Use your helmet

Materials World magazine
,
1 Apr 2018

This month, Dr Jennifer Unsworth, Patent Attorney at intellectual property law firm Withers and Rogers, looks at how a graphene-reinforced helmet saved a competitive cyclist’s life. 

Travelling hundreds of kilometres at average speeds of 50km/h, supported by a 25mm-wide tyre on unpredictable roads, surrounded by fierce competitors and overzealous spectators – these are the conditions faced by competitive road cyclists, and the only protection they have, is a helmet.

It is, therefore, no surprise that there is considerable competition when it comes to manufacturing a helmet with optimal shock-absorbing capabilities. Spanish sports equipment manufacturer Catlike Sports Components is among those trying to identify the deficiencies in current designs and use the latest, innovative materials to find a solution.

High-energy shock-absorption can often result in catastrophic destruction of a product, and this isn’t always a bad thing if it is done in a controlled manner. For instance, consider the crumple zones on cars that maximise energy absorption in the event of a crash. 

The need for an aerodynamic and ultra-light helmet in road cycling makes this a particularly challenging task. 

A typical cycling helmet consists of an expanded polystyrene core, surrounded by an external plastic shell, and is formed with a number of weight-reducing recesses. The result is a protective helmet that is sufficient for light impact, but likely to break apart in high-impact situations.

While the helmet separating into pieces will help absorb some of the impact, Catlike has been developing a solution to improve this process. 

Advanced protection 

As described in European patent, EP2837300, Catlike’s innovation features the same shock-absorbing body and external shell expected of a conventional helmet, with the addition of an innovative interior reinforcement structure. 

This is distributed throughout the helmet’s interior and in between the recesses of the helmet, thereby forming a net. In the event of impact, it acts as a skeleton to hold the various portions of the now broken helmet together, helping to absorb more energy and offering more protection to the wearer.

To be able to sustain this force, the skeleton-like structure is made using filaments, which are bound and reinforced by a graphene nanofibre-infused resin. 

Graphene is one of the strongest materials in the world, owing to its lattice structure of strong covalent bonds. With its large surface area and innate stiffness, this structure is ideal for transferring stress away from the much weaker resin.

Adding graphene to the resin increases its strength and stiffness considerably. It also ensures that any cracks are forced to propagate indirectly through the resin and around the graphene sheets – creating a so called tortuous crack path. 

Amazingly, this can all be achieved with only a tiny fraction of between 0.5% and 1.5% of graphene dispersed in the resin.

This innovative combination of materials and design has resulted in an improved helmet that is capable of withstanding harsh treatment –  and no one is more grateful for this than Adriano Malori.

The lifesaver 

Malori is a former professional road cyclist, who was involved in a crash when cycling at 60km/h on the Tour de San Luis in Argentina in January 2016. The resulting head trauma left him in a critical condition and he was placed in an induced coma for four days. 

Despite this brush with death, eight months later Adriano made an astonishing recovery and returned to competition for a short while. (Read more here bit.ly/2FB3dmt).

There is little doubt that the helmet saved Adriano’s life, and the shock-absorbing properties of the graphene-reinforced skeleton may well have made the difference.

This innovation shows how sometimes relatively minor improvements can enhance a product’s overall design significantly. In this case, they could even make the difference between life and death. As long as the improvements are novel and inventive, the innovator will be able to secure patent protection, affording them a 20-year period of commercial exclusivity in which to recoup their R&D investment.  

Read the full patent here: bit.ly/2oSRDcN