Distinguished Member of Technical Staff at Sandia National Laboratories
Q: You have had a long career in chemical engineering research. Who were your role models growing up that helped lead you into your profession?
A: I was born in Berkeley because my dad was going to graduate school in mechanical engineering at UC Berkeley. I was raised with the idea of being an engineer or maybe being a scientist. It was always in the back of my mind. I originally was thinking about being a chemist. I was really interested in chemistry and Dr. Teller from College Prep was very inspiring as a chemistry teacher. I talked to him about going into chemistry and he said, “If you don’t go to graduate school, it’s probably better to be a chemical engineer because with the Bachelor’s degree there are better opportunities and more interesting jobs.” So thanks to Dr. Teller, I ended up choosing chemical engineering without really knowing too much about it when I started at UC Berkeley.
Q: When you went to UC Berkeley, were there a lot of women in that major?
A: No, at Berkeley in Chemical Engineering, it was very lonely. I was used to having a lot of female friendships in high school and then suddenly I felt alone. At first, I didn’t think I loved my major. Some of the early chemical engineering classes are really boring. I was used to physics, chemistry, calculus, and subjects that seemed more rigorous, but I did learn to love chemical engineering. I loved transport phenomena and the physics of it, and the underlying math and partial differential equations.
Q: Your research focus has been the computational fluid mechanics of complex fluid. Can you explain that to us?
A: I had a great conversation with my kids about this recently. If you understand the flow of water coming out of the shower it’s very easy to understand, relatively speaking. It follows a linear kind of principle and we know what it will do. But have you ever tried to get ketchup out of a bottle? Do we know what it’s going to do? Do we know if it’s going to even come out? No, we don’t. We squeeze on it. We shake it a little bit. It doesn’t move. Ketchup has a yield stress, meaning that you kind of have to push on it to start it moving. It’s like toothpaste. It can be non-linear; it can also be transient. It’s the idea of looking at conservation of mass and momentum, and conservation of energy in the form of equations. We call it colorful fluid dynamics because you can make movies of transient phenomena that show the stresses and the temperature field—it makes for exciting visualizations.
Q: What is a real-world problem that is being addressed through your research?
A: I have a project with industry right now looking at ways of distributing consumer products like shampoos, conditioners, and cleaning products without plastic bottles, transported just in compostable boxes. This is a whole new product line where there is no water and it’s a solid product where you add your water at home to make your own foamy shampoo. You can apply it yourself or you make your own cleaning product on the spot by adding water. This saves in transportation costs because you’re not paying to ship the water and it saves energy. It also reduces the amount of plastic waste in the world. That’s one of my exciting projects and we’re trying to optimize the process.
Q: Through your work you have addressed critical national security problems in energy-production processes. What would you say is the most pressing issue you’re facing in the field at present?
A: In the past I’ve worked on proppant placement to try to improve recovery from shale oil fields for natural gas recovery because companies were drilling anyhow and we want to make sure as much gas is removed as possible. I’ve also worked on batteries and nuclear energy. For the future, I’m very invested in this idea of renewables. Sandia has had big programs with renewable energy since the seventies and the gas crisis. We have a huge amount of work going on in batteries and in storage. With renewables, you have issues of how do you store it when it’s only made during the day, and what are you going to do at night? I still think that nuclear energy has a place in a diversified portfolio with more small reactors that could be safer. So renewable energy, nuclear energy, battery storage, and a diversified energy portfolio—I think all of these things are where we’re going to manage climate change.
Q: Can you talk about your research in nuclear accidents and nuclear waste and some of your findings?
A: Because energy security is national security, in research you have to address accidents and waste disposal. The nuclear regulatory agency uses a nuclear safety code developed at Sandia. It can model nuclear reactor accidents, and look at different scenarios for what would happen and predict outcomes depending on the design and other things. One team had the idea to use sacrificial materials to try to mitigate reactor accidents like the one that happened in Fukushima. Using sacrificial material, such as calcium carbonate from seashells and having this ground up on the floor below the reactor could provide a type of barrier to the reaction with the concrete and water. Upon heating calcium carbonate, it will decompose into calcium, oxide, and carbon dioxide. Then it’s an endothermic reaction, so it absorbs all that heat. We’re quenching the flow and we’re also producing carbon dioxide, which will offset any hydrogen—two different ways of preventing the escape and loss of containment of the nuclear waste. There’s still not a good national strategy for managing nuclear waste. Thirty years later, no one’s done anything other than store waste onsite.
Q: You have advocated extensively for women in research. What are the challenges women face and what is the crucial aspect of your advocacy?
A: When I started at Sandia, 5% of the technical staff members were female and now we’re up to 23% of the staff. It’s a lot harder for women to get promoted. We founded a Women in Research Symposium to try to help women on the technical ladder and we’ve had senior scientists, which is one of the highest technical levels attainable, come and give talks. We’ve had some female vice presidents share their career paths to getting promoted, being successful, and having visible research careers. I think that’s been really powerful, especially for early career staff, because they can see how they can advocate for themselves and build a successful career. As women, we end up taking longer to get our PhDs or tenure because we’re still primary caregivers, comparatively. We still do more of the housework. We still are the ones who take off for maternity leave. I am the first female officer of the US Association of Computational Mechanics and I’ll be the first woman president in 2024. The main reason I got there is because other women voted for me. Women who had been going to my events about mentoring and networking. I assumed they voted for me because we hadn’t ever had a woman at this level before and what is exciting is I saw the ballot for the new set of candidates for the executive committee and it’s more female dominant—that’s impressive. Seeing me there has helped to break the glass ceiling.
Q: What are your memories of math and science at
College Prep? Did any other courses have an impact on you?
A: I loved math and science at College Prep. I remember taking geometry in tenth grade and my teacher was very supportive of me and encouraging. She told me how good at math I was and recommended me for the accelerated math class so I got to take AP Calculus as a senior. I loved Chemistry and Biology, too. I liked the humanities and as an engineer, I had very few humanities classes in college. I learned so much about writing from Dr. Cohen. We were packed with the engineering, math, and science classes so it was nice that I had that humanities experience to fall back on from my high school education.
Q: What advice would you give young women today who want to get into chemical engineering and research?
A: I’ve spent years where I was the only woman in the room and the only woman of color also in many rooms. The advice I give is: Work on raising your hand, even if you don’t want to. You can work on your confidence, don’t doubt yourself, believe in yourself. Believe that you’re smart, that you belong there, that you have value. Volunteer for the extra lab work or go meet your professors, try to create relationships with them as you go through your college career and that will be important if you decide you want to go to graduate school and have a research career. For future researchers or future chemical engineers, develop a support system, find those mentors. Also, mentor people yourself. Help bring women up alongside you.