Scientists and innovators are working towards creating a new generation of silk fabrics that can match the textile’s positive attributes without harming the environment, according to the latest report from the Material Innovation Initiative (MII).

“Fashion designers love to use silk,” said Thomaine Dolan Dow, director of materials innovation and design at MII. “It’s one of the most luxurious and ancient textile fibres, and silk’s smooth, continuous filament gives silk yarn unique properties such as strength, elasticity, and resistance to pilling.”

The dark side of silk

Environmental impact assessments of silk production indicate that mulberry farming and silk processing are energy- and water-intensive and have a high global warming contribution.

Moreover, the silk industry’s supply chains lack transparency and accountability. Employees in many silk processing plants work long hours with little pay. Child and bonded labour are used in some factories, particularly in India, where they have minimal health and safety standards.

“The silk industry accelerates climate change and environmental degradation, relies on inhumane and unsustainable animal agricultural practices, and offers few protections for workers in processing plants,” adds Dow.

The most common method for extracting silk involves boiling worms alive in their cocoons. An alternate method of producing silk that is promoted as humane is the “Ahimsa” method; while the worms aren’t directly killed to make silk using this method, moths are crushed in mixers and discarded after mating. 

Meanwhile, synthetic alternatives to silk, like polyester and nylon, contain microplastics that accumulate and persist in ecosystems for hundreds of years.

Next generation of sustainable silk

However, innovators are working towards creating sustainable alternatives to synthetic silk materials.

“We’re already seeing some promising innovation in this area,” added Nicole Rawling, CEO and co-founder of MII. “Our goal with this report is to inspire a new generation of scientists and entrepreneurs to develop high-performance, luxurious, and sustainable next-gen silk materials.”

Australia’s Nanollose has developed a textile called Nullarbor. It is made from bio-waste like coconut water from the F&B industry and processed via fermentation.

Fermentation, typically associated with vinegar and kombucha, is also used to extract proteins from microorganisms. These organisms are fed nutrients like sugars or starches to grow, and the fermentation happens inside a bioreactor. After fermentation, the protein is extracted, dried into pellets, melted down, and spun into filament fibre.

Nullarbor fibre and fabrics behave like lyocells but are significantly stronger than traditional lyocells from trees. It can also be hand or machine-washed.

Scientists have also been studying the genetic potential of tiny arachnids and ocean molluscs for decades. These creatures have special proteins with incredible versatility and strength, which can be used in various applications, including producing silk filament fibre.

Researchers have also discovered that plants make excellent hosts for growing silk proteins. This process involves encoding silk genes in plants, which are then harvested and processed to extract the silk proteins. These proteins can then be transformed into silk filament fibre.

Bamboo is another versatile plant that has proven its worth. When treated with non-toxic chemicals, it produces a soft and fine fibre that can be easily coloured and naturally performs.

Scientists have also found a way to capture CO2, even from textile plants, and convert it into filament cellulosic lyocell by treating it with special enzymes.

Sustainable silk’s potential 

“Silk innovation is a great opportunity for early next-gen innovators to produce comparatively large amounts of silk fabrics,” said the report. “The smaller global production of silk makes it easier for innovators to scale production and meet the demands of the fashion industry.”

With ongoing developments in sustainable silk, the fashion industry has the potential to reduce its carbon footprint and contribute to a more sustainable future.

The complete list of next-gen silk material innovators is available in MII’s 2023 Silk Report.