Getting the very best from nature through biomimicry

The invention of Velcro back in 1941—inspired by burrs clinging to a dog’s fur—was one of the earliest examples of a biomimicry-influenced textile development. Since then, product scientists have continued to draw inspiration from the natural world at a micro level.

Spider silk, for example, has long laid claim to being the world’s strongest natural fibre. Its strength is four times that of steel, its elasticity rivals that of nylon, and it can withstand temperatures exceeding 300°C. Spiders, however, have cannibalistic tendencies that make their large-scale breeding for commercial applications extremely difficult.

Scientists in Japan, however, have now discovered a surprising challenger to spider silk—the humble bagworm.

Bagworm silk

Research by Japan’s National Agriculture and Food Research Organization (NARO) and Kowa, a manufacturer of pharmaceuticals and optical equipment that also imports and exports textiles, has discovered that bagworm silk surpasses spider silk in all indicators of durability.

It has approximately 2.3 times greater toughness in terms of its flexibility to withstand deformation without breaking, and about 1.8 times higher tensile strength. This research has already been published in the international scientific journal Nature Communications.

Some 1,000 bagworm species exist worldwide, about 50 of which are found in Japan. The giant bagworm—Eumeta variegata—is the most well-known species in Japan. Bagworms spin their own silk to bind fragments of leaves and twigs to form the nests they wrap themselves in, as well as to hang from branches for protection from predators and to move from place to place.

“Bagworm silk is made of protein, just like silkworm and spider silk,” explains Asanuma Akimune, senior manager of Kowa’s Future Business Development Office. “When we analysed the amino acid sequences that make up the protein, we found that it has a highly ordered hierarchical structure, which is what provides its high strength.

To commercialise this potentially revolutionary natural fibre, Kowa has now established the Kowa Research Laboratories for Advanced Science in Tsukuba City, Ibaraki Prefecture, and commenced joint research with NARO on the artificial breeding of bagworms.

With no bagworm specialists on hand, team members initially spent their time collecting, breeding, and observing bagworm behaviour. The first step towards industrial application came with the discovery of a breeding method that leverages the characteristics of the bagworm lifecycle.

Zig-zag ladders

Whereas silkworms spin silk only for two or three days just before pupation, bagworms begin spinning silk immediately after birth and continue throughout their larval stage.

The team then developed indoor breeding methods and established a system for continuous silk collection.

Bagworms spin zig-zag ladder-like silk threads and use them as scaffolding for their movement. Based on this ‘foothold silk’, Kowa has successfully created ultra-thin nonwoven fabric-like sheets at a rate of up to 1,000 square metres annually.

In November 2024, Kowa successfully commercialised this development for the first time with the launch of its Minolon brand.

The first product to utilise Minolon was a new series of Ezone tennis rackets by sports equipment manufacturer Yonex. Minolon was used in the racket shaft by fusing it with advanced carbon materials. With Minolon’s combination of strength and flexibility, the racket’s vibration damping performance improved by 5.8 per cent compared to conventional products.

“Bagworm silk is made of protein and is biodegradable,” says Asanuma. “Since it is not derived from fossil fuels, there is no risk of it turning into microplastics after disposal or negatively impacting ecosystems. We currently use it in composites with plastic, but if we can eventually produce composites with bioplastics, we should be able to develop products with even lower environmental impact.”

Kowa is currently pursuing low-volume, high-value-added applications that make use of the special properties of bagworm silk. The company anticipates the development of applications in unexplored fields such as aerospace where the fibre’s strength can be employed to maximum effect.

Success with sharkskin

Other natural phenomena such as the lotus leaf’s superhydrophobic surface, for example, have inspired self-cleaning fabrics, while the shark’s skin has significantly influenced drag-reducing swimwear, most notably in driving the success of Speedo.

Bottom of Form

Back in the 1970s, Speedo’s research into hydrodynamics led to the development of swimwear designed to mimic the skin of the shark which culminated in the launch of the Speedo LZR Racer in 2008, developed with input from NASA. The LZR Racer was worn by many athletes during the 2008 Beijing Olympics, contributing to a wave of world records and this success remained undiminished at the Paris Olympics and Paralympics in 2024, when a total of 75 medals were won by athletes using Speedo Fastskin swimsuits, including both world records and Olympic records.

Speedo introduced its Fastskin LZR Intent and LZR Valor swimsuits developed by its Aqualab research and development facility in November 2023. These suits have the lowest water absorption available on the market and are the most durable and water repellent to date, providing a feeling of weightlessness.

Butterfly wings

The optical structure of butterfly wings has spurred developments in dye-free textiles and adaptive display technologies and the colour-changing abilities of cephalopods like squid have further opened doors to adaptive camouflage clothing and bioluminescent fashion.

Omni-Heat Arctic

In other recent developments in this field, Columbia Sportswear’s Omni-Heat Arctic draws inspiration from the polar bear—an animal evolved to survive temperatures as low as –50°C.

Although polar bears appear white, their black skin absorbs solar energy while translucent fur retains warmth. Columbia has replicated this heat-trapping function with a lining made from black yarn that captures solar heat, combined with traditional insulation to maintain both external and internal warmth.

Unlike earlier Omni-Heat technologies that focused on reflecting body heat, Omni-Heat Arctic actively absorbs and stores solar energy, turning garments like the Arctic Crest Down Hooded Jacket into self-warming shells. This development builds on Columbia’s legacy of nature-inspired innovation, including OutDry Extreme’s breathable waterproof outer layer, Omni-Wick’s moisture management system, Omni-Heat Infinity’s heat-reflective gold dots and Omni-Heat Helix’s foam pad warmth-trapping structure.

Design inspiration

Designers also continue to find fascination in the possibilities of bio-inspired new materials.

At July’s Paris Haute Couture Fashion Week AW2025, for example, Iris van Herpen unveiled a groundbreaking bridal gown created in collaboration with biomaterials company Spiber, crafted from Brewed Protein, a lab-engineered fibre inspired by both natural silk and spider silk.

The Brewed Protein materials of Spiber, headquartered in Yamagata, Japan, are produced from plant-derived biomass using a proprietary fermentation process and can be processed into a variety of forms, with examples ranging from delicate filament fibres with a silky sheen to spun yarns that boast features such as cashmere-like softness or the thermal and moisture-wicking properties of wool.

Featuring laser-cut boning, moon-shaped organza panels and cascading coral-like petals, van Herpen’s design embodied a winning blend of scientific innovation and organic elegance.

All of these developments continue to underline the fact that there is still much to be gained from studying the biological forms, functions and ecosystems that have evolved through millions of years of adaptation.

ALCHEMPro News Desk (CG)