Architectural Self-Assembled Fungal Mycelium for Nanofluidic Ion Regulation.

Abstract

Conventional nanofluidic platforms rarely achieve the simultaneous combination of ion regulation, structural tunability, and scalable fabrication. Here, we demonstrate using fungal mycelium as a self-grown morphology-adaptable nanofluidic medium. Leveraging the natural growth of blue oyster mycelium, we directly fabricate 1D twisted fibers, 2D membranes, and 3D foams─without chemical modification─through simple lyophilization and mechanical shaping. These architectures preserve interconnected hyphal nanochannels with a naturally negative surface charge (-1.85 to -2.77 mC m^-2, tunable via growth time), enabling stable ionic conductivities of 0.2-0.5 mS cm^-1 in dilute potassium chloride (KCl) electrolyte (<1 × 10^-3 mol L^-1), several orders of magnitude above bulk values. Distinct from inorganic and polymeric analogues, the mycelium-based nanofluidic material system is shape-adaptable, flexible, biocompatible, and environmentally benign, offering a scalable pathway to green shape-adaptable ionic devices. By uniting intrinsic biological architectures with engineering control, this work establishes fungal mycelium as an emerging platform for next-generation nanofluidics.