Biovegan Leather Sensor: A Mycelium Functionalized Material for Electrophysiological Signal Monitoring

Electrode patches are becoming increasingly vital in the fields of wearable electronics and physiological health monitoring. However, the nondegradable nature and complex functionalization process of traditional dry electrodes limit their widespread use. In contrast, mycelium-based biovegan leather offers an ideal alternative for flexible electrodes, providing benefits such as biodegradability and ease of preparation. To overcome the mechanical performance and stability challenges inherent in pure mycelium, this study develops a mycelium–polypyrrole composite material (P-MCM) that demonstrates reliable mechanical and electrical properties, making it suitable for the daily monitoring of human electrophysiological signals. The P-MCM exhibits a tensile strength of 3 MPa, an elongation at break of 13%, a conductivity of 51.10 S/m, and an interface impedance of 52.6 kΩ/cm2 for the electrode–skin system at 10 Hz. The low interface impedance of P-MCM electrodes allows for the stable acquisition of electrocardiogram, electromyogram, and electroencephalogram signals with performance on par with commercial electrodes. It is expected that this work will provide valuable insights and foundational materials for the advancement of flexible electrodes.