Flywire

Nike Flywire is a thread, composed of Vectran or nylon, and developed by Nike, used in the upper of a shoe. The goal of Flywire is to minimize weight and maximize support. Shoes containing Flywire became available for consumer purchase in 2008.

Flywire was created by Jay Meschter, Director of Innovation at Nike. He began by taking a last (an object shaped like a foot used to design shoes) and marking the key points of where a shoe needs to support the foot. When Meschter saw an embroidery machine, he determined the machine could be used to make long stitches. Long stitches, containing strong, lightweight fibers, would allow fibers to support the foot in key points, instead of using layers of material that support the whole foot.

The goal of the design is to help and support the foot using the lightest and strongest material possible, Vectran. The Flywire design (threads placed in key parts of the upper) prevents the foot from slipping when running. Flywire is also a minimalist idea (the idea that items should only contain necessities), since the upper only contains the fundamental features. This allows the maximum amount of energy to be moved forward each stride.

Nike adapts Vectran fibers, which are produced by Kuraray, into embroidery threads, before use in the shoe. Vectran fibers are thinner than human hair, and relatively inexpensive. Vectran is lightweight, flexible, and high in tensile strength, the stress at which material deforms (five times stronger than steel), which makes it an ideal component for synthetic fibers. Vectran has also been used by NASA and in bicycle tires, among other things. .

Nike designed Flywire with inspiration from a suspension bridge, where many cables provide support. This allows support to be placed where necessary, especially in the forefoot (metatarsus and toes) and heel. The cables are designed to wrap around the foot like tendons. Since the support does not come from layers of material, the shoe is also more flexible. The only layers of material on the shoe are in place to prevent dirt and rocks from reaching the foot.

...
Wikipedia