The ultimate self-wash

Here is an answer to the prayers of every slovenly student - clothes that clean themselves. Scientists have developed a chemical coating which devours dirt on clothes.

Garments simply need to be exposed to sunlight for the process to begin. Cinema dreamed up such a scenario for 1951 classic The Man In The White Suit.

Sir Alec Guinness played a scientist imprisoned by the clothes industry after inventing a fabric that never got dirty or wore out.

The real breakthrough came when scientists at Hong Kong Polytechnic University coated clothing with tiny particles of titanium dioxide, which breaks down carbon-based molecules.

Each particle is just 20 nanometres across - 2,500 times narrower than a human hair. But more research is needed before self-cleaning clothes hit the shops, Nature magazine said.