Real-Time Soil Moisture Monitoring Using a Graphene Oxide Sensor Powered by a Solar Cell-Based Energy Harvester

In this study, we propose a humidity monitoring system that integrates a solar cell-based energy harvester, a supercapacitor, a sensor interface, and a graphene oxide (GO)-based humidity sensor. The system is characterized by an energy management module that includes the aforementioned components. The GO sensor has demonstrated enhanced performance in detecting humidity and soil moisture levels compared to conventional sensors. Experimental results revealed that soil humidity at specific depths varied from 31 to 50 pF following rainfall events. Owing to the large capacity of the supercapacitor, the system maintained continuous operation even in conditions of limited sunlight. These findings offer significant potential for practical applications in the fields of environmental and agricultural monitoring.