A wearable and breathable sensor based on gradient porous electrodes for real-time leaf moisture monitoring

Abstract

The real-time monitoring of plant physiological status is essential for precision and postharvest agriculture. Although wearable plant sensors have been used in leaf moisture and growth monitoring, the breathability and biocompatibility of such sensors still need to be improved. Herein, we propose a wearable and breathable sensor based on a thin electrode with gradient porous structure to realize real-time monitoring of leaf moisture. The wearable electrode can be conformably attached to the leaf surface forming a capacitance-based sensor to measure the leaf moisture content. The gradient porous electrode offers a good water vapor permeability of 51.98 g h⁻¹ m⁻², which is much higher than the value of natural leaf (20 g h⁻¹ m⁻²). Moreover, a wireless system enables continuous real-time moisture monitoring and the electrode achieves high-quality leaf moisture monitoring with non-damage to plants for 30 days wearing. This work indicates a new strategy for developing efficient and robust wearable sensor for real-time monitoring of plant physiological information.