U-M Department Chairs Sharon Glotzer, Tuija Pulkkinen and Elizabeth Holm revolutionize their fields, leveraging computational science for advanced material design, space weather prediction and materials behavior.
Written by the Michigan Institute for Computational Discovery & Engineering and originally published in their Spring Magazine.
In an era marked by rapid advances in science and engineering, MICDE shines a spotlight on three women, each of whom is a star researcher while also chairing her department. Through their leadership and innovative contributions to computational science, these women are transforming their fields.
Sharon Glotzer, Anthony C. Lembke Department Chair of Chemical Engineering, redefines material design through “digital alchemy,” applying statistical thermodynamics principles to create advanced materials at the molecular level.
Tuija Pulkkinen, Chair of the Climate and Space Sciences and Engineering Department and esteemed professor of Space Science, utilizes intricate computational models to further space weather research. This pivotal work is instrumental in protecting both space-bound and terrestrial technologies from solar disturbances.
Elizabeth Holm, the forward-thinking department chair of Materials Science and Engineering, integrates computational science and materials science, paving the way for crucial discoveries and new teaching methods in material behavior and design.
These women are not only pushing the scientific frontier with their singular accomplishments; theyre also mentoring the next generation of scientists and engaging them in interdisciplinary studies. Their impact is evidenced by increased scholarly citations, enhanced material functionalities, and more interest in computational science disciplines.
As they inspire and lead, these trailblazers raise pivotal questions: what does the future hold for computational science as more women ascend to leadership roles? The trajectories of Glotzer, Pulkkinen, and Holm suggest that a future rich in innovation and collaboration awaits.
Long before our current age of labs filled with precision equipment and databases with nearly limitless information about the elements that make up our world, alchemists studied materials hoping to unlock processes for transforming materials. Most famously, alchemists hoped to turn base metals like lead into noble metals like gold. As time passed and humanity came out of the dark ages, alchemy gave way to the more modern practices of chemistry. Alchemists’ aspirations of studying and transforming materials remains a core tenet in many realms of engineering.
Today, scientists like Sharon Glotzer, the University of Michigan’s Anthony C. Lembke Department Chair of Chemical Engineering, are using computation to explore how we can manipulate matter at the molecular, nanoparticle, and colloidal level to create “designer” structures and engineer new materials. The frameworks that Glotzer and her students have developed have been referred to as digital alchemy, allowing scientists to reverse-engineer new materials.
“We’re in the age of materials by design,” says Glotzer. “Future materials won’t be just elemental materials like silicon, or gold, or copper. We’ll have smart materials systems made of many different little subsystems of different kinds of materials that we can mix and match together using nanoparticles to make something new that didn’t exist before. Now you’re doing not just materials by design, but materials on demand.”
A physicist by training, Glotzer’s journey into science began at UCLA. She went on to study at Boston University and then work at the National Institute of Standards and Technology, before joining the University of Michigan in 2001. Glotzer brought a physicist’s eye to chemical engineering, unraveling how the tiniest particles- atoms, molecules, and nanoparticles -come together to create the materials that shape our everyday life. Her cross-disciplinary expertise isn’t confined to a single department. She explores the intersection of materials science, physics, and macromolecular science, showcasing the multidimensional nature of her research pursuits.
At the heart of Glotzer’s scientific inquiries is statistical thermodynamics- the study of the unseen forces and motions that dictate the behavior of particles in large numbers. This area of study doesn’t focus on individual particles but rather on how they work as parts of a whole, displaying commonalities in behavior that transcend their nature or size.
The beauty of statistical thermodynamics lies in its versatility. Whether dissecting the dance of DNA strands or the patterns assembled by nanoparticles, the same statistical principles apply, offering a lens through which entirely different systems can be viewed and understood. It is this insight that drives her and her team forward-an eagerness to decode the self-assembly pathways of complex particle systems that dictate how certain materials form and why they have the features that they do.
Taking that process one step further by utilizing computational methods, Glotzer and her group can learn how to control and manipulate certain forces in the materials synthesis process, providing blueprints to engineer new materials with specific traits.
Glotzer also focuses heavily on the concept of entropy in complex particle systems, where it is a measure of the number of different ways particles can be arranged. Glotzer’s team showed that, through entropy, nanoparticles can form the same complex structures formed by atoms. She’s proposed the entropic bond in analogy with chemical bonds.
Glotzer has a passion for computation, and relishes its vast exploratory possibilities. Where traditional lab experiments have their limits, computational models open up worlds of “what-ifs.” She explains that one simulation can often lead to findings that suddenly inspires her and her research team to travel down new branching paths, chasing up their curiosity or finding a new perspective. Computation gives Glotzer, her collaborators, and her students the ability to pursue a vast array of hypothetical scenarios to understand how materials behave under different conditions.
“Not only do you get to control exactly what it’s doing, the computer will only do exactly what you’ve told it to do,” says Glotzer. “You can say ‘Turn this force on. What happens then? ‘Turn this force off, make this one bigger, make this one smaller, and change things in a way that you just can’t in an experiment.”
Beyond the codes and models, Glotzer finds profound joy in mentorship. The lab she leads is not just a scientific hub but a nurturing ground for young minds. Here, students and early-career researchers find guidance and countless opportunities for collaboration.
Glotzer’s enthusiasm for science is infectious, and her approach is akin to a jazz ensemble- every member brings a unique strength to the collective, leading to a harmonious composition of ideas and discoveries.
“Do what you love to do,” Glotzer advises her students and early career faculty. “It’s really hard to do your best science if you’re not obsessed or fascinated with the question.”
“Do what you love to do. It’s really hard to do your best science if you’re not obsessed or fascinated with the question.”
Sharon GlotzerAnthony C. Lembke Department Chair of Chemical Engineering
“We’re so fortunate to be among the tiny percentage of people in the history of time who get to do science and ask these ‘what if’ questions. You owe it to yourself to align what you’re doing with what you love. If you have the privilege to do that, you will do your best work and the rest of us will benefit the most from it.”
For Sharon Glotzer, the journey to becoming a world-leading researcher has been one of intellectual courage and collaboration. Her work epitomizes the vision of an integrated scientific community where barriers between disciplines blur, and new understanding flourishes. As she continues to shape the future of materials research with her contributions, her biggest impact might just be in those she mentors, instilling in them the same insatiable curiosity and passion for exploration that has defined her own illustrious career.
Imagine a weather forecast that calls for wind and storms. But these arent your average meteorological events. These winds are streams of charged particles in a plasma state, moving at speeds up to 800 km/s (or 1,800,000 mph).
That is about 5,000 times stronger than F6 tornadoes (F6 top wind speed is 0.17 km/s or 379 mph) This is what is known as space weather, the applied field of space physics that forecasts the environment surrounding our planet. At the forefront of this field is Tuija Pulkkinen, chair of the Climate and Space Sciences and Engineering Department and a professor of Space Science at the University of Michigan. For Pulkkinen, space weather isn’t just a research specialty, it is an applied science essential for safeguarding spacecraft, astronauts and the essential infrastructures of our technology-driven society, including satellite communications, power grids and GPS systems.
Originally from Finland, Pulkkinen obtained her of charged particles in a plasma state, moving at speeds up to 800 km/s (or 1,800,000 mph). Her path, however, took an unexpected turn when Finland joined the European Space Agency, marking a new era for the nation – and for Pulkkinen. Recalling the unexpected moment, she said, “So, suddenly somebody be the first graduate student in the field?’ and I raised my hand and said, ‘Yes!’
While most of her peers pursued the more cosmology, Pulkkinen was drawn to the prospect of working in a discipline that blends experimental techniques with theoretical principles. Over the course of her career, the field has evolved from early crude simulations of the space environment to complex computational models employing artificial intelligence and data assimilation. These sophisticated data banks allow for exceptionally complex simulations.
Pulkkinen’s simulation work is centered around the use of modular simulation frameworks to tackle multi-scale and multi-physics problems, making intricate space phenomena more comprehensible and predictable, such as the dynamics of the solar system, magnetospheric phenomena, and the impact of space weather on planetary systems. She uses the Space Weather Modeling Framework (SWMF), a comprehensive tool for studying solar, heliospheric, and planetary space environments. Developed at the University of Michigan, the SWMF integrates multiple physics domains through a modular approach, enabling detailed simulations of phenomena such as coronal mass ejections, space weather effects on Earth, and interactions between the magnetosphere and ionosphere, making it a useful tool for both academic research and operational space weather forecasting.
Pulkkinen notes that increased traffic in low Earth orbit (LEO) presents both great opportunities and great challenges in her field. It is an opportunity because of the boost it has given the space engineering program.
Traditionally the undergraduate program at the University of Michigan focused on preparing students for graduate studies in research. That has shifted, however, with companies like Blue Origin and SpaceX inspiring many students to seek engineering careers, thereby expanding enrollment and providing Pulkkinen an opportunity to work with a more diverse student body.
In contrast, it is a challenge because the space weather affects atmospheric density. When the Sun is active with especially strong magnetic fields up to 1,000 times stronger than average, its additional energy is absorbed by the Earth’s atmosphere. This absorption causes the outermost, low-density layers of air to expand upward, which are then replaced by higher-density air from lower altitudes. As a result, the LEO spacecraft are forced to fly through the higher density atmosphere, experiencing a stronger drag force. Similarly, orbiting space debris is impacted by this higher drag force, necessitating more accurate models to manage space traffic.
It is in this transitional region, at an altitude of around 200 kilometers, where space and plasma physics meets atmospheric science.
Atmospheric science examines neutral gasses, their dynamics and chemistry. However, the two fields converge in this region where the atmospheric density is still significant enough to affect spacecraft via drag and where electromagnetic forces come into play, influencing atmospheric science.
To more accurately forecast this region, it is necessary to integrate space environment models with Earth system models. In an effort to address this need, NASA allocated $9.7 million to establish Space Weather Centers for Excellence at the University of Michigan. One of the centers, The Space Weather Operational Readiness Development (SWORD) Center, is led by Pulkkinen under Principal Investigator Thomas Berger at the University of Colorado in Boulder. The SWORD Center aims to tackle the process of integrating these models together for more accurate simulations.
Pulkkinen credits her excellent mentor, Dan Baker at the Goddard Space Flight Center for creating a solid foundation for her early career as a scientist. She now aims to cultivate the next generation of scientists in the same way.
“I’ve tried to pay that back to the next generation,” Pulkkinen said. “Working with grad students is great. It’s so great to see them grow and get their own ideas and give them the support to pursue whatever they find interesting.”
Above all, Pulkkinen encourages young scientists to seize opportunities as they present themselves. “They never come at a convenient time,” Pulkkinen cautions. “I’ve so many times said to myself, ‘You know, this would be a great opportunity, but it’s really not a good time. And then I’ve always said, ‘Well, the second time won’t come if I don’t seize this now it’s gone.”
Through her embrace of unexpected opportunities in a field where the sky is not the limit but the starting point, Pulkkinen expanded not only her own career but also the frontiers of space weather research, inspiring a new generation to look upwards and dream of possibilities beyond our atmosphere.
In the realm of materials science, where advanced computer simulations provide a virtual arena to experiment beyond the confines of the physical world, Elizabeth Holm has been a pioneering force. Her unique background blending traditional materials science with computational science distinguishes her as an influential leader on the international stage. Her recent appointment as the department chair of Materials Science and Engineering at the University of Michigan has brought her full circle, back to the institution where her academic journey first began.
Much of Holm’s research focuses on physical simulation and modeling of materials systems. Drawing upon scientific fundamentals, she writes computer code to simulate the behavior of these systems. “It’s a little bit like we’re universe builders,” Holm said. “I’m able to take in the parts of the problem that I think are relevant, to manipulate them in ways that the real world won’t let me. But if I’m doing it right, it’s not just an unrealistic simulation. It’s insight as to what really does matter.”
This ability to use a simulation to design and optimize problems opens endless possibilities to explore the world. In a simulation, Holm can eliminate factors, such as gravity or atmosphere that cannot be removed in the physical world. Seeing whether these changes alter her results can help guide her. The possibilities only continue to expand with the introduction of Al and machine learning, providing new insights from complex models.
Holm’s path into science began at the University of Michigan as an undergraduate student studying materials systems. In 1989, amid the ceramic superconductor excitement post-Nobel Prize, Holm pursued graduate studies at MIT, facing a rigorous research environment. Struggling with the volatility of her materials in the lab, her fortunes changed when presented with a computer modeling project using a grant-funded IBM workstation.
This pivotal moment led Holm to discover her passion for computational materials science, directing her back to the University of Michigan. There, a dual Ph.D. program in Materials Science and Engineering and Scientific Computing, currently administered by MICDE (see fall 2023 issue for more details), together with an IBM-funded fellowship catalyzed her expertise in efficient coding and complex simulations.
With this new passion and unique skillset, Holm moved on to a successful twenty-year career as a scientist at Sandia National Laboratories, a Department of Energy laboratory in Albuquerque, New Mexico before transitioning to Carnegie Mellon University as a professor of Materials Science and Engineering. The change added a new dimension to her work with the integration of machine learning techniques for better understanding the physics and chemistry of materials. Holm was particularly focused on computer vision interpretation of the visual data, a key element of materials science.
Much like radiology is critical in the field of medicine, visual data allows Holm to extract data from images repeatedly, and without bias. Bayesian Learning is still another potential impact for the future of her field, helpful for optimization in materials processes.
But it was in Holm’s contribution to a pivotal study as a member of a National Academies committee that she played a significant role in elevating computer simulation to the same stature as traditional experimentation within materials science. The study laid the groundwork for the Materials Genome Initiative, a collaborative federal program designed to expedite the discovery, development, and deployment of advanced materials efficiently and cost-effectively. Prior to the initiative, computational approaches were not widely recognized as valid alongside traditional hands-on experiments. Holm’s contribution was instrumental in shifting this perception, creating a lasting impact on the discipline of materials science.
Beyond her groundbreaking work, Holm also blazed a trail as one of the pioneering women in engineering. “I had almost no women professors when I went through engineering,” she recalls. As one of just a few women in engineering during her early years, a sense of camaraderie formed among the women that endures to this day. Now, as she observes the transformation of women’s roles in STEM, Holm expresses awe and pride, “I love the fact that I sit in a room with my other department chairs and half of us are women. I never imagined that early in my career and it’s extraordinary – it’s rewarding and fulfilling.”
“I love the fact that I sit in a room with my other department chairs and half of us are women. I never imagined that early in my career and it’s extraordinary – it’s rewarding and fulfilling.”
Elizabeth Holm
Richard F. and Eleanor A. Towner Professor of Engineering and Department Chair
But while female role models were scarce, Holm emphasizes that this did not equate to a lack of support. “I was very lucky that I received such strong support, both at home and from my (male) mentors,” she said. Her father, an M.D. from Michigan Medical School, was adamant that his daughter should face no barriers in her career path. He was likely inspired by his own mother’s fortitude who graduated from the University of Michigan at a time when few women attended college.
Likewise, Holm’s mother was a strong advocate for her daughter’s education. The daughter of Polish immigrants and the first in her family to receive a college degree, Holm’s mother was determined to see her daughter push past traditional boundaries.
Throughout her career, Holm had consciously steered away from department chair positions, as they did not align with what motivated her work. However, when she received the call from the University of Michigan, her “home place”, offering the position it was an offer she couldn’t refuse.
“It’s an opportunity to make positive changes, to leave a legacy to this place that means so much to me,” she explained. “I wasn’t going to do that for anyone else. But when Michigan called and offered that; this is the place that I want to leave the legacy of my career.”
The journeys of Sharon Glotzer, Tuija Pulkkinen, and Elizabeth Holm embody the transformative power of computational science as a tool for exploration beyond the reach of traditional experimentation. Their academic evolutions-from physics to chemistry, low-temperature physics to space weather, and hands-on experimentation to computational modeling-highlight an extraordinary adaptability and foresight into the uncharted territories of their disciplines. Together, these pioneering women are leading their departments with distinction and have harnessed the vast potential of computational experiments to probe the unseeable, challenge the status quo, and uncover what-ifs that push the boundaries of innovation.