Graduate Student Research

What happens inside a wildfire? One PhD student is finding out

alse6588 — Wed, 19 Aug 2026 18:36:40 +0000

What happens inside a wildfire? One PhD student is finding out alse6588 Wed, 08/19/2026 - 12:36

Alexander Servantez

What happens during a wildfire? The short answer is: much more than we know.

As wildfires burn through trees, grasses and other vegetation, heat from the flames set off thousands of chemical reactions at once. Molecules break apart, recombine and transform into new compounds, releasing gases, soot and other carbon-rich particles into the air.

Charred vegetation after burning in a wildfire is a product of combustion.

While scientists can see the products of these reactions, what happens in between is much harder to understand. Many of the chemical reactions that drive combustion take place so quickly that they are nearly impossible to observe.

That’s where Jas Shahanand comes in.

Shahanand, a sixth-year PhD student in the Paul M. Rady Department of Mechanical Engineering at CU �鶹ӰԺ, is finding ways to capture and identify some of these fleeting molecules, giving researchers a closer look at the hidden chemistry of combustion.

He believes the work, recently published in the American Physical Society’s PRX Energy journal, could be the foundation for more accurate wildfire emissions models, improved climate prediction and even cleaner fuel sources in the future.

“These chemical reactions are often very generalized because they occur in a black box. But there’s actually a lot of good information hidden in those intermediate processes," said Shahanand. “My goal is to analyze those processes from a gas-based perspective to help provide a deeper understanding of how combustion chemistry really works.”

Tiny chemical thieves

The key to Shahanand’s research lies in a type of tiny molecule called radicals.

Sixth-year PhD student Jas Shahanand working in the laboratory.

Radicals, created by heat and other high energy environments, act as the driving force behind combustion. They come with an unpaired electron, making them extremely unstable and reactive.

When they react with other stable molecules, they steal an electron to create a pair. This sets off a chain reaction of molecular-level theft—new radicals crashing into molecules and robbing electrons over and over again.

Eventually, these reactions facilitate molecular growth, where gas-phase chemistry proceeds to particle-phase. This can especially be seen during wildfires, when gases like methane or ethylene transform into char and soot.

Understanding these “radical” reactions can tell us a lot about different forms of combustion, from how engines work to interstellar and planetary behavior. But according to Shahanand, they are very short-lived.

“We’re talking nanoseconds,” Shahanand said. “It’s very difficult to run experiments and watch them propagate at that speed.”

To combat this, Shahanand and his team in the Particulate Chemistry and Diagnostics Lab, led by Professor Hope Michelsen, began studying a specific kind of radical: resonance-stabilized radicals.

Unlike normal radicals, the unpaired electron in these molecules is spread out across multiple atoms, allowing them to be more stable and live longer. This gives researchers a much better chance at detecting and studying them, revealing chemical behavior that has largely remained unknown.

“We’ve always known the chemical pathways, but determining which radicals are causing the reaction has always been based on educated guesses,” said Shahanand. “Now, we can confirm those chemical species in our experiments and create models that identify and characterize them for future tests.”

The “fingerprints” of the future

One particular experiment, conducted by Shahanand and his team at Lawrence Berkeley National Laboratory’s Advanced Light Source in Berkeley, California, analyzed chemical reactions when lignin—a material found in plants and trees—is heated without oxygen during a process called pyrolysis.

Lignin pyrolysis is widely known for generating aromatic compounds called substituted anisoles, which have potential to be transformed into a renewable biofuel. But the process can also produce unwanted byproducts such as char and tar.

The process of pyrolysis, starting with lignin and ending with biofuels or char, tar and other particles.

Shahanand and his group discovered that by slightly modifying anisole molecules, they were able to drastically increase the amount of radicals produced under natural lignin pyrolysis conditions.

He says this finding could one day help scientists “control” these chemical reactions, allowing them to better produce useful compounds while limiting undesirable ones.

“If we want to better fight wildfires or produce clean, cost-effective fuel, we need to have a fundamental understanding of the chemistry,” Shahanand said. “We need to know which reactions are good for our goals and which reactions create bad byproducts. To do that, we need to know what’s actually happening inside of the reaction, which is where our research comes into play.”

They also are the first researchers to create a complete “fingerprint” for some radicals they detected that are especially relevant to combustion. Much like a fingerprint can identify a person, these results can help researchers identify a specific molecule or radical.

Previously, scientists only had a reference curve covering part of the spectrum. Shahanand and his team filled in the gaps, producing a complete set of data across the full range and giving researchers a clearer way to identify the radical in future experiments.

Going forward, Shahanand says he wants to continue studying all types of chemical reactions and the radicals behind them. His next work will examine chemicals and conditions more akin to what takes place when an actual forest is burning.

But he believes his research has the power to impact many other aspects of society, as well.

“Maybe we want to explain why certain warming effects exist in different ecosystems. Or maybe understand how chemistry facilitates combustion in space or other planets with different atmospheres,” Shahanand said. “Whatever it is, it all comes back to these fundamental ideas.”

As wildfires burn through trees, grasses and other vegetation, heat from the flames set off thousands of chemical reactions at once. But while scientists can see the products of these reactions, what happens in between is much harder to understand. Sixth-year PhD student Jas Shahanand is finding ways to study these chemical reactions, giving researchers a closer look at the hidden chemistry of combustion. He believes the work could be the foundation for more accurate wildfire emissions models, improved climate prediction and even cleaner fuel sources in the future.

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Wind tunnel research could help predict how wildfires spread

Alexander James Servantez — Fri, 05 Dec 2025 18:15:00 +0000

Wind tunnel research could help predict how wildfires spread Alexander Jame… Fri, 12/05/2025 - 11:15

PhD student Laura Shannon, alongside Professors Greg Rieker and Peter Hamlington are setting fires inside wind tunnels to gain a better understanding of how fire spreads across different terrain. The team says their findings could help keep communities safer in a world where climate-driven wildfire is becoming more common—and more dangerous.

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ME grad student probes industrial pollution in Mississippi neighborhood

Alexander James Servantez — Fri, 25 Jul 2025 21:55:39 +0000

ME grad student probes industrial pollution in Mississippi neighborhood Alexander Jame… Fri, 07/25/2025 - 15:55

Caroline Frischmon is a graduate student leading a critical study documenting industrial pollution near the Cherokee Forest subdivision in Pascagoula, Mississippi. Her findings show that industrial activities are leading to negative impacts on human health and the residents of the neighborhood are looking to take action.

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PhD student advances sustainable and ethical battery technology

Matthew Cumpton — Wed, 19 Feb 2025 15:31:01 +0000

PhD student advances sustainable and ethical battery technology Matthew Cumpton Wed, 02/19/2025 - 08:31

Madison Seckman

Imagine a future where renewable energy storage is not just efficient but also sustainable, scalable, and ethical. This vision is what drives Charley Thomas, a fifth-year PhD student working on cutting-edge battery technology. From solid electrolytes to sodium-ion batteries, Thomas is tackling some of the most pressing challenges in energy storage.

In her current research with the Ban Surface Science and Engineering Research Group, Thomas works on two distinct projects: stress-testing solid electrolytes and developing cathodes for sodium-ion batteries. While both are pivotal in advancing battery science, each presents its own unique challenges and rewards.

Solid electrolytes are a promising alternative to traditional liquid-based systems in lithium-ion batteries. However, testing them is notoriously complex. “Stress-testing solid electrolytes sucks,” Thomas said. “There’s no perfect method for evaluating their performance.”

One commonly used test involves symmetrical cells, where the same electrode is placed on both sides of the solid electrolyte. Critical current density testing—ramping up the current until a short circuit occurs—is used to evaluate the material's performance. But this method has its flaws. “Critical current density isn’t a true material property. It’s influenced heavily by the experimental setup,” Thomas explained.

Despite these challenges, Thomas is dedicated to refining her methods, even when it involves tedious and high-stakes procedures like dipping electrolyte pellets into molten lithium at 180 C. “It’s frustrating when the pellets shatter during the process, but each failure teaches us something valuable,” she said.

Thomas’ second project, focused on sodium-ion batteries, offers a hands-on approach to cathode development. Sodium-ion technology has the potential to address ethical and material scarcity concerns associated with lithium-based systems, as sodium is far more abundant and affordable.

“What excites me about this project is that I get to start from the ground up,” Thomas shared. Using common salts—sometimes even dietary supplements—she synthesizes particles, cleans and dries them, and assembles them into electrodes for testing.

This process has deepened Thomas’ understanding of battery fundamentals. “Unlike solid electrolyte testing, which uses symmetrical cells, working with cathodes involves real chemical potential differences and redox reactions. It’s helping me truly grasp how batteries work,” she said.

Thomas’ ultimate goal is to contribute to sustainable energy storage systems that could revolutionize how we power our world. While initially drawn to academia for its teaching opportunities, she is now exploring postdoctoral research as the next step.

“Work-life balance is important to me, so I’m reevaluating my long-term plans,” she said. “But no matter where I end up, I want to be part of the shift towards renewable, ethical energy storage.”

As she continues refining solid electrolytes and advancing sodium-ion technology, Thomas’ work embodies the intersection of innovation, sustainability, and first-principles science. “When a project finally works—when a battery has great capacity or lasts a long time—it’s the best feeling,” she said.

Fifth-year PhD student Charley Thomas is driven by a vision of renewable energy storage that is efficient, sustainable, scalable, and ethical. Through her work with the Ban Surface Science and Engineering Research Group, Thomas tackles two key challenges in battery technology: stress-testing solid electrolytes for lithium-ion batteries and developing cathodes for sodium-ion batteries.

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PhD student wins national award for fluids research in stroke therapy

Alexander James Servantez — Fri, 17 Jan 2025 20:43:07 +0000

PhD student wins national award for fluids research in stroke therapy Alexander Jame… Fri, 01/17/2025 - 13:43

Alexander Servantez

Nick Rovito, a first-year PhD student in the Paul M. Rady Department of Mechanical Engineering, was living on top of the world.

After submitting a technical publication to the American Society of Mechanical Engineers (ASME) Fluids Engineering Division, he was named one of five finalists for the Young Engineer Paper Competition and was invited to present his research at the International Mechanical Engineering Congress & Exposition (IMECE) conference in Portland, Oregon.

Nick Rovito, first-year PhD student and winner of the American Society of Mechanical Engineer's Young Engineer Paper Competition.

Rovito’s award-winning research article is titled “In Silico Analysis of Flow-Mediated Drug Transport For Thrombolytic Therapy in Acute Ischemic Stroke.” The piece featured a multi-physics model coupling fluid dynamics, drug transport and reactions that emulates the clot-dissolving process in stroke treatment.

Simply being recognized amongst the other finalists at such a prestigious gathering was already the honor of a lifetime, he said. With over 1,600 research leaders across nearly 20 technical tracks, the IMECE conference features one of the largest and most diverse conference communities that ASME has to offer. It’s often touted as the largest mechanical engineering conference in the country.

But when presentations had concluded and the judges were done deliberating, Rovito wasn’t just a finalist. He was the winner.

As a graduate research assistant in the FLOWLab, led by Assistant Professor Debanjan Mukherjee at the �鶹ӰԺ, Rovito conducts computational fluid dynamics research analyzing the mechanisms of thrombolysis in the blood vessels of the brain. This primary mode of stroke therapy involves administering medication to help restore blood flow by dissolving blood clots that may be causing a stroke.

“The FLOWLab is very multidisciplinary,” Rovito said. “We study stroke and medicine by analyzing fluid motion and transport through the cardiovascular system. Recognizing this allows us to apply principles of mechanical engineering to an otherwise medically focused field.”

His work aims to answer two questions: why do stroke treatments fail, and how can we increase their efficacy in the future?

“When you have a stroke, there’s an artery in your brain that is being blocked by a blood clot. Tissue plasminogen activator is the only drug approved by the FDA to treat this, but nearly 50 percent of patients don’t actually see the clot fully dissolve,” Rovito said. “A stroke left untreated could spell permanent disability or death, so we want to study the fluid mechanics within the vascular structure and see exactly how that drug is being delivered to the blood clot.”

Thrombolysis is known to present other dangerous issues, as well. Tissue plasminogen activator is categorized as an anticoagulant or a blood thinner. The drug’s job is to interfere with the clotting process and prevent blood clots from forming or growing.

However, the drug is not capable of targeting specific blood clots. It will dissolve any blood clot, including those that are not causing the stroke. Rovito says this can lead to severe bleeding if the drug goes elsewhere in the brain, or if it is overused.

Assistant Professor Debanjan Mukherjee (left) and Nick Rovito (right). Rovito is a graduate research assistant in the FLOWLab, led by Mukherjee.

“Around twenty percent of the patients who receive this drug experience major bleeding whether the stroke treatment is successful or not,” he said. “Understanding drug delivery from a flow physics standpoint helps us understand what the drug is doing when it’s administered so we can potentially mitigate those issues in the future.”

“I felt confident about my work,” Rovito said. “But I was just happy to be there. Everybody’s work was phenomenal. Any of the finalists could have won. So when the results came out, I was thrilled.”

Mukherjee, a co-author of the publication, had no doubt that Rovito’s work had what it took to win.

“Drug delivery investigation is at the core of our research group, and a lot of the strides we’ve made in modeling and simulation tools have been because of Nick’s efforts,” said Mukherjee, also a faculty member in biomedical engineering (BME) at CU �鶹ӰԺ. “This is a very complicated problem, and his research is novel. The fact that he was able to win this award three semesters into his PhD pursuit speaks to his great ability to accomplish these technical tasks.”

Rovito hopes to continue improving this model and solving problems related to the clinical challenges of today. Their next steps in this project related to stroke therapy will be in collaboration with the neurology team at the University of Colorado Anschutz Medical Campus, a frequent collaborator with the FLOWLab.

Beyond his research, Rovito also hopes to translate his technical skills into a long-term teaching career.

“One of my passions is teaching and scientific communication,” he said. “CU �鶹ӰԺ is a great place for me to continue my technical work and develop as an educator.”

First-year PhD student Nick Rovito has been named the winner of the Young Engineer Paper Competition at this year's International Mechanical Engineering Congress & Exposition (IMECE) held by the American Society of Mechanical Engineers. His novel research aims to answer two questions: why do stroke treatments fail, and how can we increase their efficacy in the future?

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PhD student Nick Rovito (middle right) accepting the Young Engineer Paper Competition Award during the International Mechanical Engineering Congress & Exposition (IMECE) conference in Portland, Oregon.

New research on exotendons advances assistive technology for runners

Alexander James Servantez — Fri, 22 Nov 2024 21:06:40 +0000

New research on exotendons advances assistive technology for runners Alexander Jame… Fri, 11/22/2024 - 14:06

Madison Seckman

Olivia Felton

Olivia Felton is a PhD student in the Welker Lab, led by Assistant Professor Cara Welker, at the �鶹ӰԺ. Their main focus: to use assistive technology to help both able-bodied individuals and those with disabilities.

Felton earned her Bachelor of Science in Mechanical Engineering from Baylor University. During her time as an undergraduate, she worked in a fluids lab. While she found the research interesting, she knew it was not what she wanted to study long term.

Currently, her work focuses on recreational runners. In her experiments, participants run on a force instrumented treadmill, which tracks their ground reaction forces. They also wear a metabolic mask to measure energy expenditure during running. The running is slightly different than what they are used to, however, since they have an exotendon attached to their feet.

The exotendon is surgical tubing with loops on both ends held in place with zip ties and s-biners to clip onto the shoes of the person being tested. It creates a force between the individual's feet as the tubing stretches and molds as they run. Dr. Welker’s research has shown that the exotendon allows a runner to expend about six percent less metabolic energy when running at a 10 minute mile pace.

Moving forward, Felton is expanding the study by understanding the effect of running with the exotendon at a range of speeds and how reducing metabolic energy expenditure affects self-selected running speed.

Throughout her research, Felton has found she enjoys working with the many different people who come through her lab.

“One really cool thing about this study is that we're recruiting recreational runners, so I do a lot of run clubs around �鶹ӰԺ to recruit participants. I've met a lot of really great people,” Felton shared.

Olivia Felton is a PhD student in the Welker Lab at the �鶹ӰԺ. Their main focus: to use assistive technology to help both able-bodied individuals and those with disabilities.

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PhD students earn top National Science Foundation fellowships

Anonymous — Wed, 24 Apr 2024 22:51:12 +0000

PhD students earn top National Science Foundation fellowships Anonymous (not verified) Wed, 04/24/2024 - 16:51

Jeff Zehnder

The National Science Foundation has bestowed three prestigious Graduate Research Fellowship Program awards to �鶹ӰԺ mechanical engineering graduate students.

The national awards recognize and support outstanding grad students from across the country in science, technology, engineering and mathematics (STEM) fields who are pursuing research-based master’s and doctoral degrees.

PhD students Reegan Ketzenberger, Caleb Song, and Jennifer Wu are each receiving the honor for 2024. Find out more about their research below.

Awardees receive a $37,000 annual stipend and cost of education allowance for the next three years as well as professional development opportunities.

Two mechanical engineering PhD students, Alex Hedrick and Carly Rowe, also received honorable mentions from the National Science Foundation program.

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Grad student helps design ‘artificial muscles’ you can toss in the compost bin

Anonymous — Sun, 23 Apr 2023 20:00:32 +0000

Grad student helps design ‘artificial muscles’ you can toss in the compost bin Anonymous (not verified) Sun, 04/23/2023 - 14:00

Say “hello” to the robots of the future: They’re soft and flexible enough to bounce off walls or squeeze into tight spaces. And when you’re done with them, you can toss these machines into a compost bin to decompose.

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Student wins national competition with photoelasticity research

Anonymous — Wed, 29 Mar 2023 16:35:41 +0000

Student wins national competition with photoelasticity research Anonymous (not verified) Wed, 03/29/2023 - 10:35

Michael Lock Swingen

Ben McMillan, a PhD student advised by Associate Professor Nathalie Vriend in the Paul M. Rady Department of Mechanical Engineering, recently took first place in the Gallery of Soft Matter Physics video competition for his research on the internal dynamics of granular flow and its effects on clogging.

The Gallery of Soft Matter Physics is a poster and video competition that showcases the elegance and aesthetics of soft matter, while highlighting the work of the soft matter community to fellow researchers and the general public. The competition was held during the 2023 American Physical Society (APS) March Meeting in Las Vegas, Nevada.

“It is a great accomplishment for Ben to win the award,” Vriend said. “He produced an outstanding video and is one of only two PhD students who won.”

In his laboratory experiments, McMillan uses a technique called photoelasticity that analyzes how patterns of light within polyurethane disks change according to the magnitude and direction of forces exerted upon them. The fluctuating patterns of light can give McMillan a picture of the stress distribution between them.

The winners of the Gallery of Soft Matter Physics receive a cash prize, an opportunity to give an invited talk at the next APS March Meeting in 2024 and are featured in American Physical Society’s journals Physical Review E and in Physics.

In his video, “To Clog or Not to Clog,” McMillan outlines how photoelasticity can predict whether a clog of granular materials attempting to pass through an opening is structurally stable or unstable.

Watch the video here:

[video:https://www.youtube.com/watch?v=CzIv3IkK3_E]

McMillan shared more details about his award-winning video and research:

Can you describe your research?

My research focuses on experimentally investigating granular materials, which are materials made up of grains or particles. We use a technique called photoelasticity, which allows us to visualize and resolve the force on each particle in our experiments.

How will your work impact society?

Clogs occur in a huge array of scenarios, many of which impact us directly. For example, salt shakers, inkjet printers and silos of grains experience clogs, but they can also be dangerous, such as blood clots or crowds of people. Despite their prevalence, our understanding of clogs is poor. We aim to improve our knowledge of clogging fundamentals, which would help design systems to be safer and more efficient.

What is the next step for this project?

Our goal is to be able to predict when a clog will form. To do this, we’re planning to use machine learning ideas to try and find patterns in the force distributions and velocity profiles that occur before a clog happens.

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PhD student advancing human tendon research

Anonymous — Thu, 26 Jan 2023 19:25:19 +0000

PhD student advancing human tendon research Anonymous (not verified) Thu, 01/26/2023 - 12:25

Michael Lock Swingen

Hannah Larson, a PhD student in the Paul M. Rady Department of Mechanical Engineering, is a 2023 recipient of the National Institutes of Health T32 for Interdisciplinary Training in Musculoskeletal Research.

The program provides research and training opportunities for the next generation of musculoskeletal investigators who intend to pursue careers in biomedical and clinical research.

The musculoskeletal system is the study of muscles, tendons, bones, and cartilage and how they interact in the human body.

At first glance, it may seem strange that a student in mechanical engineering is conducting research on the human body.

But a key aspect of mechanical engineering is the study of materials and their behavior. Materials like steel, concrete and aluminum undergo tests that analyze characteristics including strength and the rate at which they experience wear and tear, which is called “material fatigue.” Engineers like Larson bridge those investigation techniques to the human body.

“I’m applying those exact same principles of mechanics to the study of tendons,” said Larson, who works in the Musculoskeletal Extracellular Matrix Laboratory with Professor Sarah Calve. “You do similar tests. It’s just totally different material behavior.”

Larson’s journey to biomechanics was a circuitous one.

As an undergraduate in mechanical engineering, she took a senior elective class called Biologically Inspired Design, which studied how nature finds solutions to engineering and design problems. She did a project on how the material structure of the Namibian beetle shell can passively collect water in the desert.

It was intriguing work, but Larson stuck to a more traditional engineering path after graduation, landing a job as a research assistant in the Massachusetts Institute of Technology Lincoln Laboratory. There she helped develop solid-state, fiber, and diode laser technologies for the scientific and defense communities. Although the job was a good experience, Larson noticed that she didn’t think about her work during off-hours.

When it came time to apply to graduate school, she recalled her senior elective and how fascinating she found biological systems like the human body.

“I like the big picture of trying to help people with their health,” Larson said. “For me, being active is essential. If I tore my Achilles heel and could never run again, that would be devasting.”

A motivator to Larson’s research is the fact that tendons don’t heal well on their own.

She is investigating a subclass of macromolecules called proteoglycans and glycosaminoglycans, whose mechanical functions in tendons are little understood. Her lab work involves dissecting tendon samples and stretching them with a force sensor. She then incubates the tendon in a fluorescent solution that sticks to parts that have been damaged, allowing the amount of damage to be studied in detail.

Larson wants to know if having more, or less, of the proteoglycans and glycosaminoglycans in tissues will help mitigate the material fatigue of tendons.

She hopes that her research can help the medical community better understand how people develop tendinopathy, which is a tendon disorder that results in pain, swelling, and impaired function and is not easily treatable.

NIH has hopes for Larson’s research, too. The T32 grant will provide additional funding to Larson’s graduate research, including money to buy new lab equipment and travel to academic conferences.

After she finishes her PhD program, Larson wants to continue using her engineering skills in a biomedical career.

“Whether it’s developing biomedical devices, tissue constructs or synthetic tendons,” Larson said, “I know this kind of work is for me.”

Hannah Larson, a PhD student, is a 2023 recipient of the National Institutes of Health T32 for Interdisciplinary Training in Musculoskeletal Research. The program provides research and training opportunities for the next generation of musculoskeletal investigators.

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