Kinetic Energy Of Atoms Research Articles

The influence of electrical/thermal fields on the microstructure and mechanical properties of Ti2AlNb alloy from the view of molecular dynamics

Abstract The mechanism of the electrical non-thermal effects on metals is still unclear. Simulations at the atomic level are used to obtain some causes of non-thermal electroplasticity. Molecular dynamics simulations are used to study the change of defects including vacancies, edge dislocations and screw dislocations in B2, α 2 and O phases of Ti2AlNb alloy in static or dynamic situations under pure thermal field and continuous/pulsed electric fields. External energy fields can restore most of these defects. Moreover, different energy input methods have the same restoration effect on defects in the same phase. Thus, the restoration of defects in Ti2AlNb alloy by an electric field is mainly based on the thermal effect. However, the uneven distribution of electro-induced atomic kinetic energy in uniaxial tension simultaneously reduces its deformation resistance. Non-thermal effects in the electrically-assisted processing of industrial-grade materials consist of the instantaneous atomic kinetic distribution imbalance induced by electrical pulses.

Research on key factors of pulsed CO2 laser annealing of Ge core fiber

The germanium (Ge) core fiber with a core diameter of 29–32 μm and a cladding diameter of 158–162 μm was annealed by pulsed CO2 laser, exploring the key factors determining the properties of annealed Ge core fiber. The experimental results shown that the single pulse energy and the laser scanning speed are key factors of pulsed CO2 laser annealing of Ge core fibers. The reasons for experimental results were preliminarily analyzed from the perspectives of Ge atomic instantaneous kinetic energy and temperature field of Ge core during annealing. For different frequencies of laser annealing, optimal samples with similar properties can be obtained by adjusting the single pulse energy and laser scanning speed. For the samples annealed by 30 kHz, 50 kHz, 60 kHz, and 70 kHz lasers, the optimal Raman frequency average value is 301.191 cm−1, 301.107 cm−1, 301.153 cm−1, and 301.174 cm−1; the lowest propagation loss is 2.174 dB/cm, 2.596 dB/cm, 2.387 dB/cm, and 2.312 dB/cm respectively, which were measured using a quantum cascade laser with the wavelength range from 4.7 to 4.9 μm.

A theoretical model considering the photochemical and photothermal behavior of arc radiation-induced gassing materials ablation

In this study, we introduce a theoretical model designed to explore both the photochemical and photothermal behavior of arc plasma radiation-induced ablation in gassing materials. We employ time-dependent density functional theory to analyze the photochemical behavior, while reactive force field molecular dynamics are used to explore the photothermal behavior. The phenomena, behavior and consequences of valence shell electronic excitation are analyzed in terms of ultraviolet (UV) absorption, electron-hole distribution, and Mayer bond order. Based on the photochemical findings, we apply a periodic electric field that corresponds to the vibration frequency of the permanent dipole moment to simulate infrared radiation, and convert UV photon energy into atomic kinetic energy to analyze UV radiation. This atomic-scale insight into photothermal behavior enables us to identify the final composition of ablation gases, including H2, CO, H2O, NH3, as well as specific cyanides, amines, and hydrocarbons. The results of the theoretical model and physical properties indicate that the concentration of hydrogen-containing gases in the ablation gas significantly affects the arc extinguishing capabilities of different polymers. Finally, we propose modification schemes suitable for polymers in power circuit breakers, considering UV absorption and smoke black production. Additionally, we present the potential application of theoretical models for calculating the ablation rate, necessitating further in-depth re-search.

Quantum motion of oxygen and hydrogen in water: Atomic and total kinetic energy across melting from neutron scattering measurements.

We provide a concurrent measurement of the hydrogen and oxygen nuclear kinetic energies in the water molecule across melting at 270K in the solid phase and 276K in the liquid phase. Experimental values are obtained by analyzing the neutron Compton profiles of each atomic species in a deep inelastic neutron scattering experiment. The concurrent measurement of the atom kinetic energy of both hydrogen and oxygen allows the estimate of the total kinetic energy per molecule due to the motion of nuclei, specifically 35.3 ± 0.8 and 34.8 ± 0.8kJ/mol for the solid and liquid phases, respectively. Such a small difference supports results from abinitio simulations and phenomenological models from the literature on the mechanism of competing quantum effects across the phase change. Despite the experimental uncertainties, the results are consistent with the trend from state-of-the-art computer simulations, whereby the atom and molecule kinetic energies in the liquid phase would be slightly lower than in the solid phase. Moreover, the small change of nuclear kinetic energy across melting can be used to simplify the calculation of neutron-related environmental dose in complex locations, such as high altitude or polar neutron radiation research stations where liquid water and ice are both present: for neutron energies between hundreds of meV and tens of keV, the total scattering cross section per molecule in the two phases can be considered the same, with the macroscopic cross section only depending upon the density changes of water near the melting point.

Mechanism of vibration on plastic deformation behavior of aluminum: A molecular dynamics simulation

The superimposed vibration during plastic deformation of the metal can improve its formability. To explain the mechanism of the vibration, it is essential to deeply understand the transient evolution of the microstructure in this process. The molecular dynamics simulation was carried out to investigate the plastic deformation behavior of pure aluminum during uniaxial tensile and compressive deformation under vibration assistance. The kinetic energy of atoms, phase transition and the evolution distribution of dislocation, as well as the macroscopic mechanical behavior were analyzed. The results show that, vibration reduces the flow stress by inhibiting the production of hard-to-move dislocations. It hinders the tendency of dislocation entanglement and accelerates the dislocation annihilation. In addition, the deformation twins are generated during the compressive deformation, limiting the propagation of the vibrational energy. The superimposed vibration causes the aluminum to be softened during the tensile deformation and be hardened during the compressive deformation.

Direct prediction of isotopic properties from molecular dynamics trajectories: Application to sulfide, sulfate and sulfur radical ions in hydrothermal fluids

In hydrothermal fluids, disulfur (S2•−) and trisulfur (S3•−) radical anions have been observed to coexist with the major hydrogen sulfide and sulfate species. These radical ions have potentially important effects on the solubility, transport and fractionation of metals and sulfur, with consequences for ore deposit formation and, more generally, for geochemical cycles of metals and volatiles. It is therefore essential to know the intrinsic isotopic properties of these important sulfur species in order to use sulfur isotopes for tracing different geological processes. Here, the theoretical equilibrium isotopic properties of the disulfur and trisulfur radical ions are computed and compared to the hydrogen sulfide (H2S) and sulfate ion (SO42−), using, for the first time, a first-principles molecular dynamics (MD) approach. The isotopic properties are calculated directly from molecular dynamics trajectories using the vibrational density of states and the atomic kinetic energy, and then compared to the more established method based on sampling of several snapshots. This comparison allowed us to validate the new modelling method and to assess its advantages and limitations. The predicted equilibrium isotope fractionation in terms of 34S/32S between S2•− and S3•− is small, i.e. <1‰, with a slight enrichment in the heavier isotope for S3•−, over the temperature range 200–500 °C. Both radical ions are slightly depleted in the heavier isotope, by 1 to 2‰, relative to aqueous H2S. Our results help tuning sulfur isotope fractionation models used for tracing the origin and evolution of hydrothermal fluids. Our method opens large perspectives for using the rapidly growing body of MD simulation data in geosciences on structure and stability of aqueous complexes to assess in parallel element isotope fractionations from MD-generated trajectories.

Study of nanoindentation behavior of NiCrCoAl medium entropy alloys under indentation process using molecular dynamics

Abstract The mechanical properties and deformation behavior of CoCrNiAl medium entropy alloy (MEA) subjected to indentation by an indenter tooltip on the substrate are explored using molecular dynamics (MD) simulation. The study investigates the effects of alloy compositions, temperature variations, and ultra vibration (UV) on parameters, such as total force, shear strain, shear stress, hardness, reduced modulus, substrate temperature, phase transformation, dislocation length, and elastic recovery. The findings indicate that higher alloy compositions result in increased total force, hardness, and reduced modulus, with Ni-rich compositions demonstrating superior mechanical strength. Conversely, increasing alloy compositions lead to reduced von Mises stress (VMS), phase transformation, dislocation distribution, and dislocation length due to the larger atomic size of Ni compared to other primary elements. At elevated substrate temperatures, atoms exhibit larger vibration amplitudes and interatomic separations, leading to weaker atomic bonding and decreased contact force, rendering the substrate softer at higher temperatures. Additionally, higher initial substrate temperatures enhance atom kinetic energy and thermal vibrations, leading to reduced material hardness and increased VMS levels. Increasing vibration frequency enlarges the indentation area on the substrate’s surface, concentrating shear strain and VMS with vibration frequency. Higher vibration amplitude and frequency amplify force, shear strain, VMS, substrate temperature, and dislocation distribution. Conversely, lower vibration amplitude and frequency result in a smaller average elastic recovery ratio. Moreover, increased amplitude and frequency values yield an amorphous-dominated indentation region and increased proportions of hexagonal close-packed and body-centered cubic structures. Furthermore, this study also takes into account the evaluation of a material’s ability to recover elastically during the indentation process, which is a fundamental material property.

Dynamical Origin of Rebound versus Dissociation Selectivity during Fe-Oxo-Mediated C-H Functionalization Reactions.

The mechanism of catalytic C-H functionalization of alkanes by Fe-oxo complexes is often suggested to involve a hydrogen atom transfer (HAT) step with the formation of a radical-pair intermediate followed by diverging pathways for radical rebound, dissociation, or desaturation. Recently, we showed that in some Fe-oxo reactions, the radical pair is a nonstatistical-type intermediate and dynamic effects control rebound versus dissociation pathway selectivity. However, the effect of the solvent cage on the stability and lifetime of the radical-pair intermediate has never been analyzed. Moreover, because of the extreme complexity of motion that occurs during dynamics trajectories, the underlying physical origin of pathway selectivity has not yet been determined. For the reaction between [(TQA_Cl)FeIVO]+ and cyclohexane, here, we report explicit solvent trajectories and machine learning analysis on transition-state sampled features (e.g., vibrational, velocity, and geometric) that identified the transferring hydrogen atom kinetic energy as the most important factor controlling rebound versus nonrebound dynamics trajectories, which provides an explanation for our previously proposed dynamic matching effect in fast rebound trajectories that bypass the radical-pair intermediate. Manual control of the reaction trajectories confirmed the importance of this feature and provides a mechanism to enhance or diminish selectivity for the rebound pathway. This led to a general catalyst design principle and proof-of-principle catalyst design that showcases how to control rebound versus dissociation reaction pathway selectivity.

Silicon surface characteristics in vibration-assisted machining process via molecular dynamics

This study investigates the impacts of vibration amplitude, vibration frequency, and sliding velocity on the characteristics of the machined silicon substrate. The results show that increasing the vibration amplitude increases atomic strain, stress, and kinetic energy distributions while decreasing subsurface damage thickness, potential energy distribution, and especially surface roughness. The surface roughness values are 7.5 Å, 6.4 Å, 6.9 Å, and 6.0 Å corresponding to vibration amplitude of 15 Å, 20 Å, 25 Å, and 30 Å. Moreover, increasing the vibration frequency results in increased atomic strain, stress, and kinetic energy levels. The surface roughness values are 7.1 Å, 7.1 Å, 6.5 Å, 6.4 Å, and 6.0 Å corresponding to the vibration frequencies of 16.7 GHz, 33.3 GHz, 50 GHz, 66.7 GHz, 100 GHz, and 200 GHz. Furthermore, increasing the sliding velocity lowers the surface quality of the silicon sample. The surface roughness values of the silicon substrate are 6.5 Å, 6.7 Å, 6.9 Å, 6.9 Å, and 7.1 Å corresponding to 50 m/s, 100 m/s, 150 m/s, 200 m/s, and 250 m/s. Improving the vibration amplitude and frequency while decreasing the sliding velocity improves surface quality by increasing the collision between the diamond tips and the substrate. Remarkably, the vibration movement of the diamond tips could leave wave marks on the substrate surface. In general, the optimal parameters that generate a good surface are 30 Å, 200 GHz, and 50 m/s.

Droplet-particle collision dynamics: A molecular dynamics simulation

Molecular dynamics simulations are conducted to investigate the normal collision of the droplet-particle system. A wide range of influencing factors including the initial Weber number (30 ≤ We≤250), equilibrium contact angle (45° ≤ θ ≤ 145°), droplet-particle size ratio (0.5 ≤ Ω ≤ 2), temperature (293 K ≤ t ≤ 573 K) and composition are examined. Based on the atomic trajectories and kinetic energy dissipation during collision, temporal evolutions of evaporation molecules, dimensionless spreading diameter and film thickness are quantified and compared with available formulations. A total of seven collision outcomes are observed, which can be summarized in the regime map. Two types of disintegration, i.e. ligament-structured disintegration and conical-structured disintegration, exhibit distinct energy dissipation modes. An increasing We and a decreasing θ would lead to an increase in the maximum spreading diameter, while the minimum film thickness is less sensitive to θ. Additionally, evaporation during collisions is primarily influenced by the initial Weber number, because of the formation of satellite droplets.

Mechanism of Surface Wettability of Nanostructure Morphology Enhancing Boiling Heat Transfer: Molecular Dynamics Simulation

In this paper, the interaction mechanism between the solid–liquid–gas interface phenomenon caused by nanostructure and surface wettability and boiling heat transfer is described, and the heat transfer theory of single wettable nanostructure surface and mixed wettable nanostructure surface is proposed. Through molecular dynamics simulation, the thermodynamic model of the wettable surface of nanostructures is established. The nanostructures are set as four rectangular lattice structures with a height of 18 Å. The solid atoms are platinum atoms, and the liquid atoms are argon atoms. The simulation results show that with the increase of surface hydrophilicity of nanostructures, the fluid temperature increases significantly, and the heat transfer at the interface is enhanced. With the increase in surface hydrophobicity of nanostructures, the atoms staying on the surface of nanostructures are affected by the hydrophobicity, showing a phenomenon of exclusion, and the evaporation rate in the evaporation area of nanostructures is significantly increased. In addition, the mixed wettable surface is influenced by the atomic potential energy and kinetic energy of the solid surface, and when compared with the pure wettable surface under the nanostructure, it changes the diffusion behavior of argon atoms on the nanostructure surface, enhances the heat transfer phenomenon compared with the pure hydrophobic surface, and enhances the evaporation phenomenon compared with the pure hydrophilic surface. This study provides insights into the relationship between the vapor film and the heating surface with mixed wettability and nanostructures.

Method and Mechanism for Adhesion Recovery of Laser-Treated Aluminum Surface Exposed to Hygrothermal Environment

Laser treatment is used to improve the surface adhesion performance of metal materials, including aluminum alloy. However, the adhesion performance of laser-treated aluminum alloy is reduced after the hygrothermal exposure during storage before bonding, obtaining the reliable surface adhesion is a challenge. In this paper, the nanosecond laser-treated aluminum alloy was exposed in a hygrothermal environment with 80°C 95%R.H. for 48h. Scanning electron microscopy, transmission electron microscopy and adhesion strength testing were used to characterize the physical/chemical properties and adhesion reduction of the aluminum surface. Subsequently, a simple and effective method of heat treatment was proposed to recover the adhesion strength. Finally, molecular dynamics (MD) simulation was utilized to explore the underlying recover mechanism. The experimental results revealed a AlOOH layer with ~410 nm thickness was generated on the laser-treated aluminum surface after hygrothermal exposure, which reduced the adhesion strength by 38% (from 30.9MPa to 18.9MPa). After heating at 120 °C for 24 hours, the adhesion strength (30.4MPa) of aluminum surface recovered to the level before hygrothermal exposure. MD results suggested that there are two mechanisms for the adhesion recovery by heat treatment: 1) the atomic kinetic energy of AlOOH increased and the structural order decreased, which strengthened its electrostatic and hydrogen bond interactions with adhesive molecules; 2) the mechanical property of AlOOH were enhanced.

Relative effects of pulsed laser deposition parameters on the stoichiometry of thin films

Pulsed laser deposition has a reputation for maintaining the stoichiometry of the ablation target in the deposited film. Exceptions to this "rule" occur, however, for materials, such as multiferroic BixDy(1-x)FeO3 (BDFO), that contain elements with large differences in volatility, like Bi and Fe. The relative effect of various pulsed laser deposition processes on the resulting stoichiometry of BDFO films as a function of time (or number of laser pulses) has been examined using an interactive spreadsheet, as well as experimentally. The adjustable parameters within the spreadsheet include target composition, target element ablation yield, ablation plume spread, background gas pressure, ablated target atom kinetic energy, and ablated element sticking coefficient on the substrate. Examples of how the calculated film composition might evolve are given, along with experimental results showing how the deposition parameters individually affect BDFO film stoichiometry. Finally, the calculated relative contributions of the various deposition processes, in terms of how much they affect the deposited film stoichiometry, are compared.

Effect of temperature on nanoscale wear behavior of graphene: a molecular dynamics study

Being a typical two-dimensional layered material, graphene has the fantastic mechanical properties at the nanoscale. However, when nanoscale components work at high velocity, the local temperature change of abrasive particles seriously affects the service life of nano-mechanical devices and the surface quality of workpieces. In this work, we construct a probe-matrix system in atomic force microscope experiment by molecular dynamics (MD) simulations. Considering the influence of interfacial temperature, the friction force in the process of abrasive wear is calculated. And the effect of temperature on nanoscale wear behavior of graphene has been investigated. Molecular dynamics simulations show the friction force fluctuates with the increasing of temperature. The effect of interfacial temperature on the atomic kinetic energy significantly determine the nanoscale wear resistance. It is also found that the friction characteristics of graphene will be affected as interfacial temperature increase. The study provides new insights on nanoscale wear considering temperature effect.

Hybrid Nanostructures and Stabilized Mechanical Properties of High‐Entropy Alloy Induced by Warm Laser Shock Peening

Recently, the manufacture of high‐entropy‐alloy (HEA) parts by selective laser melting (SLM) has been extensively studied. However, the problems of high tensile residual stress, undesirable microstructure, and unstable mechanical properties in HEA parts caused by SLM process are difficult to be solved simultaneously. Herein, a warm laser shock peening (WLSP) process is used to obtain high strength, stable mechanical property, and favorable residual stress in SLMed FeNiCrCo HEA by regulating the microstructure in material. Experimental and simulation results show that WLSP treatment can induce high‐density dislocations and nanotwins in the HEA, resulting in a 39.4% increase in the surface strength of the HEA. Moreover, because of the high atomic kinetic energy brought by high temperature in WLSP processing, WLSP‐treated sample has higher density of dislocations and nanotwins than the sample treated by the LSP process at room temperature (RLSP), resulting in higher surface strength and better mechanical stability of the WLSP‐treated HEA. Meanwhile, the WLSP treatment enables the tensile residual stress generated in the SLM process to be transformed into compressive residual stress, which can enhance the fatigue performance of the HEA. Therefore, WLSP has great potential in obtaining SLMed HEAs with excellent mechanical properties.

Molecular dynamics study of acoustic softening effect in ultrasonic vibration assisted tension of monocrystalline/polycrystalline coppers

Ultrasonic vibration assisted metal forming is a promising technology, but the microscopic mechanism of the ultrasonic effect on metal deformation has not been fully understood yet. In this paper, by molecular dynamics simulation, the microscopic mechanism behind the acoustic softening effect of ultrasonic vibration was studied. The stress superposition and acoustic softening can be simulated simultaneously by molecular dynamics method, and the stress–strain response of the polycrystalline copper simulations agrees well with the experimental results. Based on the analysis of atomic kinetic energy and dislocation density, it is found that ultrasonic vibration increases the atomic kinetic energy and promotes the generation, multiplication, motion, and annihilation of dislocations in the plastic deformation process, resulting in a reduction of dislocation tangles and pile-ups. Therefore, the hindrance to crystal sliding is significantly decreased, which promotes the plastic deformation accompanied by a macroscopic reduction in flow stress of copper. As for different ultrasonic parameters, the influence laws of ultrasonic amplitude and frequency on the deformation behaviors of coppers are different. These findings play an essential role in revealing the mechanism of ultrasonic vibration assisted plastic forming.

A molecular dynamics study on the mechanism of heterogeneous bubble nucleation of mixed liquid

The nucleate boiling of mixed boiling is widely utilized in natural gas, hydrogen liquefaction process, and other fields. In this paper, the molecular dynamics study of heterogeneous bubble nucleation of pure argon liquid and the argon‑krypton mixed liquid on the platinum surface was conducted. The nucleate boiling characteristics were presented and the variations of the density, temperature, nucleation embryo volume, and heat flux were analyzed. The difference in the nucleation mechanism of pure liquid and mixed liquid was explained based on the competition of atomic potential energy and atomic kinetic energy. The effect of the component mole fraction on the bubble nucleation of mixed fluid was also discussed. The results showed that the onset superheat of boiling of argon‑krypton mixed liquid is higher than that of pure argon. The higher the mole fraction of the component with a lower saturation temperature, the lower the onset superheat of the liquid nucleate boiling. When x < 0.5, the growth rate of the nucleation embryo is dominated by the x value, when x > 0.5, the growth rate is dominated by wall temperature. Moreover, the difference in diffusion coefficients of each component is one of the direct causes of determining the growth rate of nucleation embryos. The findings provide insights into the mechanisms of differences in boiling nucleation between mixed liquid and pure liquid, as well as guide the reasonable utilization of mixed liquid.

Influence of atomic incident kinetic energy on crystalline quality of epitaxial GaN thin films: A molecular dynamics study

The high-quality GaN thin films is of great significance for increasing the lifetime and performance of GaN devices. There are still few studies analyzing the effect of different incident energies on the crystalline quality of GaN thin films during epitaxy at the atomic scale. In this paper, the molecular dynamics (MD) method was adopted to simulate the epitaxial growth of GaN thin films under different particle incident energies. The crystal structure, surface morphology, dislocation evolution and internal stress of GaN films deposited under different growth energies were analyzed. The results showed that increasing the incident energy of the particles could help improve the epitaxial surface quality and make the atoms in the film more densely arranged. The tighter arrangement of atoms increased the nucleation height of dislocations in the film to a certain extent. In addition, as the thickness of the epitaxial films increased, the influence of the interfacial stress on the internal stress of the films gradually weakened.

Development of kinetic energy density functional using response function defined on the energy coordinate

AbstractA kinetic energy functional was developed within the framework of the density‐functional theory (DFT) based on the energy electron density for the purpose of realizing the orbital‐free DFT. The functional includes the nonlocal term described with the linear‐response function (LRF) of a reference system. As a notable feature of the present approach, the LRF is represented on the energy coordinate ϵ defined for each system of interest. In addition, an atomic system is taken as a reference system for the construction of the LRF, which shows a clear difference from the conventional approach based on the homogeneous electron gas. The explicit form of the functional was formulated by means of the Taylor series expansion of the kinetic energy. The functional was applied to the calculations of the kinetic energies of the pseudo atoms that mimics H, He, Ne, and Ar. Explicitly, the kinetic energy of each atom was computed using the functional with respect to the variation of the valence charge Zv of each atom. In these calculations, the electron density n optimized by the Kohn‐Sham DFT was adopted as an argument of the functional. It was found that the results are in excellent agreements with those given by the Kohn‐Sham DFT. We also devised a method to perform the self‐consistent field calculation utilizing the functional . The method was applied to the computation of the radial distribution functions of the electrons in the pseudo Ne and Ar atoms. It was demonstrated that the results reasonably agree with those yielded by the Kohn‐Sham DFT.

Cutting characteristics of monocrystalline silicon in elliptical vibration nano-cutting using molecular dynamics method

Based on the molecular dynamics method, the model of monocrystalline silicon in elliptical vibration nano cutting (EVNC) is established. The effects of amplitude ratio (ratio of amplitude in parallel cutting direction to amplitude in vertical cutting direction) on the mechanical properties, thermal properties, crystal phase transition and morphology are systematically investigated. The results show that with the amplitude ratio increasing from 0.0 to 3.0, the hydrostatic compressive stress during cutting in the contact area decreases from 12.31 GPa to 8.31 GPa, and the tensile stress on the machined surface decreases from 5.23 GPa to 3.07 GPa. The depth of tensile stress layer after cutting is reduced from 12.02 Å to 4.8 Å. During cutting the maximum temperature of the machined surface decreases from 1419 K to 1236 K, and the chip maximum temperature increases from 1730 K to 2994 K. The number of diamond structures (bond length is 2.35 Å) is reduced during the cutting process, and the moderately increasing in the amplitude ratio can inhibit the formation of the bct-5 phase. After cutting, the number of diamond structures (bond length 2.35 Å) on the workpiece surface increases. The scratch morphology quality is effectively improved. With increasing amplitude ratio, the extrusion impact of the tool increases, resulting in the length and direction of the atomic displacement vector in the cutting area changing periodically, and the atomic kinetic energy and potential energy also change periodically, which may be the reason for EVNC to obtain better surface integrity. The research results provide theoretical reference for the application of ultrasound vibration assisted process in the field of atomic or near-atomic scale manufacturing.