An accident, in which one man was knocked off his bicycle, has inspired him to invent a totally new design for a cycling helmet. Londoner Anirudha Surabhi was riding his bike down a hill when a car driver opened his door, causing Surabhi to smash into it and come off his bike. “I hit the door, did a couple of somersaults and fell straight on my head. My helmet was completely cracked, completely unusable.” Thankfully Surabhi was able to get up after the accident and did not suffer any major symptoms; it did however leave the then design student thinking, when he saw the state of his mangled crash helmet.
Surabhi developed a new crash helmet, the Kranium Helmet, and instead of using the standard polystyrene, decided to substitute paper for the main material. Paper does seem to be an odd choice for a safety helmet, but experts at the UK Transport Research Laboratory concur that it could offer more protection against head injuries than polystyrene. Jolyon Carroll spoke to the BBC: “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. 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 added: “It’s this action that puts you at risk of injury – from breaking blood vessels to damaging brain tissue.”
The design behind the paper helmet is to create a mini crumple zone, similar to that you’d find in a car, to absorb some of the energy the crash generates and give your brain time to slow down before stopping. In tests it has been shown that even just a few extra milliseconds can reduce the amount of compression the brain suffers and could mean the difference between brain damage or mild concussion.
Surabhi looked to nature to help him design a new safety helmet, and in particular studied 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.”
Using this as a template for his design, he constructed the paper helmet using several layers of double honeycombed paper, to imitate the woodpecker’s crumple zone. Once he had developed the honeycomb paper, he could then cut it to construct a cycle helmet. “What you end up with is with tiny little airbags throughout the helmet, so when you have a crash, what these airbags do is they go pop, pop, pop, pop, pop – and they go all the way to the bottom, without the helmet cracking. That’s what absorbs the energy.”
The paper helmet has already been tested to European standards, and comparisons with standard helmets are proving to be favourable. Surabhi says: “If you crash at 15 miles per hour in a normal helmet, your head will be subjected to around 220G [G-force], whereas the new design absorbs more of the impact and means you experience around 70G instead.” With international safety standards advising that any impact over 300G will arise in serious brain damage, the paper helmet is already impressing the experts.
It is not yet compulsory for cyclists to wear safety helmets in the UK, but Surabhi thinks that more people will wear the paper ones: “I think the public will accept it because if you think about it, stuntmen have been jumping onto cardboard boxes for decades, which are all made out of paper,” says Anirudha Surabhi. “They risk their lives from five-storey buildings purely because they know that paper actually works.”
Source: BBC Health