Virtual reality visual feedback for hand-controlled scanning probe microscopy manipulation of single molecules

• Philipp Leinen,
• Matthew F. B. Green,
• Taner Esat,
• Christian Wagner,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2015, 6, 2148–2153, doi:10.3762/bjnano.6.220

• environment is not fully known. Here we present a further technical development that substantially improves the effectiveness of HCM. By adding Oculus Rift virtual reality goggles to our HCM set-up we provide the experimentalist with 3D visual feedback that displays the currently executed trajectory and the

• the analysis of manipulation trajectory data much simpler. It would also help to transfer knowledge between different users and/or experiments, thus facilitating systematic learning during which manipulation protocols are refined and corrected in multiple steps. Visualization of the manipulation

• trajectory data should therefore greatly increase the effectiveness of HCM and extend the range of its possible applications. Here we introduce a system that visualizes HCM data in real time by displaying the actual tip position as well as the history of its movements in 3D using Oculus Rift DK 2 (ORt

Possibilities and limitations of advanced transmission electron microscopy for carbon-based nanomaterials

• Xiaoxing Ke,
• Carla Bittencourt and
• Gustaaf Van Tendeloo

Beilstein J. Nanotechnol. 2015, 6, 1541–1557, doi:10.3762/bjnano.6.158

• discussed in the next subsection. The previous discussion of Cs correctors applies to the post-field of the objective lens, which corrects the electron trajectory of the exit electron wave after interaction with the specimen, and provides a more straightforward interpretation of the projected potential of

Continuum models of focused electron beam induced processing

• Milos Toth,
• Charlene Lobo,
• Vinzenz Friedli,
• Aleksandra Szkudlarek and
• Ivo Utke

Beilstein J. Nanotechnol. 2015, 6, 1518–1540, doi:10.3762/bjnano.6.157

• more detailed discussion on the applicability range can be found in [10]. For high-aspect ratio structures either a full Monte Carlo electron trajectory approach can be chosen [54] or the continuum equations outlined in our present work need to be solved on a curvilinear reference surface, see [13] and

Surface excitations in the modelling of electron transport for electron-beam-induced deposition experiments

• Francesc Salvat-Pujol,
• Roser Valentí and
• Wolfgang S. Werner

Beilstein J. Nanotechnol. 2015, 6, 1260–1267, doi:10.3762/bjnano.6.129

• of a simple superposition of Drude–Lindhard oscillators [33]. Assuming a projectile that moves with a velocity v along a trajectory r = vt, one can conveniently solve the Maxwell equations in Fourier space to obtain the following expression for the induced electric field [31] where ρ(q,ω) is the

• model for SE emission: every time that the primary electron undergoes an energy loss, a SE trajectory is started with the energy loss as an initial energy (see [55] for the simulation details). Having the experimental data as a guideline, the interaction cross sections described above were used down to

Scanning reflection ion microscopy in a helium ion microscope

• Yuri V. Petrov and
• Oleg F. Vyvenko

Beilstein J. Nanotechnol. 2015, 6, 1125–1137, doi:10.3762/bjnano.6.114

• trajectory with the increasing in the magnification. Accordingly, the simplest test to check for the presence of the effect of beam charge bending is a comparison of results of two scans preformed with different magnifications. Similar results will provide evidence of the accuracy of the lateral size

• obtain sharp images of an insulator surface without the need for charge compensation or a conductive coating. A positive surface charge produced by ions attracts SEs but does not significantly change the RI trajectory and their detection. The changes in trajectory caused by the electric field of the

Superluminescence from an optically pumped molecular tunneling junction by injection of plasmon induced hot electrons

• Kai Braun,
• Xiao Wang,
• Andreas M. Kern,
• Hilmar Adler,
• Heiko Peisert,
• Thomas Chassé,
• Dai Zhang and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2015, 6, 1100–1106, doi:10.3762/bjnano.6.111

• ) with the respective spectrally integrated intensity trajectory (iii). Electroluminescence spectra excited by inelastic tunneling (b) without laser illumination as a function of the bias voltage (i), (ii). All spectra were recorded with the same tunneling current (1 nA) and are normalized to 1 s

Fabrication of high-resolution nanostructures of complex geometry by the single-spot nanolithography method

• Alexander Samardak,
• Margarita Anisimova,
• Aleksei Samardak and
• Alexey Ognev

Beilstein J. Nanotechnol. 2015, 6, 976–986, doi:10.3762/bjnano.6.101

• trajectory distribution of electrons produced by Monte Carlo simulations shows that the upper third part of the pillar is very narrow and can be easily removed by developer (Figure 4). Figure 6 shows the experimental dependence of the outer diameter dout and the core diameter din on the radiation dose for

Manipulation of magnetic vortex parameters in disk-on-disk nanostructures with various geometry

• Maxim E. Stebliy,
• Alexander G. Kolesnikov,
• Alexey V. Ognev,
• Alexander S. Samardak and
• Ludmila A. Chebotkevich

Beilstein J. Nanotechnol. 2015, 6, 697–703, doi:10.3762/bjnano.6.70

• applied during measurements. It is found that manipulation of the magnetic vortex chirality and the trajectory of the vortex core in the big disk is only possible in asymmetric nanostructures. Experimentally studied peculiarities of a motion path of the vortex core and vortex parameters by the magneto

• . Moreover, the trajectory of a vortex core is distorted and its gyrotropic motion frequency changes significantly. Recently, by using magnetic force microscopy (MFM), we have demonstrated a reliable method to control the vortex parameters in a big disk if a disk with smaller diameter is placed on its top [8

• of the vortex nucleation process as well as the vortex core trajectory under an impact of bias fields have been observed. Experimental findings have been interpreted by micromagnetic simulations [9]. Results and Discussion Figure 1a shows scanning electron microscopy (SEM) images of disk-on-disk

The effect of surface charge on nonspecific uptake and cytotoxicity of CdSe/ZnS core/shell quantum dots

• Vladimir V. Breus,
• Anna Pietuch,
• Marco Tarantola,
• Thomas Basché and
• Andreas Janshoff

Beilstein J. Nanotechnol. 2015, 6, 281–292, doi:10.3762/bjnano.6.26

• travelled a significant distance: short (with back-and-forth contour-like movement) and long (directed motion of QDs, supposedly being dragged by motor proteins); random trajectories were assigned to disordered motion. For both trajectory types, we observed two modes of confined motion in the MSD plots of

• ). Each row shows the trajectory and the corresponding displacement vs time representation. (d) Average velocities of CA–QDs, DHLA–QDs and DPA–QDs exhibiting organized movement in different zones of cellular interior after 4 h (top) and 22 h (bottom) of QD incubation. Fluorescent micrographs of untreated

Modeling viscoelasticity through spring–dashpot models in intermittent-contact atomic force microscopy

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

Beilstein J. Nanotechnol. 2014, 5, 2149–2163, doi:10.3762/bjnano.5.224

• Linear Maxwell sample has yielded sufficiently to allow the tip to oscillate at its free oscillation amplitude, without any tip–sample interaction). Since we are interested in the response of the Linear Maxwell sample with an intermittent contact probe, we have used a prescribed tip trajectory for the

• jump in the FD curve. This is an obvious problem precluding the application of this model to tapping mode AFM. This artifact can also be seen in the inset of Figure 2c which shows the force as a function of time as well as the position of the surface and tip trajectory in time. It can be seen that the

• horizontal axis is intentionally plotted by using a logarithmic scale to show the inflection point corresponding to its single relaxation time. (c) Force–distance tip trajectories (the trajectory proceeds in the counterclockwise direction) for a prescribed sinusoidal tip trajectory given by z(t) = 80 nm

Dissipation signals due to lateral tip oscillations in FM-AFM

• Michael Klocke and
• Dietrich E. Wolf

Beilstein J. Nanotechnol. 2014, 5, 2048–2057, doi:10.3762/bjnano.5.213

• limited to very narrow ranges of frequency ratios. Quality factor We studied the influence of the quality factor on the energy dissipation rate (Figure 6). For high Q-values, the trajectory of the tip in the strong interaction region is nearly unaffected by the damping in the lateral degree of freedom

• . Therefore, the approximation leading to Equation 5 is applicable, which explains the Q−1-dependence shown in Figure 6. At lower Q-values, the effect on the trajectory becomes stronger. The energy transfer into the lateral degree of freedom slows down and, being limited in time by the normal cantilever

Patterning a hydrogen-bonded molecular monolayer with a hand-controlled scanning probe microscope

• Matthew F. B. Green,
• Taner Esat,
• Christian Wagner,
• Philipp Leinen,
• Alexander Grötsch,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2014, 5, 1926–1932, doi:10.3762/bjnano.5.203

• successfully, despite lacking full knowledge of their complex interaction potential? Generally, the manipulation act is defined as a trajectory that connects the initial and the final states of the junction in its multidimensional state space. In SPM such trajectories can only be executed by controlled changes

• of the spatial coordinates of the tip. The other degrees of freedom of the junction, namely the centre of mass and the internal degrees of freedom of the manipulated molecule, cannot be directly controlled; instead they relax spontaneously as the tip is moved along its 3-D trajectory. Their

• were known at each point of its state space, the identification of the desired tip trajectory would become a mathematical problem. In reality, since the potential is not known “successful” trajectories can only be determined with the help of an experiment in which the relevant regions of the potential

Dynamic calibration of higher eigenmode parameters of a cantilever in atomic force microscopy by using tip–surface interactions

• Stanislav S. Borysov,
• Daniel Forchheimer and
• David B. Haviland

Beilstein J. Nanotechnol. 2014, 5, 1899–1904, doi:10.3762/bjnano.5.200

• in the different detected voltages, V1 ≠ V2. In the case of small deflections, zn is proportional to Vn with some coefficient αn called optical lever inverse responsivity. The tip–surface force (Equation 6) used in the simulations. The white dashed line corresponds to a phase space trajectory of the

Spin annihilations of and spin sifters for transverse electric and transverse magnetic waves in co- and counter-rotations

• Hyoung-In Lee and
• Jinsik Mok

Beilstein J. Nanotechnol. 2014, 5, 1887–1898, doi:10.3762/bjnano.5.199

• momentum; multiplexing; nanoparticle; orbital; Poynting; spin; trajectory; Introduction Electromagnetic (EM) waves are now fairly well understood at least in terms of angular momentum (AM) and Poynting vector (PV). For instance, the AM of spin-one photons is divisible into the spin and orbital parts [1][2

• terms of as a function of ρ [22]. First, consider the interior for the counter-rotational case, where . Taken together, the PV flows make two-dimensional circular patterns infinite times [22], according to the trajectory m(θ – θ0) = c(t – t0) with (θ0, t0) constant. Now consider based on Equation 11

• , we added a straight vertical line at (x,y) = (0,0) over 0 ≤ kz ≤ 10 in black color along with a circle of unit radius at kz = 10 in blue color. Now the red curve is the trajectory for q = i, whereas the green curve is that for q = ±1. Incidentally, the latter curve is just the projection of the

Synthesis of Pt nanoparticles and their burrowing into Si due to synergistic effects of ion beam energy losses

• Pravin Kumar,
• Udai Bhan Singh,
• Kedar Mal,
• Sunil Ojha,
• Indra Sulania,
• Dinakar Kanjilal,
• Dinesh Singh and
• Vidya Nand Singh

Beilstein J. Nanotechnol. 2014, 5, 1864–1872, doi:10.3762/bjnano.5.197

• local melting (thermal spike) [29] occurs along the ion trajectory due to the energy deposition into the electronic subsystem (within 10−16 s). The local thermalization of the electronic sub-system takes place within 10−14 s. The deposited energy is transferred to the atomic subsystem by electron–phonon

• coupling. The melting of materials along the ion trajectory generates a surface tension gradient due to an imbalance of the surface and the interface energies, which further gives rise to mass transport through capillary action. The migration of metallic atoms and subsequent agglomeration can result in the

• formation of the nanoparticles. The ion trajectory formation in insulators and semiconductors after passage of high energy ions is mainly explained by the Coulomb explosion model [30]. However, ion beams with high nuclear energy loss (which dominates at low energies) in the materials undergo elastic

Probing viscoelastic surfaces with bimodal tapping-mode atomic force microscopy: Underlying physics and observables for a standard linear solid model

• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 1649–1663, doi:10.3762/bjnano.5.176

• -linear behavior of the tip–sample forces and the non-ideal shape of the tip trajectory during impact, both of which make mathematical analyses extremely difficult (these complexities are further discussed in the Results section). In amplitude modulation AFM (tapping-mode, AM-AFM), Cleveland et al. [30

• loop in the tip–sample force trajectory, whereby the cantilever would be required to perform additional work in order to break free from the surface. All of the above non-conservative effects influence the observables during measurements of conservative and dissipative interactions with AFM, and it is

• the tip–sample interaction for the standard linear solid model Sample response to prescribed sinusoidal trajectories As starting point, consider the interaction of an SLS surface with a cantilever tip that oscillates along a perfect sinusoidal trajectory. To simulate this, we prescribe that the tip

Multi-frequency tapping-mode atomic force microscopy beyond three eigenmodes in ambient air

• Santiago D. Solares,
• Sangmin An and
• Christian J. Long

Beilstein J. Nanotechnol. 2014, 5, 1637–1648, doi:10.3762/bjnano.5.175

• time-dependent trajectory of the tip and individual eigenmodes through simulation of ideal cantilevers. Figure 2a illustrates typical tip trajectories simulated for pentamodal operation when imaging a polymer sample. Here the first eigenmode free amplitude is 80 nm and the higher mode free amplitudes

• are set to either 3 or 8 nm, as indicated on the graphs, which correspond to typical amplitude ratios used in bimodal and trimodal AFM. As the higher mode amplitudes are increased, the tip trajectory has the appearance of becoming increasingly noisy, which occurs in part because the various

• surface to different depths every successive impact, which is not surprising given the irregular tip trajectory. Furthermore, the graph shows that impacts become less regular as the higher mode amplitude increases, which is also as expected. Such irregular impacts constantly generate new transients that

Synthesis, characterization, and growth simulations of Cu–Pt bimetallic nanoclusters

• Subarna Khanal,
• Ana Spitale,
• Nabraj Bhattarai,
• Daniel Bahena,
• J. Jesus Velazquez-Salazar,
• Sergio Mejía-Rosales,
• Marcelo M. Mariscal and
• Miguel José-Yacaman

Beilstein J. Nanotechnol. 2014, 5, 1371–1379, doi:10.3762/bjnano.5.150

• parameters, the mean square displacement (MSD) of the Pt atoms in the nanoalloy was calculated by taking previous configurations in the recorded trajectory as reference configuration. Moreover, the MSD reflects the relative change of diffusivity of the atoms at different temperatures and the activation

Double layer effects in a model of proton discharge on charged electrodes

• Johannes Wiebe and
• Eckhard Spohr

Beilstein J. Nanotechnol. 2014, 5, 973–982, doi:10.3762/bjnano.5.111

• behavior cannot be based solely on the electrochemical potential (or surface charge) but needs to resort to the molecular details of the double layer structure. Keywords: electrocatalysis; interfacial electrochemistry; proton discharge; reactive force field; trajectory calculations; Introduction One of

• trajectories are aligned in a straightforward manner at their starting position. Thus, the average of some observable O over trajectories i, is calculated according to where the sum runs over all trajectories and denotes the initial time of the ith trajectory run. Figure 3 shows the average distance of the

• discharge occurs fluctuatively. Note that, in order to avoid excessive noise for long times (when few trajectories contribute to the average, since many trajectories have been terminated already after discharge), we have artificially extended each terminated trajectory by using the constant final value of

Energy dissipation in multifrequency atomic force microscopy

• Valentina Pukhova,
• Francesco Banfi and
• Gabriele Ferrini

Beilstein J. Nanotechnol. 2014, 5, 494–500, doi:10.3762/bjnano.5.57

• given in units of the first free flexural frequency f1 = 11.7 kHz. The theoretical scaling for the force constants (ki) is reported for each flexural mode [1]. Optical sensibilities σi and the damped harmonic oscillator parameters used for the reconstruction of the tip trajectory [5]. Total dissipated

Challenges and complexities of multifrequency atomic force microscopy in liquid environments

• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 298–307, doi:10.3762/bjnano.5.33

• with high accuracy (unfortunately this is not practical and only possible within highly controlled experiments) and the cantilever behaves in an ideal manner, it is not possible to determine the true tip trajectory from the photodetector reading. This is because the photodetector measures cantilever

• are not meaningful unless the true probe trajectory is known. This is a challenge that remains unsolved even in the most sophisticated base-excitation experiments, which is further compounded by the non-ideal behavior of piezo shaker systems, cantilevers and the surrounding fluid [19][23][24]. One

• a Hamaker constant of 2 × 10−19 J (no screening was considered for the simulations in air). Unless otherwise indicated, the trajectories shown indicate the true eigenmode or tip response, as opposed to the photodetector reading, which does not necessarily correspond to the true trajectory (as

The role of surface corrugation and tip oscillation in single-molecule manipulation with a non-contact atomic force microscope

• Christian Wagner,
• Norman Fournier,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2014, 5, 202–209, doi:10.3762/bjnano.5.22

• one, mostly by smearing out the sharp ∂Fz/∂z(ztip) peak. Finally, we combine our findings regarding surface corrugation and tip stiffness to perform the most realistic simulation of our single-molecule manipulation experiments yet. As in the experiment, we use a strictly vertical tip trajectory that

Manipulation of nanoparticles of different shapes inside a scanning electron microscope

• Boris Polyakov,
• Sergei Vlassov,
• Leonid M. Dorogin,
• Jelena Butikova,
• Mikk Antsov,
• Sven Oras,
• Rünno Lõhmus and
• Ilmar Kink

Beilstein J. Nanotechnol. 2014, 5, 133–140, doi:10.3762/bjnano.5.13

• certain limitations. AFM is used for both displacement and visualization of the initial and the final position of the NPs, but these two procedures cannot be performed simultaneously. Therefore there is no real-time visual feedback in a single line scan concerning the trajectory of the particle and its

• type of motion (sliding, rolling or rotation) during the manipulation event. It is possible to extract trajectory and motion type data from complete AFM images as it was recently demonstrated in several works [4][7][8][9]. However, such a process is time consuming, since it requires a large amount of

• their trajectory, in order to distinguish between continuous and abrupt motions (jumps), and to correlate the movement of the NPs with the measured tip–NP interaction force. The first series of measurements was carried out with 19 Au NPs. Figure 5 represents a typical manipulation experiment with Au NPs

Exploring the retention properties of CaF₂ nanoparticles as possible additives for dental care application with tapping-mode atomic force microscope in liquid

• Matthias Wasem,
• Joachim Köser,
• Sylvia Hess,
• Enrico Gnecco and
• Ernst Meyer

Beilstein J. Nanotechnol. 2014, 5, 36–43, doi:10.3762/bjnano.5.4

• trajectory angle of the manipulated particle is mainly a function of the intrinsic particle–substrate contact radius R. With exception for the first scan line, the displacement angle of a particle θ with respect to the fast scan axis is given by: where α0 = arcsin [1−(b/R)]. The theoretical predicted

• deflection angle depending only on the particle-substrate contact radius derived from Equation 1 is illustrated in Figure 1a. By reading out the trajectory angle of the deflected particles we get the particle–substrate contact size distribution. For the case of particles with plane facing adsorbed on smooth

• and atomically flat substrates, such as mica, the trajectory angle distributions can be approximately regarded as the size distribution of the synthesized particles. In order to calculate the power dissipation from the phase-lag of the cantilever relative to the excitation, we used the method of

Simulation of electron transport during electron-beam-induced deposition of nanostructures

• Francesc Salvat-Pujol,
• Harald O. Jeschke and
• Roser Valentí

Beilstein J. Nanotechnol. 2013, 4, 781–792, doi:10.3762/bjnano.4.89

• . A particle trajectory is represented as a series of states (rn,en,dn), where n labels the scattering event at rn that leads to an energy En and a direction dn (see below in Figure 1). Several random variables are sampled from their respective probability distribution functions. The length of the

• positive charge in the material and to new particles, thus leading to a “shower” of particles. If an electron crosses a boundary into an adjacent material, its trajectory history is stopped at the other side of the interface and restarted with the new material transport properties. This can be done any

• time, since electron trajectories are modelled as Markov processes (the future of the trajectory is dependent only on the present state, and not on the past). The trajectory history of an electron is stopped when its energy drops below 50 eV. The electron is then considered to be absorbed by the medium