Controllable bending behavior of nanotube driven by the polar water molecules under the orthogonal electric fields

The convenient strategy for controlling deformation of nanomaterials has great application in nanoswitch, nanochip and so on. In this work, by using an electric field with two mutually orthogonal components, it is discovered that the bending deformation of water-filled CNTs could be precisely controlled. The molecular dynamics simulations indicate that the bending deflection increases with the intensity of transverse electric field, while the bending direction could be conveniently altered through switching the direction of longitudinal electric field. This controllable deformation primarily originates from the response of polar water molecules to electric field, and two theoretical models are established considering the coupling effects of bending moment or shear force with tension. The results show that the shear force mechanism has less deviation. This work uncovers the deformation characteristics of liquid-filled CNTs under an electric field and lays a solid foundation for their potential applications in nanoelectromechanical systems, sensors, etc.