Flexible orientation control of ultralong single-walled carbon nanotubes by gas flow.

Gas flow is used to guide the growth of ultralong single-walled carbon nanotubes (SWCNTs) with complex shapes. Large-area cross-shaped networks of ultralong SWCNTs are obtained by a two-step chemical vapor deposition process. Also non-straight SWCNTs of different shapes are prepared by modifying the gas flow with tiny barriers. The shapes of the SWCNTs replicate the streamline patterns accordingly. The SWCNTs with designed patterns and shapes may be used in high performance nanoelectronics.