manipulation

The use of gold metal in astronautics, electronics and medical sciences has led to its consideration. Therefore, structural studies and changes have been made to improve the properties or establish special atomic arrangements in nanoscience for this particular metal. Atomic force microscopy(AFM) is one of the most widely used tools for these purposes. Therefore, in this paper, the displacement of gold nanoparticles during manipulation using the atomic force microscopy, which is one of the objectives of the second phase, in the environmental conditions of water, plasma and methanol, has been investigated. For this purpose, the process is first modeled in two dimensions and the intermolecular forces of van der Waals, the double layer force and the hydration force are considered. Then, the displacement diagrams are drawn considering the forces between the molecule and the studied environments. Finally, according to the simulation results in different environments, the highest displacement of gold nanoparticles in the second phase of manipulation was in water and the lowest in plasma.

Nowadays, atomic force microscopy has widely attracted researchers’ attention in manufacturing of micro/nano equipment. For this purpose, the displacement and manipulation equations for micro/nano-particle are essential. Although surface forces such as friction and adhesion are ignorable in macro scale, increased surface to volume ratio in micro/nano scale makes them very important. Various friction models have been used for two-dimensional manipulation in previous works. In this paper, HK friction model has been used to model and simulate three dimensional manipulation dynamically in order to have closer results to real manipulation. For this purpose, the important friction models have been studied and developed to use in micro/nano scale. Then, three-dimensional manipulation equations have been obtained and stiffness coefficient matrix for beam is extracted and all these equations have been combined to calculate the critical force and time of manipulation. Finally, simulation of obtained equations was used to calculate the critical force and time values of the three-dimensional manipulation for gold particle using HK friction model. The results indicate that rolling starts around x-axis before y-axis, and sliding starts along y-axis before x-axis.

In this paper, the modeling and simulation of manipulation of carbon nanoparticles have been investigated. The geometry plays a significant role in the dynamic behavior of nanoparticles manipulation and the evaluation of different geometric shapes of nanoparticles in this process is very important. To examine the geometry effects, the manipulation of a different kind of the nano-carbon allotropes has been studied. Furthermore, the manipulation of carbon nanotubes with different diameter has been simulated. For this purpose, the molecular dynamics method has been used to improve our knowledge and understanding about the nanomanipulation processes and dynamics. In the manipulation of carbon allotropes, the results indicated that more spherical allotrope Modes away, the easier manipulation process occurred and the forces on the probe have been reduced; this is due to the curvature of tip and nanoparticle. The results of nanotubes manipulation showed that increasing the diameter of the nanotube causes to increase the force on the probe. The indentation depth was extracted for each nanotube during the manipulation process. The results indicated that the indentation depth increases versus diameter increasing. According to the application of carbon-based structures and nanotubes as the drug carriers in medicine, such this simulation studies can reduce time and cost of experimental projects in this field.

Hexapod walking robots can be employed for both walking and manipulation purposes. When manipulating, they have 6 degrees of freedom for top platform, high rigidity, high load capacity, high speed, and accuracy. On the other hand, it is very well known that they have limited workspace when they are fixed in place for manipulation. Designing a hexapod robot resulting in a maximized workspace can greatly affect the efficiency of the robot when manipulating. Since radially symmetric hexapod walking robots can be modeled as three 2-RPR planar parallel mechanisms, we have used the methods and calculations that used in this kind of mechanism for designing a radially symmetric hexapod walking robot. In this paper, after a thorough review on existing methods for calculating and improving 2-RPR planar parallel mechanism workspace, an algorithm is presented, which results in a maximized reachable workspace. The merit of the method is that there is no need to calculate the workspace volume when maximizing the workspace volume. Also, following this algorithm is necessary for design of the maximized-workspace robot. In other words, the output of the presented optimization algorithm is a set of robot kinematic parameters, which guarantees the maximized volume of the robot’s reachable workspace.

Object manipulation techniques in robotics can be categorized in two major groups including manipulation with and without grasp. The aim of this paper is to develop an object manipulation method where in addition to being grasp-less, the manipulation task is done in a passive approach. In this method, linear and angular positions of the object are changed and its manipulation path is controlled. The manipulation path is a screwed track with constant radius and incline. As there is no actuator and active controller in the mechanism, the system requires a kind of mechanical intelligence to navigate the object from initial to goal configuration. This intelligence is achieved by geometry of the object and dynamical and kinematical characteristics if the object and the track. A general set up for the components of the system is considered to satisfy the required conditions. Then after kinematical analysis, detailed dimensions and geometry of the mechanism is obtained. M.SC-ADAMS is exploited to simulate the proposed mechanism

Using the soft fingers increases stability and dexterity in object grasping and manipulation. This is because of the enlarged contact interface between soft fingers and object. Although slippage phenomenon has a crucial role in robust grasping and stable manipulation, in the most of previous researches in the field of finger manipulation, it is assumed that the slippage between finger and object does not occur. In this paper, slippage dynamic modeling in object grasping and manipulation using soft fingers is studied. Because of the enlarged contact interface between soft fingers and object, a frictional moment along with tangential frictional force and normal force is applied on the contact interface. Therefore, a novel method for dynamic modeling of planar slippage using the concept of Friction Limit Surface is presented. In this method, equality and inequality relations of different states of planar contact is rewritten in the form of a single second-order differential equation with variable coefficients. These coefficients are determined based on the slippage conditions. This kind of dynamic modeling of contact forces can be used for designing the controllers to cancel the undesired slippage. The method is used in study of slippage analysis of a three-link soft finger manipulating a rigid object on a horizontal surface. In order to increase the accuracy of dynamic modeling of soft finger, dynamics of soft tip is integrated with the dynamic of finger linkage. Dynamic behavior of this system is shown in the numerical simulations.

In nanoparticles manipulation with atomic force microscope for modeling exact manipulation dynamics and prevent of damaging nanoparticles, it is necessary to compute critical force. For modeling dynamics and computing critical force that apply to nanoparticles it is necessary to modeling cantilever stiffness and determine sensitive geometrical parameters which are effect cantilever stiffness and critical force. In this paper at first it is investigated on two common different kinds of cantilevers which are V-shaped and dagger cantilevers. For modeling V-shaped cantilever stiffness this cantilever is divided into two parts a triangular head section and two slanted rectangular beams. After that the stiffness of each part is modeled separately and the total stiffness is computed. For modeling dagger cantilever stiffness it is used the same method and cantilever is divided into two parts a triangular head section and a rectangular beam and then the total stiffness is computed. Cantilevers stiffness and critical force in manipulation of biological particles and non-biological particles are very important because of that it is used EFAST sensitivity analyses for selecting suitable cantilever and its parameters. In this paper it has been shown that the dagger-shaped cantilever is more suitable for the manipulation of biological particles.

Nowadays one of the arguments that have been raised in the world of nanotechnologies is moving or manipulation nanoparticles. This discussion is important because the displacement of nanoparticles can make structurally different than what is currently available. So to achieve this goal, the atomic force microscope probe is used as manipulator. In this way, the use of nanoparticles by pulling or pushing on the surface, are displaced and brought to the desired point. If you apply too much force is needed, Nanoparticle Continued movement (sliding or rolling) after standing atomic force microscopy probes and away from the desired final. On the other hand, if the force is low, so that it can’t overcome the static friction force, Nanoparticles will be no movement. So finding the optimal force is important in nanomanipulation. In this paper, with using nanoparticle dynamic simulation, the governing equations on nanoparticle are derived and simulated during manipulation happen that they can be used to obtain the critical force and time for gold, yeast and platelets nanoparticles, in gaseous, water, alcohol, and plasma environments. By comparing the results obtained in this paper, it is concluded that the movement of particles in different biological environments starts later and by a force of higher magnitude relative to the gaseous medium.

In this paper we developed and modeled elastic - plastic contact theories for soft spherical nano - bacteria to be applied in manipulation of various micro/nanobio particles based on atomic force microscopy. First, we simulated elastic contact for three types of nano - bacteria: S. epidermidis, S. salivarius and S. aureus, using Hertz contact model and finite element. Comparing simulation results of elastic contact with experimental data showed that considering elastic contact for simulating the contact of nano - bio particles is not appropriate and will yield incorrect results. Therefore, in this research, we tried to develop and simulate Chang elastic - plastic contact theory to be applied in simulation of contact mechanics for application in simulating manipulation. Comparing simulation of Chang contact theory with available experimental data and the results from contact simulation of Chen et al showed that Chang’s complete elastic - plastic theory yields desirable results. Comparing the diagram of contact radius in terms of indentation in Hertz and Chang theories showed that the created contact radius in elastic - plastic state is larger than contact radius in elastic state.