Researchers at Tsinghua University have used molecular dynamics simulations to examine thermal gradient-induced actuation in double-walled carbon nanotubes and believe that heat flux can actuate the relative motion of double-walled carbon nanotubes. The thermal driving force is on the order of pico Newtons for a 1 K nm–1 temperature gradient. The driving force is found to be approximately proportional to the temperature gradient.

Heading in the right direction

The motion was found to be dependent on the chirality pairs of the double-walled carbon nanotubes. Based on different chirality pairs, the relative motion of the double-walled carbon nanotubes is confined within the minimum energy track and can be rotational, translational or helical (combination of rotational and translational) when the system temperature is less than its critical temperature. The behaviour offers a pathway towards directional control, which could be helpful in the design of future nanodevices.

Full details can be found in the journal Nanotechnology.