Invisible helmet wins world's biggest tech prize

Although cycle helmets have become more and more stylish in recent years, anyone who commutes to work will admit that not wearing one is still the better look. If a colleague starts talking to you as you're locking your wheels up, you feel about as inconspicuous as Lord Dark Helmet.

Alas, cycling bareback throws up that niggling debate that you could well be risking your life.

The answer? An invisible airbag for your head, by Swedish technology outfit Hövding.

Shaped as a collar worn around your neck it pops open when it senses impact from a car. And we're not the only ones that think it rocks. It has won the world's largest monetary prize for design.

The winners of the 2011 Index design awards were presented at a gala in the Danish capital Copenhagen. The Index: Award focuses on "Design to Improve Life – designs that target and solve daily problems. The award is split into five categories – Body, Home, Work, Play and Community – with the winner of each category walking (or riding) away with 100,000 euros (£88,000 or $140,000.)

Studies have shown that helmets are an impediment to cycling for some, particularly women, who don't like what it does to their hair. Anna Haupt and Terese Alstin spent six years on the problem, and cracked it by using accelerometers that detect abnormal movements.

It is costs about £300 ($490).