On October 12, MIT mechanical engineering alumnus Vishnu Jayaprakash SM ’19, PhD ’22 was named first in the graduate category of the University Inventor Competition. An annual competition organized by the National Inventors Hall of Fame to honor college student inventors. Jayaprakash was awarded for his pesticide innovation, AgZen-Cloak, which he developed while a student in the laboratory of mechanical engineering professor Kripa Varanasi.
Currently, only 2% of pesticides are sprayed on crops. Many crops are naturally water repellent, causing pesticide-laden water to bounce off them. Farmers are forced to overspray massively to ensure proper spray coverage of crops. Not only is this a waste of expensive pesticides, but it also comes at an environmental cost.
Runoff from the pesticide treatment polluted the soil and nearby streams. Droplets can become airborne, causing illness and death in nearby people. Pesticide contamination is estimated to cause 20,000 to 200,000 deaths and up to 385 million acute illnesses including cancer, birth defects and neurological disorders each year.
With his invention, AgZen-Cloak, Jayaprakash found a way to prevent pesticide-laden water droplets from bouncing off crops by “hiding” the droplets in a small amount of vegetable oil. As a result, farmers only need to use one-fifth the amount they spray, minimizing water waste and costs to farmers, and eliminating air pollution and toxic runoff. It can also improve the retention of pesticides, thereby improving crop yields.
“By covering each droplet with tiny amounts of vegetable oil, we can promote water retention on even the most hydrophobic plant surfaces,” said Jayaprakash. “AgZen-Cloak provides a versatile, inexpensive and environmentally sustainable way to protect against pesticides.” Overused and wasted.”
Agriculture is in Jayaprakash’s DNA. His family runs a 10-acre farm near Chennai, India, where they grow rice and mangoes. After joining the Varanasi research group as a graduate student, Jayaprakash was immediately attracted to Varanasi’s work on agricultural pesticides.
“Growing up, I sprayed crops on the family farm with a knapsack sprayer on my back. So I always wanted to do research that would make life easier for farmers,” says Jayaprakash, CEO of start-up AgZen.
Helps droplets stick
Varanasi and his lab at MIT work on so-called interfacial phenomena — or the study of what happens when different phases touch and interact with each other. Understanding how a liquid interacts with a solid or how a liquid reacts with a certain gas has endless applications, which explains the diversity of research conducted in Varanasi over the years. He and his team have developed solutions for everything from consumer product packaging to power plant emissions.
In 2009, Varanasi gave a speech at the United States Department of Agriculture (USDA). There, he learned from the U.S. Department of Agriculture just how big of a problem the runoff from pesticide spraying is for farmers around the world.
He, with the help of then graduate student Maher Damak SM ’15, PhD ’18, applied their work on interfacial phenomena to pesticide sprays. Over the next few years, the Varanasi research group developed a technique that uses charged polymers to prevent droplets from bouncing off hydrophobic surfaces. When droplets containing positively and negatively charged additives meet, their surface chemistry allows them to stick to plant surfaces.
Using polyelectrolytes, the researchers were able to reduce the amount of spray needed for cover crops by a factor of ten in the lab. This prompted Varanasi Research Group to conduct three-year field trials with various commercial growers around the world, where they were able to demonstrate significant savings for farmers.
“We’ve had fantastic feedback from farmers on our technology. We’re really excited to change the paradigm of farming. Not only is it good for the environment, but we’ve heard from farmers that they love it. If we can reinvest the money farm, it will help the whole society,” Varanasi added.
In response to positive feedback, Varanasi and Jayaprakash co-founded startup AgZen in 2020.
While testing their polyelectrolyte technology in the field, Varanasi and Jayaprakash came up with an idea to explore using entirely plant-based materials to help farmers achieve the same savings.
Invisible Droplets and Engineered Nozzles
Jayaprakash found that by wrapping a small amount of vegetable oil around a water droplet, the water droplet clings to plant surfaces that would normally repel water. After conducting several studies in the lab, he discovered that oil only needs to make up 0.1% of the total volume of the droplets to adhere to the crop and provide full, even coverage.
While his stealth solution worked in the lab, Jayaprakash knew that to have a tangible impact in the real world, he needed to find an easy, low-cost way for farmers to apply pesticide spray droplets in oil .
Jayaprakash focuses on the nozzle. He developed a proprietary nozzle that coats each droplet with a small amount of oil as it forms. Nozzles can be easily added to any hose or agricultural equipment.
“What we’ve done is figured out a clever way to hide these droplets by using a very small amount of oil on the outside of each droplet. Because of this, we get a significant performance increase, which is really good for farmers. can be a game changer,” Jayaprakash said.
AgZen-Cloak solves a second problem in addition to improving pesticide retention in crops. Farmers have traditionally sprayed pesticides in tiny mist-like droplets because large droplets can easily break up and bounce off crops. These tiny water droplets are often carried by the wind, exacerbating pesticide pollution in nearby areas.
When using AgZen-Cloak, the insecticide-laden droplets are larger and still stick to the crop. These larger droplets are not carried by the wind, reducing the risk of contamination and minimizing the health impact on the local population.
“We’re actually solving two problems with one solution. With stealth technology, we can spray larger droplets that are less likely to drift with the wind and stick to plants,” adds Jayaprakash.
Bringing AgZen-Cloaks to Farmers Around the World
This spring, Varanasi encouraged Jayaprakash to submit the AgZen-Cloak to a competition for university inventors. Out of hundreds of applications, Jayaprakash was one of 25 student inventors selected as finalists.
On Oct. 12, Jayaprakash demonstrated his technology to a jury of National Inventors Hall of Fame inductees and USPTO officials. Meeting with such a group of brilliant inventors and officials impressed Jayaprakash.
“These are people who invent things that change the world. So getting their feedback on what we’re doing is really valuable,” he said. Jayaprakash received a $10,000 prize for winning the first prize.
As AgZen’s full-time CEO, Jayaprakash is shifting focus to field testing and commercialization. He and the AgZen team have conducted field tests around the world, including at Prosecco vineyards outside Venice, a ranch in California and Ward’s Berry Farm in Sharon, Massachusetts. The Vegetable Extension Program at the University of Massachusetts Amherst, led by program director Susan Scheufele, recently completed a field test to validate AgZen’s performance in the field.
Two days after winning the University Inventor Competition, Jayaprakash has been named the first prize winner in the World Food Day student video competition at MIT’s Abdul Latif Jameel Water and Food Systems Laboratory. A few hours later, he was flying across the country to an agtech conference in California, eager to meet farmers and discuss plans to bring AgZen’s innovations to farms everywhere.