A microneedle-based Leaf Patch with IoT Integration for Real-time Monitoring of Salinity Stress in Plants

This work reports a novel microneedle-based leaf patch for real-time monitoring of sap pH levels, which is an early indicator of stress levels in plants. The leaf patch was interfaced with a data acquisition and processing unit to develop a low-cost, portable and field-deployable sap pH monitoring system. We demonstrated the application of this system in early detection and monitoring of the dynamics of soil salinity stress in a live cabbage plant.