Conformable Ferrimagnetic Tattoo Electrodes for Plant Electrophysiology

ABSTRACT Increasing global food demand and environmental stress call for technologies enabling continuous plant monitoring in precision agriculture. Electrical signals generated by plants during stress responses provide valuable information. However, their recording remains challenging, as conventional silver/silver chloride (Ag/AgCl) electrodes require gel electrolytes to interface with plant tissues, limiting mechanical stability. Here, we report conformable ferrimagnetic tattoo electrodes for minimally invasive recording of plant electrophysiology. The electrodes are based on a PEDOT:PSS ink spray‐coated onto tattoo carrier paper to form free‐standing electrodes. They adhere to plant leaves via van der Waals forces and remain attached for several days. Their performance was evaluated in Arabidopsis thaliana and Solanum lycopersicum (tomato). In both, the recordings of wound‐activated surface potentials were comparable to those of conventional Ag/AgCl electrodes. The incorporation of ferrimagnetic particles enables magnetic coupling to the acquisition system, reducing mechanical stress and allowing repeatable electrical connections. This approach enables seamless monitoring of signal propagation and supports on‐demand recordings. Importantly, electrophysiological measurements were successfully performed outside a Faraday cage, demonstrating robustness under realistic conditions. These conformable ferrimagnetic tattoo electrodes provide a scalable and adaptable interface for plant electrophysiology and open new opportunities for studying plant stress signaling and developing sensing technologies for precision agriculture.