Dynamic 3D modeling and simulation of nanoparticles manipulation using an AFM nanorobot

Robotica ◽  
2013 ◽  
Vol 32 (4) ◽  
pp. 625-641 ◽  
Author(s):  
M. H. Korayem ◽  
A. K. Hoshiar
Keyword(s):  
Dynamic Model ◽  
Substrate Surface ◽  
Lateral Force ◽  
Effective Parameters ◽  
Disk Model ◽  
Atomic Force ◽  
Process Implementation ◽  
Dynamic Forces ◽  
The Moment ◽  
Good Agreement

SUMMARYDue to the growing use of Atomic Force Microscope (AFM) nanorobots in the moving and manipulation of cylindrical nanoparticles (carbon nanotubes and nanowires) and the fact that these processes cannot be simultaneously observed, a computer simulation of the involved forces for the purpose of predicting the outcome of the process becomes highly important. So far, no dynamic 3D model that shows changes in these forces in the course of process implementation has been presented. An algorithm is used in this paper to show in 3D, the manner by which the dynamic forces vary in the mentioned process. The presented model can simulate the forces exerted on the probe tip during the manipulation process in three directions. Because of the nonlinearity of the presented dynamic model, the effective parameters have been also studied. To evaluate the results, the parameters of the 3D case (cylindrical model) are gradually reduced and it is transformed into a 2D model (disk model); and we can observe a good agreement between the results of the two simulations. Next, the simulation results are compared with the experimental results, indicating changes in lateral force. With the help of the offered dynamic model, the cantilever deformation and the forces interacting between probe tip and particle can be determined from the moment the probe tip contacts the nanoparticle to when the nanoparticle dislodges from the substrate surface.

Computer Modeling of a Tire under Cornering Loads

1989 ◽  
Vol 17 (2) ◽  
pp. 86-99 ◽  
Author(s):  
I. Gardner ◽  
M. Theves
Keyword(s):  
Finite Element Analysis ◽  
Geometric Approach ◽  
Lateral Force ◽  
Slip Angle ◽  
Element Analysis ◽  
Pressure Distributions ◽  
Slip Effects ◽  
Improved Accuracy ◽  
Nonlinear Geometric ◽  
Good Agreement

Abstract During a cornering maneuver by a vehicle, high forces are exerted on the tire's footprint and in the contact zone between the tire and the rim. To optimize the design of these components, a method is presented whereby the forces at the tire-rim interface and between the tire and roadway may be predicted using finite element analysis. The cornering tire is modeled quasi-statically using a nonlinear geometric approach, with a lateral force and a slip angle applied to the spindle of the wheel to simulate the cornering loads. These values were obtained experimentally from a force and moment machine. This procedure avoids the need for a costly dynamic analysis. Good agreement was obtained with experimental results for self-aligning torque, giving confidence in the results obtained in the tire footprint and at the rim. The model allows prediction of the geometry and of the pressure distributions in the footprint, since friction and slip effects in this area were considered. The model lends itself to further refinement for improved accuracy and additional applications.

Dynamic model for high-speed rotors based on their experimental characterization

2017 ◽  
Vol 2 (4) ◽  
pp. 25
Author(s):  
L. A. Montoya ◽  
E. E. Rodríguez ◽  
H. J. Zúñiga ◽  
I. Mejía
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Experimental Characterization ◽  
Rotating Systems ◽  
Computing Performance ◽  
The Impact ◽  
Stiffness Distribution ◽  
Good Agreement

Rotating systems components such as rotors, have dynamic characteristics that are of great importance to understand because they may cause failure of turbomachinery. Therefore, it is required to study a dynamic model to predict some vibration characteristics, in this case, the natural frequencies and mode shapes (both of free vibration) of a centrifugal compressor shaft. The peculiarity of the dynamic model proposed is that using frequency and displacements values obtained experimentally, it is possible to calculate the mass and stiffness distribution of the shaft, and then use these values to estimate the theoretical modal parameters. The natural frequencies and mode shapes of the shaft were obtained with experimental modal analysis by using the impact test. The results predicted by the model are in good agreement with the experimental test. The model is also flexible with other geometries and has a great time and computing performance, which can be evaluated with respect to other commercial software in the future.

Diffusion model for deposition of epitaxial GaAs layers prepared by the MOCVD method

1991 ◽  
Vol 56 (10) ◽  
pp. 2020-2029
Author(s):  
Jindřich Leitner ◽  
Petr Voňka ◽  
Josef Stejskal ◽  
Přemysl Klíma ◽  
Rudolf Hladina
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Kinetic Model ◽  
Gas Phase ◽  
Substrate Surface ◽  
Deposition Process ◽  
Hydrogen Atmosphere ◽  
Epitaxial Gaas ◽  
Kinetics Of ◽  
Good Agreement

The authors proposed and treated quantitatively a kinetic model for deposition of epitaxial GaAs layers prepared by reaction of trimethylgallium with arsine in hydrogen atmosphere. The transport of gallium to the surface of the substrate is considered as the controlling process. The influence of the rate of chemical reactions in the gas phase and on the substrate surface on the kinetics of the deposition process is neglected. The calculated dependence of the growth rate of the layers on the conditions of the deposition is in a good agreement with experimental data in the temperature range from 600 to 800°C.

scholarly journals 3D phonon microscopy with sub-micron axial-resolution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Richard J. Smith ◽  
Fernando Pérez-Cota ◽  
Leonel Marques ◽  
Matt Clark
Keyword(s):  
Signal To Noise Ratio ◽  
Single Cells ◽  
Optical Resolution ◽  
Acquisition Time ◽  
Label Free ◽  
Axial Resolution ◽  
Force Microscopy ◽  
Atomic Force ◽  
Accuracy And Precision ◽  
Good Agreement

AbstractBrillouin light scattering (BLS) is an emerging method for cell imaging and characterisation. It allows elasticity-related contrast, optical resolution and label-free operation. Phonon microscopy detects BLS from laser generated coherent phonon fields to offer an attractive route for imaging since, at GHz frequencies, the phonon wavelength is sub-optical. Using phonon fields to image single cells is challenging as the signal to noise ratio and acquisition time are often poor. However, recent advances in the instrumentation have enabled imaging of fixed and living cells. This work presents the first experimental characterisation of phonon-based axial resolution provided by the response to a sharp edge. The obtained axial resolution is up to 10 times higher than that of the optical system used to take the measurements. Validation of the results are obtained with various polymer objects, which are in good agreement with those obtained using atomic force microscopy. Edge localisation, and hence profilometry, of a phantom boundary is measured with accuracy and precision of approximately 60 nm and 100 nm respectively. Finally, 3D imaging of fixed cells in culture medium is demonstrated.

Boundary Friction for a Line Contact Model: An Empirical Approach

2015 ◽  
Vol 642 ◽  
pp. 8-12
Author(s):  
William W.F. Chong ◽  
Miguel de La Cruz
Keyword(s):  
Steel Plate ◽  
Friction Model ◽  
Boundary Friction ◽  
Slider Bearing ◽  
Base Oil ◽  
Atomic Force ◽  
Alternative Approach ◽  
Nanoscale Friction ◽  
Friction Measurements ◽  
Good Agreement

The paper introduces an alternative approach to predict boundary friction for rough surfaces at micros-scale through the empirical integration of asperity-like nanoscale friction measurements. The nanoscale friction is measured using an atomic force microscope (AFM) tip sliding on a steel plate, confining the test lubricant, i.e. base oil for the fully formulated SAE grade 10w40. The approach, based on the Greenwood and Tripp’s friction model, is combined with the modified Elrod’s cavitation algorithm in order to predict the friction generated by a slider-bearing test rig. The numerical simulation results, using an improved boundary friction model, showed good agreement with the measured friction data.

scholarly journals Simultaneous acquisition of current and lateral force signals during AFM for characterising the piezoelectric and triboelectric effects of ZnO nanorods

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yijun Yang ◽  
Kwanlae Kim
Keyword(s):  
Linear Regression Analysis ◽  
Zno Nanorods ◽  
Lateral Force ◽  
Mechanical Force ◽  
Force Microscopy ◽  
Atomic Force ◽  
Simultaneous Acquisition ◽  
Afm Probe ◽  
Triboelectric Effect ◽  
Conversion Efficiencies

AbstractAtomic force microscopy (AFM) is central to investigating the piezoelectric potentials of one-dimensional nanomaterials. The AFM probe is used to deflect individual piezoelectric nanorods and to measure the resultant current. However, the torsion data of AFM probes have not been exploited to elucidate the relationship between the applied mechanical force and resultant current. In this study, the effect of the size of ZnO nanorods on the efficiency of conversion of the applied mechanical force into current was investigated by simultaneously acquiring the conductive AFM and lateral force microscopy signals. The conversion efficiency was calculated based on linear regression analysis of the scatter plot of the data. This method is suitable for determining the conversion efficiencies of all types of freestanding piezoelectric nanomaterials grown under different conditions. A pixel-wise comparison of the current and lateral force images elucidated the mechanism of current generation from dense arrays of ZnO nanorods. The current signals generated from the ZnO nanorods by the AFM probe originated from the piezoelectric and triboelectric effects. The current signals contributed by the triboelectric effect were alleviated by using an AFM probe with a smaller spring constant and reducing the normal force.

On the Influence of a Heat Treat for an Aluminizing Progress Based on Al Microparticles Slurry for Model Ni and Ni20Cr. Experimental and Theoretical Approaches.

2012 ◽  
Vol 323-325 ◽  
pp. 373-379 ◽  
Author(s):  
B. Rannou ◽  
M. Mollard ◽  
B. Bouchaud ◽  
J. Balmain ◽  
G. Bonnet ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Substrate Surface ◽  
Single Step ◽  
Alloying Element ◽  
Aluminum Particles ◽  
New Approach ◽  
Theoretical Approaches ◽  
Barrier Coating ◽  
Coating Characteristics ◽  
Good Agreement

The use of thermal barrier coating systems allows superalloys to withstand higher operating temperatures in aeroengine turbines. Aiming at providing oxidation protection to such substrates, an aluminum-rich layer is deposited to form the α-Al2O3scale over which a ceramic layer (i.e. YSZ layer) is applied to provide thermal insulation. A new approach is now being investigated within the FP7 European project « PARTICOAT », in which a single step process is employed by applying micro-sized aluminum particles. The particles are mixed in a binder and deposited by brushing or spraying on the substrate surface. During a heat treatment, the particles sinter and oxidize to form a top coat composed of hollow con-joint alumina spheres and simultaneously, an Al-rich diffusion zone is formed in the substrate. For a better understanding of the diffusion / growth processes, preliminary tests were carried out on pure nickel and Ni20Cr model alloys prior to further application on commercial superalloys. The effect of the heat treatment on the coating characteristics (number of layers, thickness, composition, homogeneity, etc.) was particularly investigated to emphasize the mechanisms of diffusion governing the growth of the coatings. The establishment of the diffused layers occurred very readily even at intermediate temperatures (650 and 700°C). However, the layers formed did not match perfectly with the thermodynamic modeling because of the quick incorporation of Ni into molten Al at intermediate temperatures (650°C). In contrast, at higher temperatures (700 and 1100°C) the phases predicted by Thermocalc are in good agreement with the observed thickness of the diffused layers. The incorporation of Cr as an alloying element restrained Al ingress by segregation of Cr even at very low temperatures aluminizing temperatures (625°C).

DIRECT GROWTH OF EPITAXIAL La0.67Ca0.33MnO3 - δ THIN FILMS

2002 ◽  
Vol 09 (05n06) ◽  
pp. 1611-1615 ◽  
Author(s):  
G. CAMPILLO ◽  
L. F. CASTRO ◽  
P. VIVAS ◽  
E. BACA ◽  
P. PRIETO ◽  
...  
Keyword(s):  
Thin Films ◽  
Substrate Surface ◽  
Electrical Characterization ◽  
Annealing Treatment ◽  
Pure Oxygen ◽  
X Ray Diffraction ◽  
Atomic Force ◽  
Transmission Electron ◽  
Afm Analysis ◽  
Direct Growth

La 0.67 Ca 0.33 MnO 3 - δ thin films were deposited using a high-pressure dc-sputtering process. Pure oxygen at a pressure of 3.8 mbar was used as sputtering gas. The films were grown on (001) LaAlO 3 and (001) SrTiO 3 substrates at heater temperature of 850° without any annealing treatment. The formation of highly a-axis-oriented films with sharp interface with substrate surface is demonstrated by X-ray diffraction, transmission electron microscope (TEM), and atomic force microscope (AFM) analysis. Electrical characterization revealed a metal–insulator transition at T MI = 276 K, and magnetic characterization showed good magnetic properties with a PM–FM transition at TC ≈ 262 K.

scholarly journals Growth of Ordered Graphene Ribbons by Sublimation Epitaxy

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 449
Author(s):  
Shuxian Cai ◽  
Xingfang Liu ◽  
Xin Zheng ◽  
Zhonghua Liu
Keyword(s):  
Substrate Surface ◽  
Graphene Film ◽  
Graphene Ribbon ◽  
High Quality ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Layer Graphene ◽  
Micro Raman Spectroscopy ◽  
Atomic Force ◽  
Few Layer Graphene

Ordered graphene ribbons were grown on the surface of 4° off-axis 4H-SiC wafers by sublimation epitaxy, and characterized by using scanning electron microscopy (SEM), atomic force microscopy (AFM) and micro-Raman spectroscopy (μ-Raman). SEM showed that there were gray and dark ribbons on the substrate surface, and AFM further revealed that these ordered graphene ribbons had clear stepped morphologies due to surface step-bunching. It was shown by μ-Raman that the numbers of graphene layers of these two types of regions were different. The gray region was composed of mono- or bilayer ordered graphene ribbon, while the dark region was of tri- or few-layer ribbon. Meanwhile, ribbons were all homogeneous and had a width up to 40 μm and a length up to 1000 μm, without micro defects such as grain boundaries, ridges, or mono- and few-layer graphene mixtures. The results of this study are useful for optimized growth of high-quality graphene film on silicon carbide crystal.

Comparative Calculations of TROI TS-2 and TS-3 Steam Explosion Experiments With TEXAS-V

2017 ◽  
Author(s):  
Taehoon Kim ◽  
Sukyoung Pak ◽  
Yongjin Cho
Keyword(s):  
Void Fraction ◽  
Steam Explosion ◽  
Peak Pressure ◽  
Severe Accident ◽  
Experiment Data ◽  
Trigger Time ◽  
Vessel Reactor ◽  
The Moment ◽  
Containment Integrity ◽  
Good Agreement

During a severe accident, contact of the molten corium with the coolant water may cause an energetic steam explosion which is a rapid increase of explosive vaporization by transfer to the water of a significant part of the energy in the corium melt. This steam explosion has been considered as an adverse effect when the water is used to cool the molten corium and could threaten reactor vessel, reactor cavity, containment integrity. In this study, TROI TS-2 and TS-3 experiments as part of the OECD/SERENA-2 project were analyzed with TEXAS-V. Input parameters were based on actual TROI experiment data. In mixing simulations, calculated results were compared to melt front behavior, void fraction in trigger time and other parameters in experiment results. In explosion simulations, corresponding to TROI experiments an external triggering was employed at the moment that melt front reached heights of 0.4 m. Calculated results of peak pressure and impulse at the bottom were compared with TROI experiment results. Melt front behaviors of the melt was different from the experimental results in both TS-2 and TS-3. Void fraction in triggering time in TS-2 was in good agreement with the experiment results and in TS-3 was slightly overestimated. The peak pressure and impulse at bottom were successfully predicted by TEXAS-V. These calculations will allow establishing whether the limitations and differences observed in the simulations of the experiments are important for the reactor case.

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