Unlike humans, plants can’t just speak up when they’re parched. And unfortunately for them the visual signs of dehydration, such as shrivelled or browning leaves, don’t show up until most of their moisture is gone.
To overcome this communication barrier, nanotechnologists have created a wearable technology for plant leaves that senses and wirelessly transmits data to a smartphone app, reported in a new study in ACS Applied Materials & Interfaces.
The electrodes come in two different patterns to satisfy your plant fashion needs – one made of nickel deposited in a narrow, squiggly shape, and the other cut from partially burnt paper coated in a waxy film, though the nickel-based electrodes perform better.
This plant-wearable technology could help farmers and gardeners to remotely monitor their plants’ health, including leaf water content, which is a key marker of metabolism and drought stress, kind of like how physicians can monitor and assess their patients’ health with a smartwatch.
The researchers created the two types of electrodes and stuck them onto soybean leaves with clear adhesive tape. They found that the nickel electrodes adhered more strongly in the wind (from a fan) – likely because the thin squiggly design of the metallic film allowed more tape to connect with the hairy leaf surface – and also produced larger signals as the leaves dried out.
Next, they a created a plant-wearable device with the nickel electrodes and attached it to a living plant in a greenhouse. As the device shared data to a smartphone app and website, a simple, fast machine-learning technique successfully converted these data to the percentage of water content lost.
The researchers say that monitoring water content on leaves can indirectly provide information on exposure to pests and toxic agents.
Because the plant-wearable technology provides reliable data indoors, they now plan to test the devices in outdoor gardens and crops to determine when plants need to be watered, potentially saving resources, and increasing yields.