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NUANCE: Nanoscale Characterization Experimental Center

Earth Day

Earth Day 2021

Featured Interviews

Songting Cai

Songting Cai

Born and raised in Harbin, China, Songting Cai completed her bachelor's degree in 2016 from the Department of Materials and Physics at Harbin Institute of Technology, a research University and one of China's elite C9 League. Now a fifth year PhD candidate at Northwestern University, Songting is co-advised by Professor Vinayak P. Dravid and Professor Mercouri G. Kanatzidis's labs working on synthesis design and structural characterization of high-performance thermoelectric materials. 

When not in the lab, you can find Songting engaged in activities like swimming, Yoga and Pilates; and as she hails from one of China's beautiful "Ice Cities" she learned to ice-skate and ski from a very young age!

Welcome Songting! Can you share with us a little about your research?

I started to work on thermoelectric materials when I was a freshman-the first moment I learned what research is and then never changed my direction since then. From a freshman introduction class, I have learned the power of thermoelectric materials not only as a promising energy material, but also its ability to consume waste heat that originally would be emitted to the atmosphere. I have then made up my mind to do research in this field; after graduating from college, I got admitted to Northwestern and joined the collaborative thermoelectric research team lead by the Dravid, Kantzidis, and Wolverton groups to develop fundamental understanding of complex thermoelectric materials.


Core-shell architecture in nanostructured PbSe-CdSe thermoelectric materials and the corresponding electron diffraction pattern. Image taken using the JEOL ARM 200

What inspired you to be in your current field of study?

As we all know, climate changes is one of the biggest concerns regarding nowadays environmental problems, and fossil fuel burning is the primary cause to it. It is remarkable to learn that globally almost 60% of all used energy is lost and most of it as heat losses. Thermoelectric (TE) materials or devices can enable direct energy conversion for the direct generation of electrical power from waste heat even in extreme environments; therefore, TE heat energy harvesting is among the most promising approaches for improving the management of energy produced from traditional fossil fuels and may aid in increasing global energy efficiency and reducing the emission of carbon dioxide. I have long been interested in using my expertise in materials science to make connections between saving the environment and benefiting basic human needs; that's why thermoelectrics became my choice of study for almost nine years.

Although the field of thermoelectric materials has grown substantially in the last decade, and many research teams have played significant roles in its continued development. Widespread uses, however, are still lagging and it is mainly ascribed to the low TE energy conversion efficiency, high cost of TE materials, and slow progress of reliable module development. Therefore, there continue to be substantial scientific knowledge gaps in our fundamental understanding of TE materials and it is essential to continue to develop advanced concepts that will ultimately lead to next generation materials with an even more enhanced thermoelectric performance.  Whenever there are challenges, there will be many interesting and inspiring scientific questions that need to be answered, and these questions remind me that there is still a long way to go.

Songting in the lab selling tubes!

What are your aspirations for your research?

The deeper we dig into a research field, the more clear it is to us how much we don't know and how much more solutions we need to figure out, which sometimes can be a little bit overwhelming. But my personal hope is that our studies can raise attention to different organizations, institutions, and individuals on the importance of developing next generation clean energy sources-for our planet, and thus for ourselves.

What, in your opinion, are the biggest challenges facing climate research?

I think in many Nations, the education in climate change to the public is far from enough. As most people are either not aware of it as an urgent problem, or they don't know exactly what to do to help. We researchers need to contribute more to environmental publicity and education, not only our research results themselves.

What are some everyday things we can all do to positively impact our environment?

As it's getting warmer outside, try to go for a walk or ride a bike instead of driving once in a while! We can all save our environment while get some fresh air and exercise!

Do you think the current quarantine due to Covid-19 will have an impact on climate change? If so, how?

Some reports suggested that since there have been less activities outside, the pollution or greenhouse gases emissions are decreased. Although I don't think this should be regarded as a 'good news' under such circumstances, we can indeed make a comparison and see more clearly how much we have been negatively affecting our planet.

Benjamin Shindel

Benjamin Shindel

Benjamin Shindel grew up in Phoenix, Arizona, and came to study and work at Northwestern for graduate school. He is now in his second year as a PhD student, in Professor Dravid’s lab group, working on materials with environmental applications.

Hi Benjamin! Can you share a little about your research and how long you have been in this field?

Currently, I am working on two projects. The first involves using nanomaterial-sponge hybrid materials to remediate heavy metals from water. This builds on work from two other members of my group, Stephanie Ribet and Vikas Nandwana, who have used similar systems for pulling nutrients out of water and cleaning up oil spills. The second project, in its nascent stages, has to do with leveraging nanomaterials for carbon capture driven by moisture, or humidity.  Both involve the fundamental science of adsorption at surfaces.

I have been interested in environmental applications for a while, but these are obviously very new fields to me. During my undergrad, I worked on 3D printing concrete using recycled glass waste, and simulating photocatalytic materials, but I didn’t know at that time that I would end up working on environmentally-relevant research for the next five years.


Nano-material coated sponges readied for testing

What inspired you to be in your current field of study? And what do you continue to find inspiring in your research?

The faster that humanity can reach a consensus on what tools to employ and what measures of austerity to enact in order to reach a sustainable relationship with our environment, the faster we can move on to tackling other problems. The ability to remove things from our environment that we accidentally put there (carbon dioxide, lead, mercury) is a great tool to have, since it lets us correct for behaviors that may provide us great benefit, at great cost to our environment.

What are your aspirations for your research

I would like to publish my research! I look forward to communicating my research with the broader audience of scientists in my field. That is the primary goal that I am working towards: getting my research to a place that I feel comfortable sharing it with my community. I would also like to demonstrate the feasibility of our material for the moisture-driven carbon capture project. It would be great if it turned out to be a practical method for lowering the energy barrier for pulling carbon out of air.

What, in your opinion, are some of the challenges facing climate research?

We live in the Anthropocene, an era where human activity has completely restructured the environment. This has been the case for more than ten thousand years, beginning with the use of agricultural practices in the levant.  Many environmental scientists view this as a morally negative thing. An enormous challenge is understanding that the “environment” can never return to the state it was in before humans became the dominant species on this planet, and envisioning a sort of “equilibrium” state where we can have a harmonious and sustainable relationship with our environment. Until we can imagine and reach some sort of consensus on what this equilibrium looks like, it is unclear what sort of environmental interventions will be beneficial for us as a species.

Testing of tea bag as absorbent

Do you think Global stages of quarantine due to Covid-19 has had an impact on climate change? If so, how?

Definitely. While the reduction in emissions from people driving and flying less will be temporary, I believe it will take much longer to correct humanity’s overcompensation when it comes to personal hygiene and the consumption of disposable items. Consider for a moment all of the resources, energy, and waste that go into the production and eradication of disposable medical supplies, masks, hygiene products (may I direct you to the scientific community’s unheeded conclusion very early on in the pandemic that fomite transmission was fundamentally non-existent), and the packaging of delivered foods and products.  This kind of shift is cultural in nature, and will affect our relationship with natural resources for a generation.

What are some everyday actions we can all take to positively impact our environment?

Some people would have you believe that shaping national/international policy and the decisions of large corporations are the only ways of alleviating the effects of climate change. I disagree. I think that the collective behavior of individuals is largely responsible for what is happening to the environment. Since governments have by and large shown a failure to act in the interests of our long-term sustainability, it’s up to citizens, both as individuals and as employees of larger ventures, to think of democratized solutions. A few examples off the top of my head: buying more second-hand products, living within walking distance of one’s place of work, reducing one’s red meat consumption. I’m no expert.

What does your time outside of the lab look like?

Lately, I’ve been enjoying normal, wholesome things. I like writing short stories, going on walks while listening to PJ Harvey or Fiona Apple in these cheap airpod knockoffs I bought on, playing basketball, and trying to bake cookies.  I also sometimes like to do unwholesome things, like playing board games where you have to lie, and forcing my friends to solve amateur crossword puzzles that I made.