Energy absorption induced oscillation of a rotating curved carbon nanotube in a nano bearing

In a nano bearing made from a curved inner carbon nano tube (CNT) and two short outer CNTs as stators, the free end of the inner tube has periodic axial translational oscillation (gap changes with time) and the amplitude of oscillation is very high when the frequency of the input rotational velocity (ωin) is close to an eigen/resonance frequency of the system, i.e., energy absorption of the inner tube from the interaction between the inner and outer tubes. The fundamental frequency of the system is higher when the inner tube has larger curvature. The free end of the inner tube also has obvious torque oscillation (asynchronous of ωout and ωin). Both of the axial translational oscillation and torque oscillation of the free end can be used as output signals of the system as working in a nano signal generator.94