Microelectrode array measurements of fungal mycelium reveal growth-associated electrical activity

Abstract Fungal bioelectricity has promising potential for biosensing in engineered living materials, but its nature remains unclear. We use a custom microelectrode array to record the extracellular electrical activity of mycelium, along with optical tracking and impedance measurements. Measurements across three mycelial growth experiments, along with a sterile control and biocide treatment, show that spontaneous signals coincide with mycelial growth. The signals contained transient spikes with rate and amplitude distributions dependent on growth. The measurements revealed distinct rise-and-fall patterns of electrical activity as mycelium overgrew the electrodes. These results establish an initial basis for future studies and living-material applications.