Carbon Nanotube Torsional Actuator Based on Transition between Flattened and Tubular States

Abstract Using a transmission electron microscope (TEM) equipped with a manipulator, we recently demonstrated the transition between the flattened state and the tubular state in rather thick carbon nanotubes (CNTs). This unique transition behavior provides a new concept of a nanosized device: a nanotorsional actuator. To realize and design the actuator, we used TEM observations and molecular dynamics simulations to examine the transition behavior and investigate how the torsion angle is determined and what the driving force is. Results indicate that a specific graphitic stacking order taken for the CNT inside determines the initial twist of a flattened CNT and thereby determines the rotational angle. Results also clarified that the transition results from thermal energy.