Self-powered and plant-wearable hydrogel as LED power supply and sensor for promoting and monitoring plant growth in smart farming

Significant energy is consumed to produce the highest-yielding agriculture, which increases greenhouse gas emission and leads to climate change. Smart farming is expected to allow to enhance efficiency and sustainability via site-specific monitoring and managing of crops. This study is a first of its kind development of versatile double-network hydrogel that can serve as: 1) a clean energy harvesting device for self-powered light fertilizer for plants, 2) a supercapacitor for energy storage, 3) plant growth sensor, and 4) an ammonia sensor. Polyacrylic acid double-networked with the conductive nanofiller reduced graphene oxide and then coated with polyaniline are incorporated with double networking (PAA-RGO-PANI, PRP) that significant improved mechanical stress from 300 KPa to 1050Kpa. The excellent stretchability (650%) and strength makes it suitable for agriculture-purposed plant-wearable senor that satisfies the plant growth. The electrical performance of the triboelectric energy harvester (PRP-TENG) provides high power density at 424 mW/m2 from sound wave, wind, and mechanic pressure. The PAA-RGO-PANI supercapacitor can maintain a stable capacitance at 2330 mF cm−2 after 5000 cycles. The self-powered system combined with PRP-TENG and supercapacitor shows great potential in modern agriculture system.