When you’re a professional athlete, your gear can make all the difference. Kenyan long distance runner Eliud Kipchoge proved this when he won the London Marathon on 22 April, wearing Nike’s super light Flyprint shoes, said to be the world’s first trainer with a 3D printed upper (the top part of the trainer normally made from fabric).

The shoe was designed especially for Kipchoge, who ran the world’s fastest marathon in September. However, his aim was to run the marathon in less than 2 hours, a record he missed by 25 seconds. During this race, it rained heavily, which left his shoes, Nike’s Zoom VaporFly Elite running shoes, developed in collaboration with athletes, soaking wet and heavy.

The aim of the Flyprint project was to develop shoes of which the uppers wouldn’t absorb water, keeping them light even when the weather is humid. The design process begins by collecting data from athletes, including their running gait and foot’s form. This data is then put into software to create the correct composition of the material, so the printer knows where to layer up and where to create a lighter weave. This creates a personalised shoe, which can be manufactured 16 times quicker than previous manufacturing methods.

The 3D printed fabric is made from thermoplastic polyurethane (TPU) filament, a material known for its elasticity, transparency and resistance to abrasion and liquids. The textile has the advantage that there is no frictional resistance like what happens between the interlaced yarns in knit or woven textile. The material is more breathable and lighter than previously used textiles, making the shoe is 6 per cent lighter than the Zoom Vaporfly Elite model.

In terms of design pace, the advantage of Flyprint method in traditional textiles is two-fold: Specific lines of the material can be adjusted locally while preserving the global construction, and rapid iteration means testing and revision cycle times are trimmed significantly.

The textile also works seamlessly with many other materials, most notably Nike’s Flyknit yarns, to provide an optimal balance of fit and structure. In fact, Flyknit yarns can be engineered to thermally bond with the Flyprint textile, eliminating any need for glue or stitching.

Photos: Nike