Flexible actuator by electric bending of saline solution-filled carbon nanotubes

As a two-phase hybrid material, liquid-filled carbon nanotubes (CNTs) provide a great opportunity to design dexterous flexible nano-manipulator actuated by electric field. Here, we report a group of saline solution-filled CNTs with the end constraint can realize 360 degrees all-round bending in a suitable electric field. The molecular dynamics (MD) simulation results show that saline solution-filled CNTs can be bent under the axial-lateral compound electric field, whereas the bending deflection increases with the increase of salinity, CNTs length and electric intensity. The deformation mechanism of saline solution-filled CNTs under the electric field is clarified by exploring the movement and distribution of salt ions in CNTs under the axial electric field. Moreover, based on the bending deformation characteristics of saline solution-filled CNTs, the MD simulations for the two-finger and four-finger nano grippers grasping diamond balls are carried out to demonstrate the micromanipulation functions of saline solution-filled CNTs. The findings will provide an important theoretical basis for the design and application of micromanipulation devices based on low dimensional carbon materials.