British scientists have created a material that replaces the screen glass for phones, tablets and smartwatches, but uses no power - meaning they could be charged weekly.

英国科学家发明了一种物质，它可以替代手机、平板电脑和智能手表的玻璃屏幕，因为该物质不耗电，所以意味着这种屏幕的手机每周充一次电即可。

The discovery is significant because more than 90 per cent of a device's battery power illuminates the screen.

Technology firms have focused on improving battery life. But the British experts say tackling the main drain on a gadget's power may give better results.

Oxford University engineer Dr Peiman Hosseini, who invented the material, told the Sunday Telegraph: 'You have to charge smartwatches every night. But if you had smart glass, you could recharge it just once a week.'

The innovation uses electrical pulses to create displays that require no power and can be viewed even in direct sunlight. Dr Hosseini's company, Bodle Technologies, hopes to have a prototype in a year.

"This is the right moment to be an academic at Oxford,' Dr Hosseini said.