Copyright Interesting Engineering
MIT mechanical engineering professor and head of the Atomistic Simulation & Energy (ASE) Research Group, Asegun Henry, has dedicated his career to a defining goal: How to decarbonize the planet without sacrificing reliability. Prior to MIT, Henry taught at Georgia Tech and held postdoctoral positions at Oak Ridge, Northwestern, and the Department of Energy’s ARPA-E. His revolutionary research ranges from atomic-level simulations of heat transport to world-record engineering feats. Among them is a liquid metal pump capable of operating above 1,473 kelvins (1,200 degrees Celsius). This innovation earned him a Guinness World Record in 2017. Then, in 2022, he and his collaborators were recognized in Physics World’s Top 10 Breakthroughs for developing a new thermophotovoltaic (TPV) cell that achieved a record efficiency of over 40 percent. In this conversation with Interesting Engineering, the Robert N. Noyce Career Development Professor discusses his journey, his vision for clean energy, and why decarbonization demands urgent investment. Interesting Engineering: What sparked your interest in mechanical engineering? Asegun Henry: “I started out as a civil engineering major. I was fortunate to have Makola Abdullah, PhD, as a mentor in the Rites of Passage program. He was also an engineering professor at FAMU [Florida A&M University]. He really set my career on its trajectory when he allowed me to work with some of the graduate students in his lab. That summer, I was studying how buildings shake and vibrate during earthquakes and simulating the phenomenon on a computer. At the end of the experience, I realized that a good chunk of civil engineering is about keeping things from moving. I thought vibration and movement were interesting. IE: What about heat transfer? I remember talking to a friend in college who told me that thermodynamics and heat transfer, or as we call it thermal fluids, were so hard you should just try to get a B and get out. I ended up enjoying the class. There was also a particular question I had in thermal fluids, which was: What is temperature? The generic answer is that temperature is a measure of the average kinetic energy of the atoms. But if it was energy, then why doesn’t it have units of energy? So that’s what drove me to heat transfer – the connection between vibration, understanding temperature, and how sound and heat, I hypothesize might be somehow related. IE: Looking back, were there any experiences that shaped the way you think about science? I wanted to be an entrepreneur, and I realized that becoming a professor was the best path to get there. And if I wanted to be a professor, I needed a PhD. One of the key names that kept coming up at the time was professor Gang Chen, PhD, from MIT. I reached out to him, and after applying for the MIT Summer Research Program, he became, my primary mentor. He really cemented in me the idea that questioning whether something is done right is always a good thing. IE: Your path has taken you from Florida A&M to MIT, Georgia Tech, and even ARPA-E. How did each stage shape the kind of engineer you are today? MIT probably had the biggest single impact. The kind of environment that exists at MIT is pretty unique. When I left, I spent time doing a postdoc at Oak Ridge National Lab, then I was at Northwestern, and later at the Department of Energy. After that, I joined Georgia Tech. Seeing all these other places made me realize how much being at MIT had shaped the way I think. IE: You’ve worked on everything from phonon transport to solar fuels. What unites your approach across such different fields? Alright, I have to give some credit here to ARPA-E. I spent some time in the Department of Energy at ARPA-E before starting as a Georgia Tech professor. I was an ARPA-E fellow. Part of my job was essentially to serve as a bit of a think tank within the Department of Energy for new areas that we should be looking to develop. There was a term we used to refer to as ‘white space,’ meaning the areas where no one has written or explored anything yet. It programmed me to start thinking that way. When I encountered new problems, I would immediately try to find the white space. IE: Your all-ceramic liquid metal pump earned a place in the Guinness Book of World Records. What sparked the idea? From a thermodynamic perspective, the hotter the heat can be, the more you can do with it. And that’s just basic thermodynamics – it all comes down to the fundamental nature of entropy. I realized that the reason we’re limited in temperature has everything to do with practical material limitations. We were using metal, nickel alloys and iron alloys that melt at 1,500 degrees Celsius [2,732 degrees Fahrenheit], yet we didn’t even utilize them above 800 degrees Celsius [1,472 degrees Fahrenheit]. Then I started exploring what else was out there and began looking into ceramics. These materials can go beyond 2,000 degrees Celsius [3,632 Celsius]. There wasn’t a great reason why we weren’t using them. Naturally, there were some challenges, but they seemed very navigable. IE: What was that moment like when you realized you’d broken a world record. What does it mean for the future of energy technology? I’d liken it to one of those sports movies where a team fights to win the championship, and finally does. Because these things don’t happen overnight. They involve numerous trials, numerous failures along the path to success, and numerous setbacks. I have very distinct memories of my students and the team wanting to quit because the pump wasn’t working and kept breaking. However, securing Nature‘s acceptance was the crown jewel. The Guinness World Record followed, and we timed that as well, and you know the rest is history. IE: Your work aims to mitigate climate change. Which technology from your research do you believe could make the biggest near-term difference? I think the technology that would make the biggest difference is the one that we are working on now at my company Fourth Power. About 70 percent of all CO2 emissions come from three sectors: electricity, transportation and industry. One of the most practical and achievable paths to decarbonization is starting with the grid. And then electrify those other two sectors so that they run off the grid. But what’s stopping us from doing that today isn’t just an economic issue – it’s the lack of a viable storage technology. Energy storage will enable renewables to replace fossil fuels truly. And if or when we solve that problem, it will trigger the key cascade that will allow us to mitigate 70 percent of CO2 emissions. IE: What do you think is the biggest bottleneck slowing the adoption of high-temperature energy systems? Money. If you look at the challenge we are up against with climate change, and the level or urgency and scale that we have to reach, this problem is so large that it deserves a Manhattan Project-level response. The fate of humanity is at stake. If we had unlimited funds at our disposal, we could move much faster. But we’re not willing to spend even a billion dollars to get the best technology that could save us, let alone the tens of trillions it would truly take. The problem right now is not treated as something that governments need to invest to save the human species. It’s treated as an opportunity for someone to make money. IE: What core belief or mental model guides the way you approach difficult engineering problems? The belief I’ve had ever since I was a kid is that something I do will have a major impact on Earth. Perhaps you’re born with it, or your parents pass it on to you, or it develops from a particular experience. IE: What’s the next big question you want your research to answer? I’m actually nearing a point where most of the scientific questions I care about for now are largely solved. But there are certain technologies that I’m looking to develop, prototype and commercialize. One of them is methane pyrolysis, and we’re looking to demonstrate and commercialize it in the coming years. There’s another one that’s in stealth, but is very exciting. And there’s a third technology, which is a refrigeration concept. IE: What advice would you give young engineers who want to work at the intersection of fundamental science and real-world energy systems? Look for the white space. Push the boundaries of everything to its extremes, to try to shake out what’s possible. And don’t be afraid or hesitant to commit your entire life to an idea. It may take decades or an entire lifetime, so prepare yourself for it.
