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

Abstract Functional biopolymeric fibers are key building blocks for developing sustainable materials within the growing bioeconomy. However, their flexible use in emerging advanced materials with smart properties typically requires processing methods that may compromise sustainability. Here, a sustainable route to generate living fiber dispersions (LFD) from mycelium that combines the excellent material‐forming properties of biopolymeric fibers, and the highly dynamic properties of living materials is proposed. This is showcased by using industrially available liquid culture and mechanical defibrillation methods to generate well‐dispersed living mycelium fibers. These fibers can form materials where precursors with good dispersibility and network formation properties are paramount and can harness dynamic properties through growth even in the absence of added nutrients. This is demonstrated in unique living emulsions with 3.6x slower phase separation and in living films with 2.5x higher tensile strength upon growth, the latter vastly outperforming the strongest pure mycelium materials to date. Further, humidity can be used to modulate mechanical properties and to trigger the superhydrophobic patterning of substrates, mechanical actuation, and degradation of lignocellulosic consumer goods at their end of life. In the future, combining synthetic biology with this promising platform for smart materials can expand the horizons for sustainable material manufacturing.