Electronic circuits reveal when a plant begins to experience drought conditions.
Forgot to water that plant on your desk again? It may soon be able to send out an SOS.
MIT engineers have created sensors that can be printed onto plant leaves and reveal when the plants are experiencing a water shortage. This kind of technology could not only save neglected houseplants but, more importantly, give farmers an early warning when their crops are in danger, says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and the senior author of the new study.
“This appears to be the earliest indicator of drought that we have for agricultural applications,” Strano says. “It’s hard to get this information any other way. You can put sensors into the soil, or you can do satellite imaging and mapping, but you never really know what a particular plant is detecting as the water potential.”
Strano has already begun working with a large agricultural producer to develop these sensors for use on crops, and he believes that the technology could also be useful to gardeners and urban farmers. It may also help researchers develop new ways to engineer drought-resistant plants, he says.
Volodymyr Koman, an MIT postdoc, is the lead author of the paper, which appears in the Nov. 8 online edition of the journal Lab on a Chip.
MIT chemical engineers have developed a sensor that detects the opening and closing of plant stomata. (Image: Volodymyr Koman/MIT Chemical Engineering)
When soil dries out, plants slow down their growth, reduce photosynthetic activity, and suffer damage to their tissues. Some plants begin to wilt, but others show no visible signs of trouble until they have already experienced significant harm.
The new MIT sensor takes advantage of plants’ stomata — small pores in the surface of a leaf that allow water to evaporate. As water evaporates from the leaf, water pressure in the plant falls, allowing it to draw water up from the soil through a process called transpiration.
Plant biologists know that stomata open when exposed to light and close in darkness, but the dynamics of this opening and closing have been little studied because there hasn’t been a good way to directly measure them in real time.
“People already knew that stomata respond to light, to carbon dioxide concentration, to drought, but now we have been able to monitor it continuously,” Koman says. “Previous methods were unable to produce this kind of information.”
To create their sensor, the MIT researchers used an ink made of carbon nanotubes — tiny hollow tubes of carbon that conduct electricity — dissolved in an organic compound called sodium dodecyl sulfate, which does not damage the stomata. This ink can be printed across a pore to create an electronic circuit. When the pore is closed, the circuit is intact and the current can be measured by connecting the circuit to a device called a multimeter. When the pore opens, the circuit is broken and the current stops flowing, allowing the researchers to measure, very precisely, when a single pore is open or closed.
By measuring this opening and closing over a few days, under normal and dry conditions, the researchers found that they can detect, within two days, when a plant is experiencing water stress. They found that it takes stomata about seven minutes to open after light exposure and 53 minutes to close when darkness falls, but these responses change during dry conditions. When the plants are deprived of water, the researchers found that stomata take an average of 25 minutes to open, while the amount of time for the stomata to close falls to 45 minutes.
“This work is exciting because it opens up the possibility of directly printing electronics onto plant life for long-term monitoring of plant physiological responses to environmental factors, such as drought,” says Michael McAlpine, an associate professor of mechanical engineering at the University of Minnesota, who was not involved in the research.
For this study, the researchers tested the sensors on a plant called the peace lily, which they chose in part because it has large stomata. To apply the ink to the leaves, the researchers created a printing mold with a microfluidic channel. When the mold is placed on a leaf, ink flowing through the channel is deposited onto the leaf surface.
The MIT team is now working on a new way to apply the electronic circuits by simply placing a sticker on the leaf surface. In addition to large-scale agricultural producers, gardeners and urban farmers may be interested in such a device, the researchers propose.
“It could have big implications for farming, especially with climate change, where you will have water shortages and changes in environmental temperatures,” Koman says.
In related work, Strano’s lab is exploring the possibility of creating arrays of these sensors that could be used to detect light and capture images, much like a camera.
The Latest on: Drought sensors
Southwest and High Plains fire conditions 'extreme to historic'
on April 18, 2018 at 11:20 am
The U.S. Drought Monitor says the region is in “exceptional” drought. All this has led to an explosive growth of wildfires across the Southwest and central and southern High Plains. Now a renewed blast of dust-filled blowing winds has raised the fire ... […]
Local, statewide burn bans extended and expanded
on April 17, 2018 at 3:24 pm
according to the U.S. Drought Monitor report released April 12. Alfalfa, Major, Woods, Woodward and part of Grant counties also are listed in extreme drought or exceptional drought, the worst category. The rest of Garfield County, along with Kingfisher ... […]
Drought in a rainforest? It's happening in Alaska
on April 17, 2018 at 2:35 pm
Image courtesy United States Drought Monitor. While drought conditions have improved somewhat through March for much of the state, the Alaska Panhandle - stretching south along the coast of British Columbia - remains classified as 'abnormally dry' to ... […]
Southwest fire threat called ‘extreme to historic’ amid brutally hot and dry conditions
on April 17, 2018 at 12:25 pm
The vegetation is bone dry, and the U.S. Drought Monitor says the region is in “exceptional” drought. All of this is stoking wildfires that ignited late last week and increasing the chances of new fires. “A particularly dangerous situation is ... […]
Cattle Market Struggles as Drought Lingers
on April 16, 2018 at 8:17 am
Extreme and exceptional drought has spread across Texas, Oklahoma, Kansas and Colorado, according to the U.S. Drought Monitor in Lincoln, Nebraska. It’s been that way for around six months, and doesn’t show signs of improving. Amid the dryness ... […]
Highest drought intensity returns to Arizona
on April 16, 2018 at 6:13 am
As of late last week, the US Drought Monitor shows over 90% of the state is in severe drought status. Nearly half of Arizona is under extreme drought, including all of Santa Cruz County & portions of Pima and Cochise Counties. Even more troubling ... […]
Dreading more drought in Southwestern US
on April 11, 2018 at 5:16 am
according to the U.S. Drought Monitor. Similar conditions are prevalent in much of the Southwest. “Drought conditions in Arizona are pretty rough as we enter into our normally dry spring,” said Michael Crimmins of the University of Arizona’s ... […]
T&D Region in severe drought; recent rains help
on April 9, 2018 at 9:48 pm
according to the United States Drought Monitor. The lack of rain hasn’t stopped farmers, though. And recent rains are helping. "Growers have been able to do field work," Orangeburg County Clemson Extension Agent Jonathan Croft said. He said the severe ... […]
Feds add more drought designations in Colorado as state snowpack sits at 66% of normal
on April 6, 2018 at 12:54 pm
Nearly 24 percent of the state is under extreme drought conditions, according to the latest U.S. Drought Monitor data. The worst drought in Colorado is seen in the southern and southwest portions of the state. But the Drought Monitor shows that 90 percent ... […]
Drought Expands, Exceptionally Dry Conditions Creep Closer To Colorado
on April 5, 2018 at 2:19 pm
DENVER (CBS4) – The latest update from the U.S. Drought Monitor shows that extreme drought conditions continue to expand across Colorado, up almost 4 percent in a week. The driest conditions can be found on the southeast plains, in the San Luis Valley ... […]
via Google News and Bing News