Advanced Materials · 2025 · DOI: 10.1002/adma.202418464

Living Fiber Dispersions from Mycelium as a New Sustainable Platform for Advanced Materials

Sinha · Greca · Kummer · Wobill · Reyes · Fischer · Campioni · Nyström | Empa / ETH Zürich

Researchers at Empa and ETH Zürich have developed a new class of living material made from fungal mycelium — grown, mechanically dispersed, and harnessed to create smart materials that can self-strengthen, self-waterproof, and even biodegrade other materials at end-of-life.

3.6×Slower emulsion
phase separation

119 MPaPeak tensile
strength

152°Water contact angle
after growth

Explore

The Challenge

Beyond Static Biopolymers

Biopolymeric fibers like cellulose are excellent raw materials — but making them "smart" typically requires unsustainable chemical modifications. Meanwhile, engineered living materials are dynamic and adaptive, yet weak and difficult to scale.

This paper proposes a third path: living fiber dispersions (LFD) from the fungus Schizophyllum commune, combining the processability of classical fiber suspensions with the dynamic self-modifying behavior of living organisms — and without any genetic engineering.

Figure 1

Fabrication

From Bioreactor to Living Material

Liquid-shaken cultures of S. commune produce entangled mycelium networks over 7 days. These are passed through a three-roll mill, disentangling the fibers into a well-dispersed, viscous gel — the living fiber dispersion (LFD).

The LFD platform bridges two worlds: the excellent network-forming and scaling properties of biopolymeric fiber processing, and the dynamic, adaptive properties of living materials — including stable emulsions, tunable films, and smart substrate modification.

4× faster growth in stirred vs.
static cultures

Figure 1: LFD fabrication and material overview

Fig. 1 — Overview of LFD production and the palette of living materials it enables: emulsions, films, and smart surfaces.

Step by Step

Four Steps to a Living Material

🍄

Liquid Culture

Wild-type S. commune (strain H-48a) is grown in shaken liquid bioreactors at 30 °C for 7 days, producing an entangled mycelium network rich in ECM.

⚙️

Three-Roll Milling

The collected mycelium passes through a three-roll mill in two passes (1400→700 µm then 400→200 µm gaps), disentangling fungal fibers into a viscous gel-like living dispersion.

🌱

Living Growth

The LFD retains full viability. Under humidity or media, fungi continue growing — consuming their own ECM and secreting hydrophobins to continuously modify material properties.

🧪

Material Casting

The LFD is cast into films, emulsions, or foams. Drying conditions — humidity level, covered vs. open, duration — tune the final mechanical and functional behavior.

Figure 2

Finding 1

Living Emulsions: Stability Through Growth

LFD acts as an all-in-one living emulsifier. Hydrophobins coat oil droplets while schizophyllan (SPG) provides viscosity. At concentrations of 1–2 wt%, emulsions remain stable for over 25 days across a wide temperature range.

Crucially, as fungi grow within an unstable emulsion, they secrete more hydrophobins — making the emulsion progressively more stable over time, without any added nutrients. The fungi feed on their own extracellular matrix.

3.6× slower phase separation
after 15 days of growth

Fig. 2 — LFD-stabilized emulsions: vial photographs, AFM images of SPG-hydrophobin complexes, and phase separation kinetics before and after fungal growth.

Figure 3

Finding 2

Living Films: Tunable Mechanics

Thin (~30 µm), transparent, flexible films are cast from diluted LFD under ambient conditions. Growth for 3 days before drying forms a coating of aerial hyphae, transforming the surface from moderately hydrophobic (WCA 83°) to superhydrophobic (WCA 152°).

Mechanical properties span an extraordinary range: from brittle acrylic-like behavior at low humidity to tough, extensible PVDF-like behavior at high humidity. A simple wet-drawing step yields a record tensile strength for pure mycelium films.

119 MPa peak strength (wet-drawn);
3× prior mycelium films

Fig. 3 — LFD films: translucent and flexible base films; water contact angle vs. growth; stress-strain curves across growth conditions and humidity levels; comparison to commercial thermoplastics.

Mechanical Data

Film Properties at a Glance

LFD films can be tuned across a remarkably wide performance envelope using only growth duration, humidity, and wet-drawing — no chemical additives required.

Film Condition	Tensile Strength	Strain at Break	Behavior
As-cast (ambient drying)	~40 MPa	~26%	Flexible film
3-day growth, then dried	~50 MPa	~13%	Stiffer thermoplastic
Growth at 80% RH during drying	67.6 MPa	15%	Conventional plastic
Wet-drawn + aligned	119 MPa	6.1%	Engineering plastic
Tested at 30% RH	74 MPa	5.1%	Brittle (acrylic-like)
Tested at 50% RH	67 MPa	15%	Standard plastic
Tested at 70% RH	42 MPa	46%	Tough (PVDF-like)

Figure 4

Finding 3

Smart Properties: Actuation, Patterning & Degradation

Films respond instantly to humidity — bending 90° in just 5 seconds when near a human hand, exceeding the speed and curvature of nanocellulose-based actuators. Repeated humidity cycles progressively stiffen the film through fiber alignment.

Directed fungal growth selectively waterproofs adjacent substrates, forming zigzag hydrophobic highways between film patches. Placed on paper, the same films act as biodegraders — actively colonizing and weakening the substrate over 21 days, enabling a biological end-of-life pathway.

5 sec to 90° bending from
~20% RH difference

Fig. 4 — Smart properties: humidity actuation sequence; mechanosorptive stiffening; directed superhydrophobic patterning; paper degradation over 21 days; 3D-molded edible LFD foams.

Significance

A New Kind of Living Material

What makes this work distinctive is the convergence of two previously separate fields: the mature pulp-and-paper industry's fiber processing infrastructure, and the emerging world of engineered living materials. By treating mycelium the way industry treats cellulose — dispersing it mechanically and processing it at scale — the researchers unlock living functionalities that neither field could achieve alone.

The result is a material that doesn't just exist statically, but continues to evolve after fabrication — strengthening itself, repelling water, communicating with neighboring colonies, and decomposing at end-of-life. No genetic modification needed. No toxic cross-linkers. Just fungi, water, and a mill.

Read Full Paper → DOI: 10.1002/adma.202418464