An aerobic office chair and a glowing green kettle are two British inventions taking on the rest of the world in a competition to find the next great inventor.

The annual James Dyson Award - which closed for entries yesterday - promotes the next generation of designers by asking students to find inventive solutions to their biggest bugbears.

Sonia Ward, 22, from Gillingham, is representing British design talent with her invention of a dynamic office chair which improves workers' health.

Inspired by a gym aerobics ball, her chair ditches the mouse and instead controls the computer's cursor with subtle body movements which gradually improve the user's balance, develop core muscles and reduce back pain.

She is joined by fellow student Chris Elsmore, 24, from Wokingham, who entered his invention - the Carbon Kettle - which glows green when the national grid has an excess supply of power and glows red when it is struggling to meet demand.

By deciding to wait for their cup of tea, users save the national grid from inefficient power generation, thereby reducing greenhouse gases.

The British designers face stiff competition from their international counterparts.

Australian student Bryce Killen entered a smart speed hump filled with a hi-tech fluid which solidifies when it is hit by a speeding motorist. But it lets drivers who obey the speed limit pass without a jolt.

German designer Eva Mullemeyer found a solution to wildlife caught in environmental disasters like the recent oil spill off the Gulf of Mexico.

Her Beaming Bird Buoy sends an ultrasonic signal to nearby birds, scaring them away from oil-affected areas.

This year 555 students from across the world entered the competition set up by British inventor Sir James Dyson.