Beyond biomimicry – next generation applications of bioinspired adhesives from microfluidics to composites

• Dan Sameoto

Beilstein J. Nanotechnol. 2024, 15, 965–976, doi:10.3762/bjnano.15.79

• approach demonstrated an order of magnitude increase in adhesion strength compared to the reversible bonding of PDMS and achieved this without any alterations to the material itself, merely the channel geometry was made to minimize crack propagation. Although the original geckofluidics application targeted

Recent advances in nanoarchitectures of monocrystalline coordination polymers through confined assembly

• Lingling Xia,
• Qinyue Wang and
• Ming Hu

Beilstein J. Nanotechnol. 2022, 13, 763–777, doi:10.3762/bjnano.13.67

• of solvent continuously arranged the particles. However, due to a non-uniform distribution of the suspension on the surface and the difference in local evaporation and flow condition, cracks could form between micrometer-sized domains (Figure 7c) [141]. The crack propagation and periodicity could be

Graphynes: an alternative lightweight solution for shock protection

• Kang Xia,
• Haifei Zhan,
• Aimin Ji,
• Jianli Shao,
• Yuantong Gu and
• Zhiyong Li

Beilstein J. Nanotechnol. 2019, 10, 1588–1595, doi:10.3762/bjnano.10.154

• α-GY. During crack propagation, the initial stress that accumulated around the impact region starts to re-distribute, and stress concentrations at the crack tips are observed (Figure 3b). Different from the pure zigzag kicking fracture mechanisms in graphene [29][31], the cracks in α-GY propagate

• along both armchair and zigzag directions. After full perforation at ca. 6.4 ps, the crack propagation stops and the stress concentration at the tip is fully released (Figure 3c). Influence of morphology It is of great interests to compare how the mechanical performance of GY would change with the

Evidence of friction reduction in laterally graded materials

• Roberto Guarino,
• Gianluca Costagliola,
• Federico Bosia and
• Nicola Maria Pugno

Beilstein J. Nanotechnol. 2018, 9, 2443–2456, doi:10.3762/bjnano.9.229

• , display setae with a graded stiffness that optimises the adhesive performance on rough surfaces [1]. Hardness and stiffness gradients are of fundamental importance in the biomechanics of contacts, since they allow increased resistance against wear, impact, penetration and crack propagation [2][3][4][5][6

Fatigue crack growth characteristics of Fe and Ni under cyclic loading using a quasi-continuum method

• Ren-Zheng Qiu,
• Yi-Chen Lin and
• Te-Hua Fang

Beilstein J. Nanotechnol. 2018, 9, 1000–1014, doi:10.3762/bjnano.9.93

• microscopic scale [1][2][3][4][5][6][7][8][9][10][11][12][13]. For face-centered cubic (FCC) metallic systems, Wu et al. [10] have investigated the fatigue crack growth in single-crystal Ni under different cyclic loading regimes. They found that different crack propagation and stress distributions lead to

• changes in fatigue crack growth rates and crack opening displacements. Ma et al. [11] have examined the effect of orientation on the fatigue crack propagation in single-crystal iron under cyclic loading, leading to differences in the crack growth rates and slip directions. The plastic deformation and

• . Zhang et al. have examined the effect of the phase boundary on the fatigue crack propagation in an α/β-iron biphasic system under cyclic tensile loading [13]. They found that the nucleation of new cracks typically appears at the phase boundary because of dislocation pile-ups. However, most of these

A new approach to grain boundary engineering for nanocrystalline materials

• Shigeaki Kobayashi,
• Sadahiro Tsurekawa and
• Tadao Watanabe

Beilstein J. Nanotechnol. 2016, 7, 1829–1849, doi:10.3762/bjnano.7.176

• . Along this line, the fraction of percolation-resistant triple junctions, fR1/(1−fR0), was evaluated, following Kumar et al. [86], as shown in Figure 4. The values of fR1/(1−fR0) were 0.26 and 0.14 for the Type A and the Type B specimens, respectively. Accordingly, the crack propagation in the Type A

• 1.1 MPa m1/2 and 0.7 MPa m1/2, for the Type B and the Type C specimens, respectively. The fraction of percolation-resistant triple junctions, fR1/(1−fR0) was 0.14 and 0.10, in the Type B and the Type C specimens, respectively. Therefore, the crack propagation can be prevented more effectively in the

Fracture behaviors of pre-cracked monolayer molybdenum disulfide: A molecular dynamics study

• Qi-lin Xiong,
• Zhen-huan Li and
• Xiao-geng Tian

Beilstein J. Nanotechnol. 2016, 7, 1411–1420, doi:10.3762/bjnano.7.132

• and Vibration, Xi’an Jiaotong University, Xi’an 710049, China 10.3762/bjnano.7.132 Abstract The fracture strength and crack propagation of monolayer molybdenum disulfide (MoS2) sheets with various pre-existing cracks are investigated using molecular dynamics simulation (MDS). The uniaxial tensions of

• model without finite size effect. Finally, the MDS results of monolayer MoS2 sheets with different angled crack are also analyzed based on the continuum fracture mechanics model. Keywords: crack propagation; fracture strength; molecular dynamics simulation; monolayer molybdenum disulfide; pre-existing

• fracture toughness and crack propagation path of monolayer MoS2 sheets with edge crack under mixed modes I and II loading by using MDS. In the present work, we focus on investigating the effect of crack tip configuration, crack location, crack length and angled crack on the fracture strength and crack

Reasons and remedies for the agglomeration of multilayered graphene and carbon nanotubes in polymers

• Rasheed Atif and
• Fawad Inam

Beilstein J. Nanotechnol. 2016, 7, 1174–1196, doi:10.3762/bjnano.7.109

• extended temperature range [122]. The addition of CNTs as secondary reinforcement in glass fiber-based polymer composites can significantly improve the resistance against cyclic delamination and crack propagation. The inter-laminar fracture toughness also improves due to the deflection of the cracks by

• CNTs. The fatigue life can be increased up to three times when in-plane cyclic loading is applied. CNTs can decelerate the crack propagation and delamination as energy is dissipated to pull-out and break the CNTs. In addition, CNTs cause crack bridging, which helps improve the mechanical properties

Nanoscale rippling on polymer surfaces induced by AFM manipulation

• Mario D’Acunto,
• Franco Dinelli and
• Pasqualantonio Pingue

Beilstein J. Nanotechnol. 2015, 6, 2278–2289, doi:10.3762/bjnano.6.234

• mechanism: A peeling process with the material pushed ahead of the contact via crack propagation. For an injection-molded polycarbonate surface, Iwata et al. [18] have found that the bundles are less stiff than the undamaged surface, which they have also interpreted as evidence of the presence of micro

Stiffness of sphere–plate contacts at MHz frequencies: dependence on normal load, oscillation amplitude, and ambient medium

• Jana Vlachová,
• Rebekka König and
• Diethelm Johannsmann

Beilstein J. Nanotechnol. 2015, 6, 845–856, doi:10.3762/bjnano.6.87

• ]. Such a contact displays a peak in tensile stress at the edge, which governs the pull-off force if the contact diameter is larger than about 100 nm. Pull-off then results in crack propagation. Partial slip in the Cattaneo–Mindlin sense also results in crack propagation, where the modes of crack opening

• are II and III, as opposed to mode I, which operates during pull-off [18]. Gao and Yao find that the crack propagation mechanism becomes inefficient once the contact diameter falls to below 100 nm. For small contacts, the stress concentration at the edge becomes less and less significant. Translated

• to the tangential load problem, the analysis by Gao and Yao shows that the transition from stick to slip may occur by crack propagation (that is, by partial slip in the Cattaneo–Mindlin sense), but that small contacts may also start to slide as a whole. Even if partial slip at individual contacts is

Mandibular gnathobases of marine planktonic copepods – feeding tools with complex micro- and nanoscale composite architectures

• Jan Michels and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2015, 6, 674–685, doi:10.3762/bjnano.6.68

• gradient in the material properties) can make these systems more resistant to damage and wear because such an architecture minimises the probability of local stress concentrations and, in the case of an initial damage, prevents further crack propagation [47][48]. It is conceivable that the soft and elastic

Multifunctional layered magnetic composites

• Maria Siglreitmeier,
• Baohu Wu,
• Tina Kollmann,
• Martin Neubauer,
• Gergely Nagy,
• Dietmar Schwahn,
• Vitaliy Pipich,
• Damien Faivre,
• Dirk Zahn,
• Andreas Fery and
• Helmut Cölfen

Beilstein J. Nanotechnol. 2015, 6, 134–148, doi:10.3762/bjnano.6.13

• aragonite platelets and an organic matrix mainly consisting of β-chitin covered with proteins [1]. This hybrid structure makes nacre 3000 times more fracture resistant as compared to aragonite which makes up ca. 95 wt % of this structure [2]. The reason for this is that crack propagation is hindered by the

Direct observation of microcavitation in underwater adhesion of mushroom-shaped adhesive microstructure

• Lars Heepe,
• Alexander E. Kovalev and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2014, 5, 903–909, doi:10.3762/bjnano.5.103

• ) accumulated to a large non-contact region in the middle of the contact area (Figure 5C1). At a certain load a channel formed (white arrow in Figure 5C2) by interfacial crack propagation balancing (at least partially) the pressure between the confined water within the contact interface and the surrounding

• of MSAMS and glass (white arrowheads). In sequences (A) and (B) microcavitation was observed indicated by the white region in images A4–5 and B5. The white arrow (C2) indicates channel formation by interfacial crack propagation between the confined water within the contact interface and the

The optimal shape of elastomer mushroom-like fibers for high and robust adhesion

• Burak Aksak,
• Korhan Sahin and
• Metin Sitti

Beilstein J. Nanotechnol. 2014, 5, 630–638, doi:10.3762/bjnano.5.74

• just the increase in contact area with mushroom-like fibers. Spuskanyuk et al. [38] used the assumption of pre-existing annular cracks and Griffith’s energy criterion for crack propagation to study the enhancement mechanism for mushroom-like fibers. They concluded that for a given load and crack length

Molecular dynamics simulations of mechanical failure in polymorphic arrangements of amyloid fibrils containing structural defects

• Hlengisizwe Ndlovu,
• Alison E. Ashcroft,
• Sheena E. Radford and
• Sarah A. Harris

Beilstein J. Nanotechnol. 2013, 4, 429–440, doi:10.3762/bjnano.4.50

• able to characterise how the nature and presence of such defects influences their mechanical response. However, this precludes the investigation of effects such as crack propagation on the material properties of the model fibrils, because these occur over longer length scales. Our simulations suggest a