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

Nanomotors with ultrahigh speed that are easy to assemble, with low friction and long service life, have been actively researched in several fields recently, owing to the relentless development of nanoelectromechanical systems (NEMS). They are based on the principle that the reorientation of the water dipole moment induced by the rotating electric field can rotate the carbon nanotubes (CNTs) immersed in the aqueous solution. The dynamic behaviors of nanomotor rotors with different radii and lengths are studied. According to molecular dynamics (MD) simulations, the lag angle between the nanomotor rotor and the water molecule dipole can be reduced by increasing the radius of the nanomotor rotor or increasing the length of the nanomotor rotor. At the same time, the synchronization speed between the nanomotor rotor and the rotating electric field can also be increased by increasing the radius of the nanomotor or reducing the length of the nanomotor rotor. These studies show that the radii and lengths of the nanomotor rotor can affect the nanomotor rotor rotation angle, rotation speed and cycle time. Our findings may have potential applications in the design of nanopropellers and nanogears of complex structure.