Pull-off and friction forces of micropatterned elastomers on soft substrates: the effects of pattern length scale and stiffness

• Peter van Assenbergh,
• Marike Fokker,
• Julian Langowski,
• Jan van Esch,
• Marleen Kamperman and
• Dimitra Dodou

Beilstein J. Nanotechnol. 2019, 10, 79–94, doi:10.3762/bjnano.10.8

• of deformation mechanisms of the substrate in the pull-off and sliding of our adhesives could be further investigated by varying the pull-off or sliding speed, since the strain rates of both substrate and adhesives are time dependent. Conclusion We used a facile, out-of-the-cleanroom method to

• was measured with a TA Instruments AG-2R rheometer. A parallel-plate geometry with a diameter of 25 mm was used. Storage and loss moduli were determined at a strain of 0.05%, for a frequency range from 1·10−1 to 1·102 rad/s, as can be seen in Supporting Information File 1 (Figure S1 and Figure S2). We

Bidirectional biomimetic flow sensing with antiparallel and curved artificial hair sensors

• Claudio Abels,
• Antonio Qualtieri,
• Toni Lober,
• Alessandro Mariotti,
• Lily D. Chambers,
• Massimo De Vittorio,
• William M. Megill and
• Francesco Rizzi

Beilstein J. Nanotechnol. 2019, 10, 32–46, doi:10.3762/bjnano.10.4

• × 500 μm × 10 μm) which bent as air flow hit the plate. While the plate received the drag force of the air flow, the cantilevers measured the drag force using platinum strain gauges. One variable resistor (strain gauge) on each of the two cantilevers and two fixed resistances on the sensor substrate

• × 100 μm × 0.7 μm) that demonstrated bidirectional sensitivity to nitrogen flow. Equipped with a 80 μm long nickel–chrome (80/20) piezoresistor (strain gauge), the artificial hair sensor was sensitive to nitrogen flow along both cantilever directions. However, the strain gauge resistance revealed an

• asymmetrical response behaviour. While the piezoresistance varied by around 0.44% in the forward flow direction (cantilever flattened), a curled-up cantilever varied only by 0.07% in the backward direction. Extending the cantilever and strain gauge length, Qualtieri et al. [45] characterized artificial hair

Characterization and influence of hydroxyapatite nanopowders on living cells

• Przemyslaw Oberbek,
• Tomasz Bolek,
• Adrian Chlanda,
• Seishiro Hirano,
• Sylwia Kusnieruk,
• Julia Rogowska-Tylman,
• Ganna Nechyporenko,
• Viktor Zinchenko,
• Wojciech Swieszkowski and
• Tomasz Puzyn

Beilstein J. Nanotechnol. 2018, 9, 3079–3094, doi:10.3762/bjnano.9.286

• both identified foreign phases and unidentified reflexes in the range of 10 to 60° (2θ). Crystallinity (Xc) refers to the degree of structural order in a solid. It is a concept that integrates diffraction domain size, crystal strain and crystal defects. The crystallinity percentage of the samples was

Hydrogen-induced plasticity in nanoporous palladium

• Markus Gößler,
• Eva-Maria Steyskal,
• Markus Stütz,
• Norbert Enzinger and
• Roland Würschum

Beilstein J. Nanotechnol. 2018, 9, 3013–3024, doi:10.3762/bjnano.9.280

• , Austria 10.3762/bjnano.9.280 Abstract The mechanical strain response of nanoporous palladium (npPd) upon electrochemical hydrogenation using an in situ dilatometric technique is investigated. NpPd with an average ligament diameter of approximately 20 nm is produced via electrochemical dealloying. A

• in combination with the internal-stress plasticity mechanism leads to a peculiar strain response upon hydrogen sorption and desorption. Critical potentials for the formation of PdHα and PdHβ in npPd are determined. The theoretical concepts to assess the plastic strain response of nanoporous samples

• studies up to this point. This work focuses on the strain response of npPd upon hydrogenation and aims to shed light on the active deformation mechanisms. Results Electrochemical characterisation A typical strain response of npPd was measured using an in situ dilatometer setup during a cyclic voltammogram

Variation of the photoluminescence spectrum of InAs/GaAs heterostructures grown by ion-beam deposition

• Alexander S. Pashchenko,
• Leonid S. Lunin,
• Eleonora M. Danilina and
• Sergei N. Chebotarev

Beilstein J. Nanotechnol. 2018, 9, 2794–2801, doi:10.3762/bjnano.9.261

• : the top with a GaAs strain-reducing layer; the bottom with a strained buffer layer (wetting layer) [15][16][17][18][19]. Thus, the simplified energy band diagram of the active region of an InAs/GaAs heterostructure is an InAs quantum dot built into a GaAs matrix in the form of a quantum well. It

• phonons of bulk-like GaAs (268 cm−1) and GaBi (182 cm−1) are also observed. This indicates a change in the selection rule under Raman scattering in the InAs/GaAs system caused by lattice strain during the incorporation of Bi into the GaAs matrix. In the spectra we can clearly see the longitudinal modes of

• shift of the GaAs-like and GaBi-like peaks to smaller wavenumbers. Due to decrease of lattice mismatch and, thus, less strain in the InAs/GaAs1−xBix heterointerface compared to InAs/GaAs, there is a Raman shift of the peaks of InAs/GaAs1−xBix heterostructures relative to the spectrum of the InAs/GaAs

Comparative biological effects of spherical noble metal nanoparticles (Rh, Pd, Ag, Pt, Au) with 4–8 nm diameter

• Alexander Rostek,
• Marina Breisch,
• Kevin Pappert,
• Kateryna Loza,
• Marc Heggen,
• Manfred Köller,
• Christina Sengstock and
• Matthias Epple

Beilstein J. Nanotechnol. 2018, 9, 2763–2774, doi:10.3762/bjnano.9.258

• properties of nanomaterials originate from the large surface-to-volume ratio and the local configuration of atoms [69]. The morphology of nanoparticles is defined by the contributions of the cohesive energy, the surface energy, the twinning energy, and the strain energy [88]. Based on the Wulff construction

Silicene, germanene and other group IV 2D materials

• Patrick Vogt

Beilstein J. Nanotechnol. 2018, 9, 2665–2667, doi:10.3762/bjnano.9.248

• might include: the substrate material external electric or magnetic fields tensile or compressive strain functionalization by atomic or molecular species This means that the apparent disadvantage of these materials to develop a (low) buckling is in fact an advantage since it facilitates control of the

Characterization of the microscopic tribological properties of sandfish (Scincus scincus) scales by atomic force microscopy

• Weibin Wu,
• Christian Lutz,
• Simon Mersch,
• Richard Thelen,
• Christian Greiner,
• Guillaume Gomard and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2018, 9, 2618–2627, doi:10.3762/bjnano.9.243

• diameter of 1 mm provided by Saphirwerk AG (Bruegg, Switzerland). The normal load for all experiments was 0.1 N and the sliding speed was 0.5 mm/s. The number of reciprocating cycles was ten. Friction force was measured with a strain gauge-based system and recorded with a custom-programmed LabView

Non-agglomerated silicon–organic nanoparticles and their nanocomplexes with oligonucleotides: synthesis and properties

• Asya S. Levina,
• Marina N. Repkova,
• Nadezhda V. Shikina,
• Zinfer R. Ismagilov,
• Svetlana A. Yashnik,
• Dmitrii V. Semenov,
• Yulia I. Savinovskaya,
• Natalia A. Mazurkova,
• Inna A. Pyshnaya and
• Valentina F. Zarytova

Beilstein J. Nanotechnol. 2018, 9, 2516–2525, doi:10.3762/bjnano.9.234

• -glutamine (Sigma-Aldrich, USA); RPMI-1640 medium; antibiotics (BioloT, Russia); fetal calf serum (Gibco, USA). Сhicken erythrocytes, MDCK cells, and influenza A virus strain A/chicken/Kurgan/05/2005 (H5N1) were from FBRI Vector, Russia. Trypsin (1 mg/mL) and penicillin-streptomycin (100 U/mL) were stored at

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

• by monitoring the total strain energy of the system, to choose a sufficiently fine discretization. We assign a velocity-dependent coefficient of friction to the contact surfaces, evolving as: where µs,i and µk,i are the static and dynamic local friction coefficients, respectively, ν is the sliding

• for the case Δ = 0. However, while in the previous case, the reason for the modification of the global friction coefficient can be found in a smaller static friction threshold, in this case, a given lateral strain produces a corresponding tangential force that is greater on the side of the material

Surface energy of nanoparticles – influence of particle size and structure

• Dieter Vollath,
• Franz Dieter Fischer and
• David Holec

Beilstein J. Nanotechnol. 2018, 9, 2265–2276, doi:10.3762/bjnano.9.211

• solid (e.g., for a sphere with the radius R, p = 2σ/R) the elastic strain energy is stored in the particle. The surface energy may be defined as the as excess energy, i.e., the difference in the energy between a particle and the same number of atoms in an infinitely extended solid [4]. This definition

• , these results are only valid for γ ≥ 0. To demonstrate the insignificant role of the specific surface strain energy on the surface energy, the insert in Figure 5 displays the particle size dependence of this quantity. Although its contribution increases drastically with decreasing particle size, its

• using Equation 5. Graph of Equation 6. Also in this case, a lower limit for the particle diameter exists (α = β = 1). Surface energy for gold nanoparticles as function of the particle diameter according to Gang et al. [26]. The insert shows the specific strain energy related to the particle surface

Lead-free hybrid perovskites for photovoltaics

• Oleksandr Stroyuk

Beilstein J. Nanotechnol. 2018, 9, 2209–2235, doi:10.3762/bjnano.9.207

• for the synthesis of stoichiometric CsGeI3 materials as well as on the development of post-synthesis HI treatment of iodide-deficient CsGeI3 absorber layers. Theoretical studies also showed a high susceptibility of the electron properties of MAGeI3 perovskite to the strain. Application of a

Filling nanopipettes with apertures smaller than 50 nm: dynamic microdistillation

• Evelyne Salançon and
• Bernard Tinland

Beilstein J. Nanotechnol. 2018, 9, 2181–2187, doi:10.3762/bjnano.9.204

• strain long molecules stretching during translocation. However, such nanopipettes can be difficult to fill. Here we describe a dynamic microdistillation technique that successfully fills all nanopipettes, whatever their shape or tip radius. Even elongated or bent nanopipettes with a small-angle tip are

Fabrication of photothermally active poly(vinyl alcohol) films with gold nanostars for antibacterial applications

• Mykola Borzenkov,
• Maria Moros,
• Claudia Tortiglione,
• Serena Bertoldi,
• Nicola Contessi,
• Silvia Faré,
• Angelo Taglietti,
• Agnese D’Agostino,
• Piersandro Pallavicini,
• Maddalena Collini and
• Giuseppe Chirico

Beilstein J. Nanotechnol. 2018, 9, 2040–2048, doi:10.3762/bjnano.9.193

• -bearing carboxylic groups.The representative stress–strain curves of the fabricated films are shown in Figure 3. The detailed information about the set-up and data analysis is provided in the Experimental section. The mechanical parameters obtained by the stress–strain curves are reported in Table 1. The

• stress–strain curves of the three types of films followed the same trend, however being characterized by different elastic modulus, maximum stress and maximum strain values. In particular, PVA films without GNSs showed the lowest stiffness value in comparison with both types of PVA-GNS films (p < 0.05

• ). At the same time films prepared with GNSs coated with SH-PEG−COOH were characterized by the highest value of maximum stress when compared to films prepared with GNSs coated with SH-PEG–OCH3 and with bare PVA films (p < 0.05). All the compositions showed instead similar values of the maximum strain

Defect formation in multiwalled carbon nanotubes under low-energy He and Ne ion irradiation

• Santhana Eswara,
• Jean-Nicolas Audinot,
• Brahime El Adib,
• Maël Guennou,
• Tom Wirtz and
• Patrick Philipp

Beilstein J. Nanotechnol. 2018, 9, 1951–1963, doi:10.3762/bjnano.9.186

• in the sample. Depending on the sample a fourth peak due to intercalated graphite compounds and increasing disorder produced by functionalization and strain can appear in the region of 1617–1625 cm−1 [1]. Further information on defects can be obtained by the intensity of optical absorbance which is

Nonlinear effect of carrier drift on the performance of an n-type ZnO nanowire nanogenerator by coupling piezoelectric effect and semiconduction

• Yuxing Liang,
• Shuaiqi Fan,
• Xuedong Chen and
• Yuantai Hu

Beilstein J. Nanotechnol. 2018, 9, 1917–1925, doi:10.3762/bjnano.9.183

• induced by the shear strain S5 in the x1–x3 plane and E2 is induced by the shear strain S4 in the x2–x3 plane. When P acts along the x2-direction, σ5(τ13) is very small, and so is S5. Thus, both σ5 and S5 produce negligible influence on electric field, carrier concentration and electric potential. S4 is

Synthesis of rare-earth metal and rare-earth metal-fluoride nanoparticles in ionic liquids and propylene carbonate

• Marvin Siebels,
• Lukas Mai,
• Laura Schmolke,
• Kai Schütte,
• Juri Barthel,
• Junpei Yue,
• Jörg Thomas,
• Bernd M. Smarsly,
• Anjana Devi,
• Roland A. Fischer and
• Christoph Janiak

Beilstein J. Nanotechnol. 2018, 9, 1881–1894, doi:10.3762/bjnano.9.180

• crystalline domains being much smaller than the bulk reference material causing lattice contraction or expansion and strain [65][66][67][68][69]. Transmission electron microscopy: TEM was performed with a FEI Tecnai G2 F20 electron microscope operated at 200 kV accelerating voltage [70]. Conventional TEM

Improving the catalytic activity for hydrogen evolution of monolayered SnSe_2(1−x)S_2x by mechanical strain

• Sha Dong and
• Zhiguo Wang

Beilstein J. Nanotechnol. 2018, 9, 1820–1827, doi:10.3762/bjnano.9.173

• non-noble metals and earth-abundant elements is a promising pathway for achieving practical electrochemical water splitting. In this work, the electronic properties and catalytic activity of monolayer SnSe2(1−x)S2x (x = 0–1) under compressive and tensile strain were investigated using density

• functional theory (DFT) computations. The results showed SnSe2(1−x)S2x alloys with continuously changing bandgaps from 0.8 eV for SnSe2 to 1.59 eV for SnS2. The band structure of a SnSe2(1−x)S2x monolayer can be further tuned by applied compressive and tensile strain. Moreover, tensile strain provides a

• direct approach to improve the catalytic activity for the hydrogen evolution reaction (HER) on the basal plane of the SnSe2(1−x)S2x monolayer. SnSeS and SnSe0.5S1.5 monolayers showed the best catalytic activity for HER at a tensile strain of 10%. This work provides a design for improved catalytic

Light extraction efficiency enhancement of flip-chip blue light-emitting diodes by anodic aluminum oxide

• Yi-Ru Huang,
• Yao-Ching Chiu,
• Kuan-Chieh Huang,
• Shao-Ying Ting,
• Po-Jui Chiang,
• Chih-Ming Lai,
• Chun-Ping Jen,
• Snow H. Tseng and
• Hsiang-Chen Wang

Beilstein J. Nanotechnol. 2018, 9, 1602–1612, doi:10.3762/bjnano.9.152

• shift of approximately 5 nm. The following two mechanisms can explain the blue shift: First, InGaN multiquantum wells (MQWs) grow because of patterned sapphire substrate (PSS) technology and the luminous blue shift is generated by compressive strain release [26]. However, this study does not consider

Correlative electrochemical strain and scanning electron microscopy for local characterization of the solid state electrolyte Li_1.3Al_0.3Ti_1.7(PO₄)₃

• Nino Schön,
• Deniz Cihan Gunduz,
• Shicheng Yu,
• Hermann Tempel,
• Roland Schierholz and
• Florian Hausen

Beilstein J. Nanotechnol. 2018, 9, 1564–1572, doi:10.3762/bjnano.9.148

• work, we employ multiple microscopy techniques to gain local chemical and structural information paired with local insights into the Li-ion conductivity based on electrochemical strain microscopy (ESM). Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) have been applied

• discussed. We demonstrate that correlative microscopy is an adjuvant tool to gain local insights into interfacial properties of energy materials. Keywords: correlative microscopy; electrochemical strain microscopy (ESM); Li1.3Al0.3Ti1.7(PO4)3 (LATP); scanning electron microscopy (SEM); solid state

• -ion mobility in Li0.33La0.56TiO3 using scanning electron microscopy (SEM) with electron backscatter diffraction (EBSD) and electrochemical strain microscopy (ESM) [21]. The authors correlate variations in the Li-ion mobility detected by ESM with limitations in the Li-ion migration pathway. ESM is a

Predicting the strain-mediated topological phase transition in 3D cubic ThTaN₃

• Chunmei Zhang and
• Aijun Du

Beilstein J. Nanotechnol. 2018, 9, 1399–1404, doi:10.3762/bjnano.9.132

• 1 eV, but its electronic properties remain largely unexplored. By using density functional theory, we find that the band gap of ThTaN3 is very sensitive to the hydrostatic pressure/strain. A Dirac cone can emerge around the Γ point with an ultrahigh Fermi velocity at a compressive strain of 8

• the d-orbital of the heavy element Ta and the p-orbital of N. Our results highlight a new 3D topological insulator with strain-mediated topological transition for potential applications in future spintronics. Keywords: Dirac cone; strain; ThTaN3; topological insulator; Introduction The ThTaN3

• external strain. All these materials possess heavy elements and the strong SOC can induce a band inversion, which is a typical mechanism for TIs [26][27]. The experimentally observed pressure-induced phase transition in ThTaN3 indicates that the electronic structure of 3D ThTaN3 is likely very sensitive to

Computational exploration of two-dimensional silicon diarsenide and germanium arsenide for photovoltaic applications

• Sri Kasi Matta,
• Chunmei Zhang,
• Yalong Jiao,
• Anthony O'Mullane and
• Aijun Du

Beilstein J. Nanotechnol. 2018, 9, 1247–1253, doi:10.3762/bjnano.9.116

• . Furthermore, band-gap tuning is also possible by application of tensile strain. Our results highlight a new family of 2D materials with great potential for solar cell applications. Keywords: density functional theory (DFT); photovoltaic applications; solar cell; two-dimensional semiconductors; Introduction

• 700 nm. It has been reported that exterior strain on semiconductor nanostructures, especially at the two-dimensional level, influences the electronic properties and the corresponding optical properties [37][38]. We, therefore, studied the PBE functional band gap variation as a function of tensile

• strain (Figure S1, Supporting Information File 1). The band gap variation depends on the viewing direction along the lattice. In the laboratory, an external strain can be imparted by different means such as adlayer–substrate lattice mismatch, external loading, bending or by applying stress on the

Imaging of viscoelastic soft matter with small indentation using higher eigenmodes in single-eigenmode amplitude-modulation atomic force microscopy

• Miead Nikfarjam,
• Enrique A. López-Guerra,
• Santiago D. Solares and
• Babak Eslami

Beilstein J. Nanotechnol. 2018, 9, 1116–1122, doi:10.3762/bjnano.9.103

• strain in the complex plane for a linear viscoelastic material with multiple characteristic times. This model describes arrheodictic (there is no steady-state flow) behavior. Gn refers to the modulus of the n-th spring. ηn refers to the viscosity of the n-th dashpot. Ge refers to the rubbery modulus. The

• Laplace transformed stress is regarded as the excitation and the transformed strain as the response. Numerical simulations corresponding to a parabolic AFM tip tapping on a polyisobutylene surface, described as a viscoelastic material containing multiple characteristic times using the generalized Maxwell

Theoretical study of strain-dependent optical absorption in a doped self-assembled InAs/InGaAs/GaAs/AlGaAs quantum dot

• Tarek A. Ameen,
• Hesameddin Ilatikhameneh,
• Archana Tankasala,
• Yuling Hsueh,
• James Charles,
• Jim Fonseca,
• Michael Povolotskyi,
• Jun Oh Kim,
• Sanjay Krishna,
• Monica S. Allen,
• Jeffery W. Allen,
• Rajib Rahman and
• Gerhard Klimeck

Beilstein J. Nanotechnol. 2018, 9, 1075–1084, doi:10.3762/bjnano.9.99

• . 10.3762/bjnano.9.99 Abstract A detailed theoretical study of the optical absorption in doped self-assembled quantum dots is presented. A rigorous atomistic strain model as well as a sophisticated 20-band tight-binding model are used to ensure accurate prediction of the single particle states in these

• effects of alloy mole fraction of the strain controlling layer and quantum dot dimensions are discussed. Increasing the mole fraction of the strain controlling layer leads to a lower energy gap and a larger absorption wavelength. Surprisingly, the absorption wavelength is highly sensitive to the changes

• in the diameter, but almost insensitive to the changes in dot height. This behavior is explained by a detailed sensitivity analysis of different factors affecting the optical transition energy. Keywords: anharmonic atomistic strain model; biaxial strain ratio; configuration interaction; optical

Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations

• Jaison Jeevanandam,
• Ahmed Barhoum,
• Yen S. Chan,
• Alain Dufresne and
• Michael K. Danquah

Beilstein J. Nanotechnol. 2018, 9, 1050–1074, doi:10.3762/bjnano.9.98

• sulfate reductases [171][174] and also in the formation of zirconium particles [175]. Moreover, yeasts namely Candida glabrata, Torulopsis sp., Schizosaccharomyces pombe and MKY3 (which is a yeast strain with tolerance of Ag) were also used in the synthesis of NPs such as CdS quantum dots [176][177], PbS