Interfacial Fracture Strength Research Articles

Substitution potential of La/Ce/Er for high-cost Sc in rare-earth Al alloys: A comprehensive first-principles study

Al–Sc alloys have high strength, plasticity, and corrosion resistance, making them ideal lightweight materials for the aerospace and automotive industries. However, the practical application of these alloys is constrained by the high cost of Sc. We investigate the substitution potential of lower-cost rare-earth elements X (X = La, Ce and Er) for the expensive Sc in Al–Sc alloys through first-principles calculations. Assessing substitution formation energy, substitutional segregation, and their impact on (001), (110), and (111) γ-Al/γ′-Al3Sc interfaces, results highlight Er as the most promising candidate among the three, thermodynamically replacing Sc in Al3Sc precipitates. Er atoms selectively segregate to γ-Al/γ′-Al3Sc interfaces, enhancing stability by reducing interface energies. The morphology of precipitates undergoes a transition from a truncated cuboctahedron to an {111}-faceted octahedron. Increased Er segregation further bolsters interfacial fracture strength, attributed to segregation-induced charge accumulation. Our work could offer reference for the design of rare-earth Al alloys with low-cost and high-performance.

Theoretical study on the effect of element segregation on the dissolution and diffusion of hydrogen at the Ni/Ni3Al interface

In this work, employing first-principles calculations, tetrahedral, octahedral, and pyramid-shaped H trap models are constructed to investigate the behavior of hydrogen (H) at the Ni/Ni3Al interfaces with Cr, Mo, and W segregation. Our study reveals that H is prone to adsorb near the Ni3Al phase, forming octahedral H trap structures. Cr segregation H trap is more suitable at the interface, due to the smaller atomic charge of Cr among the three elements, resulting in the lowest dissolution energy required for H dissolution. All the segregation elements exhibit inhibitory effects on H aggregation and segregation, with Mo showing the most pronounced effect due to its highest diffusion barrier. The solubility, diffusion coefficient, and permeability of H at the element segregation interfaces are found to be positively correlated with temperature. Furthermore, the incorporation of segregation elements in the interface trap structure demonstrates a significant enhancement in fracture toughness, while simultaneously mitigating the adverse effects of H on the interface fracture strength. The yield strength and tensile strength exceed those of the original interface. These findings offer theoretical guidance for the design of Ni-based high-temperature alloys with superior performance in the future.

Ice Adhesion Characterization Using Mode-I and Mode-II Fracture Configurations

Abstract The ice buildup on airborne structures operating in cold weather conditions has detrimental impacts on their safety and performance. Due to practical applications, there has been a significant interest in ice removal strategies. However, the current body of literature lacks comprehensive insights into the mechanistic aspects of the ice adhesion/breakage process, resulting in a wide range of reported adhesion strengths that differ by two orders of magnitude. To address this gap, we employed a fracture mechanics-based approach to investigate the fracture behavior of a typical ice/aluminum interface in terms of mode-I and mode-II fractures. We examine a range of surface roughness values spanning from 0.05 to 5 micrometers. An experimental framework employing a single cantilever beam and direct shear tests were developed. The near mode-I and mode-II interfacial fracture toughness and strength values were extracted from the experimentally measured force and displacement by both analytical and numerical models employing cohesive surfaces. The combined experimental and numerical results show that ice adhesion is primarily driven by cohesive interfacial failure, which exhibits almost mode-independent fracture behavior. Mode-I fracture shows directional instability of crack propagation, which is attributed to thermally induced residual tensile stress at the ice layer-substrate interface. The fractographic inspection reveals similar ice-grain size over the examined range of substrate roughness values. For the examined range of surface roughness and temperature, which induces the Wenzel state with full surface wetting at the interface, the ice adhesion is insensitive to the interfacial roughness in both mode-I and mode-II fracture.

Micromechanical Adhesion Experiments and Simulation on Cu-Damascene Processed Test Devices

A novel experimental setup for testing interface properties of single copper interconnect structures is presented. The method is based on in-situ SEM nanoindentation experiments, utilized to probe customized copper structures manufactured by the Dual Damascene process. In this way the testing structures resemble product-like length-scales and properties. For the investigation of interface properties, the experimental load-displacement data is reviewed. Focused ion beam (FIB) cross sections are performed to validate the delaminated interface. FEM-simulations, based on the measured load-displacement data are used to determine the stress state in the test structures and to derive values for the interface fracture strength of the investigated interface.

Effect of Ta and Re on the fracture strength and creep strength of Ni/Ni<sub>3</sub>Al interface

The first principle method based on density functional theory and generalized gradient approximation is used to investigate the interaction of Ta and Re elements at Ni/Ni<sub>3</sub>Al interface and their influence on the interface strength. According to the calculations of the dissolution energy of these two alloying elements at 7 different positions, it can be concluded that in most of the stoichiometric ranges, Ta atoms preferentially occupy Ni sites in the <i>γ</i> phase, while Re atoms occupy preferentially Al sites in <i>γ'</i> phase. The doping positions do not change when these two atoms are co-alloyed. The calculation of Griffith fracture work of Ni/Ni<sub>3</sub>Al interface system shows that the doping of Ta atoms can improve the interface fracture strength of the phase boundary region between the <i>γ</i>/<i>γ'</i> coherent atomic layer and <i>γ</i> atomic layer. The interface is easier to fracture in the phase boundary area between <i>γ</i>/<i>γ'</i> coherent atomic layer and <i>γ'</i> atomic layer after Ta atoms have been doped. The doping of Re atoms can improve the interface fracture strength of the phase boundary region between <i>γ</i>/<i>γ'</i> coherent atomic layer and <i>γ'</i> atomic layer. The interface is easier to break in the phase boundary area between <i>γ</i>/<i>γ'</i> coherent atomic layer and <i>γ</i> atomic layer. The calculation results of the unstable stacking fault energy under the interface slip system <inline-formula><tex-math id="M1">\begin{document}$ [110](001) $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="6-20222103_M1.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="6-20222103_M1.png"/></alternatives></inline-formula> before and after Ta and Re alloying show that the doping of these two types of atoms increases the value of the unstable stacking fault energy of the interface, and the slip system<inline-formula><tex-math id="M2">\begin{document}$ [110](001)$\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="6-20222103_M2.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="6-20222103_M2.png"/></alternatives></inline-formula> becomes difficult to start, which enhances the ability of the interface to block the movement of dislocations, thus enhancing the creep strength of the nickel base superalloy. When doping Re atoms, the effect is greater, and the unstable stacking fault energy of the interface increases by 11.1%, which is better for improving the creep strength of the system. By studying the influence of alloying atoms on the path of vacancy migration and the energy barrier, it is concluded that the doping of Ta and Re atoms can increase the vacancy formation energy and the potential barrier of vacancy migration at the interface. The doping of Re atoms increases the migration energy barriers on both sides of the interface, and the doping of Ta atoms increases the migration energy barriers of <i>γ</i> phase. The increase of the migration barrier hinders the emission and absorption of vacancies, thereby improving the creep capability of the alloy.

Hydrogenated vacancy induced changes in thermodynamic stability and mechanical properties of Re-containing γ-Ni/γ'-Ni3Al phase interface

Re is an important alloying element to improve the high temperature performance of Ni-based single crystal superalloys, and has a segregation tendency to the γ/γ' phase interface. Hydrogen embrittlement introduced by hydrogenated vacancies (H-Vacs) severely reduces the service life of alloys. However, the formation mechanism of hydrogenated vacancy (H-Vac) and its effects on the Re-segregated γ/γ' phase interface are still unclear. In this work, the first-principles simulations are applied to clarify the formation of H-Vac and its effects on the thermodynamic stability and mechanical properties of Re-containing γ/γ' phase interface. We find that at the Re-containing γ/γ' phase interfaces, the hydrogen atom is more likely to dissolve in the first-nearest-neighbor (1st-NN) octahedral interstices of vacancy than in the 2nd-NN octahedral interstices. The Vac-containing γ/γ' phase interface can be stabilized when hydrogen atom dissolves in 1st-NN octahedral interstices to form H-Vac complex. For the Re-containing γ/γ' phase interface, the formation of the H-Vac complex does not change its preferential cleavage plane. Moreover, the fracture strength of the Re-containing γ/γ' phase interface is always higher than that of the Re-free γ/γ' phase interface. Thus, Re can enhance the interfacial fracture strength, which is also verified by the first-principles computational tensile tests.

An interface-width-insensitive cohesive phase-field model for fracture evolution in heterogeneous materials

In heterogeneous materials, such as fiber-reinforced composites, composite laminates, and coating systems, failure depends on the fracture behavior of the component materials and their interfaces. Modeling crack evolution in heterogeneous materials has been a significant challenge due to the complex interactions between the cracking at the interface and within the material. This paper proposes a cohesive phase-field model based on diffused interface to deal with failure at interfaces. The effective interfacial fracture toughness is obtained based on the fracture toughness of the diffused interface being equivalent to a sharp representation. The effective interfacial fracture strength is approximated using the brittle fracture condition. Then, we propose an approach to minimize the modification of the interfacial fracture parameters. The novelties of this approach are that 1) it is flexible enough to handle brittle and cohesive failure in the interface and bulk; 2) it can capture the crack nucleation at weakly singular interfaces in heterogeneous materials; and 3) compared with other approaches, the calculated fracture behavior is insensitive to the width of the diffused interface. The approach is verified under cases of brittle and cohesive failure. In addition, we demonstrate the approach in describing the fracture behavior of fiber-reinforced composites and ceramic coating systems, finding it to conform exactly with theoretical and experimental results. Hence, the proposed approach shows great potential in predicting crack evolution in heterogeneous materials.

Interfacial adhesion assessment of SiN/GaAs film/substrate system using microcantilever bending technique

In this study, a microcantilever bending technique was applied to evaluate the interfacial adhesion of a silicon nitride (SiN) film on a gallium arsenide (GaAs) substrate. Miniaturised cantilevers in micrometre scale were machined on the SiN/GaAs cross-section using focused ion beam milling. Subsequent bending tests was performed on a nanomechanical testing system. Static and cyclic loadings were applied to bend the cantilevers until they fractured. All cantilevers failed at the SiN/GaAs interface. A finite element analysis (FEA) model was used to simulate the deflection of the cantilevers and the stress state at the locus of failure was analysed. Interfacial fracture strength σ in was derived from the FEA model. The mean values of σ in from the static and cyclic loading tests were 0.8 ± 0.2 and 0.5 ± 0.1 GPa, respectively. An energy balance analysis was then used to evaluate an interfacial toughness of G in = 0.18 ± 0.05 J m−2.

On the crack propagation and fracture properties of Cr-coated Zr-4 alloys for accident-tolerant fuel cladding: In situ three-point bending test and cohesive zone modeling

The cracking behavior of a Cr-coated Zr-4 alloy for accident-tolerant fuel cladding at room temperature was investigated using an in situ three-point bending test and finite element (FE) analysis. The initiation and propagation of vertical and interfacial cracks were captured in real time. Moreover, the fracture properties of the Cr-coated Zr-4 alloy were evaluated by in situ observations and FE simulations based on the cohesive zone model. The results indicated that vertical cracks were generally initiated from the interface and promptly penetrated through the coating thickness at a small deflection. Under continuous external loading, the vertical crack density increased rapidly and finally reached a plateau. Additionally, interfacial cracks were initiated from the vertical crack tips and propagated gradually along the interface, which was driven by large local interfacial peeling and shear stresses. Through FE analyses, the fracture toughness of the Cr coating was estimated to be 65 J/m2, and the interfacial fracture strength and toughness were evaluated as 150 MPa and 200 J/m2, respectively.

Shear strength and fracture analysis of Sn-9Zn-2.5Bi-1.5In and Sn-3.0Ag-0.5Cu pastes with Cu-substrate joints under different reflow times

Sn-Zn solders have been considered as promising lead-free solders. This study investigated the shear strength and fracture mechanism of Sn-9Zn-2.5Bi-1.5In and Sn-3.0Ag-0.5Cu pastes with Cu-substrate joints. It is found that the intermetallic compounds (IMC) in Sn-Ag-Cu joints are Cu6Sn5 and Cu3Sn, while the IMC of Sn-Zn joints are particular Cu5Zn8, different from other Sn-based solders, which grow more slowly. Both solder joints fracture by a mixed mechanism. The cracks tend to form and propagate at the interface of the solder and IMC in the cases of too short or too long reflow times, resulting in more interfacial fracture and lower shear strength. An optimum soldering zone of reflow time will bring about more reliable joints, which fracture mainly in the solder. Sn-Zn joints have more solder fracture and less interface fracture, therefore have higher shear strength and reliability, compared with Sn-Ag-Cu joints. For Sn-Zn joints, the optimum reflow times are 20 s–120 s with the shear strength of 62 MPa–70 MPa, while for Sn-Ag-Cu joints, the optimum reflow times are 50 s–180 s, with the strength of 50 MPa–62 MPa.

Unraveling the formation mechanism of hydrogenated vacancy at γ-Ni/γ'-Ni3Al phase interface and its roles in interfacial stability and strength

γ/γ' phase interfaces are hidden troubles that threaten the service safety of Ni-based single crystal superalloys due to their thermodynamic instabilities and lower mechanical strengths. To gain insights into the role of hydrogenated vacancy in the stability and cohesion of γ/γ' interfaces, the formation mechanism of hydrogenated vacancy at (001) γ-Ni/γ'-Ni3Al interface and its influences on interfacial stability and fracture strength were systematically studied by using first-principles calculations. Our results show that the short-range interplay between monovacancy and single hydrogen atom at (001) γ-Ni/γ'-Ni3Al interface causes the formation of Vac-H complex structure (i.e., hydrogenated vacancy) as separated by a certain distance rather than a direct recombination. The hydrogen atom in the first nearest-neighbor interstices of Ni vacancy (site 6) deviates from the interstitial centers to the vacancy, owing to the interattraction between monovacancy and hydrogen atom. The formation of hydrogenated vacancy at (001) γ-Ni/γ'-Ni3Al interface can promote the interfacial thermodynamic stability as compared with the vacancy-containing γ/γ' interface, but weaken the interfacial fracture strength and change the preferable fracture place of γ/γ' interface. The underlying mechanisms of stabilizing and weakening effects on the γ/γ' interface were revealed by using spin-polarized density of states and differential charge densities.

Segregation of alloying elements and their effects on the thermodynamic stability and fracture strength of γ-Ni/γ′-Ni3Al interface

The γ/γ’ phase interface, being the main plane defect in nickel-based single-crystal superalloys, can have a significant effect on the microstructural stability and mechanical properties of superalloys. To improve the thermodynamic stability and fracture strength of the γ-Ni/γ’-Ni3Al interface and gain insight into the underlying micro-mechanisms, the segregation tendency of 12 alloying elements X at the γ-Ni/γ’-Ni3Al interface and their effects on the interfacial formation and Griffith fracture works were investigated by using first-principles calculations. It is found that all alloying elements X can segregate to the corner-point site of the γ-Ni (001) layer except the element Y. The Re-, Ti-, Mo-, W-, Cr-, Nb-, Ta-, Hf- and Zr-segregated interfaces are more stable than the unalloyed interface due to the presence of pseudogap and lower values of densities of states at the Fermi level. The segregation of Ru, Co, Re, Mo, W, Cr, Nb and Ta strengthens the interfacial fracture strength, which can be mainly attributed to the enhanced bonding strengths of X–Ni bonds formed in these segregated interfaces. The interfacial segregation of Cr, Re, Mo, W, Nb and Ta can not only improve the thermodynamic stability but also enhance the fracture strength of the phase interface. The segregation of Ta and Re is able to improve the thermodynamic stability and fracture strength of the γ-Ni/γ’-Ni3Al interface to the maximum extent, respectively. The effect of interfacial segregation of alloying elements on the fracture strength and thermodynamic stability of the γ-Ni/γ’-Ni3Al phase interface and the underlying mechanisms are studied.

In-situ study on the tensile behavior of Cr-coated zircaloy for accident tolerant fuel claddings

In this study, the tensile behavior of Cr-coated zircaloy (Zr-4) for accident tolerant fuel claddings was investigated by in-situ observation and finite element (FE) analysis. The evolution of surface cracks in the Cr coating was experimentally observed, and the surface crack density was precisely predicted by the shear–lag model considering the effect of the residual stress. Moreover, the interfacial cracking behavior was numerically analyzed using the cohesive zone model. Finally, the interfacial fracture parameters of the coating system were evaluated based on the experimental results and FE calculations. The results exhibited that after the initiation, the surface crack density increased rapidly with the tensile strain, followed by a plateau stage under continuous tension. The fracture strength and interfacial shear strength of the Cr coating were evaluated as 382 MPa and 108 MPa, respectively. In addition, no interfacial spallation occurred under tension, indicating excellent interfacial adhesion properties of the Cr coating. However, a few short interfacial cracks were found to be initiated from the vertical crack tips, owing to the large local interfacial peeling and shear stresses. The FE analyses suggested that the lower limits of the interfacial fracture strength, σ0, and the fracture toughness, Gc, of the Cr coating were in the range of 100 MPa–150 MPa and 100 J/m2–125 J/m2, respectively. Concurrently, σ0 and Gc for the entire Cr coating–Zr-4 substrate system were estimated to be generally large, i.e., above 250 MPa and 200 J/m2, respectively.

Dependence of mechanical properties on microstructure of high-textured pyrocarbon prepared via isothermal and thermal gradient chemical vapor infiltration

In order to explore the dependence of mechanical properties on the microstructure of high-textured (HT) pyrolytic carbon (PyC), the microstructure and properties of HT PyC specimens prepared by isothermal isobaric chemical vapor infiltration (ICVI) and thermal gradient chemical vapor infiltration (TCVI) processes were investigated. The HT PyC of ICVI was uniform and exhibited a more distinct long-range order compared to that of TCVI. Besides, a spatial gradient in texture existed within the HT PyC of TCVI, demonstrating the micro-nonuniformity of the whole matrix. The orientation angle (OA) of HT layers in TCVI increased gradually from the fiber surface to outside, whereas the OA of HT layers in ICVI with better microcrystalline was nearly similar. According to the results of three-point bending and micro-indentation, the flexural strength, interfacial fracture strength, and micro-hardness of TCVI specimens were slightly higher than those of ICVI specimens. Furthermore, the residual thermal stress distribution of TCVI specimens was complex owing to the spatial gradient in temperature of TCVI process, while the residual thermal stress distribution of ICVI specimens was relatively uniform. This work provides meaningful guidance for the process selection and industrial applications of C/C composites.

A SEM-X-Ray assisted experimental approach for the determination of mechanical and thermal load – induced damage in MMCs

An experimental technique is presented to evaluate mechanical and thermal load-induced microstructural damage, based on the Electron Probe Micro-Analysis (EPMA) principle, by which certain ana­lyti­cal potentialities of Scanning Electron Micro­scopy (SEM) are used. The aim of the study is to apply this technique in the case of metal matrix composites (MMCs). Based on earlier findings it is shown that by this technique the damage-con­trolled micro­­structural integrity distribution ahead of an edge-notch under tension is deter­mined with sufficient reliability. To demonstrate this fact two MMCs were tested. Dog-bone specimens with an edge notch were subjected to slow tension up to their ultimate stress, the loading process was terminated and the EPMA technique was applied. The procedure was also applied after sudden cooling of the specimens by immersion in liquid hydrogen. It is shown that the MMC with larger differences between the elastic and plastic constants of the inclusion and the matrix exhibit increased prone­ness to mechanical and thermal load-induced damage. The findings obtained are discussed on the basis of the dominating com­bined influence of macro-microscopic mechanical and thermo-elastic stress concentration processes on the matrix-particle interfacial fracture strength.

Mechanical and Structural Degradation of LiNi x Mn y Co z O2 Cathode in Li-Ion Batteries

The structural and mechanical stability of NMC plays a vital role in determining the electrochemical performance of batteries. However, the dynamic mechanical properties of NMC during Li reactions are widely unknown because of the microscopic heterogeneity of composite electrodes as well as the challenge of mechanical measurement for air-sensitive battery materials. We employ instrumented nanoindentation in an inert environment to measure the elastic modulus, hardness, and interfacial fracture strength of NMC of a hierarchical meatball structure as a function of the state of charge and cycle number. The mechanical properties significantly depend on the lithiation state and degrade as the electrochemical cycles proceed. The results are further compared with the properties of bulk NMC pellets. We perform first-principles theoretical modeling to understand the evolution of the elastic property of NMC on the basis of the electronic structure. This work presents the first time systematic mechanical measurement of NMC electrodes which characterizes damage accumulation in battery materials over cycles.

Interfacial fracture strength evaluation of Cu/SiN micro-components: applicability of the linear fracture mechanics criterion under a hydrogen environment

The strength against fracture initiation from an interface free-edge of bonded copper (Cu) and silicon nitride (SiN) micro-components is studied. Quantitative fracture tests are conducted either in a vacuum environment or in a gaseous hydrogen (H $$_{2})$$ environment. By using two kinds of specimens, Types I and II, having the same free-edge geometry (135 $$^{\circ }$$ /135 $$^{\circ }$$ ) but different outer shape, the validity of the linear fracture mechanics criterion is critically evaluated. For specimens tested in vacuum, fracture initiation strength represented by the elastic stress intensity factor of the near-edge normal stress component is found to be the same irrespective of the specimen type, indicating that the fracture mechanics criterion holds. For specimens tested in H $$_{2}$$ gas, the strength of both types is reduced and, interestingly, Type II strength shows greater reduction than Type I. In other words, the fracture mechanics criterion does not hold in H $$_{2}$$ gas. Such a difference may be attributable to the difference of local plasticity in each specimen type.

Measurement of Interfacial Fracture Toughness of Surface Coatings Using Pulsed-Laser-Induced Ultrasonic Waves

This research develops a new technique for the measurement of interfacial fracture toughness of films/surface coatings using laser-induced ultrasonic waves. Using pulsed laser ablation on the bottom substrate surface, strong stress waves are generated leading to interfacial fractures and coating delamination. Simultaneously, a laser ultrasonic interferometer is used to measure the normal (out-of-plane) displacement of the top surface coating in order to detect coating delamination in a non-destructive manner. We can thus determine the critical laser energy for delamination, yielding the critical stress (that is, the interfacial strength). Subsequently, to examine the interfacial fracture toughness, additional pulsed laser irradiation is applied to a pre-delaminated specimen to show that the delamination area expands. This type of interfacial crack growth can be visualized using laser ultrasonic scanning. Furthermore, the calculation of elastic wave propagation was carried out using a finite-difference time-domain method) in order to accurately estimate the interfacial stress field. In this calculation, the stress distribution around the initial delamination is calculated to obtain the stress intensity factor. Based on the experimental and computational results, interfacial fracture toughness can be quantitatively evaluated. Since this technique relies on a two-laser system in a non-contact approach, it may be useful for a quantitative evaluation of adhesion/bonding quality (including both interfacial fracture strength and toughness) in various environments.

The atomistic simulation study of Ag/MgO interface tension fracture

Metal/ceramic interfaces have wide applications and the interface fracture plays an important role in determining mechanical behaviors of related structures. The cohesive zone model is widely used to modelling the crack opening and extension, especially used to modelling the interface crack. Although this model is widely used, it is a macroscopic phenomenological model, and its atomistic scale mechanism attracts great attention. In this paper an interface atomistic model of Ag/MgO is used to study the microscopic interface opening mode and some interesting results are discovered. By considering all atomic interaction potentials related to the interfacial structure in the molecular mechanics calculation, the interface tension stress-displacement curves for several interface structures with different sizes are simulated, and fracture properties upon displacing Ag and MgO adjacent to the interface are revealed based on the simulation results and by developing a series model on interface fracture properties. The results indicate that the interface fracture strength is independent of the size of interface structures for ideal interfaces, the total tension displacement of interface structures increases and the fracture appears catastrophic characteristic with increasing unit thickness, which is explained well by the series model. Furthermore, the interface separation behaviors of interfaces with the atomic vacancy and dislocations are simulated, the study indicates that the interface strength decreases for the interfaces with defects, and the defects decrease the catastrophic tendency.

Controllable load sharing for soft adhesive interfaces on three-dimensional surfaces

For adhering to three-dimensional (3D) surfaces or objects, current adhesion systems are limited by a fundamental trade-off between 3D surface conformability and high adhesion strength. This limitation arises from the need for a soft, mechanically compliant interface, which enables conformability to nonflat and irregularly shaped surfaces but significantly reduces the interfacial fracture strength. In this work, we overcome this trade-off with an adhesion-based soft-gripping system that exhibits enhanced fracture strength without sacrificing conformability to nonplanar 3D surfaces. Composed of a gecko-inspired elastomeric microfibrillar adhesive membrane supported by a pressure-controlled deformable gripper body, the proposed soft-gripping system controls the bonding strength by changing its internal pressure and exploiting the mechanics of interfacial equal load sharing. The soft adhesion system can use up to ∼26% of the maximum adhesion of the fibrillar membrane, which is 14× higher than the adhering membrane without load sharing. Our proposed load-sharing method suggests a paradigm for soft adhesion-based gripping and transfer-printing systems that achieves area scaling similar to that of a natural gecko footpad.