Galvanic Cell Enables Copper Reuse and Energy Harvesting for Sustainable Plant Micronutrient Delivery with Potential Wireless Sensor Network Applications

[EN] Recent advances in circular economy strategies have accelerated the development of low-cost electrochemical systems for energy harvesting, and resource reutilization in intelligent Wireless Sensor Networks (WSNs). This study proposes a zinc¿copper (Zn¿Cu) galvanic cell platform for copper reuse and evaluates the residual solution as a potential sustainable plant micronutrient source within a conceptual framework for edge-enabled precision agriculture. A five-cell Zn¿Cu galvanic assembly was electrochemically characterized, producing a cumulative open-circuit voltage of 5.286 V (~1.10 V per cell), consistent with theoretical redox behavior. The system (180.6 g total mass) exhibited a specific power and specific energy of 0.0114 W kg¿1 and 0.0114 Wh kg¿1, respectively, indicating its potential as a low-power energy source for future WSN and edge-computing applications. The residual copper solution was diluted and applied to Rosmarinus officinalis at graded concentrations. Image-based phenotyping revealed a concentration-dependent response, with the 50 mg L¿1 treatment producing the strongest improvement in vegetation indices, including excess green index, vegetative index difference, normalized green-red difference index, triangular greenness index, and color index of vegetation extraction. Multivariate analysis confirmed clear treatment separation driven primarily by spectral traits. Overall, the results demonstrate that the residual copper-containing electrolyte solution left after galvanic cell operation might serve as a potential micronutrient source, while highlighting the prospective integration of galvanic energy harvesting into future intelligent WSN-based precision agriculture systems.