Weaving a web for the future - Canadian researchers make film from spider silk

Anyone who has walked into a spider’s web knows how tear-resistant the silken thread of a spider is – once you’ve become tangled in the cobweb, it isn’t easy to free yourself from its thin, delicate threads. Spider silk is incredibly tear-resistant and elastic in order to enable spiders to catch their prey.

The Canadian researchers at Cambridge University noticed these amazing properties and started to wonder whether they could mimic them in order to use them in packaging materials. It all started with research into proteins. Yusuf Hamied of the Department of Chemistry investigates what happens if proteins fold incorrectly, and how this is related to conditions such as Alzheimer’s disease. Here, he discovered the positive properties of spider silk: “It was a real surprise to find out that we could also address a big sustainability issue with our research,” comments Tuomas Knowles, who led the research.

The result was a polymer film that mimics the structure of elastic spider silk. The researchers used soya proteins to achieve this. To ensure that the film was also presented to the general public, the University of Cambridge founded the spin-off Xampla with the objective of further developing and marketing this discovery. With this discovery, the researchers have found more than just an alternative to single-use plastic and microplastic. This polymer film is as durable as the plastics that are already widely used in the market and could therefore replace them, particularly for household products.

Before this happens, an alternative made from this spider silk still needs to be rendered ready for the market, and Xampla is up to the task. Up until this point, the company has been testing the first sustainable film packaging for dishwasher tablets.

On the path to creating a marketable product, the researchers specifically focused on the positive properties of sticky spider silk. “Within the scope of our protein research, we were also interested in looking at why materials such as spider silk are so strong even though they have such weak molecular bonds,” explains Dr. Marc Rodriguez Garcia, who was previously a postdoctoral researcher in Knowles’ group and is now Head of the Research and Development Department at Xampla.

Again, the actual research into the properties of proteins was put to use, as the order of the proteins can be controlled – therefore, they can be made to mimic the structure of the spider silk proteins. A further sustainable advantage of plant proteins also became clear: They can be sourced sustainably as by-products of the food industry and are available in abundance.

The film made of vegan spider silk can even keep up with high-performance plastics. Technically speaking, it is similar to low-density polyethylene (LDPE) and also provides the important barrier properties that this plastic manifests: the oxygen and grease barrier properties are amazing. In terms of its reactions to moisture, vegan spider silk is comparable to conventional bioplastics. A further benefit: The polymer film can be produced on an industrial scale and is designed as a drop-in solution. However, the research isn't stopping there. Currently, the vegan spider silk is being tested for manufacturing waterproof coatings.

Vegan spider silk sets itself apart as a very sustainable packaging alternative because it can be composted at home, and this is an important factor in environmental protection. Maybe a few real spiders will get in on the composting action and show us the amazing properties of spider silk live!