(Nanowerk Spotlight) Synthetic plastics derive their exceptional properties from complex molecular structures—structures that make them both highly useful and environmentally problematic. Creating sustainable alternatives requires materials that offer similar performance without long-term persistence. Living organisms already produce materials with remarkable capabilities: they adapt to environmental conditions, repair damage, and modify their properties over time. But converting living tissue into manufacturable materials while preserving these biological advantages has proven exceptionally difficult.
The field of engineered living materials aims to overcome these challenges by incorporating biological components into material design. In a previous Nanowerk Spotlight (“Engineering sustainable living materials for a greener future”), we have highlighted how integrating living systems with synthetic materials could lead to self-assembling, self-repairing, and environmentally responsive products. This approach takes inspiration from natural systems, where organisms construct functional materials with properties difficult to replicate synthetically.
Aligning with this vision, scientists at Empa and ETH Zürich have developed living fiber dispersions (LFDs)—a new class of materials that retain the ability to grow and adapt while being as processable as conventional fiber-based materials. These materials integrate living fungal mycelium with manufacturing techniques similar to those used for synthetic fibers, producing structures that evolve over time without external nutrient supplementation.
The researchers worked with Schizophyllum commune, a fungus that naturally forms thread-like mycelium networks. Unlike previous approaches that removed the fungus’s extracellular coating, this study preserved the natural proteins and sugar-based polymers that strengthen and stabilize fungal networks. By passing liquid-grown mycelium through industrial-style roller mills, they created well-dispersed fibers while maintaining biological activity.
Functional properties that improve over time
LFDs showed remarkable versatility in different applications. When mixed with oil and water at 1-2% fiber content, they formed highly stable emulsions. Unlike conventional mixtures that separate quickly, these emulsions remained stable for over 25 days. Most strikingly, the living fungi continued producing stabilizing compounds, leading to a 3.6-fold reduction in phase separation over time. This means that instead of breaking down, these emulsions became more stable as the fungi grew—a property that could benefit food, cosmetics, and biomedical applications.
The researchers also produced thin films from LFDs using different processing methods. Films created through wet-drawing alignment reached a tensile strength of 119 MPa, making them stronger than most other pure mycelium materials. They also responded dynamically to humidity. At 30% relative humidity, the films behaved like brittle materials, while at 50%, they softened and stretched more like plastics. At 70% humidity, the films remained strong while elongating up to 46% before breaking.
Fabricating a palette of functional, living materials. A) Production of the living fiber dispersion (LFD) from inoculation to completion. Liquidshaken cultures produced entangled mycelium networks, which were passed through a three-roll mill to yield well-dispersed components in the LFD. B) Creation of living emulsions, stabilized by growth of the mycelium. C) Preparation of living films under various humidity conditions and their new property limits. D) Dynamic properties and potential applications of these materials. (Image: Reprinted with permission from Wiley-VCH Verlag) (click on image to enlarge)
Materials that sense, adapt, and self-repair
One of the most unique properties of these films was their moisture-responsive behavior. When exposed to humidity, they bent rapidly, curving up to 150 degrees in seconds. This ability to change shape in response to environmental conditions suggests potential applications in soft robotics, sensors, and smart textiles.
Another unexpected property emerged when researchers allowed the fungal fibers to grow before drying. This resulted in films with a superhydrophobic surface, repelling water without any chemical treatments. The material achieved a water contact angle of 152 degrees, making it comparable to engineered water-repellent coatings.
LFD films also demonstrated self-repair and biodegradability. When placed on paper and given moisture, the fungi actively broke down the cellulose structure. This natural decomposition suggests a role in sustainable waste management, where materials could not only degrade at the end of their life but also help break down other organic materials.
Future applications
Rather than working against biological processes, this research demonstrates how materials can be designed to harness fungal growth for stability, self-repair, and surface modifications. The ability of fungi to form interconnected networks could be used to create naturally patterned surfaces, hydrophobic coatings, and even living circuits for bio-based electronics.
With further development, these materials could transform packaging, textiles, foams, and structural components. Because the fungal fibers can be grown in liquid bioreactors at scale, the approach aligns with industrial production methods while reducing reliance on petroleum-based materials. As synthetic biology advances, LFDs could be engineered for even more specialized applications, from biodegradable plastics to self-assembling construction materials.
By integrating biological adaptability with traditional fiber-processing methods, this research represents a major step toward materials that not only sustain themselves but also contribute to a circular, regenerative economy.
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