SDSU Researchers Develop Graphene Sensors to Track Corn Growth
Wearable plant bands record stalk and ear expansion every ten minutes to help agronomists time fertilizer treatments.
A new agricultural invention developed at South Dakota State University tracks the diameter of cornstalks and ears in real time. Assistant professor Mazhar Sher and graduate student Chamika Kuruppuarachchi built wearable plant bands that take readings every ten minutes to measure crop response to fertilizer. The university team plans to file for a patent on the system ahead of planned field trials.
Graphene strips and spring-loaded silicone bands
The devices rely on laser-induced graphene mounted to a flexible, food-grade silicone band, as reported by Phys.org. When a cornstalk or ear expands, the graphene bends, altering its electrical properties to measure physical growth without damaging the crop. To avoid choking the plant as it thickens, inventor Mazhar Sher integrated a spring mechanism into the band that lets the structure stretch continuously while keeping the sensor in direct contact with the tissue.
Refining the material inside the laboratory
Laser-induced graphene dates back to work at Rice University in 2014, where scientists converted commercial polyimide sheets into porous carbon using a carbon dioxide laser, according to Phys.org. The base plastic sheets cost less than one dollar. At South Dakota State University, former doctoral student Sikander Ameer worked from August 2022 until December 2025 to optimize the laser power and scanning speed, reducing defects in the carbon lattice to increase measurement sensitivity.
Logging greenhouse data every ten minutes
Kuruppuarachchi expanded the hardware at the Raven Precision Agriculture Center, where the prototype tracked corn plants in an indoor greenhouse, as documented by Phys.org. The electronics package runs on battery power and logs stalk and ear growth every 10 minutes to a standard microSD memory card. Sher, who previously worked on human disease sensors at the University of Pennsylvania, confirmed he hopes to patent the sensor configuration as tests advance to protect the intellectual property behind the invention.
Agronomic trials and future field testing
The researchers do not intend to sell the wearable sensors directly to commercial farmers, according to Phys.org. Instead, the system is designed for agronomists and plant breeders who study how specific corn lines respond to nitrogen and water applications. The research team is now seeking additional funding to deploy the sensor bands in outdoor university test plots.
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