Juarez to study soft condensed matter phenomena at the microscale

9/2/2016 Miranda Holloway, MechSE Communications

  New Assistant Professor Gabriel Juarez grew up on a farm in west Texas, where he learned the value of diligence and hard work – traits that have paid off on his journey through academia.

Written by Miranda Holloway, MechSE Communications

New Assistant Professor Gabriel Juarez grew up on a farm in west Texas, where he learned the value of diligence and hard work – traits that have paid off on his journey through academia. Helping his family tend to chores on the farm allowed him to learn that he loved to work with his hands – something that he utilizes in the lab as an experimentalist. In the summers, irrigating crops allowed him to witness how fluids flowed and interacted with the environment at different scales: water droplets on blades of grass, pattern formation in mud cracks, and a sense of fluid transport by watching leaves and insects trapped at the surface.
With a background in physics, Juarez has studied at the crossroads of chemistry, physics, and mechanical and chemical engineering, looking at various aspects of heterogeneous fluid environments. Specifically, he has been intrigued by novel and unexpected phenomenon displayed in soft condensed matter systems at the microscale, despite the familiarity of these materials in our everyday life.
“Much of my research involves using microfluidics and microscopes to get up close and personal with what we’re studying at the small scale, quantifying what we can find from these images – things like shape and flow fields,” Juarez said.
He studies soft, flexible molecules, like DNA, and how flow forces on these molecules can lead to unique mechanical properties of complex fluids. He is particularly interested in bacterial cells at the micro scale and how they interact with various interfaces—research that is useful in bioremediation efforts such as cleaning pollutants from the ocean and other bodies of water. 
Using techniques such as phase contrast and florescent microscopy, high-speed cameras, and microfluidics, Juarez recreates these heterogeneous fluid environments in a controlled manner in order to study physical interactions or chemical reactions at certain interfaces at the microscale. 
“For example, there are certain bacteria found in the ocean that actually convert hydrocarbon pollutants, like crude oil in the ocean. They feed on these pollutants and help clean our water sources,” Juarez said. 
“This occurs not only in the ocean, but in other heterogeneous environments such as in the ground water that we drink. Once we understand the bacteria’s behavior in reaction to fluid forces or interfaces, we can go back and scale up again. If I’m interested in how the ocean gets cleaned up, that’s a big difference in scales. But if we understand the unique, fundamental interactions at the single-cell, single-droplet level, it is possible to extrapolate on larger scales and length and time. The direction that I’m now trying to push is using these observations to develop models at the macroscale.”
Juarez comes to Illinois with a diverse background, which he believes is what makes his research so adaptable. He received a bachelor’s degree from Cornell University and a PhD from Northwestern University – both in physics. He completed two post-docs – at the University of Pennsylvania (in mechanical engineering and applied mechanics) and MIT (in civil and environmental engineering). Seeking an interdisciplinary work environment filled with dedicated people and access to world-class research facilities, Juarez said Illinois was an easy choice for his next journey.
With that in mind, he is also hoping to connect with researchers studying the microbiome and trying to understand what it does for the body—an environment that’s soft, condensed, and involves many aspects of mechanics. 
“I would like to understand the interplay in biological fluid systems, which are inherently complex. These systems have bulk material properties that are non-Newtonian and ultimately arise from nonlinear interactions between individual agents, such as cells, and their dynamic fluid environment, such as the human gut. In general, the environment affects the cells and the cells respond in a way that affects the environment, creating a feedback loop—a common theme in my research.”
Juarez’s position on the MechSE faculty also brings with it a familiar challenge: teaching. 
“Teaching is one of those things where you can really get a sense of how you can affect someone in that moment,” he said. “If you prepare a lecture well, you see the rewards and you see the students become engaged.” 
Juarez was a teaching assistant throughout graduate school and enjoys working with and learning from his students. In his first semester in MechSE, he is already part of the faculty team funded by a SIIP grant (Strategic Instructional Initiatives Program) and is teaching TAM 210 (Intro to Statics). He is also on track to be a Collins Scholar, a College of Engineering program that provides teaching, research, and service support to new faculty. 
He said being part of the SIIP team helped with his transition to Illinois and accelerated his integration into the MechSE department. 
“It’s refreshing to see the effort everyone puts into introducing new ways of teaching. I am excited by the challenge of effective teaching and to further improve my methods of presenting and communicating ideas, not only in the classroom but also in research,” he said. 
“My interactions with faculty and students regarding teaching and research in such a short time have convinced me that Illinois is the environment I was looking for and I look forward to things to come.”

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This story was published September 2, 2016.