Scientists invent electronic plant tattoos to tell when they're thirsty

Imagine being able to tell if a houseplant is thirsty, if a farmer's crops need watering, or if a forest is at risk from a wildfire. All by just checking a stick on tattoo - well that's what a team of scientists have invented.

Researchers from The University of Texas in the US have created a tiny electronic tattoo which can be stuck onto the leaves of plants without damaging them.

The tattoos are made from a flexible and sustainable material called graphene, which connects to a computer to track water levels in the plant.

The researchers say that previously tests to figure out a plant's water levels would have to be gathered by cutting off branches or leaves at different times of the day.

"Instead of having to send people out at all different times of day, we can collect data nearly instantaneously in critical periods like early morning and late afternoon, or on a hot windy day so we can see how it responds to that environmental signal,"

said Ashley Matheny, an associate professor in the Jackson School of Geosciences' Department of Earth and Planetary Sciences.

"We're able to gather so much more information than what our current technology can, and in a much easier way." they said.

"Being able to directly measure and monitor the live leaf over time, at the point of photosynthesis, gives us more information to understand the health of our plant ecosystems, whether that's an individual plant or an entire forest," said Jean Anne Incorvia, one of the leaders on the new research, who works at Cockrell School of Engineering's Chandra Family Department of Electrical and Computer Engineering.

The invention works by sending a small jolt of electricity from the tattoo into the leaf.

This then causes ions - tiny atoms with an electrical charge - within the leaves, to move toward, or away from the tattoo, depending on if it is positivly or negativly charged.

From this the scientists can then work out the plant's hydration levels.

The researchers hope that the technology can be used to help predict wildfires, and even improve the amount of crops farmers are able to be produce.