Stomatal Transpiration Monitoring using a Wearable Leaf Sensor

In this work, we demonstrate, for the first time, a direct approach for transpiration monitoring using a simple screen-printed flexible paper sensor. Filter paper acts as an excellent sensing material and provides a change in capacitance owing to change in its dielectric constant with moisture absorption and desorption. We measure the transient response of the sensor and accordingly define an appropriate sampling to monitor the transpiration by measuring capacitance over a period of time. The low cost flexible paper-based sensor provides a simple, efficient, and smart way to monitor transpiration.