Biodegradable shoes made from mushrooms, chicken feathers

Washington: Scientists have created biodegradable shoes using mushrooms, chicken feathers and textile waste, paving the way for more sustainable fashion. The researchers from University of Delaware (UD) in the US created a bio-composite material - sourced sustainably from common regional products - that forms the sole of their prototype shoe. "The fashion industry produces a lot of waste, so sustainability is an issue everyone is trying to address," said Jillian Silverman, master's degree student at UD. 

"It's hard to believe that people are going to change their consumption habits, but with this shoe, when someone gets tired of it or it wears out, it can go into the compost pile and not the landfill," said Silverman. The project began in 2015, when researchers made fabric from mushroom mycelium, the interlocking root system from which the part of the mushroom that we eat on our pizza grows. 

The researchers then experimented with growing different species of mushrooms and using different materials, known as substrates, in which the mycelium forms its network of roots. They grew numerous samples, dried them and tested them for potential use as the sole of a shoe. The nutrients in which the samples grew included chicken feathers and a textile waste product that is most often used as a packing material. 

The team hopes to experiment in the future with discarded natural-fibre clothing, perhaps shredding it to create a fluffy addition to the feathers as a growth medium. "The chicken feathers and the textile products provide the nutrients for the mycelium, and they also are a supporting material for it to grow in. 

They act like a kind of glue to form a matrix and create a network structure for the mycelium," said Huantian Cao, professor at UD. Using textile waste from discarded clothing fits with another sustainability project that UD's fashion and apparel studies department has taken on. 

Once the mycelium samples grown by the research team were tested and analysed for the best species and composition, work began on a prototype shoe. Mycelium was grown in a soft mold in the shape of a sole, so that no waste was generated from cutting it into that shape, said Cao. The team used a type of vegan "leather" to cover the sole and make it more durable. 

Researchers then designed and made the top of the shoe, using discarded scraps from the muslin fabric that apparel design students use in the clothing they create. She used a sewing technique called smocking, in which she gathered the fabric to give it bulk and shape. "I used vegetable dyes and 100 percent cotton thread. 

The design looks like mushrooms look when they're stacked, and everything is completely biodegradable," said Wing Tang, undergraduate student at UD. More work remains on moving from a prototype to a potentially marketable shoe, but the team is optimistic.