Orbiting Buckyballs Inside Nanotori

The discovery of carbon nanostructures, such as carbon nanotubes and the so-called buckyballs (or C60 fullerenes), have generated considerable interest for potential nanomechanical device applications. One such device is the high frequency nanoscale gigahertz oscillator. A number of studies investigating these oscillators find that sliding an inner-shell inside an outer-shell of a multi-walled carbon nanotube can generate oscillatory frequencies in the gigahertz range. It is found that the oscillation is sensitive to diameter and helicity of the tube and that the inner tube length can be used to tune the frequency, where the buckyball provides the highest frequency. More recently, toroidal carbon nanotubes, termed fullerene "crop circles" were observed in experiments. Researchers observe single continuous toroidal nanotubes with no beginning or end, effectively a single-walled carbon nanotube wrapped around onto itself so that the two open ends join, and are stabilized by van der Waals forces alone, to form a perfect "nanotorus". The question arises as to whether it is possible to create a C60-nanotorus oscillator, whereby a buckyball would orbit around the inside of a nanotorus. As far as the authors are aware, the C60-nanotorus oscillator is yet to be constructed and the aim here is to understand the mechanics and dynamics of this potential nanoscale device. As in previous studies, the Lennard-Jones potential is used to calculate the forces acting on the fullerene due to the non-bonded interactions. A body force diagram is constructed to balance the Lennard-Jones potential with other relevant forces, such as the centrifugal force. Here, we present a synopsis of recent work examining the equilibrium position of a buckyball orbiting inside a nanotorus, followed by investigation into its orbital velocity.