Rubber, commonly used for shoe soles, is non-biodegradable and difficult to recycle, while some companies explore eco-friendly alternatives these are often costly and not widely accessible.

With this in mind the group had the task of exploring cost-effective, durable materials that would substitute these conventional shoe sole materials

Japanese knotweed, an invasive species in Europe, as a viable solution. Repurposing this abundant plant into bio-engineered materials, could turn this ecological challenge into a sustainable design opportunity.

Developing the material involved testing various recipes and combinations, as knotweed alone didn't meet the criteria. The final product is a hard, wood-like composite made from all-natural ingredients. It is scratch-resistant, waterproof, and machinable like conventional wood

Shoes as a starting point.

knotweed composite samples

3 point bending test

sample creation

The knotweed composite was developed and tested as a potential shoe sole material.

Physical and computational analyses assessed its durability under daily use, while public surveys evaluated its appeal, including texture, color, and smell.

Although the prototype, named Weed Walkers, proved too stiff and hard for shoe soles, the project successfully introduced a new bio-material with promising applications in construction, decoration, among other potential opportunities.

Suitable for a shoe sole?

concept for a shoe with knotweed sole

SolidWorks FEA analysis of knotweed made sole

knotweed mixture to plaster mold