Susannah Cox

Susannah Cox is almost apologetic about her path to becoming a scientist. There was no sudden epiphany, and she became interested in chemistry only as an undergraduate. When you grow up in a small town in Indiana, “you don’t really know what a chemist does,” she says.

But talk to her some more, and it becomes clear that she was always curious about the world and driven to make it a better place. She recalls how her parents—particularly her mother, a schoolteacher—encouraged her love of learning. “One of my early memories is of me sitting on the kitchen counter, and we’re talking about which component in the banana bread is the most white,” she recalls. “I think I could say the word albumen at, like, 3.”

Cox is now applying her curiosity and drive at the agrochemical firm Corteva Agriscience, where she is a formulation chemist. Her work involves determining the right combination of ingredients to make a stable product that will work in a controlled and reproducible manner. But Cox is also focused on improving the sustainability of Corteva’s products and processes and curbing their environmental impact.

There are strong parallels between her work in formulation development and her early cookery experiences, she says. Scaling up an agrochemical manufacturing process might have unintended effects on the product, for example, just as doubling a baking recipe to fit into a larger pan might produce a sad and soggy cake. And if chemists want to adjust an agrochemical formulation, they need to consider what role an ingredient fulfills so they can identify the best replacement, the same way a baker would approach making a gluten-free version of their cake. “It’s important to consider the broader picture,” Cox says.

Cox joined Corteva in 2019 after completing her PhD in organometallic chemistry at Purdue University. “She was one of the best graduate students in my group,” says her former PhD supervisor, Tong Ren, “and a real intellectual driver” who mentored others in the lab and beyond.

She scored an early win at Corteva by replacing microplastics in a specific solid formulation of a pesticide product. Her improvement is going through the regulatory process before it can make its way to farmers. “It’s very exciting for an early-career research scientist,” says her boss at Corteva, Hui Shao.

Less than 2 years after Cox joined the company, Shao took a chance and promoted the young researcher to a leadership position. He says it was one of his best decisions: Cox has the technical leadership and the people management ability to get projects done. “She is one of the top talents, with this unique combination of leadership skills,” he says.

Cox now leads the development of high-throughput experimentation (HTE) for formulation development. HTE uses automation to run multiple experiments in parallel, using very small volumes of material in microwell plates. That approach enables Cox to rapidly test a large number of slightly different recipes for her formulations, and it offers big improvements in sustainability. HTE means that rather than asking her synthetic chemistry colleagues to make a few grams of a particular compound for testing, she can use one-tenth the amount, which saves resources and reduces waste.

The challenge lies in designing experiments to give useful answers, Cox says. Lab-based formulation chemists have a variety of ways to monitor changes in the formulation. Cox is rethinking how to collect and analyze data to automate formulation development and characterization.

Shao hopes that these data could eventually be used by machine learning or artificial intelligence systems that propose recipes from a set of formulation requirements. Or algorithms could determine which samples to screen on the basis of the results from previous screening rounds.

When Cox first interviewed for her job at Corteva, she was excited to learn that there was more to formulation science than she’d realized. “I definitely still use my background knowledge here and there, but I’ve definitely pivoted to learning more about robotics and programming,” she says. “My one constant is I just like to dive into that new thing.”