Spider silk could replace elastane: Danish research spins greener threads

One of the last things you would want anywhere near your underwear is a creepy-crawly with eight hairy legs, but researchers at SDU now wish to imitate the spider’s silk and use it to replace elastane in tights and knickers.

A research team at SDU has just received one million Danish kroner from the Novo Nordisk Foundation for the EkoSilk project, which aims to replace elastane – the stretchable, oil-based material found in everything from running tights to underwear – with spider-inspired threads.

These threads are stronger than steel, more elastic than elastane, and completely biodegradable.

“It’s a close collaboration between the Faculty of Engineering and the Faculty of Science at SDU. We are building a factory the size of a postage stamp that can spin a thread without leaving behind a single piece of plastic,” says Associate Professor Jacek Fiutowski from the Mads Clausen Institute at SDU.

Microplastics in the washing machine
Plastic is a keyword here. When we wash our sportswear, socks or running tops, thousands of microscopic plastic fibres are rinsed out into the water. They end up in the oceans, the fish, and ultimately in us.

According to researchers, synthetic textiles account for over 30 per cent of the world’s total microplastic pollution.

Elastane, better known as Spandex or Lycra, is one of the main culprits. It gives clothing its stretch, but it remains in nature for decades after we throw it away. The search for a green alternative has intensified with the EU’s new requirements for sustainable products.

Microplastics are one issue; CO₂ emissions are another. If just one per cent of the global elastane consumption were replaced with spider silk, it would reduce CO₂ emissions by the equivalent of 80,000 transatlantic flights a year.

A chip that can spin like a spider
The EkoSilk project will develop a 3D-printed lab-on-a-chip that can mimic the spider’s silk-spinning process on a microscopic scale.

Inside the chip, liquid silk building blocks are pressed, twisted, and treated exactly as in a spider’s spinning glands – until they leave the machine as ultra-thin, strong threads.

Initially, the researchers will use artificial silk components from a British partner, but the goal is to switch to naturally derived proteins from real spiders.

“The hard part isn’t making the silk. The hard part is making it exactly as nature does – at a scale where we can control the strength and elasticity down to the nanometre,” explains Fiutowski.

To create the lab-on-a-chip, the team is using the Quantum X bio — a bioprinter funded by Novo Nordisk in 2023. This state-of-the-art facility, managed by Associate Professor Francesca Serra from SDU’s Faculty of Science (NAT), combines ultra-high precision with the ability to work with living cells, making it a powerful tool for creating advanced biological materials and systems.

Francesca is also a member of the EkoSilk consortium, contributing her expertise in protein extraction and high-resolution bioprinting to the project’s development. 

The Quantum X bio is a groundbreaking bioprinter that combines ultra-high precision with the ability to work with living cells. In short, it can print living material.

This makes it a powerful tool for research and development of advanced biological materials and systems.

Close collaboration with a clothing manufacturer
The market for artificial spider silk is estimated at nearly USD 8 billion and is growing rapidly. However, where other companies focus on strength, the EkoSilk project focuses on elasticity and sustainability.

“We believe we can deliver something that isn’t just a niche product but can compete directly with elastane – for the benefit of both the environment and consumers,” says Fiutowski.

If all goes to plan, a finished prototype will be ready in a year. The end user for the technology will be Biomimica A/S, also part of the EkoSilk consortium. In the longer term, the industry could replace a significant share of elastane production — making sportswear cleaner, greener, and free of hidden plastic threads.

Fact Box

The EkoSilk project is led by Jacek Fiutowski from the Mads Clausen Institute at SDU, with Casper Kunstmann (also MCI) and Francesca Serra from SDU’s Faculty of Science contributing expertise in microfluidics, protein chemistry, and high-resolution bioprinting.

Commercialisation is driven by Irina Iachina and Eric Rozario at Biomimica A/S, while Chris Holland of the Natural Materials Group at the University of Sheffield provides scientific guidance on silk protein formulation and spinning processes. Together, the team unites research, industrial know-how, and international collaboration to deliver a sustainable, high-performance alternative to elastane.