Towards the demonstration of actuator properties of a single carbon nanotube

Owing to its huge elastic modulus, good conductivity and large free surface area per mass, a single carbon single-walled nanotube (SWNT) should present optimal intrinsic actuation properties. Our aim is to demonstrate the viability of such a single nanotube-based actuator ("nano-actuator"). To achieve this goal, the primary focus was on how to obtain and manipulate an isolated and suspended SWNT. Several strategies have been attempted to produce such nanotubes (NTs), among them the "stamping" of tubes on functionalised substractes, or the direct growth of tubes from an oxide catalyst layer on a pre-designed substrate. Characterisation of these structures was carried out by atomic force microscopy, scanning electron microscopy and transmission electron microscopy. Manipulation of NT on flat surfaces was first demonstrated, before attempts were made to probe the suspended NTs. The final and most important step will be the use of an atomic force microscope to probe the deformation of the nanotube which should occur under a bias voltage in an electrochemical cell. (C) 2001 Science B.V. All rights reserved.