Fluctuotaxis: Nanoscale directional motion away from regions of fluctuation.

Regulating the motion of nanoscale objects on a solid surface is vital for a broad range of technologies such as nanotechnology, biotechnology, and mechanotechnology. In spite of impressive advances achieved in the field, there is still a lack of a robust mechanism which can operate under a wide range of situations and in a controllable manner. Here, we report a mechanism capable of controllably driving directed motion of any nanoobjects (e.

Nanoscale directional motion by angustotaxis.

Directing motion of a nanoscale object on solid surfaces, in particular in an intrinsic way, is crucial for many aspects of nanotechnology applications. Here we report a novel intrinsic mechanism for nanoscale directional motion, termed angustotaxis, where a wide single walled carbon nanotube in a tapered channel drives itself toward the narrower end of the channel. The underlying physics of angustotaxis is attributed to the lower system potential when the nanotube is at a narrower region of the channel due to the increased contact area between the nanotube and the channel.

An intrinsic energy conversion mechanism via telescopic extension and retraction of concentric carbon nanotubes.

The conversion of other forms of energy into mechanical work through the geometrical extension and retraction of nanomaterials has a wide variety of potential applications, including for mimicking biomotors. Here, using molecular dynamics simulations, we demonstrate that there exists an intrinsic energy conversion mechanism between thermal energy and mechanical work in the telescopic motions of double-walled carbon nanotubes (DWCNTs). A DWCNT can inherently convert heat into mechanical work in its telescopic extension process, while convert mechanical energy into heat in its telescopic retraction process.

Negative Thermophoresis in Concentric Carbon Nanotube Nanodevices.

Positive and negative thermophoresis in fluids has found widespread applications from mass transport to molecule manipulation. In solids, although positive thermophoresis has been recently discovered in both theoretical and experimental studies, negative thermophoresis has never been reported. Here we reveal via molecular dynamics simulations that negative thermophoresis does exist in solids.