Welcome back to the Unsung Women’s Project! We’ll be highlighting amazing women in STEM, sharing the stories of all of the incredible, meaningful things women have done in their STEM careers that haven’t gotten the recognition they deserve.
[insert Shirley’s bio]
In your own words, can you describe what your job is?
I am a professor at the Department of Nanoengineering at UC San Diego. I’m basically a materials scientist who is working on research that’s related to materials for energy storage and conversion– things like batteries and solar cells that we need to convert energy between different forms for use. At the same time, I’m also a teacher and a mentor to many young students.
Tell us your origin story– how did your childhood and academic experiences prepare you for what you do?
I was born in a city called Hangzhou, China, which is where Alibaba is now, for people who haven’t heard of it! I was born there, and in 1994, I was fortunate to be selected as one of the scholars to go to Singapore for my undergraduate education. As far as my learning experience in China, the training in mathematics and the sciences was very rigorous, and at that time I was interested in subjects beyond science and engineering. I was good at math and engineering, but I was really interested in law and politics as well. As you know, China is a communist country, so actually I suffered quite a bit during the cultural revolution because of my dad, who was serving in the labor camp for over a decade. I had really hoped that I could contribute to democracy for the progress of China, but unfortunately, my dad thought that I would probably end up in jail. A lot of people tried to recruit me to become a junior party member, but I was unwilling to do that, and in China your career can be seriously affected if you had a dissenting opinion. Because of that, I was very fortunate that Singapore recruited people from China to study engineering or business-related subjects, and I studied materials science and engineering with a minor in business at Nanyang Technological University.
In Singapore, our engineering training was really quite rigorous, and in my second year, we got experience by doing labs every week. I was most fascinated by airplanes, because the metal subject can fly up and down and for long distances, and I was really determined to study airplane structures– where a lot of non-destructive testing methods were used to diagnose the materials and how they might fail, due to degradation or something else. It sounds really unrelated to what I do today, but in fact it’s very much related, because in my battery materials research, I do a lot of diagnosis and characterization of materials used in the batteries. Because the battery is usually enclosed, you need to use advanced techniques like x-rays or neutrons and electrons to probe, since you can’t really see with your eyes what happened.
Then in 2000, the Singapore MIT alliance was built, so a group of scholars from Singapore were very fortunate to go to MIT. At that time, I met my PhD mentor, who is a pure theorist who actually specialized in first principles calculations for materials, and I was one of his first experimental students to really think about how computation can help us design materials, and to accelerate the pace of optimization and the improvement of materials. As far as growing up in my childhood, though, I think that I was always in the spirit of being open to learning something new. Sometimes things work out in your life and sometimes they don’t, but learning is a lifelong experience and practice. I later learned to connect the dots and found out that everything I did was really interconnected, and I really enjoy what I’m doing now!
So is your research mostly on batteries, then, or do you do other things surrounding nanoengineering?
Yes. I think that when people think of working on batteries, they don’t really think about the materials of those batteries, which is what we actually work in– like the black powders inside of the batteries, so a lot of the tools that I developed study how an interface changes when it’s exposed to extreme conditions, like high voltage or high temperature in the batteries. The tools I develop are neutral to any materials. For instance, in solar, like perovskite solar cells, the materials also degrade in the device when it remains under the sun– so we also apply those tools there, and of course you have to make modifications, but those diagnosis tools are useful for optical materials, semiconductors, transistors… We have been applying some of our tools to study these mini transistors, because now the trend is less than twelve nanometers, towards a few nanometers. So for that, you definitely need the nanoengineering nanotechnology to be able to diagnose and see those things, to then manipulate and improve those things.
When I finished my PhD, my thesis was on designing materials to replace the very expensive element called cobalt. It’s a very rare and expensive element and its mining involves a lot of unethical practices in the world right now, so I started working on designing materials that have equivalent good performance, without cobalt.
In your words, what is nanoengineering?
Nanoengineering is really the ability to see and improve things at nano scales– so, exactly what I’m doing! Batteries are just my particular passion because they are a bottleneck for many renewable technologies. A battery itself is not a renewable technology, but this technology is very critical to the future grid and future transportation, which personally I am passionate about, too. My group research activities mostly surround that, but we do have other projects related to magnetic devices and solar cells.
Do you have any stories from when you were younger where you realized this was something that you wanted to do, like an “a-ha moment?” What led you to batteries?
I definitely did have that sort of moment. During my undergraduate year in Singapore, I actually failed to get an internship from Boeing, since like I said, I was very passionate about airplanes and non-destructive testing. I was a bit disappointed, but one of the professors told me that he had a very good project called a superconductive oxide. Superconductivity at that time was a very hot topic, because what superconductive materials do is that once you lower the temperature below a certain critical temperature, you actually get the materials to transport electrons with no resistance. So superconductive oxides were actually what led me through this lifelong study of oxides– some key elements in battery materials are actually oxides. It’s called a lithium transition metal oxide, where of course you need the lithium and you have all the other metal elements like copper, cobalt, nickel or manganese.
When I worked with the superconductive oxides as an undergraduate student, I was not really expecting much, but because of the good mentorship and good teamwork, me and my labmate actually made the superconductive oxides and the first time when we poured the liquid nitrogen on it and the magnetic levitation happened, I was absolutely blown away. I think from that moment I learned that in science, if you do things right, magic can happen. For me, it was a magic moment, and I was just hooked on doing research on oxides. Years later, I was shocked to learn that the battery materials are all transition metal oxides, which is actually how I started my journey. That was a true a-ha moment for me.
It sounds like you had a lot of great mentorship! Can you talk a little bit more about anyone who inspired you growing up?
Yeah, I think this is the reason I became a professor. I was very fortunate in high school and in college, and then at MIT for my graduate studies. I met a lot of good mentors, but I do also want to mention my father. Maybe every daughter says that her inspiration is her father, but I think my father had very unique stories to tell, and he was not a good fit in communist China at all. I think what he really inspires in me is a very strong sense of justice, in that he is unwilling to give up what he thinks is the right thing to do. He also instilled in me a very strong respect for the truth, since when I was very little, when I went to school everyday, I had to say things like, “I love Mao, I love the communist party,” but my dad always told me to not believe what other people tell you. You have to go in search of the truth yourself. This mentorship from my father was very important to me for the rest of my life. In China, the corruption was very, very serious, but my dad was the kind of person who never ever gave up his principles, no matter what happened, even though he had some terrible experiences because he refused to do things that he didn’t agree with. My dad always told me that the respect to the truth and a strong sense of justice are the most important principles as a member of humanity, so he was probably the first and one of the biggest inspirations for me.
Of course, later, a lot of professors also did a wonderful job to teach me how to be a good scientist, but I think before you learn to be a good scientist, you have to learn how to be a good person.
Do you have anyone who inspires you today, professionally or otherwise?
I’m not really the kind of person who has “idols” so to speak, but certain perspectives of people can really inspire. For instance, Bill Gates giving up his fortune to support humanitarian efforts is really inspiring. It might be a little bit of a cliche, but I also really admired Marie Curie growing up; I read her biography when I was very little and I was really fascinated by this female scientist who was able to nail two Nobel peace prizes.
People like Elon Musk are inspiring to me, too, even though he’s done some questionable things lately, but his vision for electric cars is absolutely inspiring. In today’s society, where people are focusing on Facebook and Google I maybe admire Elon Musk more because he actually envisioned something that would make people’s lives better. Obviously this is a fictional example, but I’ve always really liked Tony Stark in the movies because he can always build these amazing things that help people.
Going off of Tony Stark, then, what would you consider to be your “superpower”?
I think I have this personality where I usually don’t take no as an answer. I have had a motto since I was studying at MIT, and it goes, “Nothing is impossible, impossible only takes longer time.” Oftentimes when I encounter difficulties, I think I just think about how important persistency is, and that it’s only natural that if you want to challenge really big questions and big problems, you have setbacks and you need to keep pushing forward.
How do you learn?
I like reading, and you can learn a lot from books, which I did a lot growing up. Nowadays, I learn a lot from my students and my postdocs, and I think of being a professor as the best career because I am constantly getting to interact with people who are younger than me and learning from them. As the age gap becomes bigger and bigger between me and my students, I do see that different generation people have different perspectives, and I’ve learned a lot and I continue to learn a lot from that.
Like I said before, learning is definitely a lifelong experience, and I’m always excited by new things, whether it’s reading or research or anything else. For professors we are very lucky to have sabbatical, where we don’t have to do a lot of teaching or service– we just have to learn! We have to be thinking about how we can stay in the cutting edge of our research and to continue to be leaders in our fields, so I always take that opportunity very seriously. I do a lot of workshops and conferences where I can go and learn, and I have this rule for myself that everyday I must learn one or two new things. That’s kind of what gets me up in the morning and excited for the new day, because I’m going to learn some new things.
What’s the biggest lesson you’ve learned in your career?
Professors who are tenured go through a tenure track process– which is usually five to six years, and it’s kind of like being on professor probation. I think one of the lessons I learned is that professors should be more willing to work on really difficult, tough problems. We become really concerned with securing tenure, so we take less risks so that we can better guarantee a good outcome to our research. If I had to do it again, I would be more risk-taking in my work. For example, I worked a lot on electric car batteries for electric cars, but EEVs are going to be coexisting with combustion engine cars for the rest of our time. A technology like a battery, or even energy storage for electronics around wind and solar energy could be so much more important. For example, sodium or magnesium batteries instead of lithium batteries– because lithium is not that abundant– could help solve a lot of these key bottleneck issues. I’m working on these problems now, but I feel like if I had let myself be a little more risk-taking, perhaps I would have started on them even earlier. Because of this tenure-track process, people in the science and technology field can be a little too much on the safe side, and that would be one of the lessons that I’d like to share with young people who will be starting their career in these fields.
What have been some of the challenges you’ve had, either in your career or personally?
Personally, my challenge is to balance my time with my child. I have an eight year old boy and I have a very supportive husband, so we share the load a lot, but on a personal level it is always challenging to maintain a balance between making sure I have a healthy and happy family life as well as a successful career. I’m really lucky, because I do have very strong support at home, and my son is very heavily influenced by me and wants to be an engineer and build electric cars.
Professionally, the major challenge I would say was learning to be a good professor. I grew up in Asia and there was this perception of “tiger parents” and that you just work really, really hard, and in my younger years as a professor I was really challenged by this sort of personal management with the students. I had to realize that each student’s learning style is unique, and that the same teaching style cannot fit with all students. The lesson there was that the demand for being a good professor and a good principal investigator of a lab is very, very high– I try my best now if we have junior professors coming in to share my experiences and lessons with them, too. Professors are trained to be good scientists, yes, but I wish we were also trained to be a good mentor to students. Now after years of teaching, I really know how to interact with students and I myself have matured quite a bit, but it was a little bit rough in the earliest stages.
What do you consider to be some of your greatest triumphs or successes in your career?
My challenge and my triumph are actually both my students. I’m very, very proud of my students who have graduated and got their PhD from me. I have 18 students who have achieved a PhD from me, and almost all of them are doing very well in their professional careers and their personal lives. For instance, my very first PhD student won the Electric Chemical Society Student Award, and is now working at Tesla. Another one of my very recent students is becoming the CEO of her start-up company; one of the very few CEOs for tech companies. The technology was actually spun out from my lab, and I personally am not interested in doing commercialization activities with my work because it’s a lot of work, but this was a brand new type of electrolyte that can enable your batteries to operate at minus 80 degrees Celsius. If humans ever need to go to Mars, we have batteries ready for that! Or, it works for high altitude balloons, and those types of applications. They started the company and I’m the only advisor, but I’m really very proud that a few students are taking things from the lab to the market and that they are risk-taking, and at the same time, they are making a real difference. So that’s a great success to me.
What’s something that keeps you up at night?
I have to say, it does keep me up at night that we haven’t found a solution for the grid storage. You look at all the facts around climate change right now, where the sea level is rising and the climate is getting a little bit crazy– I was travelling a few times this year, and was hit by typhoons, hit by all of these natural disasters… It’s just that the Earth is suffering from these consequences of the industrial revolution. I teach the course thermodynamics, where we talk about how things get burned, like coal, oil, or natural gas, which generates heat, which pushes the mechanical motions, which we then use to generate electrons.
But, in fact, if you think about batteries. There’s energy stored in batteries, like in your phone, but there’s no burning; there’s no combustion. We can do that, with things like solar cells too– the sun comes in and generates electrons, and there’s no burning involved. We can do things that are not thermomechanical; we can do electrochemistry, where we can actually change the way that humans do things. Sometimes when I think about continuously what’s going to happen in the world, it really makes me worry, and we still have no solution. Hopefully, this will motivate a lot of people to really, really work to solve these issues.
If you had three more hours in a day, how would you spend them?
I actually never finish my work everyday. There’s always work left unfinished, but I would say that I am really craving for mentorship and to be able to spend more time talking to people who inspire me. I think as you grow older and more senior in the workplace, the frequencies of those mentorship experiences really decreases, but it’s so valuable. So I think if I had three more hours, I’d like to spend some time talking to inspiring colleagues and inspiring people a little bit more. I think we spend too much time in the office doing work, and the work can’t even be finished! I would still probably work a bit more, I’ll admit, but I would also like to spend more time with my son. I don’t think that I spend enough time with him, and I wish I could spend more. I feel guilty that I should have spend more time each day to teach him Mandarin– because being bilingual can be such an advantageous thing.
You gave a talk at the Forum on Energy and Climate Justice, on energy storage for electric vehicles in renewables integration. How do you see that role influencing your work?
When we talk about energy storage and the conversion for transportation and grid storage, there are still quite a few big questions that haven’t been addressed. For instance, why can’t batteries last thirty years? Why do cell phone batteries fail after three or five years, even if we’ve done a very good job? And why do I have to use lithium– it isn’t very abundant, so why can’t we make batteries that are as good as lithium ion batteries? And then, for instance, what about recycling? At the moment, most people don’t know what to do with their batteries once they’ve been used. So, I think this field is really just starting.
If you look back at the history, for instance, to Alessandro Volta who invented the Volta pile, like alkaline batteries, to lead acid batteries about 150 years ago, lithium ion batteries are only 26 years from their first commercialization. We really have to think about the progress in this technology and think about what it might look like in 50 years, and what the world will be like if we have major breakthroughs again in the battery technologies.
For me, I do a lot of materials diagnosis and characterization as I mentioned, so it’s a little bit like if you think about how doctors need need to have really full pictures of what happens to patients to give them diagnoses, that’s what I have to do for batteries and solar cells. But by using these advanced diagnosis tools, I can provide the full pictures of what’s going on, not just when things are made, but when it’s in operation, and then this kind of knowledge will be given to the industry and the relevant stakeholders that they think about together as a team, really to address those big questions like, can we make batteries last 100 years? Can we have a fully sustainable ecosystem for the batteries, from materials being made to recycling them?
I want to emphasize, though, that this isn’t a job that can be done by one person, or even one research team or center at UC San Diego. You need the interdisciplinary efforts from many parts, and for me, the energy challenge is not a simple science and technology challenge. It’s really a humanitarian issue, and it requires all parts of society to work together. I always try to emphasize that engineers and scientists can solve one part of the puzzle, but social science policy, economics, and everyone else has to really work together to actually implement this technology and to change things.
What do you see for the future of nanoengineering?
So, UC San Diego’s nanoengineering department is is one of the first departments in the world that is officially named as nanoengineering. This is really fitting to the characteristics of UCSD– UCSD’s bioengineering department was also the first bioengineering department, and now, 50 years later, almost all major research universities have bioengineering programs. I believe that nanoengineering will play a similar role, and that this is the true platform for interdisciplinary research. This is where we can collaborate without any boundaries.
In nanoengineering here, we have faculty that come from physics, chemistry, materials science, engineering… all working under the same roof. The challenging questions we are dealing with, like for example, how do you do things at the nanoscale– at say, one nanometer to 100 nanometers– have actually significantly changed the properties of the materials we use. Now, we have a whole new range of new devices that we can make, and for me, the people who come to nanoengineering are the people who believe in thinking outside of the box. We build our strong foundations on the traditional discipline, of course, but we want to go a step further– how can we do things that are non-traditional? How can we look for solutions for big, big questions and problems?
Onto the more “fun” questions! What’s something that someone who knows you well would be surprised to learn about you?
I actually didn’t speak any English before I was 18 years old and I went to Singapore. I spoke no English at all, and I’m always grateful for the Singapore government, who sent me to language training for six intensive months, where I also learned a lot of the culture differences between the East and the West. So I think people might be surprised that if you put your heart into learning something, it can happen, even at a much later stage.
What do you geek out about, other than what we’ve already covered?
I got my Tesla car last Saturday, almost a week ago, and I haven’t found the way to charge the batteries. I was just learning how to do it, and it was fascinating. So many people have electric cars, so every time I drive to the station it was always filled. I would have to ask my students how to efficiently find a charging station for my electric car– it’s this week’s major challenge that I have not yet resolved!