A new method for obtaining model-free viscoelastic material properties from atomic force microscopy experiments using discrete integral transform techniques

• Berkin Uluutku,
• Enrique A. López-Guerra and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2021, 12, 1063–1077, doi:10.3762/bjnano.12.79

• at the micro- and the nanoscale is commonly performed with the aid of force–distance relationships acquired using atomic force microscopy (AFM). The general strategy for existing methods is to fit the observed material behavior to specific viscoelastic models, such as generalized viscoelastic models

• correspondence. We illustrate the proposed technique on a model experiment involving a traditional ramp-shaped force–distance AFM curve, demonstrating good agreement between the viscoelastic characteristics extracted from the simulated experiment and the theoretical expectations. We also provide a path for

• unbounded inputs traditionally used to acquire force–distance relationships in AFM, such as ramp functions, in which the cantilever position is displaced linearly with time for a finite period of time. Keywords: atomic force microscopy; force spectroscopy; material properties; viscoelasticity

An overview of microneedle applications, materials, and fabrication methods

• Zahra Faraji Rad,
• Philip D. Prewett and
• Graham J. Davies

Beilstein J. Nanotechnol. 2021, 12, 1034–1046, doi:10.3762/bjnano.12.77

• useful dosages of drugs and vaccines is a key issue, since the active area of microneedles in a patch device is limited by the force which must be applied to achieve skin penetration. This is a clear limitation of the dissolving microneedle approach [37]. A reservoir, separate from the microneedles, for

• or height, and shaft and tip shape. Other parameters including fluid flow rates, biocompatibility, penetration force, fragility, relative simplicity, and cost of fabrication are all key design considerations. The final design will depend on the limitations of the fabrication method and the mechanical

• penetration are obviously dependent on microneedle tip dimensions and skin puncture stress. Consequently, there is increased interest in ultrasharp microneedles with tips having minimum lateral dimensions below 1 µm. The penetration force linearly increases with array size and the use of controlled force

Revealing the formation mechanism and band gap tuning of Sb₂S₃ nanoparticles

• Maximilian Joschko,
• Franck Yvan Fotue Wafo,
• Christina Malsi,
• Danilo Kisić,
• Ivana Validžić and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 1021–1033, doi:10.3762/bjnano.12.76

• . Atomic force microscopy (AFM) as an additional method of size determination was applied to confirm the TEM results of the sample obtained after 30 s reaction time. AFM enables imaging of the nanoparticles under milder conditions than TEM and at ambient conditions so that thermal damage of the

Molecular assemblies on surfaces: towards physical and electronic decoupling of organic molecules

• Sabine Maier and
• Meike Stöhr

Beilstein J. Nanotechnol. 2021, 12, 950–956, doi:10.3762/bjnano.12.71

• . To a lesser extent, metal oxides have also been used, for which defects and charging often pose additional challenges [44][45][46]. On electronically insulating surfaces, non-contact atomic force microscopy (AFM) is the method of choice to study molecular assemblies and individual molecules in real

Self-assembly of Eucalyptus gunnii wax tubules and pure ß-diketone on HOPG and glass

• Miriam Anna Huth,
• Axel Huth and
• Kerstin Koch

Beilstein J. Nanotechnol. 2021, 12, 939–949, doi:10.3762/bjnano.12.70

• is unknown. In this study, extracted wax of E. gunnii leaves and pure ß-diketone were recrystallized on two different artificial materials and analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM) to study their formation process. Both the wax mixture and pure ß-diketone

• formation of the tubules [26]. Atomic force microscopy (AFM) investigations further showed that the elongation of secondary alcohol tubules is based on a helical growth mechanism [27]. Recrystallization experiments with nonacosan-10-ol on non-biological substrates showed that the chemical and physical

• morphologically different type of wax tubules is unknown. On Eucalyptus gunnii leaves mainly the characteristic ß-diketone tubules are present (Figure 1), but helically wound ribbons and a transitional form between both shapes are also present. Atomic force microscopy investigations of tubule formation on living

Modification of a SERS-active Ag surface to promote adsorption of charged analytes: effect of Cu²⁺ ions

• Bahdan V. Ranishenka,
• Andrei Yu. Panarin,
• Irina A. Chelnokova,
• Sergei N. Terekhov,
• Peter Mojzes and
• Vadim V. Shmanai

Beilstein J. Nanotechnol. 2021, 12, 902–912, doi:10.3762/bjnano.12.67

• microscopy (SEM) images were recorded using a Zeiss LEO SUPRA 25 (Germany). Transmitting electron microscopy (TEM) images were recorded using a Zeiss LEO 906E (Germany). SEM and TEM images were treated using ImageJ 1.51k freeware. AFM images were scanned in air using a BioScopeResolve (Bruker) atomic force

• microscope in PeakForceQNM mode with recording the adhesion force maps and topographic images. SERS measurements were carried out by using a scanning probe Raman microscope “NanoFlex” (Solar LS, Belarus). The source of excitation at 488.0 nm was an argon ion laser (Melles Griot, USA). Excitation and

The role of convolutional neural networks in scanning probe microscopy: a review

• Ido Azuri,
• Irit Rosenhek-Goldian,
• Neta Regev-Rudzki,
• Georg Fantner and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2021, 12, 878–901, doi:10.3762/bjnano.12.66

• , convolutional neural networks, and how it is transforming the acquisition and analysis of scanning probe data. Keywords: atomic force microscopy (AFM); deep learning; machine learning; neural networks; scanning probe microscopy (SPM); Review Introduction: traditional machine learning vs deep learning Machine

• conditions for band-excitation piezoresponse force microscopy (PFM) [134]. Band excitation collects a band of frequencies around the contact resonance frequency of the tip–sample system, which is modeled by a simple harmonic oscillator equation. This allows for the determination of several physical

• analysis gave the best result. The authors suggest that using data obtained before from neural network analysis as input to model fitting could be extended to other modalities of SPM, such as magnetic force microscopy and Kelvin probe force microscopy. Another recent example of application to a non

Effects of temperature and repeat layer spacing on mechanical properties of graphene/polycrystalline copper nanolaminated composites under shear loading

• Chia-Wei Huang,
• Man-Ping Chang and
• Te-Hua Fang

Beilstein J. Nanotechnol. 2021, 12, 863–877, doi:10.3762/bjnano.12.65

• properties in various fields, such as supercapacitors, integrated electrodes, catalysis, and sensors [10][11][12][13]. Furthermore, the interaction between graphene and matrix materials directly affects the mechanical properties of composites [14]. The van der Waals force between graphene and metals can

Comprehensive review on ultrasound-responsive theranostic nanomaterials: mechanisms, structures and medical applications

• Sepand Tehrani Fateh,
• Lida Moradi,
• Elmira Kohan,
• Michael R. Hamblin and
• Amin Shiralizadeh Dezfuli

Beilstein J. Nanotechnol. 2021, 12, 808–862, doi:10.3762/bjnano.12.64

• modality, it is attractive to combine it with rationally designed nanoparticles for theranostics. The mechanisms of US interactions include cavitation microbubbles (MBs), acoustic droplet vaporization, acoustic radiation force, localized thermal effects, reactive oxygen species generation, sonoluminescence

• quest for more potent treatment and diagnostic procedures. In this review, the mechanisms of action of US-responsive nanomaterials, including cavitation, acoustic radiation force (ARF), phase transition, reactive oxygen species (ROS) production, and hyperthermia will be discussed in the first step. A

• application of US would affect the tissues and US-responsive nanomaterials through five distinct mechanisms, leading to the therapeutic or diagnostic activities of US-responsive nanomaterials. Cavitation, acoustic radiation force, acoustic droplet vaporization, hyperthermia, and free radical species

Reducing molecular simulation time for AFM images based on super-resolution methods

• Zhipeng Dou,
• Jianqiang Qian,
• Yingzi Li,
• Rui Lin,
• Jianhai Wang,
• Peng Cheng and
• Zeyu Xu

Beilstein J. Nanotechnol. 2021, 12, 775–785, doi:10.3762/bjnano.12.61

• Zhipeng Dou Jianqiang Qian Yingzi Li Rui Lin Jianhai Wang Peng Cheng Zeyu Xu School of Physics, Beihang University, Beijing 100083, China 10.3762/bjnano.12.61 Abstract Atomic force microscopy (AFM) has been an important tool for nanoscale imaging and characterization with atomic and subatomic

• can be used to speed up the generation of training data and vary simulation resolution for AFM machine learning. Keywords: atomic force microscopy; Bayesian compressed sensing; convolutional neural network; molecular dynamics simulation; super resolution; Introduction Atomic force microscopy methods

• and 0.1 Å vertical resolution [3]. Then, functionalizing the tip with closed-shell molecules and using a qPlus force sensor enabled the imaging of the internal structure of the molecules [4][5][6][7], resolving features of weak-bonded molecules [8][9][10][11][12], and measurement of bond-order

9.1% efficient zinc oxide/silicon solar cells on a 50 μm thick Si absorber

• Rafal Pietruszka,
• Bartlomiej S. Witkowski,
• Monika Ozga,
• Katarzyna Gwozdz,
• Ewa Placzek-Popko and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 766–774, doi:10.3762/bjnano.12.60

• the tested PV cells, as measured with atomic force microscopy (AFM). The results for the photovoltaic cell modified with zinc oxide nanorods are shown in Figure 4a and Figure 4c. The results for the planar cell are shown in Figure 4b and Figure 4d. There are significant differences in the roughness

Recent progress in actuation technologies of micro/nanorobots

• Ke Xu and
• Bing Liu

Beilstein J. Nanotechnol. 2021, 12, 756–765, doi:10.3762/bjnano.12.59

• design, build, and navigate. Some traditional robotic theories and technologies cannot be applied in micro/nanorobots. When the size of an object drops to the micro/nanoscale, the micro/nanorobot movement in fluids is in the regime of low Reynolds numbers [14][15]. In this case, the viscous force is

• dominant, and the inertial force is negligible. Hence, micro/nanorobots must be continuously powered for actuation. However, due to the tiny size, power sources such as batteries and engines are difficult to be loaded on micro/nanorobots. Therefore, actuation technologies have been a core content of

• research in the field of micro/nanorobots [16]. One way to actuate micro/nanorobots to achieve motion is to transform energy. Micro/nanorobots can convert magnetic energy, light energy, acoustic energy, or other forms of energy into kinetic energy or actuation force, so as to perform work tasks flexibly

Recent progress in magnetic applications for micro- and nanorobots

• Ke Xu,
• Shuang Xu and
• Fanan Wei

Beilstein J. Nanotechnol. 2021, 12, 744–755, doi:10.3762/bjnano.12.58

• transportation of cargo [22][23], and transmit energy. Compared with other concepts, magnetic MNRs that combine diamagnetic, paramagnetic, and ferromagnetic materials [24] could have a greater driving force and exhibit characteristics such as biocompatibility [25]. Hence, magnetic nanoparticles (MNPs) are widely

• showed stability, specificity, and semi-permeability, together with cell compatibility [25], which could be well applied to MNRs and enhance the driving force of MNRs under certain conditions. Energy transmission and control of the MNRs could be realized by wireless power transfer (WPT) systems [16]. The

• iron oxide nanoparticles [46] has advantages over magnetic surface coatings, such as cobalt or nickel. Diamagnetic nanoparticles Applying an external magnetic force to manipulate the MNRs has become a frontier field of research. Uvet et al. [47] proposed a new microrobot manipulation technology based

Physical constraints lead to parallel evolution of micro- and nanostructures of animal adhesive pads: a review

• Thies H. Büscher and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2021, 12, 725–743, doi:10.3762/bjnano.12.57

• CC BY 4.0). (D–G) Atomic force microscopy (AFM) height images of the footprint droplets of the beetle Coccinella septempunctata (D,F) and the fly Calliphora vicina (E,G). (D) and (E) share the same colour scale. Brighter pixels correspond to higher z values. (F,G) Three-dimensional impressions of the

Electromigration-induced formation of percolating adsorbate islands during condensation from the gaseous phase: a computational study

• Alina V. Dvornichenko,
• Vasyl O. Kharchenko and
• Dmitrii O. Kharchenko

Beilstein J. Nanotechnol. 2021, 12, 694–703, doi:10.3762/bjnano.12.55

• . The electron wind force, which arises during the transmission of the momentum by the conduction electrons, pushes the ions in the direction of the electron flow. As a result, the diffusion processes in the material become anisotropic and directed. This results in the exchange of atoms and the

• properties. The electric field applied to a substrate with a direction parallel to the substrate results in a change in the internal local electric field leading to a directed force Fel = eZE. The strength |E| = −Φ/L is determined by the potential difference Φ and the linear size of the substrate L (distance

• between anode and cathode); e is the electron charge. The direction of the force Fel is defined by the effective valence Z, which is negative for most metals. Thus, the adsorbed atoms move in the opposite direction to the electric field. In the general case if the electric field is applied across the

Nanogenerator-based self-powered sensors for data collection

• Yicheng Shao,
• Maoliang Shen,
• Yuankai Zhou,
• Xin Cui,
• Lijie Li and
• Yan Zhang

Beilstein J. Nanotechnol. 2021, 12, 680–693, doi:10.3762/bjnano.12.54

• capability can be enhanced. Moreover, AI technology can also enhance the performance of sensor. Traffic sensors PENGs are also applicable in intelligent transportation systems. Self-powered vehicle sensors based on PENGs/TENGs can collect the signal of force changes when the vehicle status changes. In 2011

• . proposed a self-powered acceleration sensor based on liquid-metal triboelectric nanogenerator (LM-TENG), which can directly detect horizontal and vertical accelerations [6]. When a vehicle crashes, the force and position data of the vehicle can be obtained through the acceleration sensor. This acceleration

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

Nanoporous and nonporous conjugated donor–acceptor polymer semiconductors for photocatalytic hydrogen production

• Zhao-Qi Sheng,
• Yu-Qin Xing,
• Yan Chen,
• Guang Zhang,
• Shi-Yong Liu and
• Long Chen

Beilstein J. Nanotechnol. 2021, 12, 607–623, doi:10.3762/bjnano.12.50

• light. This was attributed to the improved wettability of P65 induced by the additional electronegative O atom and to the decreased ionization potential of trimethylamine (TEA) accelerating its oxidation through the higher driving force of P65 for overall TEA oxidation [79]. In addition, Wang et al. [80

• thermodynamic driving force for proton reduction is still hard to achieve for a single CP component. In this respect, the combination of CPs with other semiconductors to form heterojunctions can further enhance the catalytic performance. Fabricating inorganic/polymer composites with complementary absorption

• ranges is an efficient strategy to extend the light-responsive region and offer enough thermodynamic driving force compared to single semiconductors. Besides, molecular heterostructures produced by two covalently bonded polymers could be a promising strategy because of effective charge carrier separation

Impact of GaAs(100) surface preparation on EQE of AZO/Al₂O₃/p-GaAs photovoltaic structures

• Piotr Caban,
• Rafał Pietruszka,
• Jarosław Kaszewski,
• Monika Ożga,
• Bartłomiej S. Witkowski,
• Krzysztof Kopalko,
• Piotr Kuźmiuk,
• Katarzyna Gwóźdź,
• Ewa Płaczek-Popko,
• Krystyna Lawniczak-Jablonska and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 578–592, doi:10.3762/bjnano.12.48

• /interface needs to be properly prepared. In the experiments described here we examined eight different paths of GaAs surface treatment (cleaning, etching, passivation) which resulted in different external quantum efficiency (EQE) values of the tested photovoltaic (PV) cells. Atomic force microscopy (AFM

• analyzed using a scanning electron microscope (Hitachi SU-70) with a secondary electron detector operating at 15 kV. The topography of the surface of the layers was analyzed using an atomic force microscope (Bruker Dimension Icon) working in peak-force tapping mode using a ScanAsyst algorithm. A ScanAsyst

Local stiffness and work function variations of hexagonal boron nitride on Cu(111)

• Abhishek Grewal,
• Yuqi Wang,
• Matthias Münks,
• Klaus Kern and
• Markus Ternes

Beilstein J. Nanotechnol. 2021, 12, 559–565, doi:10.3762/bjnano.12.46

• , CH-1015 Lausanne, Switzerland II. Institute of Physics, RWTH Aachen University, D-52074 Aachen, Germany 10.3762/bjnano.12.46 Abstract Combined scanning tunnelling and atomic force microscopy using a qPlus sensor enables the measurement of electronic and mechanic properties of two-dimensional

• the contact potential difference measured by Kelvin probe force microscopy. Using 3D force profiles of the same area we determine the relative stiffness of the Moiré region allowing us to analyse both electronic and mechanical properties of the 2D layer simultaneously. We obtain a sheet stiffness of

• 9.4 ± 0.9 N·m−1, which is one order of magnitude higher than the one obtained for h-BN/Rh(111). Using constant force maps we are able to derive height profiles of h-BN/Cu(111) showing that the system has a corrugation of 0.6 ± 0.2 Å, which helps to demystify the discussion around the flatness of the h

Influence of electrospray deposition on C₆₀ molecular assemblies

• Antoine Hinaut,
• Sebastian Scherb,
• Sara Freund,
• Zhao Liu,
• Thilo Glatzel and
• Ernst Meyer

Beilstein J. Nanotechnol. 2021, 12, 552–558, doi:10.3762/bjnano.12.45

• the first molecules studied in HV-ESD experiments [5][30]. Here, we present a comparison between TE and HV-ESD regarding the adsorption and structure formation of C60 molecules on surfaces at low coverages, that is, below one monolayer down to single molecules. We used a non-contact atomic force

• were obtained. Room-temperature AFM Room-temperature nc-AFM measurements were performed with a custom-built non-contact atomic force microscope with Nanonis electronics RC5. PPP-NCL cantilevers (Nanosensor) were used as sensor (typical resonance frequency of f1 = 170 kHz, oscillation amplitude A1 = 2–5

On the stability of microwave-fabricated SERS substrates – chemical and morphological considerations

• Limin Wang,
• Aisha Adebola Womiloju,
• Christiane Höppener,
• Ulrich S. Schubert and
• Stephanie Hoeppener

Beilstein J. Nanotechnol. 2021, 12, 541–551, doi:10.3762/bjnano.12.44

• glass capillaries or on scanning force microscopy tips) in a very economic and fast (less than five minutes) coating process. The formed substrates, which are coated with a monolayer of silver nanoparticles, have been demonstrated to be highly reproducible and to perform very well in the detection of

Determining amplitude and tilt of a lateral force microscopy sensor

• Oliver Gretz,
• Alfred J. Weymouth,
• Thomas Holzmann,
• Korbinian Pürckhauer and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2021, 12, 517–524, doi:10.3762/bjnano.12.42

• Oliver Gretz Alfred J. Weymouth Thomas Holzmann Korbinian Purckhauer Franz J. Giessibl Institute of Experimental and Applied Physics, Department of Physics, University of Regensburg, 93053 Regensburg, Germany 10.3762/bjnano.12.42 Abstract In lateral force microscopy (LFM), implemented as

• frequency-modulation atomic force microscopy, the tip oscillates parallel to the surface. Existing amplitude calibration methods are not applicable for mechanically excited LFM sensors at low temperature. Moreover, a slight angular offset of the oscillation direction (tilt) has a significant influence on

• for a given amplitude and tilt. Finally, the amplitude and tilt are determined by fitting the simulation output to the data with oscillation. Keywords: frequency-modulation atomic force microscopy; lateral force microscopy; amplitude calibration; tilt estimation; Introduction Frequency-modulation

Boosting of photocatalytic hydrogen evolution via chlorine doping of polymeric carbon nitride

• Malgorzata Aleksandrzak,
• Michalina Kijaczko,
• Wojciech Kukulka,
• Daria Baranowska,
• Martyna Baca,
• Beata Zielinska and
• Ewa Mijowska

Beilstein J. Nanotechnol. 2021, 12, 473–484, doi:10.3762/bjnano.12.38

• due to fossil fuels used in the energy industry, the combustion of which generates CO2 emissions. The ideal solution of these problems appears to be the use of photocatalysis. The solar light, as a driving force, has been widely used in different fields, such as water in water-splitting to generate

• , carbon, oxygen, and chlorine in Cl-PCN was performed and showed homogeneous distribution of all elements in the sample. As analyzed via atomic force microscopy (AFM, Figure 2a and Figure 2b) the as-prepared PCN aggregated as large sheets with thickness ranging from 1 to 4 nm (corresponding to 3–11 atomic

A review on nanostructured silver as a basic ingredient in medicine: physicochemical parameters and characterization

• Gabriel M. Misirli,
• Kishore Sridharan and
• Shirley M. P. Abrantes

Beilstein J. Nanotechnol. 2021, 12, 440–461, doi:10.3762/bjnano.12.36

• AgNPs with light leads to surface plasmon resonance (SPR) effect when the incident light frequency coincides with the frequency of the oscillating electrons on the surface. The surface of AgNPs stores the conducting electrons inside the particles and establishes a restorative force which creates a