Plant Tattoo Sensors to Compile Microenvironment DataImagine real-time water sensors, pulling instantaneous water consumption data directly from the cannabis crop. The future isn’t as far away as one might think, at least according to new research published in the December 2017 issue of Advanced Materials Technologies.
Thanks to the work of scientists out of Iowa State University, 'tattooing' plants with a wearable sensor is within the industry's grasp. They have developed graphene-based nanomaterials, which can be easily patterned and then taped to a variety of surfaces. Some of the areas they have already explored for future applications of this technology are monitoring flexible mechanical sensors and sensor arrays, wearable technology for humans, and plant leaf sensors.
The authors termed the agricultural application of their nano-thin sensor a “plant tattoo sensor.” The sensors are made out of graphene oxide film, which lays on top of a pre-cut honeycomb pattern. Surprisingly enough, the researchers used something as familiar as Scotch tape to transfer the now fully customized sensor pattern to an applicable surface, like the underside of a leaf.
Photo of "plant tattoo sensors" is courtesy of Liang Dong.
Graphene oxide is a single, atom-thick, layer of graphite which easily conducts both heat and electricity. When it encounters water, even in the form of water vapor, the conductivity of the graphene oxide will suddenly shift.
This characteristic has made it effective at capturing water transpiration data from plants as they pull water from their roots and into their leaves. Importantly, according to the authors, the sensors are small enough that they do not affect the overall growth of the plant.
Applications Within the Cannabis Industry
The trajectory of the cannabis industry only continues to grow. But with this unforeseen growth, comes unforeseen concerns regarding the industry's water consumption. Cannabis is one of the thirstiest cash crops on the planet, sucking up an estimated 22 liters of water a day in outdoor grow operations. A grapevine, one of the most comparable cash crops, uses only 12 liters a day. Water conservation in cannabis is of major concern for farmers, neighboring communities, and regulators.
There are already cloud technologies available, built specifically for the cannabis industry, which use atmospheric and soil sensors to predict cannabis water consumption. However, many in the industry are predicting that a plant-based technology, the plant tattoo sensor, could revolutionize water conversation in both indoor and outdoor marijuana operations.
The researchers from the study hope that through accurate, plant-based (instead of soil or atmosphere based) data on water consumption, farmers will eventually succeed in breeding strains with lower water requirements. For the cannabis industry, in particular, this could have wide-reaching trickle-down effects for the environment, and for the farmer's bottom line.
Cost Savings with Plant Tattoo Sensors
Part of the selling point for these tiny plant-based nano-thin sensors, is their relatively low cost. Especially when compared against the standard sensors used across the sector today, relying on a graphene oxide strip of tape could drastically reduce the overall cost of data collection.
According to one of the lead authors of the study, Liang Dong, “You just use tape to manufacture these sensors. The cost is just cents.” A standard indoor cloud-based sensor system can never hope to come that cheap. Theoretically, a grower could invest in a sensor per plant, to compile microenvironment data on water consumption across their facility.
Beyond the water conservation opportunities presented by direct plant-based sensors, and the expected low cost of implementation to these sensors, down the line the data could lead to new less-thirsty strains of marijuana. If cannabis growers can use the technology to predict the water consumption of their harvest, they just might be able to use it to breed out the thirstiest plants in their crop. Over time, new hardier plants could become the norm, saving operations thousands of dollars over the lifespan of harvest in hydro bills.
The Next Steps for Plant Tattoo Sensors
Dong, alongside William Frankenberger and Patrick Snable, co-authors of the original paper, will team up to lead a newly funded study into these innovative wearable plant sensors. The group recently received a grant from the U.S. Department of Agriculture as well as the Food Research Initiative to take these sensors into the cornfields of Iowa. The grant, worth close to half a million dollars will investigate water consumption of corn plants, in the field.