Sharif Digital Repository

In this paper we have studied the motion of a nanocar and nanotruck on gold substrate using the classical molecular dynamics method. Analyzing the motion regime of the nanocar at different temperatures is one of the main goals of this paper. In the past years, similar molecules such as Trimmer, Z-car and nanotruck have been simulated by Konyukhov and Akimov. To increase the modeling accuracy in this paper we have used classical molecular dynamics contrary to previous works which used a rigid body molecular dynamics method. The result of our simulations were compared qualitatively to the experimental tests performed by Zhang et al. [12]. There was a good agreement between the results achieved... 

In recent years, nanocars with p-carborane wheels have been a subject of interest as an artificial molecular machine. Researchers aim to discover compositions that are easier to fabricate, efficient and are more stable on the surface. The p-carborane molecule has all these key elements, making it a viable choice as a nanocar wheel, and the mobility of a nanocar is heavily influenced by the motion of its wheels. In this research, we use classical Molecular Dynamics (MD) in isothermal conditions to specify the regime of motion of p-carborane at different temperatures. We find that by raising the temperature, three different regimes of motion may be observed: jumps to adjacent cells, long... 

The rotational and translational motions of nanocars and nanotrucks as well as their motion regimes at different temperatures are investigated. In recent years, few similar types of molecular machines have been simulated. In contrast to previous studies, which have used the Rigid-Body Molecular Dynamics (RBMD) method, an all-atom model and classic atomistic dynamics have been employed in this paper to achieve better accuracy. Our results demonstrated that the exibility of the chassis and its attachment to the gold surface played an important role in the motion of a nanocar. In fact, a heavier and more exible nanocar chassis reduces its speed compared to a nanotruck. In addition, the results... 

In the previous years, a few types of nanocars have been built with the promising potential to transport other molecules, to provide bottom-up assembly, or to perform other mechanical tasks. In this study, we propose a method to convert the diffusive displacement of nanocars to a guided motion in a desired path by adding some impurity atoms in the substrate. We investigated the motion of C60 as well as the nanotruck and the nanocar on a flat gold substrate containing silver contamination and conversely a silver substrate containing gold contamination at the different temperatures. The results showed that silver impurity on the gold substrate act as a repellent obstacle in the path of C60... 

In this paper, we have studied the motion of buckminsterfullerene (C60) on a gold surface by analyzing its potential energy and using classical molecular dynamics method. The results can be employed to investigate the motion of C60-based nanocars which have been made in recent years. For this purpose, we have studied the translational and rotational motions of C60 molecule independently. First, we have calculated the potential energy of a C60 molecule on a gold surface in different orientations and positions and employed this data to predict fullerene motion by examining its potential energy. Then we have simulated the motion of C60 at... 

The motion of a C60 molecule over a graphene sheet at finite temperature is investigated both theoretically and computationally. We show that a graphene sheet generates a van der Waals laterally periodic potential, which directly influences the motion of external objects in its proximity. The translational motion of a C60 molecule near a graphene sheet is found to be diffusive in the lateral directions, while in the perpendicular direction, the motion may be described as diffusion in an effective harmonic potential which is determined from the distribution function of the position of the C60 molecule. We also examine the rotational diffusion of C 60 and show that its motion over the graphene... 

Molecular machines and surface rolling molecules show great potential to accomplish different tasks in several fields, such as bottom-up assembly and nanomanipulation. Many researchers have investigated molecular machines, most of which was on a flat single-crystal substrate. In this paper, we studied the influence of vacancies in different sizes on the motion of a nanocar, a nanotruck, and C60 on a gold substrate at different temperatures by employing classical all-atom molecular dynamics. At the temperature of 200 K, a hole or vacancy appears as a repellent obstacle in the path of C60, and at higher temperatures, C60 can enter this hole. Although C60 has enough energy to escape single-atom...