. Solution blow spinning is an appealing technique for creating bilayer nonwovens as it can produce high yields at a low cost. Yet, even though natural rubber boasts a well-established safety record in biomaterials, it remains an underexplored candidate for generating micro-nanofibrous structures. In this study, solution blow spinning was employed to fabricate bilayer composite nonwovens for wound dressing materials. The material architecture consisted of a bottom layer composed of a blend of natural rubber, poly(lactic acid) (PLA), and polyethylene glycol in the respective proportion of 2:1:3 w/w and a top layer composed of PLA and ZnO nanoparticles added in concentrations of 1%, 2.5%, and 5% based on the PLA mass of this layer. The top layer was further functionalized with Ag nanoparticles through spraying. The obtained materials demonstrated satisfactory hydrophobicity for cellular adhesion in the bottom layer, ranging from 51.95° to 92.20° of water sessile drop contact angle, and tunable mechanical strength, which could be controlled by varying the content of ZnO nanoparticles. Additionally, the material showed antimicrobial properties due to the presence of added Ag nanoparticles, able to inhibit E. coli, S. enterica serovar Typhimurium, and S. aureus by direct contact. Besides, the nonwoven prevented the passage of microorganisms due to the pore size of the structure. Overall, the unique properties of the developed material, such as its low cost, ease of production, and remarkable wound-healing properties, make it a promising candidate for wound dressing applications.

The loss of resin cement adhesion to ceramic influences the fatigue behavior of bonded lithium disilicate restorations

When partial and/or non-retentive preparation, such as those for occlusal veneers, is indicated, a proper and stable adhesion is essential. Therefore, the aim of this in vitro study was to evaluate the effect of loss of adhesion in different regions of the bonding interface on the fatigue behavior of simplified lithium disilicate restorations. For this, lithium disilicate (IPS e.max CAD) discs (1 mm thick and Ø = 10 mm) were fabricated, polished with #400-, #600-, #1200-grit silicon carbide (SiC) papers, and crystallized. As substrate, fiber-reinforced resin epoxy discs (2.5 mm thick and Ø = 10 mm) were fabricated and polished with #600-grit SiC paper. The ceramic bonding surface was treated with 5% hydrofluoric acid and a silane-containing primer (Monobond N), while the substrate was etched with 10% hydrofluoric acid followed by the application of the bonding system primers (Primer A + B). A lacquer (nail polish) was used to simulate the loss of adhesion in specific areas according to the study design to compose the testing groups: bonded (control; did not received nail polish application); – non-bonded (loss of adhesion in the whole specimen area); – margin (loss of adhesion in the ceramic margin); – center (loss of adhesion in the ceramic central area). The adhesive area of partially bonded groups was 50% of the adhesive surface. Then, the discs (n = 12) were bonded to the respective substrate using a resin cement (Multilink N), light-cured, water-stored for 90 days, and subjected to thermocycling (25,000 cycles, 5° to 55 °C) before testing. A cyclic fatigue test was run (20 Hz, initial load of 200 N for 5000 cycles, 50 N step size for 10,000 cycles each until specimen failure), and the fatigue failure load and number of cycles for failure were recorded. As complementary analysis, finite element analysis (FEA) and scanning electron microscopy analysis were performed. Kaplan-Meier log-rank (Mantel-Cox) was conducted for survival analysis. The results showed that as the loss of adhesion reaches the central area, the worse is the fatigue behavior and the higher is the stress peak concentration in the ceramic bonding surface. The bonded specimens presented better fatigue behavior and stress distribution compared to the others. In conclusion in a non-retentive preparation situation, proper adhesion is a must for the restoration fatigue behavior even after aging; while the loss of adhesion reaches central areas the mechanical functioning is compromised.

Улучшение точностных характеристик формообразующей оснастки с применением композитных силовых каркасов, полученных с использованием бесконтактной измерительной системы

Aviation industry presents the increased demand to geometric accuracy of a product. Component production from the polymer composite materials is based on obtaining final geometric characteristics of a product, as a result of machining on the precision molding equipment. Experience in manufacture of forming equipment from the polymer composite materials demonstrated that a shell reinforced with walls was most effective both structurally and technologically; and it could be considered as the main design scheme for the forming equipment. One of the critical factors influencing the equipment shape accuracy is connection between the frame and the form-building shell. To increase accuracy in manufacturing the form-building equipment, a method is proposed that involves scanning the backside of the form-building shell and subsequent machining of the composite support frame on a CNC machine based on the scanning results, which allows reducing maximum deviations from the shell theoretical contour. Analyzing results of testing this method showed an increase in the frame contact area with the form-building shell and, as a consequence, the adhesive connection area, which made it possible to increase the equipment service life.

Cultural Heritage Image Analysis and Support Modeling Using X-ray Computed Tomography: Focused on the Byeongsan Mask ‘Eul’ of the Hahoe Masks and Byeongsan Masks of Andong

Before conservation treatment, the Byeongsan Mask ‘Eul’ was damaged, and the face was separated on both sides and attached with stiffeners. For conservation treatment, it was necessary to remove the existing stiffeners and adhese the faces together. At this time, a support was needed to fix both faces that were separated during conservation process and to structurally stabilize the adhesion area where pressure could be concentrated even after adhesion. In order to manufacture new support, the shape analysis was first performed using the X-ray computed tomography data, and then the re-adhesion position was set. Next, modeling was conducted considering the function of the support and aesthetic conditions using the digital haptic modeling system. The completed model was printed by 3D printing using transparent material. The support produced in this study is significant in that it played a major role in the conservation process, such as being used not only to hold and store the masks but also to fix them during the conservation process. In addition, by producing support using digital methods and data, support optimized for the shape of artifact could be produced with minimal contact with artifact. This study presented a method for conserving and displaying artifacts using digital technology, and is expected to be expanded and applied to various cultural heritages.

Design and Analysis of a Stable Support Structure for a Near-Infrared Space-Borne Doppler Asymmetric Spatial Heterodyne Interferometer

As spectral resolution increases, the dimension of the Doppler Asymmetric Spatial Heterodyne (DASH) interferometer increases. The existing approach for stably mounting the interferometer is limited to mounting a normal-sized DASH interferometer. In this study, a novel and stable structure is proposed, with its effecti1veness exemplified for a near-infrared (NIR) DASH interferometer. The mathematical model of a flexible structure was established. The parameters of the support structure were optimized by requiring the mechanical stress of the flexible structure and shear stress at the bonding surface to be less than the strength value. The spring constants were optimally designed to adjust natural frequency and minimize stress. The finite element analysis (FEA) results show that the maximum mechanical stress was 65.56 MPa. The maximum shear stress was 3.4 MPa. All stress values had a high safety margin. The mechanical material and adhesive area were optimally designed. Therefore, the thermal resistance of the structure was improved by 7.5 times. The test results indicate that the proposed flexible support structure could satisfy the requirements of the launch environment. The results from FEA and vibration tests were consistent with the model calculation results. Compared to existing structures, the mechanical performance and thermal resistance were improved.

Cellulose nanofiber‐incorporated high‐solid siloxane acrylic latex by mini‐emulsion polymerization for hydrophobic coating and wood adhesive

AbstractIn order to contribute to the thriving research on bio nanocomposites for sustainable future, here we developed a cellulose nanofiber (CNF)‐based siloxane acrylic nanocomposite aiming to the application as hydrophobic coating and wood adhesive. CNF was incorporated in a copolymer matrix of poly (methyl methacrylate‐co‐butyl acrylate) [P(MMA‐co‐BA)] cross‐linked with methacrylate‐terminated siloxane (MTS). The copolymer was prepared by mini‐emulsion polymerization at a high solid content of about 57 wt%, where CNF was incorporated to the latex both by in‐situ polymerization and ex‐situ mixing process. The impact of the process of CNF incorporation and its content in the copolymer matrix were evaluated by measuring the thermal, mechanical, water repelling and adhesion properties. All the nanocomposites showed improved mechanical properties (tensile strength: upto 3.9 MPa) and wood adhesion strength (upto 1178 N) compared to the pristine copolymer. In addition, they showed significantly high water‐repelling properties on spray‐coated cotton (water contact angle: 110°–124°). Such siloxane acrylic/CNF nanocomposite has the potential as a sustainable material in the application area of hydrophobic coatings and adhesives.

Reducing Wheel Loading in the Grinding of Titanium Alloys through Ultrasonic-Assisted Plasma Oxidation Modification

To reduce wheel loading caused by chip adhesion in the grinding of titanium alloys, a new method named ultrasonic-assisted plasma oxidation modification grinding is suggested. The processing principle was introduced in this research, and based on that, the experimental apparatus was established. Then, the surface and cross-sectional morphologies of a workpiece with an oxide layer were characterized, followed by the detection of its microhardness and surface composition. On this basis, in the absence and presence of the oxide layer, the dynamic changes in wheel loading on the grinding wheel surface and the evolution behavior of chip adhesion on the grains were both investigated after gradually increasing the grinding passes. Finally, the effects of wheel loading on the ground surface morphologies were analyzed. The results showed that the oxide layer with low microhardness was mainly composed of TiO2 and Al2O3. Moreover, with an increase in grinding passes, the overall occupied area of chip adhesion on the grinding wheel surface increased proportionally in the absence of the oxide layer, which finally caused severe wheel loading. Conversely, yet at almost the same rate, the overall occupied area of chip adhesion increased after remaining comparatively unchanged in a short range of grinding passes in the presence of the oxide layer, which effectively inhibited the wheel loading. Compared with the ground surface obtained without an oxide layer, the generation of plastic-stacking was significantly restrained with the assistance of the oxide layer, thereby improving the ground surface quality.

Using a convex ostomy appliance to manage peristomal skin complications: introducing Aura Plus Soft Convex.

This article explores convex stoma appliances, introduces Aura Plus Soft Convex (CliniMed) and presents three case studies of its use. Convexity applies pressure to flatten uneven peristomal skin and form an effective adhesive seal, as well as increase protrusion of a poorly spouted stoma. This reduces the risk of leaks and peristomal skin damage, as well as minimising accessory use. Excess pressure can damage the skin, so convexity should be used with caution at the appropriate depth and firmness for the ostomate's body profile and stomal complications. Aura Plus Soft Convex has a soft and flexible baseplate for easy application and adherence, as well as a unique shape, comfort curves and a large adhesive area to reduce creases and leaks. The hydrocolloid contains Manuka honey to promote skin health, and integral belt loops offer additional security. The case studies show how this appliance can restore peristomal skin integrity and relieve stoma-related anxiety; provide gentle support for a flush stoma and a rounded abdomen; and prevent leaks and improve quality of life after years of stoma-related complications.

Using a convex ostomy appliance to manage peristomal skin complications: introducing Aura Plus Soft Convex.

This article explores convex stoma appliances, introduces Aura Plus Soft Convex (CliniMed) and presents three case studies of its use. Convexity applies pressure to flatten uneven peristomal skin and form an effective adhesive seal, as well as increase protrusion of a poorly spouted stoma. This reduces the risk of leaks and peristomal skin damage, as well as minimising accessory use. Excess pressure can damage the skin, so convexity should be used with caution at the appropriate depth and firmness for the ostomate's body profile and stomal complications. Aura Plus Soft Convex has a soft and flexible baseplate for easy application and adherence, as well as a unique shape, comfort curves and a large adhesive area to reduce creases and leaks. The hydrocolloid contains Manuka honey to promote skin health, and integral belt loops offer additional security. The case studies show how this appliance can restore peristomal skin integrity and relieve stoma-related anxiety; provide gentle support for a flush stoma and a rounded abdomen; and prevent leaks and improve quality of life after years of stoma-related complications.

Aphid-Inspired and Thermally-Actuated Soft Gripper Using 3D Printing Technology.

Herein, a thermo-actuated aphid-inspired dry adhesive (TADA) that offers tunable and reversible adhesion isreported. It is easily fabricated through 3D printing using a polylactic acid (PLA) filament and silicone elastomer, avoiding the use of unfavorable methods for micro- and nanofabrication and unwanted particles for actuation. The tunable adhesive system mimics aphid biology to achieve adhesion switchability. Switching between adhesion states is enabled by the thermo-actuated PLA, which has shape memory properties. Additionally, silicone elastomer enables adherence to flat substrates such as glass, silicon wafers, and acrylic plates. The detachment time of the TADA can be controlled by changing the printing layer height, which is a 3D-printing parameter that results in a short detachment time when the printing layer height is small. The adhesion strength ismeasured by applying different preloads and varying the size of the adhesive area. The reversibility between the adhesion-on and adhesion-off states, revealing good repeatability with similar adhesion strengths isalso demonstrated. The TADA has potential applications in transferring silicon wafers. In addition, it can be printed to fit a flat plate of any shape, enabling it to grip the plate stably.

Comparative Evaluation Shear Bond Strength of Resin Composite Cement to Coronal Enamel, Cementoenamel Junction and Root Cementum: An in Vitro Study

Aim: To compare shear bond strength of resin composite cement to coronal enamel, cementoenamel junction and root cementum. Materials and Methods: Twenty one extracted human permanent teeth were selected and randomly divided into three groups(n=21) according to area of adhesion. group 1(n=7): coronal enamel. group 2(n=7): cementoenamel junction. group 3(n=7): root cementum. An area of 5mm x 5mm was selected on tooth of each specified group. Area was etched for 15 seconds with 35% phosphoric acid and washed off. Bonding agent was applied on area and light cured, composite was applied and light cured for 30 seconds. Teeth were mounted in acrylic resin and stored in distilled water. Specimens were subjected to shear load using universal testing machine at cross head speed of 0.5mm/min. Results: According to results obtained from the study comparative shear bond strength (in Mpa) of resin composite cement to coronal enamel, cementoenamel junction and root cementum, highly statistically significant (p&lt;0.001) difference was observed among three groups. Discussion: The cervical area of teeth is most unpredictable region for durable adhesive bonding. This study was performed to evaluate adhesion potential of composite cement to coronal and cervical structures of teeth. Conclusion: Under this study, we can conclude that adhesion to root cementum is less favorable compared to adhesion to CEJ and coronal enamel.

A Novel Nickel-Plated Carbon Fiber Insert in Aluminum Joints with Thermoplastic ABS Polymer or Stainless Steel.

New types of hybrid aluminum joints: Al-acrylonitrile butadiene styrene (ABS) carbon fiber reinforced thermoplastic polymer (CFRTP) designated Al/Ni-CFP/ABS, and Al-18-8 Stainless steel, Al/Ni-CFP/18-8, by Ni-plated carbon fiber plug (Ni-CFP) insert not before seen in the literature have been fabricated. The goal is to take advantage of extremely high ~6 mm CF surface area for high adhesion, to enhance the safety level of aircraft and other parts. This is without fasteners, chemical treatment, or glue. First, the CFP is plated with Ni. Second, the higher melting point half-length is spot welded to the CFP; and third, the remaining half-length is fabricated. The ultimate tensile strength (UTS) of Al/Ni-CFP/ABS was raised 15 times over that of Al/ABS. Normalized cUTS according to CFP cross-section by Rule of Mixtures for cAl/Ni-CFP/18-8 was raised over that of cAl/Ni-CFP/18-8 from 140 to 360 MPa. Resistance energy to tensile deformation, UT, was raised 12 times from Al/ABS to Al/Ni-CFP/ABS, and 6 times from Al/CFP/18-8 to Al/Ni-CFP/18-8. Spot welding allows rapid melting followed by rapid solidification for amorphous metal structures minimizing grain boundaries. The Ni-coating lowers or counters the effects of brittle Al4C3 and FexC formation at the interface and prevents damage by impingement to CFs, allowing joints to take on more of the load.

Influence of adhesive thickness and defect on mechanical property of adhesive bonded joint of flexible polymer substrate and cable for solar panel application

Flexible polymer substrate and flat polymer cable were adhesive bonded to fabricate the solar panel in the present study. The relationship between the adhesive thickness, mechanical properties and fracture morphologies of the joints were systematically investigated to figure out how the adhesive layers with different thickness affected the joints’ mechanical properties. The influence of the defects on the joint quality was also studied via an artificial defect introduction method. Adhesive failure accompanied with low tensile-shear strength was easy to occur to the joints with extremely thin adhesive thickness due to the weak boundary formation between the adhesive and the adherent. When the adhesive thickness increased, the joints started to show the cohesive failure with higher tensile-shear strength since the adhesive completely fill the surface crevices. The joints’ mechanical properties however decreased again with further increasing the adhesive thickness, owing to the generation of more defects and higher residual stress within the thicker adhesive layer. On the other hand, adhesive failure was more likely to occur around the defect, which significantly deteriorated the joints’ mechanical properties. The defect located in the center of the bonding area led to a larger adhesive fractured area, thereby having a greater impact on the mechanical properties in comparison to the same-size defect located in the corner or the marginal center.

Push-pull mechanics of E-cadherin ectodomains in biomimetic adhesions

E-cadherin plays a central role in cell-cell adhesion. The ectodomains of wild-type cadherins form a crystalline-like two-dimensional lattice in cell-cell interfaces mediated by both trans (apposed cell) and cis (same cell) interactions. In addition to these extracellular forces, adhesive strength is further regulated by cytosolic phenomena involving α and β catenin-mediated interactions between cadherin and the actin cytoskeleton. Cell-cell adhesion can be further strengthened under tension through mechanisms that have not been definitively characterized in molecular detail. Here we quantitatively determine the role of the cadherin ectodomain in mechanosensing. To this end, we devise an E-cadherin-coated emulsion system, in which droplet surface tension is balanced by protein binding strength to give rise to stable areas of adhesion. To reach the honeycomb/cohesive limit, an initial emulsion compression by centrifugation facilitates E-cadherin trans binding, whereas a high protein surface concentration enables the cis-enhanced stabilization of the interface. We observe an abrupt concentration dependence on recruitment into adhesions of constant crystalline density, reminiscent of a first-order phase transition. Removing the lateral cis interaction with a “cis mutant” shifts this transition to higher surface densities leading to denser, yet weaker adhesions. In both proteins, the stabilization of progressively larger areas of deformation is consistent with single-molecule experiments that show a force-dependent lifetime enhancement in the cadherin ectodomain, which may be attributed to the “X-dimer” bond.