Self-organized nanotube serpentines.

Carbon nanotubes have unique mechanical, electronic, optical and thermal properties, which make them attractive building blocks in the field of nanotechnology. However, their organization into well-defined straight or curved geometries and arrays on surfaces remains a critical challenge for their integration into functional nanosystems. Here we show that combined surface- and flow-directed growth enable the controlled formation of uniquely complex and coherent geometries of single-walled carbon nanotubes, including highly oriented and periodic serpentines and coils. We propose a mechanism of non-equilibrium self-organization, in which competing dissipative forces of adhesion and aerodynamic drag induce oscillations in the nanotubes as they adsorb on the surface. Our results demonstrate the use of 'order through fluctuations' to shape nanostructures into complex geometries. The nanotube serpentines and loops are shown to be electrically conducting and could therefore find a wide range of potential applications, such as receiving and transmitting antennas, heating and cooling elements, optoelectronic devices and single-molecule dynamos.