The secret ingredient for a safer bike helmet: paper

"I was riding my bike down a hill, wearing a helmet and a guy opened his car door," says Anirudha Surabhi, who lives in London, BBC News reports. "I hit the door, did a couple of somersaults and fell straight on my head. My helmet was completely cracked, completely unusable." Luckily for him, Anirudha was able to walk away from the accident with whiplash and mild concussion. But the sight of his mangled helmet got the then design student thinking about new ways of protecting cyclists. His unusual solution was to substitute the standard polystyrene design with intricately engineered paper - a decision that's already proving to be a hit with bike-lovers . But how can paper be safer? And what else can it offer to the future of head protection? Feel the force "The danger with falling off your bike is that you subject your head to a dramatic change of speed in just a fraction of a second," says Jolyon Carroll, a safety researcher at the UK's Transport Research Laboratory. "When you hit the pavement your hard skull will stop or decelerate quickly. However, being a relatively soft organ, your brain tends to keep going. If you imagine dropping a blancmange onto a plate then you can see how bits at the back start compressing and piling up against other bits of brain at the front," he told the BBC. "It's this action that puts you at risk of injury - from breaking blood vessels to damaging brain tissue." The basic idea behind cycle helmets is to create a mini crumple zone - a bit like you'd find in a car - that absorbs some of the energy and gives your skull and brain more time to slow down before coming to a stop. Those extra few milliseconds can reduce the amount of compression in the brain and potentially make the difference between brain damage and a mild case of concussion. At the moment, the material used to protect us in a crash is polystyrene. But Anirudha Surabhi isn't convinced that it's the best choice for the job. Instead, he decided to look to the natural world for inspiration. "The animal that stood out was the woodpecker. It pecks at about ten times per second and every time it pecks it sustains the same amount of force as us crashing at 50 miles per hour," says Surabhi. "It's the only bird in the world where the skull and the beak are completely disjointed, and there's a soft corrugated cartilage in the middle that absorbs all the impact and stops it from getting a headache." Details also here