Molecular dynamics simulation of Y-type nanomotors with different angles in aqueous solution

Abstract

Nanomotors are of great importance when studying nanoelectromechanical systems that contain carbon nanotube (CNT) based nanomotors for controlled motion in water using a rotating electric field. In this paper, Y-type nanomotor structures based on CNTs immersed in an aqueous solution are designed, and systems with different Y-type structure angles are simulated using molecular dynamics. The simulation results suggest that when the rotating electric field speed is appropriate, changing the Y-type structure angle can adjust the hysteresis (forward and backward motion) of nanomotor rotors during rotation. Precise control over the rotation angle of the nanomotor rotor improves its working efficiency. The enclosed simulation results are an important reference when designing nanoscale propellers and complex structured nanogear systems in aqueous solutions.

Effects of Radius and Length on the Nanomotor Rotors in Aqueous Solution Driven by the Rotating Electric Field

“…The MD simulations are performed by employing GROMACS 5.1.4. , The ensemble for the simulation is NVT ; i.e., the number of atoms, volume, and temperature remain constant. The rescaling velocity method (V-rescale) is used to maintain the temperature at around 300 K. Furthermore, the transferable intermolecular potential three-point (TIP3P) water model is used during the simulation process with the Lennard-Jones (LJ) parameters at σ cc = 0.34 nm and ε cc = 0.3664 KJ · mol –1 . ,− The equilibrium bond length between the carbon atoms is 0.1418 nm. The Harmonic potential energy function is used to constrain the bonds, where the constrained energy coefficients are 393960 kJ·mol –1 and 527 kJ·mol –1 ·rad –2 , respectively.…”

“…The truncated algorithm is used for LJ potential energy during the simulation with a truncation radius of 1 nm. The electrostatic interaction is subjected to the particle–mesh–Ewald (PME) algorithm, , where the truncation radius for short-range action is 1 nm, the time step is 2 fs, and the data sampling frequency is one frame per 0.5 ps. The method of steepest descent is applied to minimize the energy in the initial system.…”

“…Despite several achievements on nanomotors in nonsolution environment, the studies over the precise control of nanomotors in aqueous solution are sparse. Owing to the peculiar properties of CNTs, − CNT-based nanomotors in liquid environment have become an important research field in NEMS in recent years. ,− According to the investigations on the orientation mechanisms of CNTs by Guo et al, when an electric field is applied, the water molecule dipoles align with the electric field and the CNT is then forced to align its surface with the electric field, which sets the basis for applying an electric field to drive CNT motor rotors in water. Wang et al reported a liquid pump (nanopropeller) synthesized by CNTs and pyrene molecules, and performed MD simulation on the pumping rate of the liquid pump.…”

Precise control of CNT-DNA assembled nanomotor using oppositely charged dual nanopores

“…Alternatively, a CNT suspended in water is subjected to a rotating electric field of appropriate size and angular velocity, which can be rotated by means of the dipole direction of the water in MD simulations. [19][20][21] In addition to the control methods mentioned above, theoretically, some atoms with inward radial deviation (IRD) are placed at the edge of the stator. The IRD atoms will repel the nanotubes in their thermal vibration-induced collisions and can drive the nanotubes to rotate when the non-zero moment around the axis of rotational symmetry of the ring is induced by the repulsion due to the IRD and the friction with the stator.…”