- 18:20 13 February 2001
- From New Scientist Print Edition. Subscribe and get 4 free issues.
- Duncan Graham-Rowe
A new type of helmet that mimics the head's own protective design could save many extra lives. And by preventing head injuries to motorists, it could also save up to £300 million a year in medical costs in the UK alone.
The helmet is designed to limit the rotational forces affecting the head during an impact and is currently undergoing bench tests. Early tests at the UK's Transport Research Laboratories showed that the helmet gave 60 per cent more protection than conventional helmets and could potentially save 20 per cent more lives.
The helmet's inventor, Kenneth Phillips from Middlesex, became interested in the area when he realised that a high number of head injuries still occur despite the use of existing helmets.
He says the head's natural design seemed to offer good protection principles and so decided to try to mimic this.
"It's important to take into account rotational forces," says Brian Chin, head of Vehicle Safety Systems at the Transport Research Laboratory. He adds that while the Phillips helmet is not the only one to try to do so, it is the first to tackle the problem using biomimicry.
"The major discovery is that the skull plays an important role in protecting against rotational acceleration," says Phillips. He says almost all head injuries involve not just a direct blow to the skull but also damage to blood vessels caused by the brain rotating within the skull.
In mechanical terms, the head is an elliptical spheroid with a single universal joint, the neck. It is therefore almost impossible to hit it without causing it to rotate. The head tries to dampen these forces using a combination of built-in defences: the scalp, the hard skull and the cerebrospinal fluid beneath it.
During an impact, the scalp acts as rotational shock absorber by both compressing and sliding over the skull. This absorbs energy from the impact.
So whilst most helmets have a hard shell-like exterior, the Phillips helmet has a soft moveable layer on the outside, simulating the scalp. The helmet will also have a hard inner layer, representing the skull, with a sealed fluid layer separating it from the wearer's head.
Phillips has just completed computerised simulations at the Transport Research Laboratory and is now experimenting with different polymers to form the scalp layer of the helmet.
He spent seven years furthering his understanding of head protection systems before coming up with his own innovative approach. He has a £30,000 SMART grant from the Government Office of London, and on Monday was awarded a further £100,000 grant from NESTA to complete a prototype.
He believes his helmet could be useful, not just to motorcyclists, but also to the police and horse riders.