Women will soon be able to change the colour of their nails at the click of a switch thanks to a bit of electronic wizardry.

　　Researcher Carlos Gonzalez has been working on an electrochromic false nail at the Cidetec research centre in Spain's Basque country. The hi-tech cosmetic accessory is fitted on top of the natural nail and, once in place, can be changed to the colour of the wearer's choice.

　　The nail is made up of a number of superimposed layers, which are sandwiched between various electrochromic polymers to allow the colours to change. A digital control device is then used to programme the desired colour on to the nails. This includes a camera which can capture the colour of any surface which is then reproduced on the nails. There is also a screen to allow the wearer to visualize their colour selection before it is transferred to the nails.

　　Mr Gonzalez said the technique, which has already won an innovation prize, could also be used to cover other surfaces.