Following on from its graphene-enhanced outsoles, the collaboration between UK-based Inov-8 and the University of Manchester is yielding more benefits for footwear.

Dodging rocks and stones and navigating uneven terrain are key skills for trail and ultramarathon runners, and footwear brand Inov-8 believes feeling a connection with the ground is crucial to speed as well as avoiding injury. While other manufacturers “seem hung up on” carbon plates to propel runners forward, the UK company has invested heavily in the potential of ‘wonder material’ graphene over the past few years. The quest for a trail shoe with better grip, adaptability, ride and fit, but which lets the foot move naturally, has culminated in its latest release, the G-Fly Max 300.

Inov-8’s relationship with the UK’s University of Manchester, home of the National Graphene Institute, began in 2017, after Dr Aravind Vijayaraghavan, a reader in nanomaterials, published a paper on how graphene could enhance rubber. Graphene is a single atomic layer of graphite — which itself was discovered in Inov-8’s home, the English Lake District, in 1555, and was originally used to mark sheep (now commonly used in pencils). Graphene was characterised by University of Manchester professors Andre Geim and Konstantin Novoselov in 2004, earning them a Nobel Prize for physics in 2010. It is the thinnest and strongest material by weight, offering strength that is 200 times that of steel, at only one atom thick, and additional properties include transparency, flexibility and an ability to conduct heat and electricity. “It is remarkable that one material has all these properties,” says Dr Aravind. “That is why we call it a wonder material.”

Its potential is such that the EU committed €1bn to the Graphene Flagship for 10 years’ research from 2013, and Manchester’s Graphene Institute and Graphene Engineering Innovation Centre are among multiple academic facilities and private companies around the world that are dedicated to finding commercial uses in sectors from transport to energy.

Trial and error

The Inov-8 team began research and development with Dr Aravind and his team, and soon after launched a graphene-enhanced outsole collection, Graphene-Grip (see WSA Jan-Feb 2018). They say the resulting rubber is stronger, stretchier and more resistant to wear than standard rubber. Its G-Series won multiple awards and was rolled out across other footwear categories. This research piqued footwear specialist Doug Sheridan’s interest. “Graphene often enhances the characteristics of the elements it’s mixed with,” he says. “Graphene is so new, it has the ability to surprise and frustrate but also it has the unique ability to make these other materials perform their best.”

Over the next couple of years, they experimented with foams: 50 mixtures tested in the lab and by 40 athletes in the field. Adding the graphene meant certain polymers were able to perform better, “but it’s a sensitive chemistry, it’s not just a question of adding more,” says Mr Sheridan.

The final foam, which they call the G-Fly, is reported to give 25% better energy return than standard EVA foam as well as longer-lasting performance. Even after accelerated aging, it still offers 10% better energy return than the standard EVA and ‘compares favourably’ with EVA TPU blends, the company states. Added to style and performance updates including 10mm underfoot grooves that increase flex, The Trail Fly Ultra maintains underfoot bounce and comfort for longer. The three patent-pending technologies (Graphene-Grip, G-Fly and Adapter-Flex) could help runners maintain a faster speed over greater distances, help feet feel and prolong the life of their footwear.

Environmental impact

The increased durability extends the shoe’s life, which the company points to when questioned on the environmental impact of adding graphene. Various graphene suppliers were considered, with the chosen one being certified to EU chemicals standard REACH. “Graphite is a natural material and we use a relatively small amount of graphene to deliver the impact so it doesn’t measurably add to the carbon footprint of the shoe,” explains Dr Aravind. “And the gains in sustainability by having a shoe that lasts a lot longer is the dominating aspect.”

Guided by Mr Sheridan and working with the university team, Inov-8’s footwear supplier was able to work with the new recipe. “Like everything else, it was a technology challenge: how do you scale up something you do as a small scale in the lab to production scale in the factory?” Dr Aravind tells WSA. “But we work very closely with Inov-8 and people in their partner factory, as well as Doug Sheridan. The manufacturability was one of the things we addressed as part of collaboration.” He adds that the foam was launched into the ultramarathon sector because the energy return over long distances provides obvious benefits, but that he sees it being used in other types of footwear and, longer-term, could yield further advancements elsewhere in the shoe.

Cost cutting

With a number of outdoor brands — including Haglöfs and Vollebak — experimenting with graphene in textiles for clothing, it would seem the athletic footwear industry has been quite slow on the uptake, but Dr Aravind argues the opposite. “Graphene itself is a brand new material, it’s less than 20 years old, and generally it takes much longer for a new material to make it into a consumer product,” he tells us.

Years of outsourced research and development generally add to the cost of any product, but Inov-8 was able to benefit from a Knowledge Transfer Partnership, a UK government scheme that provides funding for innovative developments. This allows brands to bring expensive innovation to the marketplace, as research can be shared, keeping the costs acceptable for the consumer.

Inov-8 aims to stay the frontrunner when it comes to using graphene in footwear. “We have made a heavy investment into graphene but our name is Inov-8 so we have to lead with innovation and it’s something CEO Wayne Edy really pushes through the company,” says Michael Price, Inov-8’s chief operating officer. “The investment is also about the future. We really believe we can grow the business and provide runners with product that makes a big difference to them and their running.”

All Credits: Inov-8

Share this story: