UNIVERSITY PARK, Pa. — As a researcher, Margaret Byron, assistant professor of mechanical engineering at Penn State, studies the movement and adaptability of underwater creatures, in the hopes of improving the technology created on land.
“In my lab, we want to understand how animals propel themselves through water and how that depends on the mechanics of their appendages,” she said. “I love using my tools as an engineer to unpack biological questions.”
As the recent recipient of a Beckman Young Investigator award and a $318,000 grant from the National Science Foundation (NSF), Byron will dive deeper into this topic.
For these projects, she studies comb jellies, which are creatures that resemble jellyfish but are unrelated, with their own distinct qualities.
“Comb jellies are unique because they use rows of flexible paddles, each made up of thousands of cilia, that interact with each other hydrodynamically to propel the animal through water,” Byron said. “They do this on a much larger scale than any other animals that use cilia to swim, so there are a lot of outstanding questions about how the dynamics scale with size.”
By understanding more about how these underwater creatures swim and interact with the water around them, a field which Byron calls bio-fluid structure interaction, she explained that the knowledge could advance human technology.
“Currently, we usually use rigid components in things like devices, vehicles and robots,” she said. “But the natural world usually prefers flexibility. For swimming and flying animals, who move by manipulating the surrounding fluid, flexibility is crucial.”
The ability to mimic these qualities has the potential to improve technology such as robotics, biodevices and environmental monitoring devices.
“Our understanding of the biological ‘source code’ — how animals use highly flexible structures and how they hydrodynamically interact — is still incomplete,” she said. “Gaining a nuanced view of how these animals generate forces can really help us design smarter systems.”
With these grants, Byron is ready to wade in and discover new knowledge.
Assembling the toolkit
Administered by the Arnold and Mabel Beckman Foundation, the Beckman Young Investigator (BYI) award provides research support to promising young faculty members in the chemical and life sciences, with the goal of fostering the invention of methods, instruments and materials that could open new avenues of research.
With $600,000 in BYI support, Byron will develop the instrumentation and methods needed to study comb jelly movement and establish the fluid dynamics knowledge to understand this movement.
While the ability to efficiently travel through fluid is a well-explored topic, the size that Byron focuses on, the scale of millimeters to centimeters demonstrated by comb jellies, is still an uncharted area.
“What we know about fluid flow, it’s often divided into really big things, like a plane, or really small things, like the blood flow in a small vein,” she said. “But my group works in the middle of those scales, where it is harder to predict from the physics how the motions will go.”
To do so, her lab will focus on developing methods and equipment to measure the fluid flow around the comb jellies in a non-invasive way. Using refractive image matching, a key part of a technique Byron developed during her own graduate studies, Byron and her research team will gather more comprehensive data about the flow surrounding the comb jellies.
Byron will create a robotic model of a comb jelly’s cilia using a refractive image matched hydrogel, a transparent material that does not distort the surrounding water. The hydrogel gives the added ability of seeing around and in between the comb jelly’s “paddles” to gather more detailed measurements about the flow.
“As an experimentalist, you sometimes have the question before you have the tools to answer the questions,” she said. “Other times, you have a cool tool. This was a combination of both: we have a question about how the deformability of the surface affects the fluid flow and I had the tools for refractive image matching using flexible surfaces in my back pocket.”
A new collaboration
With a new NSF grant, Byron will continue to build upon her research through a collaboration with Chengyu Li, assistant professor of mechanical engineering at Villanova who specializes in computational fluid dynamics (CFD). By combining their expertise in fluid flow, the researchers are poised to make a splash.
“On the small scale, we know movement is dominated by friction and viscosity,” Byron said. “At the larger scale, inertia is more significant. But at the scale we are looking at, both are important, and everything needs to be considered.”
With this project, the researchers’ plan to gather and test data that could bring new understanding across the full range of size scales where cilia are found in nature.
To do so, they will once again study the movement of comb jellies, by recording high-speed videos of their movements and funneling the data into a computational simulation. Researchers from Byron’s lab will collect data on living animals both at Penn State and at a coastal marine field station. They will then use these data to create robotic models of comb jelly paddles in Byron’s lab, which will help validate and provide new hypotheses for the computational simulations.
Equipped with biological, robotic and computational versions of the comb jellies’ paddles, the hope is to tinker with the parameters and discover new information about the animals’ movement and how it can be translated to human-built systems.
As Byron and the graduate student researchers in her lab prepare to return to campus, she said these projects represent an exciting new phase in their work.
“My students have been working so hard and it’s been such a challenging year,” Byron said. “Having this recognition and some new tools to really hit the ground running after the pandemic is thrilling. I am excited to learn new things about the world and really let my students fly.”