Platinum is playing an important role in the drive to develop the possibilities of nanotechnology, the minute robotic and computer tools that could revolutionise the way we live.

Researchers at the University of Louisville and Rensselaer Polytechnic Institute have used tiny platinum wires to make nano tubes only a twentieth larger than a blood vessel, which could be used in complex retinal surgery, and all manner of other scientific, medical and commercial contexts.

They could be used also to detect and locate tiny amounts of chemicals in the human body, administer similarly minute amounts of drugs or as components in near-field scanning optical microscopes.

The team found that immersing platinum wires in methane/hydrogen plasma made sheets of carbon atoms wrap round a central nanotube whose outer walls tapered by a factor of several hundred, reducing the tube to the infinitesimal dimensions required.

The process saw the outer walls of nanotubes taper from as many as 700 nanometers to only a few nanometers, leaving a conical shape that could be used to administer molecular droplets of liquid.

The 'nanopipettes' created were approximately 6,000 nanometers long, slightly longer than the 5,000 nanometer diameter of a single red blood cell.