New plant-wearable electronics could help farmers monitor water movement, detect drought stress and improve crop management without damaging delicate plant tissues.
Plant-wearable electronics are emerging as a promising approach to precision agriculture, with researchers developing flexible sensors capable of monitoring plants continuously. The work highlighted by AZo Sensors focuses on a plant-wearable sap-flow sensor, designed to measure internal water movement while remaining attached to growing plants.
The technology addresses a key limitation in conventional crop monitoring: many existing methods provide indirect measurements or require invasive procedures. By monitoring sap flow directly, wearable sensors can provide information about transpiration, water efficiency and the movement of nutrients through the plant.
The reported system uses a thermal-pulse method, in which an eight-second heat pulse produces a local temperature change along the stem. The resulting downstream-to-upstream temperature difference is used to estimate sap flow across a range of 0 to 128 microlitres per minute, with a reported detection limit of 4.4 microlitres per minute.
Performance testing also showed that the sensor could withstand repeated stretching and flexing, 1,000 cycles of water immersion and wind speeds of up to four metres per second. Its kirigami-inspired structure achieved a reported vapour transmission rate of 20.45 milligrams per square millimetre over 10 days.
Thermal spreaders helped reduce relative thermal variation from 26.56% to 15.42%, improving measurement stability. Tests using chlorophyll fluorescence found no detectable physiological stress or growth impairment during the reported monitoring period, while plant tissue remained free of visible necrosis after 15 days of continuous operation.
The researchers also examined drought detection, linking changes in sap velocity with environmental conditions including solar intensity. The findings suggest that plant-wearable electronics could eventually support continuous crop-health monitoring, helping identify water stress earlier while reducing the need for invasive measurements.
