Researchers from the Spanish National Research Council, Universitat Autònoma de Barcelona, and the Catalan Institute of Nanotechnology claim to have created the first nanomotor that is moved by changes in temperature.

The carbon nanotube is capable of transporting cargo and rotating like a conventional motor, but is a million times smaller than the head of a needle. This research is said to open the door to the creation of new nano-scale devices designed to carry out mechanical tasks, which, in the future, could be applied to the fields of biomedicine or new materials.

The 'nanotransporter' consists of a carbon nanotube - a cylindrical molecule formed by carbon atoms - covered with a shorter concentric nanotube that can move back and forth or act as a rotor.

A metal cargo can be added to the shorter mobile tube, which could then transport this cargo from one end to the other of the longer tube or rotate it around its axis.

Researchers are able to control these movements by applying different temperatures at the two ends of the long nanotube. The shorter mobile tube thus moves from the warmer to the colder area in a similar manner to the way in which air moves around a heater. This is believed to be the first time a nanometre-sized motor has been created that can use changes in temperature to generate and control movements.

The movements along the longer tube can be controlled with a precision of less than the diameter of an atom. This ability to control the objects at the nanometre scale can be extremely useful for future nanoelectromechanical applications.

The research has been published in the journal Science and can be consulted online at the Science Express website. It has been directed by Adrian Bachtold, researcher at CIN2 (Nanoscience and Nanotechnology Research Centre, CSIC-Catalan Institute of Nanotechnology) and at CNM (National Microelectronics Centre, CSIC), and by Eduardo Hernández at ICMAB (Institute of Material Science, CSIC), all of which form part of the UAB Research Park. Research members include Riccardo Rurali from the UAB Department of Electronic Engineering, and Amelia Barreiro and Joel Moser from CIN2 (CSIC-ICN), with the collaboration of researchers from the University of Vienna, Austria and from EPFL in Lausanne, Switzerland.

Universitat Autònoma de Barcelona