6/2/2025 Taylor Parks
Written by Taylor Parks
Researchers including MechSE Professor Sameh Tawfick recently published critical new findings regarding the significance of fish gill morphology for material deformation strategies.
Their study, “Dynamic elastocapillary coalescence of fish gill lamellae,” was published in Interface Focus. Tawfick worked alongside first author and recent graduate Chengzhang Li (PhD ME 2024) as well as Assistant Professor Andy Turko and graduate student Olivia Stanton, both from the Department of Integrative Biology at the University of Guelph in Ontario.
Aquatic animals have flexible gills with a large surface area that facilitates gas exchange between their blood and the surrounding water. These animals “breathe” by taking in oxygen from the water and exhausting carbon dioxide. Their gills are composed of delicate layers of tissue called lamellae, which contain capillary networks that provide the surface area for the exchange. However, when these gills are exposed to air, their surfaces can be compromised.
“If exposed to air, the fine lamellar structures typically collapse and coalesce, which leads to suffocation,” Tawfick explained. Some amphibious fishes, however, have evolved strategies to preserve gill function during emersion. The research team examined the deformations of artificial elastomeric gill lamellae under quasistatic and dynamic liquid crossing scenarios inspired by real-life conditions.
“We provide simple experiments and theoretical analysis for strategies that could control the gills’ morphology as the amphibian animals cross the water surface,” Tawfick said.
Understanding gill lamellae behavior is critical for the ongoing study of the evolution of amphibians and other water-breathing animals. “We want to get into more detail regarding the different species and the precise different strategies [they use],” Tawfick said. Indeed, treating the gills’ significant deformation as the result of a fluid-structure interaction problem provides interesting new design insights.
“We are looking to produce devices inspired by this phenomenon, where flexible lamellae, or fins, are deformed at the water interface to provide optical patterns,” Tawfick said of the ongoing work, which builds on his previous publication that investigated the use of robotic flapping fins to produce multipixel displays.