An apparatus according to the present invention comprises a chamber into which carbon nanotubes dispersed in a non-polar solvent may be received. The nanotubes are impelled along the chamber by the application of an external electrical field and will pass through a charging element that imposes an electrical charge on the nanotubes, and a template (180), such that the nanotubes are deposited on a substrate located next to the template. The substrate may be moved relative to the template such that the nanotubes are deposited on the substrate in a predetermined selective manner.