Current-induced mechanical torque in chiral molecular rotors

• Richard Korytár and
• Ferdinand Evers

Beilstein J. Nanotechnol. 2023, 14, 711–721, doi:10.3762/bjnano.14.57

• affects the passage of the particle. The trajectory (path) at rest ( = 0, ϑ = 0) will be expressed parametrically in a cylindrical coordinate system: The parameter s could be the distance along the path; for the purpose of this work it is not required. For simplicity, we further stipulate that z(s) is

• monotonously increasing with s, and that the trajectory never intersects itself. The model contains two dynamical variables, the degree of freedom of the particle, s(t), and ϑ(t), the latter being the angle of the path with respect to a static coordinate system. Our aim is to investigate the dynamics of ϑ

Thermal transport in kinked nanowires through simulation

• Alexander N. Robillard,
• Graham W. Gibson and
• Ralf Meyer

Beilstein J. Nanotechnol. 2023, 14, 586–602, doi:10.3762/bjnano.14.49

• , that are local minima for the number of reflections occurring for most paths. Cook and Varga [40] show that this can be the case in 1D nanowires, where kinks in general result in poor transmission, but there can be resonant states for certain geometries. Note that the trajectory of a phonon travelling

• scatter and will continue past, while for the low flux areas, unscattered phonons may continue their trajectory there. This has the effect of muting the difference between the high and low flux regions. Essentially, while increasing the kink angle seems to promote corner cutting, the ballistic behaviour

Specific absorption rate of randomly oriented magnetic nanoparticles in a static magnetic field

• Ruslan A. Rytov and
• Nikolai A. Usov

Beilstein J. Nanotechnol. 2023, 14, 485–493, doi:10.3762/bjnano.14.39

• , Hac = 200 Oe. Obviously, at Hdc = 0, the potential wells of the nanoparticle located at θ = 0 and θ = π are separated by a high potential barrier, which is independent of the angle φ. However, if the perpendicular dc magnetic field increases to Hdc = 200 Oe, a saddle trajectory appears on the barrier

Quantitative dynamic force microscopy with inclined tip oscillation

• Philipp Rahe,
• Daniel Heile,
• Reinhard Olbrich and
• Michael Reichling

Beilstein J. Nanotechnol. 2022, 13, 610–619, doi:10.3762/bjnano.13.53

• . Experimentally, however, the sampling path representing the tip oscillating trajectory is often inclined with respect to the surface normal and the data recording path. Here, we extend the mathematical description of dynamic AFM to include the case of an inclined sampling path. We find that the inclination of

• step, the time averages are transformed to spatial averages similar to the formerly introduced cup and cap average functionals [3]. The harmonic approximation constrains the tip movement within the phase space to a closed trajectory. Consequently, the parametrisation with a spatial coordinate along

Nanoscale friction and wear of a polymer coated with graphene

• Robin Vacher and
• Astrid S. de Wijn

Beilstein J. Nanotechnol. 2022, 13, 63–73, doi:10.3762/bjnano.13.4

• . The two regions where the graphene carbon atoms are fixed are located in stripes along the x-direction, which is the sliding direction, as far away from the trajectory of the tip as possible (Figure 3). Indentation and sliding procedure Once graphene is deposited, we start indenting with a modelled

Effect of lubricants on the rotational transmission between solid-state gears

• Huang-Hsiang Lin,
• Jonathan Heinze,
• Alexander Croy,
• Rafael Gutiérrez and
• Gianaurelio Cuniberti

Beilstein J. Nanotechnol. 2022, 13, 54–62, doi:10.3762/bjnano.13.3

• teeth of both gears start jiggling around. Moreover, there is a finite phase-shift or time delay for the second gear compared to the first one, whose trajectory is a linear straight line. This phenomenon is due to the nonzero distance between the teeth of both gears during their collective rotation

• other again via the lubricant and slightly accelerate the second gear until they become coherent again. As for the other cases, one can see that a net delay happens. Consider, for instance, ω = π rad/ns with dCM = 10.4 nm (yellow in Figure 3a): After investigating the full trajectory (see Figure 4), we

The effect of cobalt on morphology, structure, and ORR activity of electrospun carbon fibre mats in aqueous alkaline environments

• Markus Gehring,
• Tobias Kutsch,
• Osmane Camara,
• Alexandre Merlen,
• Hermann Tempel,
• Hans Kungl and
• Rüdiger-A. Eichel

Beilstein J. Nanotechnol. 2021, 12, 1173–1186, doi:10.3762/bjnano.12.87

• further improved by applying a copper tape connecting the sample and the graphite tape. To identify the particles decorating the nanofibres, EDX was performed using an Octane Super EDX detector (EDAX). The programme “monte CArlo SImulation of electroN trajectory in sOlids” (CASINO) [23], which simulates

Is the Ne operation of the helium ion microscope suitable for electron backscatter diffraction sample preparation?

• Annalena Wolff

Beilstein J. Nanotechnol. 2021, 12, 965–983, doi:10.3762/bjnano.12.73

• study on Ga-induced phase transformations in copper [34]. A lower ion dose (2247 ions/nm2) was also evaluated as it corresponds to the dose that is achieved for commonly reported EBSD polishing time values over larger areas [39]. 30 keV Ga ion irradiation at 0° incidence angle The ion trajectory plot

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

• controlled, so as to make the robot move along the surface of a graphene film in a desired trajectory. This study provided a lot of useful insight in the design of nanorobots. In the future, such designed nanorobots could be integrated into a silicon-based chip to perform specific actions. Also they could be

• used, which could control the driving speed and movement of the particles along a desired trajectory by changing the frequency range of the transducer and the scanning time and other parameters. Although this concept has limitations such as being interfered by media in actual body tissues, it provides

• previous research, Bao et al. [38] innovatively designed a V-shaped micro/nanorobot made of platinum only. The nanorobot is propelled by oxygen molecules generated by the decomposition of H2O2 and can maintain a rotating motion and navigate in a stable trajectory. Compared with previous studies, the

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

• method to complete medical tasks with the optimal trajectory of controllable movement of MNRs in cardiovascular system was proposed. Some multiferroic nanomaterials exhibit ferromagnetism and antiferromagnetism by adjusting electricity and magnetism. A variety of multifunctional devices can be prepared

• magnetic torque on the long axis of the microrobot, which generated torque on the microswimmer through a magnetic axis defined perpendicular to the helical axis. The double helix could compensate instabilities of the trajectory, which can improve the hydrodynamic efficiency to meet the power demand. It is

• in cell culture medium), if the trajectory of the target motion is preset, it could follow the path and transfer the payload with the help of the rotating magnetic field. Different from the device in [42], an electromagnetic control system composed of three pairs of Helmholtz coils was used to

The patterning toolbox FIB-o-mat: Exploiting the full potential of focused helium ions for nanofabrication

• Victor Deinhart,
• Lisa-Marie Kern,
• Jan N. Kirchhof,
• Sabrina Juergensen,
• Joris Sturm,
• Enno Krauss,
• Thorsten Feichtner,
• Sviatoslav Kovalchuk,
• Michael Schneider,
• Dieter Engel,
• Bastian Pfau,
• Bert Hecht,
• Kirill I. Bolotin,
• Stephanie Reich and
• Katja Höflich

Beilstein J. Nanotechnol. 2021, 12, 304–318, doi:10.3762/bjnano.12.25

• consequence is the deep implantation of light ions. He and Ne are chemically inert and may therefore diffuse out of the substrate after a while. Diffusion in solids, however, is extremely inefficient, such that the majority of the primary ions will be implanted at their final trajectory position [22]. Hence

Design of V-shaped cantilevers for enhanced multifrequency AFM measurements

• Mehrnoosh Damircheli and
• Babak Eslami

Beilstein J. Nanotechnol. 2020, 11, 1525–1541, doi:10.3762/bjnano.11.135

• round, the optimum parameters are selected and used for the next round of simulation for optimizing the other parameters. At the end, all parameters are optimized, providing the maximum phase contrast between Au and PS. In Figure 2, the tip trajectory of the first and second mode for the setpoint value

• geometrical parameters. Tip trajectory of a V-shaped cantilever interacting with a Au sample (L = 85 µm, = 15 µm, bref = 86 µm, tref = 0.4 µm, Rtip = 9 nm, α = 0°) in time. Left: First eigenmode. Right: Second eigenmode. The setpoint is 60% for the first eigenmode amplitude. Ratio of second eigenmode to

On the frequency dependence of viscoelastic material characterization with intermittent-contact dynamic atomic force microscopy: avoiding mischaracterization across large frequency ranges

• Enrique A. López-Guerra and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2020, 11, 1409–1418, doi:10.3762/bjnano.11.125

• methods have found niches of application and have provided physical insight into a wide variety of materials. In keeping with the above trajectory in the development of new AFM methods for viscoelastic materials, in recent years we have focused on the application of linear viscoelasticity within quasi

• cantilevers used to properly characterize it. However, one should be surprised to see hardly any hysteresis in the force trajectory of material 2 despite its obvious viscoelastic nature depicted in Figure 2. One must therefore consider whether the cantilever stiffness used is appropriate, since the force

• the cantilever stiffness over the sample stiffness. Figure 5b compares the force trajectory during impact for both values of the force constant, and indeed, we observe significantly greater indentation and repulsive forces for the stiffer cantilever. Furthermore, the force trajectory now shows an

Thermophoretic tweezers for single nanoparticle manipulation

• Jošt Stergar and
• Natan Osterman

Beilstein J. Nanotechnol. 2020, 11, 1126–1133, doi:10.3762/bjnano.11.97

• trapping potential was characterized using the standard procedure for optical tweezers calibration [33]: from the recorded trajectory of the particle positions, the probability density ρ(x) distribution was obtained. Although the discussed process is a non-equilibrium process one can still define the

• a delta-correlated stationary Gaussian process with zero-mean, satisfying ⟨R(t)R(t’)⟩ = δ(t – t’). The equation was solved with a finite difference method with a time step of 100 µs. The particle trajectory for a duration of 1000 s was simulated for each combination of parameters. Figure 3 presents

• for a single 200 nm particle. (a) 2D histogram of particle positions. (b) Cross section of the effective potential in x- and y-directions. Manipulation of a 200 nm nanoparticle in water. (a) The trajectory of the particle. (b) Time dependence of x- and y-position of the particle during the

Current measurements in the intermittent-contact mode of atomic force microscopy using the Fourier method: a feasibility analysis

• Berkin Uluutku and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2020, 11, 453–465, doi:10.3762/bjnano.11.37

• dynamic current measurements, this manuscript discusses three different cases: (i) a noncontact dynamic current measurement where the cantilever follows an ideal sinusoidal trajectory, (ii) a similar case, but considering a more realistic trajectory where the tip oscillation is perturbed by the presence

• trajectory Consider an AFM tip oscillating over a surface with a perfect cosine trajectory, without impacting the surface (Figure 1). In this case the distance between the AFM tip and the surface can be written as where d is the instantaneous tip–sample distance, h is the equilibrium tip position, A is the

• analyse the result, we take the Fourier transform of the series in Equation 7: We will return to this expression in order to analyse and visualize it in the Results section. Case 2: Dynamic noncontact current measurement with realistic tip trajectory A real AFM tip trajectory exhibits perturbations due to

Understanding nanoparticle flow with a new in vitro experimental and computational approach using hydrogel channels

• Armel Boutchuen,
• Dell Zimmerman,
• Abdollah Arabshahi,
• John Melnyczuk and
• Soubantika Palchoudhury

Beilstein J. Nanotechnol. 2020, 11, 296–309, doi:10.3762/bjnano.11.22

• related to flow of NPs such as the quantity of NPs lost during transport and flow trajectory greatly affect the clinical efficiency of NP drug delivery systems. Currently, there is little knowledge of the physical mechanisms dominating NP flow inside the human body due to the limitations of available

• vivo methods for a more efficient and reliable evaluation of NP drugs [12]. However, many variables such as the size, surface chemistry, and interaction of the NPs with different biological compounds within the body influence the trajectory of NPs in vivo [13][14][15]. This makes it challenging to

• trajectory of NPs. In the case of soft hydrogel-based flow channels constructed to mimic vascular networks, the larger sized NPs moved slower than the smaller NPs, similar to trends seen in macroscale objects. This phenomenon could be explained in terms of two factors, a dominance of Brownian forces over

Long-term entrapment and temperature-controlled-release of SF₆ gas in metal–organic frameworks (MOFs)

• Hana Bunzen,
• Andreas Kalytta-Mewes,
• Leo van Wüllen and
• Dirk Volkmer

Beilstein J. Nanotechnol. 2019, 10, 1851–1859, doi:10.3762/bjnano.10.180

• extracted from the previous force field scan trajectory and all atomic positions were allowed to relax during subsequent optimization steps, except for the position of the sulfur atom of SF6, which was fixed at the corresponding c/N coordinate of the transition path. The PW-DFT+D calculations were performed

Choosing a substrate for the ion irradiation of two-dimensional materials

• Egor A. Kolesov

Beilstein J. Nanotechnol. 2019, 10, 531–539, doi:10.3762/bjnano.10.54

• assumed in [16]. The overall most pronounced effect is naturally observed for the copper substrate, with the results for Al2O3 being remarkably close. While inelastic collisions with the electronic sea naturally do not change the ion trajectory, the maxima in Figure 2 correspond to the strongest relative

Intuitive human interface to a scanning tunnelling microscope: observation of parity oscillations for a single atomic chain

• Sumit Tewari,
• Jacob Bakermans,
• Christian Wagner,
• Federica Galli and
• Jan M. van Ruitenbeek

Beilstein J. Nanotechnol. 2019, 10, 337–348, doi:10.3762/bjnano.10.33

• to the motion control system that provides a continuous visual feedback to the operator during atomic manipulation. This allows the operator to become a part of the experiment and to make any adaptable tip trajectory that could be useful for atomic manipulation in three dimensions. The strength of

• ]. Therefore, the knowledge about the structure of the junction at the atomic scale is critical to the understanding of these transport measurements. The system that we have developed addresses this problem. We have added a 3D motion control system to our STM that helps in making any required tip trajectory

• then choose to make a desired trajectory for better control of the manipulation process. This is especially important in the case of 3D manipulation of single molecules and atomic chains, as there are no predefined accurate trajectories [5][6] that one can set to do those manipulations. Therefore an

Investigation of CVD graphene as-grown on Cu foil using simultaneous scanning tunneling/atomic force microscopy

• Majid Fazeli Jadidi,
• Umut Kamber,
• Oğuzhan Gürlü and
• H. Özgür Özer

Beilstein J. Nanotechnol. 2018, 9, 2953–2959, doi:10.3762/bjnano.9.274

• images of a graphene surface are shown in Figure 1. In this experiment, the forward scan was performed in constant current mode and the backward scan in constant height mode, for a proper extraction of the tip–sample force, which might have been potentially affected by the varying tip trajectory. STM

• ) and constant-height (CH) scans. The force corrugation contrast between carbon and hollow sites is found to be about 0.1 nN for both CC and CH modes. Thus, as far as the force is concerned the tip trajectory in CC mode does not have a considerable influence on the measurement of the oscillation

Time-resolved universal temperature measurements using NaYF₄:Er³⁺,Yb³⁺ upconverting nanoparticles in an electrospray jet

• Kristina Shrestha,
• Arwa A. Alaulamie,
• Ali Rafiei Miandashti and
• Hugh H. Richardson

Beilstein J. Nanotechnol. 2018, 9, 2916–2924, doi:10.3762/bjnano.9.270

• Taylor cone angle. The sampling time reduces to 2 μs at the tip. (B) A plot of temperature calculated along the trajectory of a Taylor cone at room temperature (296 K) and at elevated temperature (306 K). The sampling time at a given distance is indicated in the figure. A schematic illustration for a

Disorder in H⁺-irradiated HOPG: effect of impinging energy and dose on Raman D-band splitting and surface topography

• Lisandro Venosta,
• Noelia Bajales,
• Sergio Suárez and
• Paula G. Bercoff

Beilstein J. Nanotechnol. 2018, 9, 2708–2717, doi:10.3762/bjnano.9.253

• domain size by considering the intensity ratio ID/IG. Likewise, Ferrari [9] proposed that the evolution of Raman spectra can be fitted by a phenomenological model in agreement with the amorphization trajectory for graphitic nanocrystallites. The authors pointed out that the ID/IG intensity ratio depends

The inhibition effect of water on the purification of natural gas with nanoporous graphene membranes

• Krzysztof Nieszporek,
• Tomasz Pańczyk and
• Jolanta Nieszporek

Beilstein J. Nanotechnol. 2018, 9, 1906–1916, doi:10.3762/bjnano.9.182

• illustration of the clustering of water molecules in the NN nanopore can be seen in Figure 10. The picture has been extracted from the simulation trajectory at a time of 5 ns. In Figure 7 (right panel, red curve) an attentive reader can see a decrease of the number of water molecules in the permeate area at a

• . The extracted frame from the simulation trajectory of the separation of CH4 + N2 + 200 H2O with an NN nanopore at a time of 5 ns. Green, blue and red molecules are methane, nitrogen and water, respectively. The temperature influence on the number of molecules passing across the pore as a function of

• ). The right plot presents the time dependence of the distance between the center of nanopore and that plane. Data were determined from the simulation trajectory of CH4 + N2 + 200 H2O at 300 K. Time evolution of the second kind of deviation. Data were determined from the simulation trajectory of CH4 + N2

Tunable fractional Fourier transform implementation of electronic wave functions in atomically thin materials

• Daniela Dragoman

Beilstein J. Nanotechnol. 2018, 9, 1828–1833, doi:10.3762/bjnano.9.174

• coordinate x and the tangent θ to the ray/quantum trajectory at a y = const. plane and the same parameters (indexed by 0) at the y = 0 plane [15]: In Equation 5, valid when or , one has in optics and in the case of Schrödinger electrons. Whether the results above regarding Schrödinger electrons are not

• of the spinorial wave function satisfy the equation which is similar to Equation 2 if , , . As a result, the FrFT of order α is achieved after a propagation distance in graphene equal to and the trajectory of charge carriers in graphene is also periodic and described by Equation 5, with . Again, the

• implements a FrFT for negative UG potentials, while that in Figure 1b implements it for positive UG values. Figure 1a and Figure 1b depict also the trajectory of a ballistic electron. From Equation 4 and Equation 8 it follows that the last configuration implements a FrFT with a given α in a shorter distance

Atomistic modeling of tribological properties of Pd and Al nanoparticles on a graphene surface

• Alexei Khomenko,
• Miroslav Zakharov,
• Denis Boyko and
• Bo N. J. Persson

Beilstein J. Nanotechnol. 2018, 9, 1239–1246, doi:10.3762/bjnano.9.115

• one of a large number of available thermostats is used. Velocity rescaling by a constant factor, which corresponds to the desired temperature, is the simplest way to maintain the necessary temperature. Here we use the Berendsen thermostat [16][17] that does not give the trajectory of the true