Walking through her lab, Lea Winter points to a contraption resting on the counter, featuring a slim glass tube wrapped in a coil. A lightning bolt shoots through the device. It looks like a cool desk toy, but it has the potential to play a big role in the future of renewable energy.
Winter's lab is taking on a complex and important challenge: Reimagining how we produce useful materials from carbon dioxide and nitrogen from the air or nontraditional water sources. Doing so could go a long way toward reducing and adapting to climate change. Typically, the chemical processes used to produce these materials have been activated by heat from burning fossil fuels. Winter, who places her research at the nexus of food, energy, water, and climate, is instead leveraging electron-driven processes such as plasma and electrochemistry.
"We are moving towards an electrified, renewable energy future, where we have all these energy sources that are driven by electrons and electricity-based sources like solar and wind," said Winter, assistant professor of chemical & environmental engineering. "So we are thinking about how we can make fertilizers, fuels, water, and various types of chemicals that we use through processes that are driven by electrons and don't rely on fossil fuels."
Winter's research team designs catalysts and membranes to control these processes. One of her go-to tools is plasma, often referred to as the fourth state of matter. It's an ionized gas made of electrically charged particles -- it's what lightning is made of. In her lab, they create it with a high-voltage electrode and a ground electrode to generate an electric field. "So you have electrons and ions and radicals and photons and all of these reactive species in your gas mixture."
With the particular type of plasma they're using, nonthermal plasma, the electrons are much smaller than the rest of the gas molecules. They move quickly, effectively at thousands of degrees Kelvin. The gas molecules, though, move much slower and stay at room temperature.
"This means that we can do reactions at room temperature in a gas phase by using these hot electrons to activate our reactants and do subsequent reactions."
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Winter has been on the Yale faculty since 2022, but her Yale and New Haven roots go much deeper:
"My dad grew up here. His parents originally moved here since my grandfather was a metallurgist, and I guess there was a lot of metallurgy going on in New Haven about 75 years ago. My dad ended up coming back here for his Ph.D. at Yale. He was in Applied Physics working with (Mechanical Engineering & Materials Science professors) Marshall Long and Mitchell Smooke, both of whom I took classes from when I was an undergrad. So my family's been in New Haven for three generations now."
When she was a senior at Wilbur Cross High School, Winter asked a volunteer from Teach for America about the reaction of two chemicals during an AP chemistry class. Unsure of the answer, the teacher told Winter to conduct her own experiments to find out for sure.
"That sparked in me this idea that you could figure out how to ask the right questions and design your own experiments to find the answer to how things work."
And that led to her designing her own research project, in which she synthesized her own chemicals, and entering the New Haven Science Fair. She also took part in a program that allowed students to take classes at Yale. She contacted Prof. Anjelica Gonzalez about taking her course Biotechnology in the Developing World. Gonzalez, who was teaching the course for the first time that year, was impressed by the student's initiative.
"Lea had reached out to ask if I would admit a high school student -- and because, one -- I wasn't even sure I would have any interest from Yale students and -- two -- Lea is tenacious and persistent, I said yes," said Gonzalez, professor of biomedical engineering. "And it was one of the best decisions I ever made."
As Gonzalez recalls, Winter did all the readings, asked questions, and led discussions. She challenged ideas presented in the class, pressed for more information on specific technologies -- "AS A HIGH SCHOOL STUDENT!" Gonzalez wrote in an email.
"She is a thoughtful individual who was a superstar even then. I was lucky to have her as a student in that class ... I learned as much from her as she might have from me."
And for Winter, it was a pivotal point in her academic career.
"That's where I really started to learn about all these challenges that exist, both in the developing and the developed world for access to health care," she said. "And I started to realize that a big reason why so many people were sick was that they didn't have access to enough nutrition or clean water, leading to all these waterborne illnesses."
Climate change also figured into this, she said. In situations of extreme heat or lack of electricity, there needs to be a way to keep vaccines viable.
After high school, she received her B.S. in Chemical Engineering at Yale, and then her Ph.D. in Chemical Engineering at Columbia. From there, she served as a NEWT Distinguished Postdoctoral Fellow at Yale in the lab of Menachem Elimelech, the Sterling Professor of Chemical and Environmental Engineering. That's when she began researching electrified membranes for the transformation of nitrate in wastewater.
"Meny's group specializes in membranes and water treatment," she said. "This was something that I was really excited about and had always cared about -- that had really been sparked during my time as an undergrad at Yale."
Conventional membranes separate contaminants from water supplies, but don't break them down.
"So you've been able to clean your water, but you're left with this concentrated waste stream that ends up back out in the environment, usually where it's going to go back to contaminating groundwater that's used for drinking," she said.
The electrified membranes that her lab develops, though, can transform these contaminants into a harmless by-product like nitrogen, or useful materials like ammonia.
"I thought 'What if we take conductive materials and catalysts and put them into water treatment membranes, and then we can get all of these new advantages,'" she said. "And there were some people in Meny's group who were also thinking about the same ideas at the same time. So it was a really good time to come here to start to work on these systems and figure out how they work and how to make them."
Growing up in New Haven, Winter showed an early interest in science and how things work. She dug for fossils in her backyard, disassembled and reassembled pens, read and re-read her favorite picture book on the La Brea Tar Pits.
"I enjoy tinkering and problem-solving, and I've always been fascinated with understanding how things work," she said. "When I got older, I realized that I wanted to apply science and engineering to safeguard people, animals, and the environment. I was inspired to find ways to use fundamental chemistry and physics to design environmentally responsible technologies that prevent illness by improving access to clean water, reliable energy, and food, while maintaining a clean and safe environment."