This new material could revolutionise rider safety apparelby Harry Fisher, on
The problem of making motorcycle riding gear both protective and comfortable has long been a thorn in clothing manufacturers sides: if it has all the protection, it’s rarely comfortable and to achieve comfort often means compromising on safety. This new product could change all that.
Could ’Chain Mail’ Be the Answer?
Motorcycling apparel needs to protect, that much is certain. But, often, that means it is impossible to make it comfortable for all-day wear, with hard pads and abrasion resistant fabrics compromising the comfort.
This new idea from a collaboration between Caltech and Nayang Technological University in Singapore could be the answer and takes inspiration from ancient battle protection chain mail, albeit with a modern twist.
The secret is that it can change from a flexible, pliant state to a rigid state on command. This is made possible by the construction, which comprises interlocking hollow octahedrons. The first examples are fabricated from 3D-printed plastic polymers but metal versions would also be possible.
In a relaxed state, the octahedrons remain freely flexible but, when compacted, will become rigid.
Chiara Daraio, a professor of mechanical engineering and applied physics at Caltech, said: "We wanted to make materials that can change stiffness on command. We’d like to create a fabric that goes from soft and foldable to rigid and load-bearing in a controllable way.
"Think about coffee in a vacuum-sealed bag. When still packed, it is solid, via a process we call ‘jamming.’ But as soon as you open the pack, the coffee grounds are no longer jammed against each other, and you can pour them as though they were a fluid."
While the fabric isn’t able to change from soft to hard on impact, such as when you fall off a motorcycle, it can be stiffened once you are in position on the bike, perhaps by pulling on drawstrings to compress the fabric. Alternatively, if the pad was encased in a plastic airtight envelope, the air could be pumped out to compress the fabric and stiffen it.
Test results have been encouraging. A flat, compressed sheet held a 1.5kg weight, 50 times its own mass. Dropping a 30g steel ball onto it showed that it deformed just 3mm in its compressed state.
"These fabrics have potential applications in smart wearable equipment: when unjammed, they are lightweight, compliant, and comfortable to wear; after the jamming transition, they become a supportive and protective layer on the wearer’s body," said Wang.
The obvious applications are in bullet and knife-resistant body armour but it’s not a stretch of the imagination to see applications in motorcycle clothing, hopefully solving the problem of comfort and protection in one fell swoop.